Feasibility Study Report Occidental Chemical Corporation 605 Alexander Avenue Tacoma, Washington Glenn Springs Holdings, Inc. 732 Broadway Suite 301 Tacoma Washington 98402 007843 C2D2 403 Report No 139 January 25 2017 Table of Contents 1. Introduction ................................................................................................................................... 1 2. Conceptual Site Model ................................................................................................................. 2 2.1 Site Description .................................................................................................................. 2 2.2 Historical Operations .......................................................................................................... 3 2.3 Physical Site Setting .......................................................................................................... 4 2.3.1 2.3.2 2.3.3 2.4 Nature and Extent of Impacts ............................................................................................ 7 2.4.1 2.4.2 2.4.3 2.4.4 2.4.5 2.4.6 2.4.7 Potential Principal Threat Waste (PTW) .......................................................................... 13 2.6 Contaminant Fate and Transport ..................................................................................... 15 2.7 4. Potential Contaminant Sources ........................................................................ 7 Soil .................................................................................................................. 10 Dense Non-Aqueous Phase Liquid (DNAPL) ................................................. 11 Groundwater ................................................................................................... 11 Sediment......................................................................................................... 12 Porewater ....................................................................................................... 13 Indoor Air ........................................................................................................ 13 2.5 2.6.1 2.6.2 2.6.3 2.6.4 2.6.5 2.6.6 3. Regional and Site Geology ............................................................................... 4 Regional Hydrogeology/Groundwater Non-Potable Classification ................... 5 Site Hydrogeology ............................................................................................ 6 Anthropogenic Density Plume (ADP) ............................................................. 15 pH Plume ........................................................................................................ 17 Chlorinated Volatile Organic Compounds (CVOC) ........................................ 17 Metals ............................................................................................................. 19 Semi-Volatile Organic Compounds (SVOC) ................................................... 20 Polychlorinated Biphenyls (PCBs) and Dioxins/Furans.................................. 21 Exposure Pathway Assessment ...................................................................................... 21 Identify Remedial Action Goals (RAGs) and Potential Applicable Local, State, and Federal Laws ................................................................. 23 3.1 Remedial Action Goals (RAGs) ....................................................................................... 23 3.2 General Response Actions (GRAs) ................................................................................. 25 3.3 Identification of Potential Applicable Local, State, and Federal Laws ............................. 26 Identify Alternatives .................................................................................................................... 27 4.1 Alternatives Development ................................................................................................ 27 4.2 Common Elements to the Remedial Alternatives ............................................................ 27 4.2.1 4.2.2 4.2.3 4.3 Institutional Controls ....................................................................................... 27 Groundwater Quality Monitoring ..................................................................... 29 Soil Vapor Monitoring ..................................................................................... 29 Containment Alternatives ................................................................................................. 29 4.3.1 4.3.2 4.3.3 4.3.4 No Action Alternative ...................................................................................... 30 Containment Alternative C100 ........................................................................ 30 Containment Alternative C150 ........................................................................ 32 Containment Alternative C200 ........................................................................ 33 GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) i Table of Contents 4.4 VOC Mass Removal/Reduction Alternatives ................................................................... 33 4.4.1 4.4.2 4.4.2.1 4.4.2.2 4.4.2.3 4.4.3 4.4.4 4.4.5 4.4.6 4.4.7 4.4.8 4.4.9 4.4.10 4.5 pH Reduction/Enhanced Containment Alternatives ........................................................ 42 4.5.1 4.5.2 4.5.3 4.5.4 4.5.5 4.5.6 4.5.7 5. No Additional Action pH Reduction/Enhanced Containment Alternative ....... 43 pH Reduction Alternative pH2 ........................................................................ 43 pH Enhanced Containment Alternative pH3 ................................................... 44 pH Enhanced Containment Alternative pH4 ................................................... 44 pH Reduction Alternative pH5 ........................................................................ 45 pH Enhanced Containment Alternative pH6 ................................................... 45 pH Enhanced Containment Alternative pH7 ................................................... 46 Containment Alternatives Initial Screening and Detailed Evaluation................................................................................... 46 5.1 Initial Screening ............................................................................................................... 46 5.1.1 5.1.2 5.1.3 5.1.4 5.2 Containment Alternative C100........................................................................ 47 Containment Alternative C150........................................................................ 47 Containment Alternative C200 ........................................................................ 48 Summary ........................................................................................................ 48 Detailed Evaluation .......................................................................................................... 48 5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 6. No Additional Action VOC Mass Removal/Reduction Alternative .................. 34 VOC Mass Reduction Alternatives M100, M150, and M200 .......................... 35 VOC Mass Reduction Alternative M100 ......................................................... 35 VOC Mass Reduction Alternative M150 ......................................................... 35 VOC Mass Reduction Alternative M200 ......................................................... 36 VOC Mass Reduction Alternative MSP (Mass Reduction by Strategic Groundwater Pumping) .................................. 36 VOC Mass Removal Alternative M3 ............................................................... 37 VOC Mass Removal Alternative M4 ............................................................... 38 VOC Mass Reduction Alternative M5 ............................................................. 38 VOC Mass Removal/Reduction Alternative M6 .............................................. 39 VOC Mass Removal/Reduction Alternative M7 .............................................. 40 VOC Mass Removal/Reduction Alternative M8 .............................................. 40 VOC Mass Removal/Reduction Alternative M9 .............................................. 41 Containment Alternative C100 ........................................................................ 49 Containment Alternative C150 ........................................................................ 50 Containment Alternative C200 ........................................................................ 52 Disproportionate Cost Analysis ...................................................................... 53 Summary ........................................................................................................ 57 VOC Mass Removal/Reduction Alternatives Initial Screening and Detailed Evaluation................................................................................... 58 6.1 Initial Screening ............................................................................................................... 58 6.2 Detailed Evaluation .......................................................................................................... 59 6.2.1 6.2.2 6.2.2.1 6.2.2.2 6.2.2.3 6.2.3 6.2.4 6.2.5 No Additional Action VOC Mass Removal/Reduction Alternative .................. 59 VOC Mass Reduction Alternatives M100, M150, and M200 .......................... 59 VOC Mass Reduction Alternative M100 ......................................................... 59 VOC Mass Reduction Alternative M150 ......................................................... 60 VOC Mass Reduction Alternative M200 ......................................................... 61 VOC Mass Reduction Alternative MSP .......................................................... 61 VOC Mass Removal Alternative M3 ............................................................... 62 VOC Mass Reduction Alternative M5 ............................................................. 62 GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) ii Table of Contents 6.2.6 6.2.7 6.2.8 6.2.9 6.2.10 7. VOC Mass Removal/Reduction Alternative M6 .............................................. 63 VOC Mass Removal/Reduction Alternative M8 .............................................. 63 VOC Mass Removal/Reduction Alternative M9 .............................................. 64 Disproportionate Cost Analysis ...................................................................... 65 Summary ........................................................................................................ 71 pH Reduction/Enhanced Containment Alternatives Initial Screening and Detailed Evaluation................................................................................... 72 7.1 Initial Screening ............................................................................................................... 72 7.2 Detailed Evaluation .......................................................................................................... 72 7.2.1 7.2.2 7.2.3 7.2.4 7.2.5 7.2.6 7.2.7 7.2.8 7.2.9 No Additional Action pH Reduction/Enhanced Containment Alternative ....... 73 pH Reduction Alternative pH2 ........................................................................ 73 pH Enhanced Containment Alternative pH3 ................................................... 74 pH Enhanced Containment Alternative pH4 ................................................... 74 pH Reduction Alternative pH5 ........................................................................ 75 pH Enhanced Containment Alternative pH6 ................................................... 76 pH Enhanced Containment Alternative pH7 ................................................... 76 Disproportionate Cost Analysis ...................................................................... 77 Summary ........................................................................................................ 82 8. Select Preferred Remedy ........................................................................................................... 83 9. References ................................................................................................................................. 84 Figure Index Figure 2.1 Vicinity Map Figure 2.2 Property Ownership and Other Historical Operations Figure 2.3 Regional Geology Figure 2.4 Conceptual Site Geologic Conditions Figure 2.5 Conceptual Site Model of Fresh Groundwater/Salt Water Distribution Figure 2.6 Potential Sources of VOC Figure 2.7 Potential Sources of Caustic Figure 2.8 Potential Source of Salt Figure 2.9 Potential Sources of Metals Figure 2.10 Potential Sources of SVOC Figure 2.11 Potential Sources of PCBs and Dioxins/Furans Figure 2.12 Early Time Anthropogenic Density Plume Figure 2.13 Early Time Anthropogenic Density Plume Influence on Total CVOC Plume Migration Figure 2.14 Current Anthropogenic Density Plume Figure 2.15 pH Plume Figure 2.16 DNAPL Distribution Figure 2.17 Total CVOC Plume in Groundwater GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) iii Figure Index Figure 2.18 Schematic of Exposure Pathways and Receptors Figure 4.1 Containment Alternative C100 Figure 4.2a Containment Alternatives Cross-Sections – TCVOC Figure 4.2b Containment Alternatives Cross-Sections – pH Figure 4.3 Schematic Cross-Section Along Embankment Within Area 5106 Figure 4.4 Containment Alternative C150 Figure 4.5 Containment Alternative C200 Figure 4.6 TCVOC Mass Target Zones Figure 4.7 VOC Mass Reduction Alternative M100 Figure 4.8 VOC Mass Reduction Alternatives M100, M150, and M200 Cross-Sections Figure 4.9 VOC Mass Reduction Alternative M150 Figure 4.10 VOC Mass Reduction Alternative M200 Figure 4.11 VOC Mass Reduction Alternative Mass Reduction by Strategic Groundwater Pumping (MSP) Figure 4.12 VOC Mass Reduction Alternative MSP Cross-Sections Figure 4.13 VOC Mass Removal Alternatives M3 and M4 Figure 4.14 VOC Mass Removal Alternatives M3 and M4 Cross-Sections Figure 4.15 VOC Mass Reduction Alternative M5 Figure 4.16 VOC Mass Reduction Alternative M5 Cross-Sections Figure 4.17 VOC Mass Removal/Reduction Alternatives M6 and M7 Figure 4.18 VOC Mass Removal/Reduction Alternatives M6 and M7 Cross-Sections Figure 4.19 VOC Mass Removal/Reduction Alternative M8 Figure 4.20 VOC Mass Removal/Reduction Alternative M8 Cross-Sections Figure 4.21 VOC Mass Removal/Reduction Alternative M9 Figure 4.22 VOC Mass Removal/Reduction Alternative M9 Cross-Sections Figure 4.23 pH Target Zones Figure 4.24 pH Reduction and Enhanced Containment Alternatives pH2 and pH3 Figure 4.25 pH Reduction/Enhanced Containment Alternatives pH2, pH3, and pH4 Cross-Sections Figure 4.26 pH Enhanced Containment Alternative pH4 Figure 4.27 pH Reduction and Enhanced Containment Alternatives pH5 and pH6 Figure 4.28 pH Reduction/Enhanced Containment Alternatives pH5, pH6, and pH7 Cross-Sections Figure 4.29 pH Enhanced Containment Alternative pH7 Figure 5.1 Containment Alternatives Common Elements Capital Cost Distribution Figure 5.2 Containment Alternatives 30-Year Cash Flow Projections Figure 5.3 Containment Alternatives Technologies Estimated Durations Figure 6.1 TCVOC Mass Targeted by Alternative Comparison Figure 6.2 Relationship Between Estimated Cost and Estimated Quantity of TCVOC Mass Potentially Addressed GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) iv Figure Index Figure 6.3 VOC Mass Alternatives 30-Year Cash Flow Projections Figure 6.4 VOC Mass Alternatives Technologies Estimated Durations Figure 6.5 Relationship Between Estimated Time and Estimated Quantity of TCVOC Mass Potentially Addressed Figure 7.1 pH (ANC) Targeted by Alternative Comparison Figure 7.2 Relationship Between Estimated Cost and Estimated Quantity of pH (ANC) Potentially Addressed Figure 7.3 pH Alternatives 30-Year Cash Flow Projections Figure 7.4 pH Alternatives Technologies Estimated Durations Table Index Tables Within Text: Table 2.2 Primary Groundwater Plumes and Related Transport Mechanisms ............................... 15 Table 2.3 Primary Human Receptors and Exposure Pathways ...................................................... 21 Table 2.4 Media and Exposure Pathways ....................................................................................... 22 Table 2.5 Primary Ecological Receptors and Exposure Pathways ................................................. 22 Table 3.1 Remedial Action Goals (RAGs) ....................................................................................... 24 Table 3.2 Estimated Plume and Impacted Water Volumes ............................................................. 26 Table 4.2 Summary of Estimated Soil Volumes and Quantity of TCVOC Mass within Target Zones ............................................................... 34 Table 4.3 Summary of Estimated Soil Volumes and Quantity of pH within Target Zones ................................................................................. 43 Table 5.2 Summary of Containment Alternatives Estimated Costs ................................................ 57 Table 6.1 Summary of VOC Mass Removal/Reduction Alternatives Estimated Costs ................... 69 Table 6.3 Summary of Estimated Quantity of VOC Mass Potentially Addressed by each VOC Mass Removal/Reduction Alternative ....................................................... 70 Table 7.1 Summary of pH Reduction/Enhanced Containment Alternatives Estimated Costs ........ 81 Table 7.3 Summary of Estimated Quantity of pH (ANC) Potentially Addressed by each pH Alternative .................................................................................................... 82 Tables Following Text: Table 2.1 Sitewide COC and Media Table 3.3 Remedial Action Goals and General Response Actions Table 3.4 Potential Applicable Local, State, and Federal Laws and Relevant and Appropriate Requirements Table 4.1 Identified Alternatives and Groupings GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) v Table Index Tables Following Text: Table 5.1 Disproportionate Cost Analysis Criteria Site-Specific Weighting Percentages and Rationale Table 5.3 Disproportionate Cost Analysis (DCA) - Containment Alternatives Table 6.2 Disproportionate Cost Analysis (DCA) - VOC Mass Removal/Reduction Alternatives Table 7.2 Disproportionate Cost Analysis (DCA) - pH Reduction/Enhanced Containment Alternatives Appendices Appendix A State of Washington Department of Ecology – Groundwater Non-Potable Determination Appendix B Delineation of Areas of Potential Principal Threat Waste (PTW) Appendix C Technical Memorandum - Revised DNAPL Mass Estimates Appendix D Technical Memorandum - Analysis of TCVOCs Concentrations in Soil to Determine Zones for Potential Targeted Remediation Appendix E Groundwater Flow Modeling for Remedial Alternatives that Incorporate Groundwater Extraction Appendix F Acid-Neutralizing Capacity (ANC) Evaluation Appendix G Alternatives Cost Estimates GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) vi List of Acronyms ADP ANC Anchor AOC ARARs ARF AWQC bgs Bluffs BML CB/NT site CD CERCLA CFR cis-1,2-DCE cm/s COC CRA CSM CVOC DCA DNAPL DOC Ecology EHEPA ENVs ERH ERT FEHs FFAs FS ft ft/d gpm GSH GRAs GWETS HASP HCB HCBD HHEPA Hylebos Anthropogenic Density Plume acid-neutralizing capacity Anchor QEA Administrative Order on Consent Applicable or Relevant and Appropriate Requirements Army Reserve Facility Ambient Water Quality Criteria below ground surface Puget Sound Bluffs below mud line Commencement Bay Nearshore/Tideflats Superfund site Consent Decree Comprehensive Environmental Response, Compensation, and Liability Act Code of Federal Regulations cis-1,2-dichloroethene centimeters per second contaminant of concern or contaminants of concern Conestoga-Rovers & Associates (now GHD) Conceptual Site Model chlorinated volatile organic compound or chlorinated volatile organic compounds Disproportionate Cost Analysis dense non-aqueous phase liquid dissolved oxygen content Washington State Department of Ecology ecological health exposure pathway assessment environmental heads electrical resistance heating Evaluation of Remedial Technologies freshwater equivalent heads Federal Facility Agreements Feasibility Study feet feet per day gallons per minute Glenn Springs Holdings, Inc. General Response Actions groundwater extraction and treatment system health and safety plan hexachlorobenzene hexachlorobutadiene human health exposure pathway assessment Hylebos Waterway GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) vii List of Acronyms ICs ISB ISCO JARPA lbs 3 lbs/ft Meq mg/kg mg/L MSP MTCA MVS/EVS NaCl NCP NGVD NPDES O&M OCC OSHA PCBs PCE PDCE barrier POT PTW RAGs ROD SCR SEPA SMCL SMS SOW SQAPP SQOs SSLs s.u. SVE SVOC TCE TCVOC TDS g/L Upland Areas US Navy USEPA Institutional Controls in situ bioremediation in situ chemical oxidation Joint Aquatic Resources Permit Application pounds pounds per cubic foot megaequivalents milligrams per kilogram milligrams per liter Mass Reduction by Strategic Groundwater Pumping Model Toxics Control Act Mining Visualization System/Environmental Visualization System software package sodium chloride (salt) National Oil and Hazardous Substances Pollution Contingency Plan National Geodetic Vertical Datum National Pollutant Discharge Elimination System operation and maintenance Occidental Chemical Corporation United States Occupational Safety and Health Administration polychlorinated biphenyls tetrachloroethene or perchloroethylene physical direct contact exposure barrier Port of Tacoma potential principal threat waste Remedial Action Goals (or Remedial Action Objectives) Record of Decision Site Characterization Report (or Remedial Investigation Report [RI Report]) Washington State Environmental Policy Act secondary maximum contaminant level MTCA Sediment Management Standards Statement of Work for the Administrative Order on Consent Sampling and Quality Assurance Project Plan Sediment Quality Objectives soil screening levels standard units of pH soil vapor extraction semi-volatile organic compound or semi-volatile organic compounds trichloroethene or trichloroethylene total chlorinated volatile organic compound or total chlorinated volatile organic compounds total dissolved solids micrograms per liter Portions of the Site inland from the Embankment Area as defined in the SOW United States Navy United States Environmental Protection Agency GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) viii List of Acronyms VC VI VOC WAC Waterway Waterways WISHA WMUs 2 yd 3 yd yrs vinyl chloride vapor intrusion volatile organic compound or volatile organic compounds Washington Administrative Code Hylebos Waterway Blair Waterway and Hylebos Waterway Washington Industrial Safety and Health Act waste management units square yards cubic yards years GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) ix 1. Introduction Occidental Chemical Corporation (OCC) has been working with the Washington State Department of Ecology (Ecology) and the United States Environmental Protection Agency (USEPA) (together referred to as the "Agencies") to address remaining environmental issues at the "Occidental" Site associated in part with the former OCC facility located in Tacoma, Washington (Site) under an Administrative Order on Consent (AOC) (USEPA, 2005a). The work activities required under the AOC are outlined in the "Statement of Work for the Administrative Order on Consent" (SOW) (Conestoga-Rovers & Associates [CRA], 2005). Additional work not anticipated in the SOW has been conducted and scheduled consistent with the AOC. This Feasibility Study (FS) Report presents the evaluation of remedial alternatives to address impacts at the Upland Areas of the Site. The evaluation was conducted in accordance with the Model Toxics Control Act (MTCA) Cleanup Regulation, as amended October 12, 2007 (MTCA Regulations) Chapter 173-340-350, and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and builds on the identification and screening of remedial technologies and process options presented in the Draft Evaluation of Remedial Technologies (ERT) Report (CRA, 2014b), the previous Draft Feasibility Study report (CRA, 2015) (2015 Draft FS report), and Agencies' comments on the 2015 Draft FS report (Ecology, 2016a and amendments). This FS Report is organized as follows: i) Section 2 Conceptual Site Model (CSM): provides a summary of the Site characterization including the physical setting, nature and extent of impacts, contaminant fate and transport and exposure pathways assessment. ii) Section 3 Identify Remedial Action Goals (RAGs) and Potential Applicable local, State, and Federal Laws: presents medium-specific goals for protecting human health and the environment based on the contaminants of concern (COC), and potential receptors and exposure pathways. It also presents General Response Actions (GRAs) that, alone or in combination, satisfy the RAGs for each medium of concern, and potential applicable local, State, and Federal laws. iii) Section 4 Identify Alternatives: identifies and describes a reasonable number and type of remedial alternatives; detailing technologies selected for media and subdivisions of the Upland Areas of the Site. iv) Section 5 Containment Alternatives - Initial Screening and Detailed Evaluation: evaluates the identified alternatives to potentially reduce the number for detailed evaluation by eliminating alternatives that do not meet the minimum Washington Administrative Code (WAC) requirements, for which costs are clearly disproportionate, or that are technically not implementable. Evaluates the remaining alternatives with respect to compliance with the minimum requirements in WAC 173-340-360(2), benefits and drawbacks, disproportionate-cost analysis and consistency with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) (USEPA, 1994). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 1 2. v) Section 6 VOC (volatile organic compounds) Mass Removal/Reduction Alternatives - Initial Screening and Detailed Evaluation: evaluates the alternatives with respect to estimated mass removed over time in addition to the same criteria in Section 5. vi) Section 7 pH Reduction/Enhanced Containment Alternatives - Initial Screening and Detailed Evaluation: evaluates the alternatives with respect to same criteria in Section 6. vii) Section 8 Select Preferred Remedy: presents a recommended remedy based on the detailed evaluation of alternatives, Agency's expectations (WAC 173-340-370), and known public concerns, discussion of proposed performance objectives for the recommended remedy, and documents reasons for the recommendation. viii) Section 9 References: lists the documents referenced in this FS Report. Conceptual Site Model This section presents a summary of the physical and chemical characterization of the Site as it relates to the development and analysis of remedial alternatives. OCC has conducted extensive investigations into the Site's physical characteristics, potential contaminant sources, nature and extent of impacts, and contaminant fate and transport. The primary sources of information presented in this summary are the approved Final Conceptual Site Model Report (CRA, 2014a) (CSM Report), the Site Characterization Report (CRA, 2014c) (SCR; also referred to as Remedial Investigation Report [RI Report] as approved on October 11, 2016 [Ecology, 2016b]) and Data Summary Report (Anchor QEA, 2016) for surface sediment and near-surface porewater in the Hylebos Waterway (Waterway or Hylebos) adjacent to the Site (Anchor Report). 2.1 Site Description The Site is located on the eastern-most peninsula of the area of ownership and operations of the Port of Tacoma (POT) that extends into Commencement Bay at the mouth of the Puyallup River Valley and is defined in the AOC. A general location map showing the Site, including the formerly OCC-owned properties and that portion of Segment 5 of the Hylebos Waterway contained within the Site, is presented on Figure 2.1. A plan showing local property ownership is presented on Figure 2.2. The properties formerly owned and/or operated on by OCC or its predecessors include:  605 Alexander Avenue property (former OCC Facility currently owned by Mariana Properties, Inc. [Mariana])  709 Alexander Avenue property (currently owned by Mariana) The properties are referred to as the '605 Alexander Ave.' and '709 Alexander Ave.' properties on Figure 2.2. The properties are bounded on the west, north, and south by former Todd Shipyards and/or United States Navy (US Navy) properties (now owned by the POT), and on the east by the Waterway. The approximate extent of groundwater impacts at the Site is shown on Figure 2.1. The Site is within the roughly 12-square-mile area Commencement Bay Nearshore/Tideflats Superfund site (CB/NT site) which includes several waterway problem areas and adjoining uplands as described GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 2 by the CB/NT site Record of Decision (ROD) (USEPA, 1989). The Site includes part of Segment 5 of the Mouth of Hylebos Problem Area where impacted sediments were dredged and disposed in 2003-05 (CRA, 2014c), or excavated and capped 2007-08 (Hart Crowser, 2013). This work was performed under the Mouth of Hylebos Consent Decree (USEPA, 2005b). 2.2 Historical Operations Historical operations at the Site in the past 100 years have included: (a) chemical manufacturing; (b) ship building, maintenance, and dismantling; and (c) petroleum and fuel storage and distribution. Those operations primarily occupied the real properties designated as 401 Alexander Avenue (now the Port of Tacoma's Early Business Center, formerly described as the Port Industrial Yard, the United States Naval Station Tacoma, and Todd Shipyards), 605 Alexander Avenue (the Former OCC Facility), 709 Alexander Avenue (now owned by Mariana Properties and formerly described as the PRI Northwest and Fletcher Oil facilities), and 901 Alexander Avenue (now Port of Tacoma property, a portion formerly designated as 721 Alexander Avenue and formerly described as the Maxwell Petroleum, General Petroleum, and United States Air Force facilities). Those historical operations have been described in previous Site reports, and are generally summarized below. See, e.g., approved CSM Report (CRA, 2014a); Draft ERT Report (CRA, 2014b), and Appendix B of SCR (CRA, 2014c) approved on October 11, 2016 (Ecology, 2016b). Chemical Manufacturing OCC's predecessor's chemical manufacturing operations began at the Site in 1929 at 605 Alexander Avenue and were continued by OCC and others until 2002. The operations primarily involved the production of chlorine and caustic soda, but during various time frames also involved the production of sodium hypochlorite, trichloroethene/tetrachloroethene (TCE/PCE), ammonia, muriatic acid, calcium chloride, saturated (hydrogenated) oil, aluminum chloride, and sodium aluminate. Chlorine and caustic soda production occurred throughout the Former OCC Facility history, using electrolysis. TCE/PCE production occurred from 1947 to 1973, primarily on the North 10 Acres of 605 Alexander Avenue. Other production processes occurred for various time periods. Wastes generated during the various manufacturing processes were managed at 605 Alexander Avenue, and included wastewater treatment (settling) ponds, settling barges, landfills, disposal pits, and waste piles. Seventeen waste management units were historically located on the property. Chemical manufacturing ceased in 2002, and nearly all buildings and structures at 605 Alexander Avenue were demolished between 2006 and 2008. The property continues to be the operations center for the groundwater treatment and containment facility installed by OCC and operated since 1996. Building, Maintenance, and Dismantling of Ships Shipbuilding began at the Site at least as early as World War One, with the establishment of the Todd Shipyards facility at 401 Alexander Avenue and on a portion of 605 Alexander Avenue (the portion described as the North 10 Acres). Shipbuilding by Todd Shipyards and by the United States occurred in those locations during both World War One and World War Two. The North 10 Acres of 605 Alexander Avenue was used during World War Two for the gathering and incineration of shipyard wastes, among other activities, and in 1945 became the location of the "Navy Todd Dump" on the shoreline of the Hylebos Waterway. The Todd Shipyards facility subsequently became the United States Naval Station Tacoma where ships were stored, maintained, and dismantled until the 401 Alexander Avenue property was acquired by the Port of Tacoma from the United States. Since 1960, numerous tenants' operations have included additional shipbuilding and dismantling. In GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 3 connection with the historical ship-related activities, waste landfilling, incineration, and disposal (among other activities) occurred along the shoreline and in the uplands. Petroleum and Fuel Storage Distribution The petroleum and fuel tank farm facilities located at 709 Alexander Avenue and 901 Alexander Avenue operated from approximately the 1930s to the 1980s. Those historical operations resulted in an area of contaminated soil and groundwater at those and adjacent properties currently being addressed under Ecology oversight and Agreed Order DE 9835 by the Port of Tacoma and Mariana Properties, Inc. The 709 Alexander Avenue property also includes an embankment fill area along the Hylebos Waterway shoreline that was associated with the former chemical manufacturing operations at 605 Alexander Avenue. The 709 Alexander Avenue embankment, as well as the 605 Alexander Avenue embankment, are being addressed as part of the Site. 2.3 Physical Site Setting Regionally, the Site, Puyallup River Valley, and surrounding area are part of the Puget Sound Lowlands, which are surrounded by the Puget Sound Bluffs (Bluffs). The Bluffs extend along the sides of the Puyallup River Valley, and correspond to the highland areas at the east and west sides of the POT. The Bluffs extend upwards from the eastern shoreline of the Waterway to approximately 350 feet (ft) above the Site peninsula. The peninsula on which the Site is located is man-made and was created in the early 1900s. The Hylebos and Blair Waterways located on the east and west sides of the Site peninsula, respectively, were dredged and the materials were used to build up the land mass. The Waterways were dredged through the existing tidal mud flats at the mouth of the Puyallup River Valley. 2.3.1 Regional and Site Geology Regional Geologic Conditions The geologic framework of the Puyallup River Valley consists of nearly 2,000 ft of unconsolidated sediments overlying bedrock. The area has experienced several glacial advances and retreats. The most recent glacial advance, the Vashon Stade of the Fraser Glaciation, scoured a channel into the pre-Vashon sediments along the Puyallup River Valley. Figure 2.3 shows a conceptual model of the regional geology where the channel scoured into the pre-Vashon sediments is in-filled by post-Vashon sediments, referred to here as deltaic deposits. The deposition of the deltaic material occurred at varying rates and under varying stream flow and sea level conditions, resulting in a series of sand units with interbedded and interfingered silt and clay units with occasional gravelly sand units. Site Geologic Conditions Figure 2.4 shows the conceptual geologic conditions for the Puyallup River Valley and Bluffs in the Site vicinity, and is based on the regional geologic conditions described in Appendix A of the approved CSM Report (CRA, 2014a). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 4 Within the Puyallup River Valley, the generalized geologic conditions are based on Site borings and described as follows (from ground surface):  Fill - variable mixture of sand, silt, and gravel material placed through dredging of the Hylebos and Blair Waterways to develop the Site peninsula. The thickness of the fill across the Site ranges from approximately 10 to 15 ft with hydraulic conductivity values that range from -4 -2 approximately 1.0 × 10 to 1.0 × 10 centimeters per second (cm/s) (0.3 to 30 feet per day [ft/d]).  Deltaic deposits - heterogeneous mixture of interbedded sands, silts, and clays. The thickness of the deltaic deposits across the Site ranges from approximately 30 to 200 ft in the eastern and northeastern portion of the Site to greater than approximately 300 ft in the southwestern portion of the Site. Hydraulic conductivity values for the deltaic deposits range from approximately -5 -2 1.0 × 10 to 1.0 × 10 cm/s (0.03 to 30 ft/d).  Glacial deposits - heterogeneous mixture of interbedded gravel, sands, silts, and clays. The thickness of the glacial deposits beneath the Site has not been determined, but based on regional information, is more than 1,000 ft. Hydraulic conductivity values for the glacial deposits -5 -3 range from approximately 5.0 × 10 to 5.0 × 10 cm/s (0.15 to 15 ft/d). The top surface of the glacially derived deposits slopes downward to the north, west, and south from a mound observed under the central portion of the Site, as shown on Figure 2.4. The glacial deposits are not encountered at borings in the west, southwest, and south portion of the Site peninsula and are inferred to dip downward in this area below the depth of the Site borings. The extensive Site stratigraphic data indicate that there is an increased frequency of lower permeability lenses, comprised mainly of silt and clay, in the lower deltaic deposits. This is shown schematically on Figure 2.4. Within the Bluffs, Figure 2.4 shows an alternating sequence of sand/gravel and silt/clay layers based on the regional geologic conditions described in Appendix A of the approved CSM Report (CRA, 2014a). 2.3.2 Regional Hydrogeology/Groundwater Non-Potable Classification Regional Hydrogeologic Conditions Regional surface water and groundwater flow through the Puyallup River Valley discharges to Commencement Bay from south to north. Shallow groundwater discharges to rivers, creeks, and waterways as they extend through the Valley. Groundwater within the Puyallup River Valley is replenished by regional upland groundwater inflow into the Valley and by precipitation infiltration. Regional groundwater flow within the Bluffs discharges through seepage faces along the Bluffs and to the waterways/Commencement Bay. Ecology's letter dated March 30, 2015 (Ecology, 2015) included as Appendix A of this FS Report, determined that the peninsula groundwater meets the MTCA Section 720 non-potable classification. The underlying and surrounding groundwater has salinity levels that exceed USEPA drinking water standards (e.g., total dissolved solids [TDS] >500 milligrams per liter [mg/L], secondary maximum contaminant level [SMCL]). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 5 2.3.3 Site Hydrogeology Groundwater beneath the Site discharges to the surrounding surface water bodies. Fresh groundwater inflow toward the Site peninsula occurs from the south due to upland regional groundwater flow along the Puyallup River Valley, and from the east due to regional groundwater flow in the Bluffs aquifers discharging to the Valley. Infiltration of precipitation over the Site peninsula contributes a further source of fresh groundwater, and establishes a shallow radial groundwater flow pattern towards the surface water bodies. The groundwater table at the Site peninsula is located in the fill that was placed on top of the native mud flats. The mud flats historically existed throughout the POT, but the mud flats have not been identified consistently in all Site borings. This might be due to a lack of precision in the stratigraphic logs, or might be due to stream channels that could have incised the fine-grained sediments of the mud flats. For the CSM, a mud flats stratigraphic unit is conceptualized as depicted on Figure 2.4. In general, the mud flats are assumed to have hydraulic conductivity similar to silts and clays identified within the deltaic deposits. While lower permeability sediments within the mud flats may not be entirely continuous, they clearly create a hydraulic separation between the fill and the underlying deltaic deposits in the southern portion of the Site. Here, groundwater elevations in the fill are approximately 2 ft higher than groundwater elevations in the deltaic deposits immediately beneath the mud flats. The majority of the Site-related impacts exist within the deltaic deposits. The extensive groundwater quality data indicate that the vertical limit of impacts appears to coincide with the increased frequency of lower permeability lenses in the lower deltaic deposits or the top of the glacial deposits. A discrete continuous layer of low-permeability material is not observed in Site borings in the lower deltaic deposits. However, the groundwater quality, density, and hydraulic evidence supports the concept that the increased frequency of lower permeability lenses inhibits vertical flow creating a zone of apparent confining effect in the lower deltaic deposits. The presence of this zone of apparent confining effect is inferred from:  Upward vertical hydraulic gradients observed from the upper glacial deposits to the lower deltaic deposits in the east, northeast, and north portion of the Site peninsula where the glacial deposits were encountered.  Fresh to relatively fresh groundwater observed within the glacial deposits.  Downward migration of the COC appears to be limited to within the lower deltaic deposits or top of the underlying glacial deposits. The glacial deposits beneath the deltaic deposits appear to be an aquifer system composed of several glacially-derived aquifers and aquitards separated from the deltaic deposits. A zone of apparent confining effect in the lower deltaic deposits is consistent with some features of the salt water and fresh groundwater distributions observed at the Site. Relatively fresh groundwater is observed in deeper parts of the deltaic deposits and in the glacial deposits. This fresh water appears to be caused by environmental heads (ENVs) in the deeper deposits that are greater than in the deltaic deposits. The higher pressures in the deeper deposits create upward vertical hydraulic gradients into the deltaic deposits. These upward gradients are supported by fresh groundwater entering the deeper deposits from up-gradient regional groundwater inflow. A zone of GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 6 apparent confining effect, corresponding to the increased frequency of lower permeability lenses in the lower deltaic deposits, explains these observed conditions. The observed salt water and fresh groundwater distributions are translated to the approved CSM of hydrogeological conditions in the Site vicinity on Figure 2.5. The salt water distributions and groundwater flow conditions illustrated on Figure 2.5 are generalized representations of pre-contamination conditions. The groundwater flow conditions illustrated on Figure 2.5 are summarized as follows:  Recharge from precipitation infiltration contributes shallow fresh groundwater in the fill. This recharge migrates laterally through the fill and downward into the underlying deltaic deposits. Lateral flow in the fill and deltaic deposits discharges to the Blair and Hylebos Waterways.  Fresh groundwater is also introduced to both the deltaic and glacial deposits from the uplands along the Puyallup River Valley and from the east from beneath the Bluffs aquifers that lie below sea level.  Elevated freshwater equivalent heads (FEHs) in the Bluffs limit the inland extent of the salt water along the east side of the Hylebos.  Available salinity data from borings completed beneath the Hylebos Waterway show a zone of fresher groundwater from the eastern bluffs extending adjacent to and beneath the Hylebos.  Available bromide data used as a tracer for identifying naturally-occurring salt water suggest a relatively complex pattern of salt water at intermediate depths underlain by fresher groundwater at depth at some locations. Releases of high-density liquids from historical Site operations/processes (lime sludge/solvent residue, caustic soda, and salt brine) have a critical influence on groundwater flow and contaminant transport, as described in Subsection 5.6.2.5.1 of the SCR (CRA, 2014c) approved on October 11, 2016 (Ecology, 2016b). 2.4 Nature and Extent of Impacts Extensive investigations have been conducted at the Site to define the nature and extent of impacts. The chemical characterization of soil, groundwater, porewater, and sediment is based upon the extensive analytical data obtained during the various investigations summarized in the approved SCR (CRA, 2014c) and Anchor Report (Anchor QEA, 2016). This subsection summarizes the potential contaminant sources, media of concern, and contaminant fate and transport. Table 2.1 presents Sitewide COC and media, which are further discussed below. 2.4.1 Potential Contaminant Sources Past operations at the property generated wastes that were managed on Site. Waste management practices included wastewater treatment (settling) ponds, settling barges, landfills, disposal pits, and waste piles. In total, 17 waste management units (WMUs) were historically located at the Site, in addition to the Navy Todd Dump. Detailed discussions of the WMUs and the chemicals associated with them were presented in the SCR (CRA, 2014c) approved on October 11, 2016 (Ecology, 2016b). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 7 Environmental investigations at the Site began in the 1980s and have shown that the following parameters are the principal COC:  Chlorinated volatile organic compounds (CVOC)  Fuel-related volatile organic compounds (fuel-related VOC)  Caustic (sodium hydroxide)  Salt (sodium chloride or NaCl)  Metals (arsenic, chromium, copper, lead, mercury, nickel, thallium, zinc)  Semi-volatile organic compounds (SVOC) (hexachlorobenzene [HCB] and hexachlorobutadiene [HCBD], which are by-products of solvent production)  polychlorinated biphenyls (PCBs)  Dioxins/furans The principal COC were either used, produced, generated, and/or stored in various locations at the Site. In addition, some wastes generated in the production processes were managed on Site. Key "potential source areas" where the vast majority of releases occurred are listed below and described more fully in the SCR (CRA, 2014c) approved on October 11, 2016 (Ecology, 2016b). The metals listed above as principal COC were not used in Former OCC Facility operations at the Site, but some of those metals were used in former ship building, maintenance, and dismantling operations at the Site. Geochemical conditions created by the release of caustic and brine (dissolved NaCl), and reducing conditions in groundwater, have resulted in the mobilization of some of these metals in the subsurface. The PCBs listed above as principal COC were used in the shipbuilding, maintenance, and dismantling operations at the Site. PCBs were not used in Former OCC Facility operations at the Site, other than in electrical equipment (such as transformers and capacitors). The dioxins/furans listed above as principal COC were used in and generated by the ship building, maintenance, and dismantling operations at the Site. Dioxins/furans were not used in Former OCC Facility operations other than potentially in spent graphite anodes used at the former chemical production facility, and in overheated electrical equipment (such as transformers and capacitors) containing PCBs. VOC Potential Sources Chlorinated solvents (TCE and PCE) were produced at the Site from 1947 to 1973. The former solvent production plant and associated WMUs are shown on Figure 2.6. A single area around the former solvent production plant and WMUs is shown on Figure 2.6 as the "potential CVOC source area". The TCE and PCE impacts in soil and groundwater appear to be primarily associated with the former solvent production plant (S1), former settling ponds (WMU A [S3], WMU G [S4], and WMU H [S5]), former settling barge (WMU F [S2]), and Area 5106. Lime sludge and solvent residue from the chlorinated solvents process were sent to settling ponds and a settling barge over time and in the first year of production were discharged to the Waterway through a direct discharge line. CVOC and fuel-related VOC groundwater impacts are present on the 709 and 721 Alexander Avenue properties. These properties are being addressed under Agreed Order No. DE 9835, effective October 3, 2013. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 8 Caustic Potential Sources The elevated pH present in groundwater at the Site is primarily due to the release of sodium hydroxide (caustic soda) produced at the Site. Historical locations of the production and handling of caustic soda are shown on Figure 2.7. The principal potential source area appears to be the Caustic House (S8). A single area around the locations of Caustic House and caustic soda storage/handling is shown on Figure 2.7 as the "potential caustic source area". Salt Potential Source Salt was used as a feedstock in the production of chlorine, chlorinated solvents, and caustic soda. Salt was delivered to the Site by ship and stored in open piles on the Salt Pad. Figure 2.8 shows the location of the Salt Pad. Uncovered salt piles were maintained on this pad from the early 1960s until operations ceased. Water was sprayed on the salt piles to make brine. The asphalt pad was diked and sloped to a sump. However, cracks, if they existed, in the asphalt pad or leaks in the sump could have led to salt impacts beneath the Salt Pad. Metals Potential Sources Figure 2.9 shows the N Landfill and the Navy Todd Dump located adjacent to the embankment of the Waterway. The N Landfill was used between 1929 and 1971 and investigations have shown that the landfill received wastes containing metals, corrosives, chlorinated organics, and non-burnable debris. The Navy Todd Dump was created in approximately 1945, as a result of World War Two ship construction and waste disposal/incineration activities. Navy Todd Dump investigations have shown that the waste material contains metals (primarily cadmium, chromium, copper, mercury, nickel, and zinc). The N Landfill and Navy Todd Dump are considered potential metals sources. The approximate boundary of metals impacted embankment fill areas is also shown on Figure 2.9. In addition to the N Landfill and Navy Todd Dump, metals impacted waste material derived from shipbuilding and dismantling activities during and after World War Two as well as chemical production were disposed along the embankment of the Waterway. The vast majority of metals in the groundwater are present as a result of geochemical conditions (high pH and ionic strength) created by the release of other COC. The geochemical conditions mobilize (dissolve) metals at concentrations above those that would exist naturally in groundwater. This process is described in Subsection 5.4.5.2 of the SCR (CRA, 2014c) approved on October 11, 2016 (Ecology, 2016b). SVOC Potential Sources Potential sources of SVOC are shown on Figure 2.10. The two SVOC detected most often at concentrations above their respective criteria are HCB and HCBD. These compounds are by-products of the production of chlorinated solvents, and are found (to some degree) in areas where chlorinated solvents were produced or stored, or where the waste products were handled and disposed. PCBs and Dioxins/Furans Potential Sources Potential sources of PCBs and dioxin/furans are shown on Figure 2.11. Significant potential sources of PCBs at the Site would be from the US Navy shipbuilding operations performed at the Site including PCB-containing materials disposed at the Navy Todd Dump, and from ship dismantling GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 9 and maintenance operations performed at the Site involving PCB-containing materials disposed and handled at the Site. Other potential sources of PCBs in the soil and sediment at the Site would be spills from equipment such as transformers and capacitors containing PCBs. Dioxins (the common name for polychlorinated dibenzo-para-dioxins) and furans (polychlorinated dibenzofurans) are two closely related groups of chemical byproducts that are found at background levels in most industrial areas. A potential source of dioxins/furans was the incinerator installed and used at the Site for waste disposal by the US Navy and Todd Shipyards during World War Two. The burning of wastes such as PCB-containing materials in the incinerator and along the embankment at the Navy Todd Dump would have been a potential source for dioxins/furans detected at the Site. Various other forms of combustion and smelting processes (e.g., welding), occurred at the World War Two shipyard, which also potentially produced dioxins/furans. Another potential source of dioxins/furans is spent graphite anodes used at the former chemical production facility, and disposed on Site. Other potential sources of dioxins/furans at the Site would have included overheated electrical equipment (such as transformers and capacitors) containing PCBs. Anthropogenic Density Plume (ADP) Potential Sources A plume of elevated groundwater density, termed the "Anthropogenic Density Plume" (ADP), exists beneath the Site due to releases of high density materials from historical operations. The potential sources for the ADP consist of:  Lime was placed in WMU A, WMU F, WMU G, and WMU H, while lime sludge/calcium chloride was placed in WMU C. Lime sludge (calcium chloride) is miscible in water, and a calcium chloride solution with water can have a specific gravity of approximately 1.3 (at 15 degrees Celsius).  Caustic soda, with a specific gravity of approximately 1.3 to 1.5, is another component of the Site ADP. The "Potential Caustic Source Area" shown on Figure 2.7 represents a potential source location for the ADP.  Brine (sodium chloride) was created at the Salt Pad and had a specific gravity of approximately 1.2 and is a further component of the ADP. The Salt Pad, shown on Figure 2.8, represents a potential source location for the ADP. The noted potential contaminant sources have resulted in contamination of environmental media at the Site. A summary of the nature and extent of Site COC in each medium is provided in the following sub-sections. 2.4.2 Soil The nature and extent of impacts in unsaturated soil is summarized as follows:  CVOC, primarily as PCE, are present in unsaturated soil at concentrations exceeding the unsaturated soil screening levels (SSLs), primarily in the vicinity of WMU A, the Salt Pad/WMU G, WMU H, and the N Landfill.  Site SVOC, primarily HCB and HCBD, are present in unsaturated soil at concentrations exceeding the SSLs within the same general areas as CVOC, as well as at several embankment locations.  PCBs are present in unsaturated soil at concentrations exceeding the SSL primarily near the Navy Todd Dump and the N Landfill. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 10  Metals, primarily copper, but to a lesser degree arsenic, zinc, and nickel, are present at concentrations exceeding the SSLs in the vicinity of the Salt Pad/WMU G, the former Caustic House, the N Landfill, and Navy Todd Dump. The nature and extent of impacts in saturated soil is summarized as follows:  CVOC, primarily as PCE, TCE, and associated degradation products, are present in saturated soil at concentrations exceeding the saturated SSLs. This presence is greatest below the Facility near WMU A, the Salt Pad/WMU G, and WMU R, as well as below the Hylebos. CVOC are present to a lesser degree along the embankment and in the vicinity of the N Landfill.  Site SVOC, primarily as HCB, are present in saturated soil at concentrations exceeding the SSLs within the same general areas as CVOC.  Pesticides and PCBs are present in saturated soil at concentrations exceeding the SSLs along the embankment primarily near the Navy Todd Dump and the N Landfill.  Metals, primarily copper, total chromium, nickel, arsenic, and zinc, are present at concentrations exceeding the SSLs in nearly all samples analyzed across the Site. The highest concentrations occur along the embankment in the vicinity of the N Landfill and Navy Todd Dump. 2.4.3 Dense Non-Aqueous Phase Liquid (DNAPL) Specific investigations were conducted at the Site to identify the presence of dense non-aqueous phase liquid (DNAPL) following the procedures presented in Kueper and Davies (Kueper, B.H. and K. Davies, 2009). Confirmed DNAPL was identified in the vicinity of the Salt Pad/WMU G and WMU R within the 15-ft and 25-ft zones. Confirmed DNAPL was also detected in the 100-ft, 130-ft, and 160-ft zones. Confirmed DNAPL was not identified in the 50- and 75-ft zones. 2.4.4 Groundwater The nature and extent of impacts in groundwater is summarized as follows:  CVOC are present in groundwater at concentrations above the groundwater screening criteria as follows: - 25-ft zone – The areas of highest concentrations are located near the Salt Pad and WMU A - 50-ft zone – The extent of PCE and TCE is similar to the 25-ft zone, but the extent of vinyl chloride (VC) increases significantly within the 50-ft zone area beyond the limits of PCE and TCE toward the eastern side of the Hylebos - 75-ft zone – The highest CVOC concentrations extend eastward under the Hylebos, with lower concentrations extending further north - 100-ft zone – The area of highest concentration is somewhat reduced, but has migrated further north - 130-ft zone – The area of highest concentration is somewhat reduced, but has migrated north and east when compared to the 100-ft zone - 160-ft zone – CVOC concentrations in the 160-ft zone are reduced compared to the 130-ft zone, but the plume continues further northward GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 11  Site SVOC, primarily HCB and HCBD, are present along the embankment and beneath the Hylebos at depths down to 111 ft below ground surface (bgs) upland and 164 ft below mud line (BML) below the Waterway.  PCBs are present in groundwater primarily along the embankment in the vicinity of the Navy Todd Dump and N Landfill and below the Hylebos.  Metals, primarily arsenic, copper, and nickel, are present at concentrations exceeding the groundwater screening criteria. The highest concentrations occur in the vicinity of the Salt Pad and Navy Todd Dump, along the embankment, and beneath the Hylebos.  Elevated pH groundwater is present above the groundwater screening criteria as follows:  - 25-ft zone – elevated pH was measured across the Site, with the highest values (>13 s.u. [standard units of pH]) detected along the eastern portion of the Site beneath the former plant production areas - 50-ft zone – the extent of the highest pH values increases in size relative to the 25-ft zone and is located more to the north toward the Salt Pad - 75-ft zone – the extent of the pH plume within the 75-ft zone is reduced relative to the 50-ft zone, but has migrated east with the highest groundwater pH (>12 s.u.) located in the vicinity of the former caustic tanks and the south end of Dock 1 - 100-ft zone – the pH plume has migrated north and east, with the highest pH near the north end of Dock 1, but is limited to beneath the facility and Hylebos - 130-ft zone – the pH plume continues further northeast - 160-ft zone – the area of high pH values is much smaller in the 160-ft zone, with the highest readings diminishing The seep study performed in the Hylebos confirmed that seepage of impacted groundwater was occurring to some extent into the Hylebos. 2.4.5 Sediment The August 2016 Anchor QEA investigation of potential CVOC in sediments in the Hylebos included collection of surface sediment samples from the 0- to 10-cm interval at 33 locations in the Hylebos adjacent to the Site and comparison of reported concentrations to the CB/NT site Sediment Quality Objectives (SQOs), which were developed in consideration of the MTCA Sediment Management Standards (SMS). The investigation determined that most CVOC were below detection and no reported concentrations exceeded the CB/NT site SQOs. Therefore, based on the results presented in the 2016 Anchor QEA Data Summary Report for sediment and porewater, there is no need to develop an FS or remedial alternatives for sediments at this time. It should be noted that it has been over 10 years since dredging was completed and re-contamination of the sediments has not occurred based on the 2016 data. Additionally, there is evidence from data collected in the Hylebos that natural recovery is occurring as predicted for the CB/NT site. Some future monitoring of COC concentrations in sediments may be appropriate to ensure that existing conditions of sediment quality do not change over time, however unlikely this may be. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 12 2.4.6 Porewater The July/August 2016 Anchor QEA investigation of potential CVOC in porewater beneath the Hylebos included attempted collection of near-bottom surface water samples from 2 to 4 cm above the mudline at 6 locations, and porewater samples from depths of 2 to 4 cm (near-surface), 10 cm, 30 cm, and 90 cm below the mudline at 33 locations in the Hylebos adjacent to the Site. The reported concentrations for near-bottom surface water and near-surface porewater samples collected at 2 to 4 cm above and below the mudline, respectively, were compared to Ambient Water Quality Criteria (AWQC). Only one parameter VC, reported in one sample (adjacent to the northern end of the 605 Alexander Avenue property), had the potential to marginally exceed the associated screening criterion at the applicable point of compliance. Therefore, this migration pathway is not considered significant at this time. Based on the fact that the remedy for the Site will include containment, it is unlikely that future impacts will occur. Some future monitoring of COC concentrations in porewater may be appropriate to ensure that existing conditions of porewater quality do not change over time, however unlikely this may be. 2.4.7 Indoor Air The vapor intrusion (VI) investigation included nine buildings in the Site area, including the Army Reserve Facility (ARF), Buildings 326, 407, 532, 592, 595, and 596, and the Guard Shack located on properties owned and/or controlled by the POT, and the OCC Office Building. The most frequently occurring exceedances of screening levels in indoor air and their potential sources were as follows:  Indoor sources: 1,2,4-trimethylbenzene, 1,4-dichlorobenzene, naphthalene, m&p-xylenes, styrene, PCE, and TCE  Outdoor sources: none  Sub-slab sources: PCE and TCE The majority of exceedances were concluded to be likely attributable to indoor sources (e.g., vehicle operations, paint operations, miscellaneous power and hand tools, parts washing tubs, chemical storage tanks, flammable material storage lockers, paint cans, cleaning products, miscellaneous building materials, aerosol cans containing chemical cleaners, lubricants, cutting oils, and diesel fuel). Only a few of the exceedances were concluded to be potentially attributable to sub-slab sources, and two of which were sources likely unrelated to the OCC Site. The recommendations for future actions at the nine buildings are as follows:  Manage occupancy: OCC Office  Continued monitoring: 595  No Further Action: ARF, 326, 407, 532, 592, 596, and Guard Shack 2.5 Potential Principal Threat Waste (PTW) An evaluation of the presence of potential principal threat waste (PTW) at the Site was undertaken and the details and results of this evaluation are presented in Appendix B. The regulatory framework regarding the identification and remediation of hazardous substances and PTW includes WAC 173-340-350, WAC-173-340-370, CERCLA §121, and the NCP [40 CFR 300.430 (a) (1) (iii)]. A summary of the PTW delineation is presented below. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 13 In general, MTCA, CERCLA, and the NCP consider hazardous substances/PTW to be those source materials that are:  Highly toxic or  Highly mobile that generally cannot be reliably contained or  Would present a significant risk to human health or the environment should exposure occur MTCA, CERCLA, and the NCP establish an expectation that treatment will be used to address hazardous substances/PTW at a site wherever practicable. This is clearly stated in WAC 173-340-370(1) as follows: "The department expects that treatment technologies will be emphasized at sites containing liquid wastes, areas contaminated with high concentrations of hazardous substances, highly mobile materials, and/or discrete areas of hazardous substances that lend themselves to treatment." However, MTCA, CERCLA, and the NCP also acknowledge that hazardous substances/PTW may be contained rather than treated due to difficulties in treating the source material. Ecology's position is stated in Focus No. 94-130 as follows: "Protecting Human Health and the Environment. The cleanup action selected must either remove or destroy the contamination, restoring the site to cleanup levels, or contain the contamination in such a way that will minimize future exposure of humans and ecological receptors (plants and animals)." (Ecology, 2013) As stated in the preamble to the NCP (55 FR at 8703, March 8, 1990), there might be situations where PTW may be contained rather than treated due to difficulties in treating the wastes. Specific situations that might limit the use of treatment are summarized in USEPA (1991) as follows:  Treatment technologies are not technically feasible or are not available within a reasonable timeframe.  The extraordinary volume of materials or complexity of the site makes implementation of treatment technologies impracticable.  Implementation of a treatment-based remedy would result in a greater overall risk to human health and the environment due to risks posed to workers or the surrounding community during implementation.  Severe effects across environmental media resulting from implementation would occur. The decision to treat or contain hazardous substances/PTW is made on a site-specific basis through the remedy selection process (USEPA, 1991 and WAC 173-340-360). The DNAPL and caustic source material that could potentially be considered hazardous substances/PTW were identified following the guidance presented in MTCA, CERCLA, the NCP, and USEPA, 1991. All confirmed DNAPL source zones were considered to be PTW because of their toxic composition and the significant risk that could result should exposure occur. The distribution of potential DNAPL PTW is shown on Figures 3a and 3b in Appendix B. All unsaturated and saturated soil where the soil or groundwater pH was equal to or greater than 12.5 s.u. was considered PTW because they are considered to be characteristically hazardous for corrosivity in accordance with the Code of Federal Regulations (40 CFR 261.22). The areas of caustic-impacted soil that could be considered PTW are shown on Figure 8 in Appendix B. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 14 As presented above, MTCA, CERCLA, and the NCP have an expectation for treatment of hazardous substance/PTW, wherever practicable. At this Site, the complete treatment of hazardous substance/PTW may be considered impracticable for the following reasons:  Feasible treatment technologies are not available  Very large volumes of hazardous substances/PTW  Complex geologic and geochemical conditions  Potential for increased risks during implementation of treatment 2.6 Contaminant Fate and Transport Site investigations have confirmed that there are four primary groundwater plumes: the ADP, pH plume, CVOC, and metals. Other COC have not developed large, distinct groundwater plumes. This is likely due to a combination of factors, such as low mobility in groundwater, limited contaminant mass, and attenuation processes. The primary groundwater plumes have migrated from the potential sources noted in Subsection 2.4.1 via several transport mechanisms that are summarized below. Table 2.2 Primary Groundwater Plumes and Related Transport Mechanisms COC Type ADP Transport Mechanism   Density-dependent flow Migration with groundwater pH plume   Density-dependent flow Migration with groundwater CVOC      DNAPL migration Migration with the ADP Displacement by the ADP Migration with groundwater Volatilization to ambient air and/or indoor air Metals   Migration with the ADP Migration with groundwater SVOC  Migration with groundwater PCBs  Migration with groundwater Metals and PCBs have also migrated from potential sources at ground surface via surface water runoff. 2.6.1 Anthropogenic Density Plume (ADP) Historical Site operations resulted in surface releases of high density fluids from the potential sources described previously (primarily the settling ponds/barge, Potential Caustic Source Area, and Salt Pad). Mixing of lime sludge/solvent residue, caustic soda (sodium hydroxide), and brine (sodium chloride) in groundwater has resulted in a comingled plume of high density that under current conditions consists of specific gravity values ranging to approximately 1.2 (density of 3 74.9 pounds per cubic foot [lbs/ft ]). The ADP tends to sink due to its higher density relative to the density of fresh groundwater and salt water. A conceptual figure showing the ADP during the early period of Site operations is shown on Figure 2.12. The early time ADP is envisioned as being within GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 15 the fill and upper portion of the deltaic deposits below the settling ponds/barge (WMU C, F, G, and H), Salt Pad, and Potential Caustic Source Area. The solvent residue, comprised of PCE and TCE, is the highest density material that was released, and thus the early time ADP is shown to extend somewhat deeper under the settling ponds/barge on Figure 2.12. Over time, the ADP migrated away from the potential source areas via density-dependent (i.e., gravity-driven) flow. While migrating downwards, the higher density plume displaced the fresh groundwater and salt water initially present beneath the release locations. The fresh groundwater and salt water displacement caused by the downward density plume migration caused lateral groundwater flow that has contributed to the lateral spreading of the density plume, as well as the spreading of impacted groundwater surrounding or comingled with the density plume. This lateral spreading has resulted in a portion of the CVOC plume migrating eastward, beneath the Waterway, opposite the average groundwater flow directions currently observed. The lateral spreading of the CVOC plume caused by the early time ADP is illustrated on Figure 2.13. The primary CVOC found beneath the Waterway currently is VC, which is a biodegradation product of the initially-released PCE and TCE. The ADP will spread laterally and migrated vertically until encountering lower permeability soil layers or counterbalancing hydraulic pressures, as follows:  Lateral migration would continue until reaching equilibrium, or counterbalancing hydraulic pressures (i.e., opposing horizontal hydraulic gradients counterbalancing the lateral density-driven gradients), or until encountering a vertical low-permeability barrier, such as the buried valley wall along the Bluffs east of the Waterway. These factors prevented eastward migration of the ADP into the sediments beneath the Bluffs.  Vertical migration would continue until reaching a combination of the upward vertical hydraulic gradients from the upper glacial deposits to lower deltaic deposits and the increased frequency of lower permeability lenses in the lower deltaic deposits (i.e., the zone of apparent confining effect). Upward vertical hydraulic gradients in the upper glacial deposits counterbalance the tendency of the dense water to sink, and the increased frequency of lower permeability lenses in the lower deltaic deposits limits the vertical rate of migration. The distribution of the current ADP is shown on Figure 2.14. The ADP is centered beneath the settling ponds/barge and Salt Pad, with the southern portion of the ADP underlying the Potential Caustic Source Area. The ADP has remained relatively consistent since 2006 based on comparison with upland groundwater density data from 2012. The highest densities of the ADP are well below the groundwater table, reflecting the fact that the major density sources ceased or were removed prior to Site investigations. The ADP has also spread laterally beneath the Waterway and to the north toward Commencement Bay. The vertical migration of the ADP is limited by the zone of apparent confining effect in the lower deltaic deposits and upward vertical hydraulic gradients within the upper glacial deposits. The ADP has migrated northward due to northward-directed hydraulic gradients. The northward ADP migration also appears to be influenced by a northwestward dipping trough in the glacial deposits observed beneath the northeastern portion of the Site peninsula. The zone of apparent confining effect in the lower deltaic deposits appears to follow the trough, and correspondingly the ADP above this. Once the density-driven gradients of the ADP dissipate, diffusion and groundwater advection were the predominant mechanisms for any further migration of the ADP, and COC comingled with the ADP. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 16 2.6.2 pH Plume Historical Site operations resulted in surface releases of high density/high pH caustic fluids from the Potential Caustic Source Area described in Subsection 2.4.1. The caustic fluids co-mingled with the brine released from the Salt Pad to form the ADP. Thus, the pH plume is largely coincident with the ADP plume. The distribution of the current pH plume is shown on Figure 2.15. Interaction of historical caustic releases with the aquifer materials has resulted in the formation of hydroxide and silicate ions, primarily within the shallow fill material. These ions react with fresh precipitation infiltration to produce high pH groundwater. Thus, shallow soil that was impacted with caustic is a continuing source of elevated pH to groundwater. The position and extents of the pH plume has remained relatively consistent since 2006. 2.6.3 Chlorinated Volatile Organic Compounds (CVOC) The migration of CVOC occurs by several mechanisms:  DNAPL migration  Migration of dissolved-phase with the ADP  Displacement migration at the perimeter of the ADP  Migration of dissolved-phase with fresh groundwater  Migration to ambient and indoor (potentially) air DNAPL Migration The distribution of DNAPL in the subsurface is shown on Figure 2.16. This figure shows the general distribution of the confirmed and potential DNAPL beneath the Site. DNAPL is observed beneath the former solvent production plant, WMU A, and WMU G. Historical DNAPL release rates and mass likely would have been highly variable, resulting in the separation between confirmed DNAPL at the upper and lower depths within the deltaic deposits shown on Figure 2.16. During vertical migration of the DNAPL, significant lateral migration has occurred, likely due to the DNAPL encountering low-permeability lenses within the deltaic deposits that increase in frequency in the lower portion of the deltaic deposits. DNAPL has also moved northwestward at depth consistent with the zone of apparent confining effect in the lower deltaic deposits following the trough in the glacial deposits. Given the significant timeframe since the initial releases occurred, the tortuous migration of the DNAPL through the heterogeneous deltaic deposits, and increased frequency of lower permeability lenses in the lower deltaic deposits, the current DNAPL distribution is likely stable. Residual DNAPL will result in a continuing source of dissolved CVOC. Additionally, diffusion into lower permeability (i.e., silt and clay) lenses adjacent to DNAPL will accumulate CVOC mass. The silt and clay then act as secondary sources of aqueous contamination through back-diffusion once groundwater concentrations in higher permeability zones decline. The process of back-diffusion from lower permeability lenses into higher permeability zones, where the bulk of the active groundwater flow occurs, will significantly prolong groundwater remediation timeframes and might result in rebounding of concentrations after certain types of treatment. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 17 Migration with the ADP and Displacement Migration at the Perimeter of the ADP Figure 2.17 shows the current distribution of CVOC in groundwater at the Site. The CVOC potential sources were in close proximity to the Salt Pad, and as a result, dissolved CVOC have comingled and migrated with the ADP. As the ADP displaced fresh groundwater or salt water in the subsurface, comingled CVOC within the ADP were carried by the ADP as it migrated laterally and downward. In addition, CVOC already dissolved in groundwater at the periphery of the ADP would have been displaced laterally and vertically in advance of the ADP migration. The lateral ADP migration is a primary reason for the presence of CVOC beneath the Hylebos east of the Potential CVOC Source Area even though the average groundwater flow direction observed under current conditions is more north to northwest. Migration in Groundwater Dissolved-phase CVOC in groundwater outside the ADP will migrate with groundwater. This will lead to northward migration as the regional groundwater flow direction in the deltaic deposits is generally toward Commencement Bay, with groundwater discharge to the surrounding surface water bodies. This northward flow has resulted in a shallow component of CVOC plume at the northern end of the Site peninsula. This component of the CVOC plume occurs above the salt water/freshwater transition zone, as illustrated on Figure 2.17. Migration of dissolved-phase CVOC in groundwater is attenuated by the following processes: adsorption; diffusion into low-permeability (i.e., silt and clay) lenses; and degradation. Adsorption of CVOC onto soil particles depends on the amount of organic matter naturally present in soil and the relative affinity of individual hydrophobic compounds to adhere to organic matter. Adsorption results in the dissolved-phase CVOC plume migrating more slowly than the average groundwater flow velocity. Diffusion of dissolved-phase CVOC into lower permeability (i.e., silt and clay) lenses also slows the rate of CVOC migration relative to the average groundwater flow velocity in higher permeability zones. The silt and clay then act as secondary sources of dissolved-phase contamination through back-diffusion once groundwater concentrations in higher permeability zones decline. Degradation of the CVOC is occurring both biologically and abiotically. Biological degradation of PCE and TCE (parent compounds) has produced cis-1,2-dichloroethene (cis-1,2-DCE) and VC (daughter products) at the Site. The distribution of the parent and daughter products in groundwater is shown on figures in the approved CSM Report (CRA, 2014a). In general, the concentrations of PCE and TCE are highest near the surface sources and DNAPL source zones. The concentrations of daughter products are highest in the source zones and beyond the PCE and TCE plume. The presence of cis-1,2-DCE and VC, which are daughter products of the biological degradation of PCE and TCE, confirms that PCE and TCE biodegradation is occurring. Ethene has also been detected in groundwater samples, indicating that complete degradation of VC is occurring at least in some areas of the Site. The abiotic degradation of PCE and TCE might also be occurring as suggested by the presence of dissolved acetylene in groundwater. It does not appear that the high ionic strength of the salt water, ADP, and pH plume have a direct effect on CVOC migration because CVOC are non-polar molecules. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 18 The concentrations of CVOC at the base of the Waterway are significantly lower than groundwater concentrations at depth. The shallow concentrations are attenuated because of flushing (dilution) with surface water, which is enhanced via tidal fluctuation. Also, within the salt water zone adjacent to the Waterway mudline, salt water recharges to the aquifer resulting in dilution of the salt water zone. These processes contribute to the presence of low to non-detectable CVOC concentrations near the mudline observed at some Waterway sample locations. In particular, this is expected to occur in areas that are not affected by the ADP where high density groundwater discharge can occur against the salt water equilibrium or in areas that are not affected by high water levels from the eastern Bluffs. Although along the center and eastern shores of the Hylebos, impacted groundwater was detected nearer the mudline. This was confirmed by the findings of the 2016 Anchor QEA porewater investigation, which found no exceedances of AWQC near the mudline in these areas (see Subsection 2.4.6). Migration to Ambient and Indoor (Potentially) Air VOC can volatilize from impacted shallow groundwater or from the impacted vadose zone soil. VOC in the vapor phase will then migrate by diffusive and advective mechanisms through the unsaturated soil and be emitted to ambient air and potentially indoor air of enclosed buildings. Concentrations of PCE and TCE above sub-slab screening levels potentially related to the OCC Site were identified in vapor samples collected from immediately beneath the concrete slabs of the POT Building 595 and OCC Office (TCE only). However, exceedances of indoor air screening levels for PCE and TCE were not identified in POT Building 595 where the sub-slab vapor concentrations are adequately attenuated. Exceedances of an indoor air screening level for TCE were identified in the OCC Office; however, the occupancy of this building is being managed by OCC to mitigate potential exposure. 2.6.4 Metals The migration of metals occurs by several mechanisms:  Migration of dissolved metals with the ADP  Migration of dissolved-phase with fresh groundwater  Metals transport in surface water runoff Migration with the ADP As the ADP displaced fresh groundwater or salt water in the subsurface, comingled dissolved metals within the ADP were carried by the ADP as it migrated laterally and downward. In addition, metals already dissolved in groundwater at the periphery of the ADP would have been forced to migrate laterally and vertically in advance of the ADP migration. Migration in Groundwater Infiltrating groundwater that comes into contact with soil containing metals will dissolve some of the metals, carrying them to the water table and into groundwater. Once in groundwater, the metals are transported along with groundwater flow. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 19 The metals concentrations and migration in groundwater are influenced by numerous mechanisms, the most important at the Site are:  Sorption onto naturally-occurring ferric oxide coatings on aquifer soil particles. This sorption slows the transport of metals in groundwater.  Suppression of sorption onto the ferric oxide coatings by the high pH of the water in the pH plume mobilizing metals (that would otherwise be adsorbed) and keeping the metals in solution longer.  Enhancement of the solubility of some metals in soil (both naturally-occurring and anthropogenic) by the high pH of the water in the pH plume.  Limitation of the sorption of metals due to ion-ion interactions associated with the high ionic strength of the ADP (i.e., competition for sorption sites) keeping the metals in solution. Migration of metals in groundwater is highly dependent on the pH plume and the ADP. As groundwater pH decreases and the ADP dissipates, natural sorption processes would precipitate metals and reduce the concentrations of metals dissolved in groundwater. Surface Water Runoff Precipitation at the Site comes into contact with surficial soil and carries soil particles with the surface water runoff, especially during heavy rainfall events. The surface water at the Site is conveyed by overland flow and the storm sewer system to adjacent surface water bodies. There has been a storm sewer monitoring program in place at the Site designed to determine if storm water discharge is within regulatory limits. The monitoring program has shown the Site to be in compliance with the Site Storm Water Pollution Plan and has not identified any significant impacts. Based on this fact, it is unlikely that future impacts will occur and this migration pathway is not considered significant. Storm water monitoring data were summarized and presented in the SCR (CRA, 2014c) approved on October 11, 2016 (Ecology, 2016b). 2.6.5 Semi-Volatile Organic Compounds (SVOC) The migration of SVOC could potentially occur via several mechanisms:  DNAPL migration  Migration of dissolved phase with the ADP  Migration of dissolved phase with fresh groundwater DNAPL Migration Because the SVOC were formed as by-products of the solvent manufacturing process, they are inferred to have been present in the DNAPL released to the subsurface at the Site. The SVOC would have then migrated downward along with the DNAPL as described in Subsection 5.6.2.5.1 of the SCR (CRA, 2014c) approved on October 11, 2016 (Ecology, 2016b). The presence of HCB and HCBD in deep soil samples is consistent with this hypothesis. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 20 Migration with the ADP and in Groundwater The most predominant Site SVOC (HCB and HCBD) tend to sorb strongly to the soil and have limited mobility in groundwater compared to the CVOC. Some dissolution will occur though, as will the sorption to suspended particles (i.e., colloids) in groundwater. However, the migration of the SVOC in the groundwater is, as expected, much more limited than CVOC. Detected concentrations above the Site screening levels tend to be near to the identified potential SVOC source areas described in Subsection 2.4.1. 2.6.6 Polychlorinated Biphenyls (PCBs) and Dioxins/Furans PCBs and dioxins/furans sorb very strongly to soil particles and therefore migration in the groundwater is limited, although some sorption to colloids might occur, which could result in a limited enhancement of PCBs and dioxins/furans migration. Surface water runoff could also potentially carry suspended soil particles with PCBs or dioxins/furans, if present, into surface water bodies. However, there are very few locations where concentrations are above screening levels on the Site and the mobility of PCBs and dioxins/furans is considered to be very limited. This observation is consistent with the distribution of PCBs and dioxins/furans in groundwater, which indicated the detected concentrations tend to be near the identified potential source areas described in Subsection 2.4.1. 2.7 Exposure Pathway Assessment An Exposure Pathway Assessment was conducted for the Site in accordance with Ecology and USEPA guidance. The assessment included a human health exposure pathway assessment (HHEPA) and an ecological health exposure pathway assessment (EHEPA). The purpose of the assessment was to identify media and locations that might need corrective action, risk-management measures, or further evaluation. The Exposure Pathway Assessment was presented in the approved SCR Report (CRA, 2014c) and is summarized below. The transport of COC may lead to the exposure and uptake of COC by human and ecological receptors. Potentially complete human and ecological exposure pathways and receptors are shown schematically on Figure 2.18. These exposure pathways and receptors are summarized below and assume that the future land use of the Site remains industrial/commercial. Human Receptors and Exposure Pathways The primary human receptors and exposure pathways at the Site are summarized below. Table 2.3 Primary Human Receptors and Exposure Pathways Receptor Industrial/Commercial Worker Exposure Pathway    Construction/Utility Worker   Inhalation of indoor air impacted by VOC volatilizing from soil and shallow groundwater Incidental ingestion and dermal contact with impacted surface soil Incidental ingestion and dermal contact of sediments in the intertidal zone Incidental ingestion and dermal contact with surface and subsurface soil Incidental ingestion and dermal contact with impacted groundwater while conducting subsurface excavations that GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 21 Table 2.3 Primary Human Receptors and Exposure Pathways Receptor Exposure Pathway extend to the groundwater table  Inhalation of soil particulates and/or ambient air Trespasser    Incidental ingestion and dermal contact with impacted surface soil Inhalation of soil particulates and/or ambient air Incidental ingestion and dermal contact of sediments in the intertidal zone Recreational User  Incidental ingestion and dermal contact with surface water in the Waterway Fisher  Ingestion of fish tissue The HHEPA identified the following media and exposure pathways that might require corrective action, risk-management measures, or further evaluation. Table 2.4 Media and Exposure Pathways Medium Soil Exposure Pathway    Inhalation of indoor air impacted by VOC volatilizing from soil Inhalation of ambient air impacted by VOC volatilizing from soil direct contact with impacted surface soil Groundwater   Inhalation of indoor air impacted by VOC volatilizing from shallow groundwater Inhalation of ambient air impacted by VOC volatilizing from shallow groundwater Direct contact with shallow groundwater  Direct contact with impacted sediment  Sediment As noted above in Subsection 2.4.5, the 2016 Anchor QEA investigation surface sediment results determined that most CVOC were below detection and no reported concentrations exceeded the CB/NT site SQOs, which were developed in consideration of the MTCA SMS. Ecological Receptors Under the industrial/commercial use of the Site, only limited exposure of terrestrial ecological receptors is expected, primarily along the embankment of the Waterway. The primary ecological exposure pathway at the Site is associated with the potential for discharge of impacted groundwater to the biologically active zone of the Waterway and Commencement Bay. The terrestrial and aquatic ecological receptors and exposure pathways at the Site are summarized below. Table 2.5 Primary Ecological Receptors and Exposure Pathways Receptor Soil invertebrates and burrowing animals Exposure Pathway   Direct contact and ingestion of soil Impacted soil gas vapors Benthic organisms in Sediment of Waterway and Commencement Bay   Impacted sediment within the biologically active zone Impacted groundwater discharge into the biologically active zone Avian carnivore,  Dietary uptake of prey/food GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 22 Table 2.5 Primary Ecological Receptors and Exposure Pathways Receptor piscivore, insectivore Aquatic vegetation and invertebrates Forage and predator fish Exposure Pathway   Exposure to impacted groundwater through root uptake and direct contact Direct contact and ingestion of sediment  Dietary uptake of plants and small aquatic species As noted above in Subsection 2.4.5, the 2016 Anchor QEA investigation surface sediment results determined that most CVOC were below detection and no reported concentrations exceeded the CB/NT site SQOs. As noted above in Subsection 2.4.6, the 2016 Anchor QEA investigation near-bottom surface water and near-surface porewater results showed that only one parameter VC, reported in one sample (adjacent to the northern end of the 605 Alexander Avenue property), had the potential to marginally exceed the associated screening criterion at the applicable point of compliance. Based on the fact that the remedy for the Site will include containment, it is unlikely that future impacts will occur. Some future monitoring of COC concentrations in sediment and porewater may be appropriate to ensure that existing conditions of sediment and porewater quality do not change over time, however unlikely this may be. 3. Identify Remedial Action Goals (RAGs) and Potential Applicable Local, State, and Federal Laws This section presents the RAGs and potential applicable local, state, and federal laws and relevant and appropriate requirements identified for the Site. 3.1 Remedial Action Goals (RAGs) In accordance with MTCA, CERCLA, and the NCP, the development of RAGs is required before the screening of remedial technologies and process options can be completed. The RAGs provide the basis for developing cleanup options that will be protective of human health and the environment. RAGs consist of medium-specific or operable-unit-specific goals expected to be achieved by the cleanup. They are protective of human health and the environment and are based on the COC, and potential receptors and exposure pathways. Media of concern are defined as those media in which chemicals exceed their respective cleanup or screening levels. The extensive Site characterization data have shown that the media of concern at the Site include soil (unsaturated and saturated), groundwater, sediment, and indoor air. A listing of all chemicals that exceeded screening levels in the media of concern is presented in Table 2.1. Examination of this table shows that types of chemicals that exceed cleanup or screening levels include VOC, SVOC, pesticides, PCBs, dioxins/furans, metals, and pH. RAGs were previously developed and agreed to among OCC and the Agencies for groundwater, surface water, and sediment. These RAGs were originally presented in the SOW (CRA, 2005). The 2005 RAGs were re-visited based on the current Site characterization and determination that future use of groundwater is non-potable. The media-specific RAGs for the Site developed cooperatively GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 23 with the Agencies based upon evaluations of site-specific risk accomplished by OCC and by the Agencies working with a contractor (Ridolfi Environmental), and are presented in the table below: Table 3.1 Remedial Action Goals (RAGs) Environmental Medium Remedial Action Goals (RAGs) Groundwater 1. Prevent discharge of contaminated groundwater to Hylebos Waterway and Commencement Bay resulting in surface water contaminant concentrations exceeding Ambient Water Quality Criteria (AWQC) and applicable health based standards for aquatic life and human consumption of resident fish and shellfish. 2. Prevent discharge of contaminated groundwater to sediments in the Hylebos Waterway and Commencement Bay at concentrations that will re-contaminate the sediments above sediment quality standards for Site contaminants and applicable health based standards for aquatic life and human consumption of resident fish. 3. Prevent use of aquifer groundwater for drinking water, irrigation, or industrial purposes which would result in unacceptable risks to human health. 4. Prevent further migration of the contaminant plume and high pH plume to prevent the spread of contaminated groundwater to the Hylebos Waterway, Commencement Bay, and non-impacted portions of the aquifer. Surface Water 1. Prevent marine ecological receptors from contacting surface waters that have contaminant concentrations that exceed surface water cleanup levels. 2. Prevent migration of hazardous substances, pollutants, or contaminants to the surface waters at concentrations that exceed surface water cleanup levels. 3. Control bioaccumulation exposures to human receptors associated with releases to surface water from the Site. Sediment 1. Reduce to protective levels risks to benthic invertebrates and other biota from exposure to contaminated sediments and debris. 2. Reduce risks from direct contact (skin contact and incidental ingestion) to contaminated sediments and debris to protect human health. Soil 1. Prevent human health risks associated with direct contact, ingestion, or inhalation of shallow soil contaminated above levels for industrial use. 2. Prevent terrestrial ecological receptors from contacting soils that have contaminant concentrations that exceed industrial soil cleanup levels. 3. Prevent migration of hazardous substances, pollutants, or contaminants from soil to the surface waters at concentrations GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 24 Table 3.1 Remedial Action Goals (RAGs) Environmental Medium Remedial Action Goals (RAGs) that exceed surface water cleanup levels. Indoor air 3.2 1. Prevent human exposure to hazardous substances, pollutants, or contaminants from subsurface soil vapor at concentrations in excess of applicable standards and risk-based cleanup levels. General Response Actions (GRAs) GRAs are those actions that, singly or in combination, satisfy the RAGs for each medium of concern. GRAs may include treatment, containment, excavation, extraction, disposal, institutional actions, or a combination of these. GRAs are applied to the media of concern. As a result, the estimates of the areas or volumes of media to which treatment might be applied were calculated. The areas and volumes are summarized below (not including indoor air, for which an area/volume could not be calculated and sediment, for which the area and volume is zero (0) since reducing risk is not required based on the 2016 Anchor QEA investigation). Unsaturated Soil The Exposure Pathway Assessment, presented in the SCR (CRA, 2014c), approved on October 11, 2016 (Ecology, 2016b), and summarized herein and in the approved CSM Report (CRA, 2014a), has shown that potential human exposure to COC in soil may result in unacceptable exposures. The potentially complete pathways that might result in unacceptable exposures were inhalation of indoor air and/or ambient air, and direct contact. The combined total area of the unsaturated 2 impacted soil is approximately 149,000 square yards (yd ) (CRA, 2014b). Assuming an average depth to water table of 7.5 ft, the estimated volume of impacted unsaturated soil is approximately 3 372,500 cubic yards (yd ). DNAPL The mass of confirmed DNAPL was estimated using the mass of total chlorinated volatile organic compounds (TCVOC) in soil/porous media. The mass was calculated using the Mining Visualization System/Environmental Visualization System (MVS/EVS) software package, developed by C Tech Development Corporation (C Tech) (C Tech, 2007) model for the Site (as described in the CRA Technical Memorandum – Revised DNAPL Mass Estimates dated November 11, 2014 presented in Appendix C). A threshold soil TCVOC concentration of 100 milligrams per kilogram (mg/kg) was used to define the maximum extent of DNAPL. The total TCVOC mass at the Site was determined to be approximately 780,000 lbs as presented in Appendix C. Groundwater The groundwater plumes with the greatest distribution are the CVOC plume, ADP, and pH plume. The volume of these three plumes (porous media + water volume) was estimated using the MVS/EVS models for these plumes. In the case of the CVOC plume, the volume at a concentration greater than or equal to 2.4 micrograms per liter (g/L) was estimated. This was based on the SSL for VC. The pH plume volume was determined at pH value greater than or equal to 8.5 s.u., based GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 25 3 on the SSL. The ADP volume was estimated at a density greater than or equal to 64 lbs/ft (specific gravity of 1.026). This value was selected because at this density the groundwater is clearly affected by anthropogenic activities. The total plume volume was then used to estimate the volume of impacted groundwater within each plume by assuming a porosity of 0.43. The estimated plume and impacted water volumes are summarized in the following table. Table 3.2 Estimated Plume and Impacted Water Volumes 3 3 Plume Total Plume Volume (yd ) CVOC 7,852,223 3,376,456 ADP 2,962,518 1,273,883 13,169,259 5,662,781 pH Impacted Water Volume (yd ) Site-specific GRAs were developed for each medium of concern to satisfy the RAGs. The GRAs and corresponding RAGs (from Subsection 3.1) are presented in Table 3.3. 3.3 Identification of Potential Applicable Local, State, and Federal Laws WAC 173-340-710 discusses requirements for identifying applicable local, state, and federal laws. The requirements in WAC 173-340-710 "…are similar to the ARAR (applicable, relevant, and appropriate requirements) approach of the federal superfund law. Sites that are cleaned up under an order or decree may be exempt from obtaining a permit under certain laws but they must still meet the substantive requirements of these laws. (See WAC 173-340-710(9).)" [(WAC 173-340-700(6)(a)]. In accordance with WAC 173-340-710(2), this section identifies potential applicable local, state, and federal laws that may be considered legally applicable or relevant and appropriate requirements for the Site. "The department shall make the final interpretation on whether these requirements have been correctly identified and are legally applicable or relevant and appropriate." [WAC 173-340-710(2)]. "Legally applicable requirements include those cleanup standards, standards of control, and other environmental protection requirements, criteria, or limitations adopted under state or federal law that specifically address a hazardous substance, cleanup action, location or other circumstances at the site." [WAC 173-340-710(3)]. "Relevant and appropriate requirements include those cleanup standards, standards of control, and other environmental requirements, criteria, or limitations established under state or federal law that, while not legally applicable to the hazardous substance, cleanup action, location, or other circumstance at a site, address problems or situations sufficiently similar to those encountered at the site that their use is well suited to the particular site." [WAC 173-340-710(4)]. Table 3.4 presents the potential applicable local, state, and federal laws and relevant and appropriate requirements identified for the Site. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 26 4. Identify Alternatives 4.1 Alternatives Development The Draft ERT Report (CRA, 2014b) presented the identification and screening of remedial technologies and process options to address impacts at the Site. The purpose of that evaluation was to identify appropriate remedial technologies and representative process options that could be used to assemble remedial alternatives for further evaluation in an FS report. The Agencies selected the remedial technologies and representative process options to be retained based on the evaluation presented in the Draft ERT Report (CRA, 2014b) and other sources. The initial remedial technologies and representative process options that were retained for the development of remedial alternatives were presented in the 2015 Draft FS report. Following Agency review of the 2015 Draft FS report, Ecology provided the Agencies’ comments on January 5, 2016. Based on these comments and subsequent discussions among the Agencies and OCC’s team, a revised list of remedial technologies and representative process options was developed that included three groups of alternatives. The groups include containment alternatives, VOC mass removal/reduction alternatives, and pH (>12.5 s.u.) reduction/enhanced containment alternatives. Along with the three groups of alternatives, there are Common Elements that will be included in the final selected cleanup action, namely, Institutional Controls (ICs) and monitoring. The following Subsection 4.2 describes the Common Elements of ICs and monitoring included in all remedial alternatives. Subsection 4.3 describes the Containment Alternatives. Subsection 4.4 describes the VOC Mass Removal/Reduction Alternatives. Subsection 4.5 presents the pH Reduction/Enhanced Containment Alternatives. Consistent with the 2015 Draft FS report, the subsurface was divided into two zones namely: the shallow zone that is defined from ground surface to -60 ft National Geodetic Vertical Datum (NGVD); and the deep zone that is defined as below -60 ft NGVD. The shallow zone corresponds to the approximate base of the Waterway and the deep zone is below the Waterway. 4.2 Common Elements to the Remedial Alternatives The following elements are common to all remedial alternatives in accordance with WAC 183-340-350(8)(c)(i)(C), except No Action alternative:  Institutional Controls (ICs)  Groundwater Quality Monitoring  Soil Vapor Monitoring 4.2.1 Institutional Controls All remedial alternatives, except No Action alternative, will incorporate ICs. ICs are measures undertaken to limit or prohibit activities that interfere with the integrity of a remedy or that might result in exposure to hazardous substances at a site. In most cases, ICs are recorded as part of the property deed to warn future property owners of the condition and to restrict activities or use of the property that could result in exposure to hazardous substances. Tenants must also be notified of the restrictions in any lease agreement. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 27 The circumstances where institutional controls are required as part of a cleanup action include the following (WAC 173-340-440):  Sites where contamination remains at concentrations that exceed the established cleanup levels.  Sites where cleanup levels are established representing concentrations that are protective of human health and the environment for specified site uses and conditions.  Sites where cleanup levels are established based on industrial land use (soil) or a site-specific risk assessment (groundwater).  Sites where a conditional point of compliance is used.  Any time an institutional control is required under WAC 173-340-7490 through 173-340-7494 (ecological concerns).  Where the department determines such controls are required to assure the continued protection of human health and the environment or the integrity of the interim or cleanup action. Types of ICs include:  Proprietary controls: easements that restrict use (negative easements) and restrictive covenants.  Governmental controls: zoning; building codes; state, tribal, or local groundwater use regulations; and commercial fishing bans and sports/recreational fishing limits posed by federal, state, and/or local resources and/or public health agencies.  Enforcement and permit tools with IC components: administrative orders, permits, Federal Facility Agreements (FFAs), and Consent Decrees (CDs), that limit certain site activities or require the performance of specific activities (e.g., monitor and report on IC effectiveness).  Informational devices: state registries of contaminated sites, notices in deeds, tracking systems, and fish/shellfish consumption advisories. ICs for the Site may include:  Physical barrier to control access to the site (e.g., constructed and routinely maintained fence).  Use restrictions such as limitations on the use of property or resources.  Maintenance requirements for engineered controls such as the inspection and repair of perimeter physical barrier, monitoring wells, treatment systems, caps (direct contact barriers), or groundwater barrier systems.  Educational programs such as signs, postings, public notices, health advisories, mailings, and similar measures that educate the public and/or employees about site contamination and ways to limit exposure.  Financial assurances.  Administrative Order used as legal tool that limit certain site activities or require the performance of specific activities (e.g., monitor and report on effectiveness of ICs).  A Washington Industrial Safety and Health Act and United States Occupational Safety and Health Administration (WISHA/OSHA) compliant worker health, safety and training program to GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 28 address current and future health and safety issues related to indoor air in the existing OCC Property buildings.  No future buildings with and without basements or crawlspaces unless engineered to prevent vapor intrusion (e.g., vapor intrusion barriers or other active engineering controls [pressurized buildings or depressurized sub-slab systems] and monitoring).  Groundwater use restrictions recorded under the deed except when used as part of remedy.  No excavation or below grade construction without appropriate worker health and safety plans and training as detailed in a Soil and Groundwater Management Plan.  No excavation or below grade construction without the proper handling, characterization, and disposal of the excavated soil/materials as detailed in a Soil and Groundwater Management Plan.  Relocation and reuse of soil consistent with the corrective measures and a Soil and Groundwater Management Plan. Where ICs are required, Agencies will conduct a review of the site every five years to ensure the continued protection of human health and the environment. 4.2.2 Groundwater Quality Monitoring The purpose of a groundwater quality monitoring program is to verify that plumes are not migrating to non-impacted areas and to verify reduction in overall contaminant concentrations in groundwater over time. WAC 173-340-410(1)(a) states that Protection Monitoring is to "confirm that human health and the environment are adequately protected during construction and the operation and maintenance period of an interim action or cleanup action as described in the safety and health plan." Groundwater quality monitoring will be part of the protection monitoring to ensure the remedy is performing as intended. A groundwater quality sampling and analysis plan will be developed and submitted to the Agencies with the operation and maintenance plan (WAC 173-340-400) for review and approval during the implementation of the cleanup action. The plan will specify the groundwater samples to be collected, the handling of the samples, and the analysis procedures to be performed per WAC 173-340-820. 4.2.3 Soil Vapor Monitoring The purpose of a soil vapor monitoring program is to monitor VOC in subsurface soil to determine if concentrations are increasing, decreasing, or remaining constant over time. Soil vapor monitoring will be part of the protection monitoring to ensure the remedy is performing as intended. A soil vapor sampling and analysis plan will be developed and submitted to the Agencies with the operation and maintenance plan (WAC 173-340-400) for review and approval during the implementation of the cleanup action. The plan will specify the soil vapor samples to be collected, the handling of the samples, and the analysis procedures to be performed per WAC 173-340-820. 4.3 Containment Alternatives Containment alternatives were determined based on the 2015 Draft FS report and Agencies' review of and comments on that report. More specifically, they are based on the Upland Remedial GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 29 Alternative#2 (URA#2) presented in the 2015 Draft FS with variations in the proposed groundwater extraction rates. The four containment alternatives include: 1. No Action. 2. C100: Physical direct contact exposure (PDCE) barrier for 605 & 709 Alexander Avenue Properties, sheet pile vertical barrier wall adjacent to Hylebos, hydraulic containment based on URA#2 estimated groundwater pumping rates, and the Common Elements in Subsection 4.2. 3. C150: PDCE barrier for 605 & 709 Alexander Avenue Properties, sheet pile vertical barrier wall adjacent to Hylebos, hydraulic containment based on up to 50 percent greater estimated pumping rates compared to C100, and the Common Elements in Subsection 4.2. 4. C200: PDCE barrier for 605 & 709 Alexander Avenue Properties, sheet pile vertical barrier wall adjacent to Hylebos, hydraulic containment based on up to 100 percent greater estimated pumping rates compared to C100, and the Common Elements in Subsection 4.2. The following subsections describe the four containment alternatives; designated as No Action, C100, C150, and C200, selected for inclusion in this FS Report, which are listed in Table 4.1 along with other grouped alternatives. 4.3.1 No Action Alternative Under the No Action alternative, the Site would remain in its present condition with no remedial action performed. This alternative is required by CERCLA and the NCP and is the baseline alternative against which the effectiveness of the other alternatives is compared. This alternative does not include the implementation of any ICs, such as deed restrictions, or future groundwater and soil vapor monitoring. It was also assumed that the current groundwater extraction and treatment system (GWETS) would not be operated. 4.3.2 Containment Alternative C100 Containment Alternative C100 was designed to eliminate, reduce, or otherwise control risks posed through potentially complete exposure pathways and migration routes, and includes the following elements:  Common Elements (ICs and monitoring) described in Subsection 4.2  PDCE Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area (See Figure 2.9)  Sheet pile vertical barrier wall adjacent to the Hylebos  Hydraulic containment through a newly constructed GWETS The C100 alternative layout is presented on Figure 4.1. Figure 4.1 includes contours for TCVOC concentrations of 0.1 mg/L and 10 mg/L, and pH of 10 s.u. and 12.5 s.u. Figure 4.2a presents north/south and east/west cross-sections showing the TCVOC plume developed from the MVS/EVS that includes the above concentrations and others. Figure 4.2b presents north/south and east/west cross-sections showing the pH plume developed from the MVS/EVS that includes the above pH values and others. The cross-section locations are shown on Figure 4.1. As shown on Figure 4.1, the TCVOC concentrations greater than 10 mg/L are generally at the north end of the 605 Alexander Avenue property and further north and east, and pH greater than 12.5 s.u. are GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 30 mostly within the east side of the 605 Alexander Avenue property. The cross-sections indicate that there are negligible areas where the TCVOC concentrations greater than 10 mg/L and pH greater than 12.5 s.u. are mixed. This was confirmed with the MVS/EVS used to develop plumes for the Site. The Upland high pH, elevated VOC and DNAPL (refer to Appendices B, C, and D), and SVOC and metals (see Subsection 2.4) in shallow soil (down to -21 ft NGVD) are covered with a physical direct contact exposure (PDCE) barrier. The elevation -21 ft NGVD represents the depth in the shallow zone corresponding to highest TCVOC concentrations in soil (See Appendix D). The PDCE barrier would be placed over the area shown on Figure 4.1 to cover the contaminants. The primary purpose of the PDCE barrier is to isolate the contaminated soil from potential direct contact with human and ecological receptors and prevent the transport of contaminated soil to other portions of the Site. PDCE barriers can consist of a membrane liner, reinforced concrete, asphalt, clay soil, or a combination of these materials and are often used in combination with physical or hydraulic containment of groundwater. For estimating cost, it was assumed that the PDCE barrier would consist of asphalt and would cover approximately 34.5 acres. The C100 alternative also includes a sheet pile vertical barrier wall placed along the eastern boundary of the Site as shown on Figure 4.1. Sheet pile technology was selected for the vertical barrier wall due to the greater implementability within a waterway, which will allow the vertical barrier to separate the upland portions of the Site from the Hylebos. Sheet pile technology has a long life expectancy in the order of 50 to 75 years, and could be repaired if necessary. The primary purpose of the vertical barrier wall is to eliminate the horizontal discharge from seeps and shallow groundwater with high pH to the Waterway. In addition, the vertical barrier wall would limit transient tidal effects on shallow groundwater levels, thereby resulting in less contaminant "flushing" in the vicinity of the embankment and more consistent performance of the groundwater extraction system in this area. The vertical barrier wall would also contain the contaminated embankment area, Navy Todd Dump, the N Landfill and the 709 Embankment Fill areas (See Figure 2.9). Additionally, approximately 25-30 percent of Area 5106 (see Figure 2.6) would be contained within (i.e., west of) the vertical barrier wall. The former intertidal zone on the upland side of the vertical barrier wall would be backfilled and covered by the PDCE barrier. The loss of intertidal zone would likely be offset by mitigation to comply with the Clean Water Act. The proposed sheet pile vertical barrier wall alignment is shown on Figure 4.1. The vertical barrier wall would be approximately 2,200 ft long and approximately 70-75 ft deep. The vertical barrier wall would be installed with a top elevation of approximately 12 ft NGVD and a base elevation of approximately -61.25 ft NGVD, a few feet below the base of the Hylebos. The bottom elevation was selected to prevent potential direct horizontal discharge of shallow impacted groundwater to the Hylebos. A schematic cross-section along the embankment within the Area 5106 removal area is shown on Figure 4.3. Impacts from shallow and deep DNAPL, TCVOC, and high pH would be contained through a GWETS in conjunction with the sheet pile vertical barrier wall. Extraction wells would be located to minimize mass discharge outside the containment area by controlling groundwater flow and contaminant migration, and to avoid pumping directly from areas of high pH (i.e., pH ≥10 s.u.). All extraction wells were modeled in upland areas where the groundwater pH was less than 10 s.u. Direct pumping from areas of high pH would be avoided in order to minimize/prevent: potential fouling of the GWETS; the need for treatment of high pH water; and disposal of additional solids associated with this high pH groundwater. Difficulties with GWETS fouling due to pumping high pH GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 31 water at the Site have been well document during 22 years of operating the existing GWETS. Additionally, the numerous treatability studies that have been conducted for the Site have not determined a practical solution for overcoming the difficulties of direct pumping of groundwater from areas of high pH. The extracted groundwater would be conveyed to an ex situ treatment system. The treatment plant would need to address groundwater with elevated VOC, as well as other chemistry. This alternative includes a network of ten new extraction wells and one existing inactive extraction well (EXT-9). The locations and depths of the proposed extraction wells were developed through a groundwater flow modeling optimization evaluation presented in Appendix E. The proposed extraction well layout and groundwater pumping rates are shown on Figure 4.1. Although some wells appear in plan view on the figure to be within higher pH, they are not because their depths (screen intervals) do not coincide with the groundwater with the high pH. The ex situ treatment system would potentially include components such as building, controls, equalization tank, clarifier, filter press, filters, air stripper, thermal oxidizer, scrubber, pumps, and meters. A contingency for pH treatment has been included as per Agencies' request in the event that some high pH water is drawn into the system at some time in the future. The contingency is based on diluting up to 50 percent of the extracted groundwater with City of Tacoma potable water at a ratio of 1:1 prior to pH adjustment within the treatment system. The 50 percent value was selected because approximately half of the groundwater extraction would be from wells closer to the high pH areas. It is reasonable to assume that if the pH increased in a well, it would do so at a gradual rate since the pH would need to be drawn from areas of high pH through areas of lower pH towards the wells. Therefore, the quantity of dilution water required would increase gradually as well. The 1:1 ratio of groundwater to dilution water was selected as a reasonable estimate of the amount of dilution water that might be needed to minimize solids/silica gel formation based on the above and the pH pilot studies completed for the Site. Based on the pH pilot studies (CRA, 2011), dilution of the groundwater using potable water would limit the amount of solids/silica gel that might form if the pH is lowered rapidly by chemical treatment within the treatment plant. The groundwater with high pH is analogous to a super saturated solution of silica and the potable water adds some additional solute volume to keep the silica dissolved during treatment to reduce the pH. Salt water or groundwater with lower pH generally has higher dissolved solids and therefore would not likely provide the same solute volume as potable water. GHD has confirmed with the City of Tacoma (email received on May 24, 2016 from Tacoma Water) that sufficient quantities of water are available at the Site (potentially up to approximately 150 gallons per minute [gpm]) for use as dilution water; however, the need for and best source of dilution water will be subject to examination and optimization during the design phase. 4.3.3 Containment Alternative C150 Containment Alternative C150 was designed to eliminate, reduce, or otherwise control risks posed through potentially complete exposure pathways and migration routes, and includes the same elements as Containment Alternative C100, but with a higher overall groundwater pumping rate. The purpose of a higher pumping rate is to evaluate the potential benefits of increasing overall drawdown on the degree and demonstrability of groundwater capture. The evaluation of the potential benefits is discussed in Section 5. The proposed extraction well layout is the same as the C100 alternative and is shown on Figure 4.4, along with the extraction well pumping rates for Alternative C150. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 32 The target groundwater pumping rates for the Containment Alternative C150 extraction wells were 50 percent higher than the pumping rates for Containment Alternative C100. If the groundwater flow model predicted that a 50 percent increased pumping rate could not be sustained in an individual extraction well, then the pumping rate in the affected extraction well was reduced until a sustainable rate was achieved in the groundwater flow model. The groundwater flow modeling presented in Appendix E showed that a combined groundwater pumping rate of approximately 226.25 gpm is achievable with the well network. This represents an overall pumping rate increase of approximately 44 percent compared to Containment Alternative C100. The ex situ treatment system would be similar to that described in Subsection 4.3.2, but sized for the combined modeled flow rate and dilution water for contingency pH treatment. 4.3.4 Containment Alternative C200 Containment Alternative C200 was designed to eliminate, reduce, or otherwise control risks posed through potentially complete exposure pathways and migration routes, and includes the same elements as Containment Alternatives C100 and C150, but with an even higher overall groundwater pumping rate. The purpose of a higher pumping rate is to evaluate the potential benefits of increasing overall drawdown on the degree and demonstrability of groundwater capture. The evaluation of the potential benefits is discussed in Section 5. The proposed extraction well layout is the same as the C100 alternative and is shown on Figure 4.5, along with the extraction well pumping rates for Alternative C200. The target groundwater pumping rates for the Containment Alternative C200 extraction wells were 100 percent higher than the pumping rates presented for Containment Alternative C100. If the groundwater flow model predicted that a 100 percent increased pumping rate could not be sustained in an individual extraction well, then the pumping rate in the affected extraction well was reduced until a sustainable rate was achieved in the groundwater flow model. The groundwater flow modeling presented in Appendix E showed that a combined groundwater pumping rate of approximately 281.5 gpm is achievable with the well network. This represents an overall pumping rate increase of approximately 79 percent compared to Containment Alternative C100. The ex situ treatment system would be similar to that described in Subsection 4.3.2, but sized for the combined modeled flow rate and dilution water for contingency pH treatment. 4.4 VOC Mass Removal/Reduction Alternatives VOC Mass Removal/Reduction Alternatives were determined based on the 2015 Draft FS report and Agencies' review of and comments on that report and subsequent discussions among the Agencies and OCC’s team. The alternatives are focused on evaluating selected potential technologies and process options for more immediately removing or reducing VOC concentrations in soil and/or groundwater. The ten VOC mass removal/reduction alternatives include: 1. No Additional Action (i.e., only a containment alternative from Subsection 4.3 is implemented). 2. VOC source area mass reduction by groundwater extraction, which includes three variations of groundwater pumping rates referred to as M100, M150, and M200, and ex situ treatment. 3. VOC source area mass reduction by strategic groundwater pumping, which is referred to as mass reduction by strategic groundwater pumping (MSP), and ex situ treatment. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 33 4. M3: VOC source area mass removal by shallow soil excavation and on-Site ex situ treatment and backfilling. 5. M4: VOC source area mass removal by shallow soil excavation and off-Site transport, ex situ treatment, and disposal. 6. M5: VOC source area mass reduction by shallow soil in situ treatment. 7. M6: VOC source area mass removal by shallow soil excavation and on-Site ex situ treatment and backfilling, and VOC source area mass reduction by shallow soil in situ treatment. 8. M7: VOC source area mass removal by shallow soil excavation and off-Site transport, ex situ treatment, and disposal, and VOC source area mass reduction by shallow soil in situ treatment. 9. M8: VOC mass reduction by shallow groundwater in-situ treatment and VOC source area mass reduction by shallow soil in situ treatment. 10. M9: VOC mass reduction by shallow and deep groundwater in-situ treatment and VOC source area mass reduction by shallow and deep soil in situ treatment. The VOC targeted by the above alternatives include TCVOC mass in shallow (ground surface to -60 ft NGVD) and/or deep (-60 ft NGVD to the bottom of the impacted aquifer) zones within portions of the upland areas. The estimated total soil volumes and quantity of TCVOC mass in the shallow and deep target zones based on the estimated total DNAPL mass of 780,000 lbs presented in Appendix C are shown on Figure 4.6 and summarized in the table below. Table 4.2 Summary of Estimated Soil Volumes and Quantity of TCVOC Mass within Target Zones Targeted Zone Shallow Deep Not Targeted Estimated Impacted Soil Volume 3 (yd ) 98,229 472,590 16,230 Estimated Quantity of TCVOC Mass (lbs) 107,260 669,430 3,310 Table 4.2 and Figure 4.6 also include the small portion that is not targeted. The following subsections describe the ten VOC mass removal/reduction alternatives, including: No Additional Action; three sub-alternatives for groundwater extraction, designated as M100, M150, and M200; MSP; and M3 through M9 selected for inclusion in this FS Report, which are listed in Table 4.1 along with other grouped alternatives. 4.4.1 No Additional Action VOC Mass Removal/Reduction Alternative Under the No Additional Action alternative, only a containment alternative (see Subsection 4.3) would be implemented with no additional remedial action performed. This VOC mass removal/reduction alternative is the baseline alternative against which the effectiveness of the other VOC mass removal/reduction alternatives is compared. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 34 4.4.2 4.4.2.1 VOC Mass Reduction Alternatives M100, M150, and M200 VOC Mass Reduction Alternative M100 Mass Reduction Alternative M100 was designed to extract shallow and deep groundwater with high concentrations of VOC outside the areas of high pH (i.e., less than 10 s.u. as noted in Subsection 4.3.2). Direct pumping from areas of high pH would be avoided in order to minimize/prevent: potential fouling of the extraction and treatment system; the need for treatment of high pH water; and disposal of additional solids associated with this groundwater. The locations and depths of two proposed extraction wells, one shallow and one deep, were developed through a groundwater flow modeling optimization evaluation presented in Appendix E. The proposed extraction well layout and pumping rates for the M100 alternative are presented on Figure 4.7. The locations are the same that were proposed for the Upland Remedial Alternative#3 (URA#3) presented in the 2015 Draft FS report. The extracted groundwater would be conveyed to an ex situ treatment system. This would be the same system constructed for one of the containment alternatives described in Subsection 4.3. Figure 4.7 depicts the layout of the Site and includes contours for TCVOC concentrations of 0.1 mg/L and 10 mg/L. Figure 4.7 also shows the target areas for all of the VOC mass removal/reduction alternatives that are further discussed in the following Subsections. Figure 4.8 presents north/south and east/west cross-sections showing the TCVOC plume developed from the MVS/EVS that includes the these concentrations and others, and identifies the approximate locations of the shallow and deep groundwater with high TCVOC dissolved concentrations targeted for extraction by the two proposed wells. The cross-section locations are shown on Figure 4.7. As shown on Figure 4.7 the TCVOC greater than 10 mg/L are generally at the north end of the 605 Alexander Avenue property and further north and east. The groundwater flow modeling presented in Appendix E showed that the combined groundwater pumping rate of 35 gpm could be maintained by the two extraction wells. The rationale for this pumping rate is discussed in Appendix E. The evaluation of groundwater pumping for mass reduction is discussed in Section 6. The total mass outside pH >10 s.u. removed over 20 years was estimated by the model to be 275,132 lbs (dissolved, sorbed, and DNAPL phases), which represent 35.3 percent of the estimated total DNAPL mass of 780,000 lbs presented in Appendix C. Note that estimated mass removal rates were determined using the three-dimensional (3D) groundwater flow model that was specifically constructed and calibrated for the Site. The Site groundwater flow model provides a useful tool to evaluate the potential effectiveness of the groundwater mass reduction remedial alternatives that incorporate groundwater extraction. It is noted that the model assumes idealized mass transport controlled by advection and equilibrium sorption and all mass is assumed to be either dissolved in the groundwater or sorbed onto the aquifer matrix. Potential effects of non-aqueous phase liquids are not included. The potential effects of diffusion into low-permeability units or areas are not included. Additionally, the estimates do not include potential effects of high pH potentially reaching extraction wells, all contributing to the uncertainty of the mass estimates. However, the evaluation approach was applied consistently for all alternatives. 4.4.2.2 VOC Mass Reduction Alternative M150 Mass Reduction Alternative M150 includes the same elements as Mass Reduction Alternative M100, but with a higher overall groundwater pumping rate. The purpose this alternative is to GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 35 evaluate the potential benefits of increasing the rate of VOC mass reduction and potentially total VOC mass reduction, noting that generally a higher overall pumping rate would result in higher overall costs. The evaluation of the potential benefits is discussed in Section 6. The proposed extraction well layout (same as M100) and extraction well pumping rates (higher than M100) are shown on Figure 4.9. The target groundwater pumping rates for the Mass Reduction Alternative M150 extraction wells were 50 percent higher than the pumping rates presented for Mass Reduction Alternative M100. The groundwater flow modeling presented in Appendix E predicted that a 50 percent increased pumping rate could be sustained for both wells. The combined groundwater pumping rate for this alternative is approximately 52.5 gpm. The total mass outside pH >10 s.u. removed over 20 years was estimated by the model to be 285,394 lbs (dissolved, sorbed, and DNAPL phases), which represents 36.6 percent of the estimated total DNAPL mass of 780,000 lbs presented in Appendix C. 4.4.2.3 VOC Mass Reduction Alternative M200 Mass Reduction Alternative M200 includes the same elements as Mass Reduction Alternatives M100 and M150, but with an even higher overall groundwater pumping rate to aid in evaluating the potential benefits of increasing the rate of VOC mass reduction and potentially total VOC mass reduction. The evaluation of the potential benefits is discussed in Section 6. The proposed extraction well layout (same as M100 and M150) and extraction well pumping rates (higher than M100 and M150) are shown on Figure 4.10. The target groundwater pumping rates for the Mass Reduction Alternative M200 extraction wells were 100 percent higher than the pumping rates presented for Mass Reduction Alternative M100. The groundwater flow modeling presented in Appendix E predicted that a 100 percent increased pumping rate could be sustained for both wells. The combined groundwater pumping rate for this alternative is approximately 70 gpm. The total mass outside pH >10 s.u. removed over 20 years was estimated by the model to be 291,648 lbs (dissolved, sorbed, and DNAPL phases), which represents 37.4 percent of the estimated total DNAPL mass of 780,000 lbs presented in Appendix C. 4.4.3 VOC Mass Reduction Alternative MSP (Mass Reduction by Strategic Groundwater Pumping) Mass Reduction Alternative MSP was designed to extract shallow and deep groundwater within areas of high concentrations of VOC outside the areas of high pH (i.e., less than 10 s.u. as noted in Subsection 4.3.2) to achieve a higher initial rate of mass reduction than the Mass Reduction Alternatives M100, M150, and M200. For this alternative, a greater number of wells were strategically placed in areas of high VOC concentrations in both saturated soil and groundwater (i.e., near DNAPL source zones). The location of extraction wells near CVOC source zones can accelerate mass dissolution from DNAPL and thus expedite source area depletion. Strategic pumping can increase mass removal efficiency and decrease mass loading to groundwater (i.e., reduces dissolved phase contamination). Similar to Mass Reduction Alternatives M100, M150, and M200, direct pumping from areas of high pH would be avoided in order to minimize/prevent: potential fouling of the extraction and treatment system; the need for treatment of high pH water; and disposal of additional solids associated with this groundwater. The locations and depths of the proposed extraction wells were developed GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 36 through a groundwater flow modeling optimization evaluation presented in Appendix E. The proposed extraction well layout and pumping rates for the MSP alternative are presented on Figure 4.11. The extracted groundwater would be conveyed to an ex situ treatment system. The treatment system would be similar to the system constructed for the M150 or M200 containment alternatives described in Subsection 4.3. Figure 11 depicts the layout of the Site and includes contours for TCVOC groundwater concentrations of 0.1 mg/L and 10 mg/L. Figure 11 also shows the target areas for all of the VOC mass removal/reduction alternatives that are discussed in the following Subsections. Figure 12 presents north/south and east/west cross-sections showing the TCVOC groundwater plume developed from the MVS/EVS, and identifies the approximate locations of the shallow and deep high TCVOC concentration areas. The cross-section locations are shown on Figure 11. As shown on Figure 11 the TCVOC concentrations greater than 10 mg/L in groundwater are generally at the north end of the 605 Alexander Avenue property and further north and east. The groundwater flow modeling presented in Appendix E showed that the combined groundwater pumping rate of 210 gpm could be maintained by the extraction wells. The rationale for this pumping rate is discussed in Appendix E. The evaluation of groundwater pumping for mass reduction is discussed in Section 6. The total mass outside pH >10 s.u. removed over 20 years was estimated by the model to be 323,883 lbs, which represents 41.5 percent of the estimated total DNAPL mass of 780,000 lbs presented in Appendix C. 4.4.4 VOC Mass Removal Alternative M3 Mass Removal Alternative M3 was designed to remove near-surface soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M3 alternative includes the following elements:  Excavation of shallow soil above -4 ft NGVD containing TCVOC concentrations greater than 100 mg/kg  Removal of VOC from the excavated soil by on-Site treatment  Backfill on Site of treated excavated soil The TCVOC concentration of 100 mg/kg is representative of areas with confirmed or potential DNAPL as presented in Appendix C and is considered PTW as presented in Appendix B. The M3 alternative layout is presented on Figure 4.13. Figure 4.13 shows the areas above -4 ft NGVD that have TCVOC concentrations greater than 100 mg/kg. Figure 4.14 presents north/south and east/west cross-sections showing the TCVOC plume developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.13. The mass of TCVOC within the volume of soil defined by the parameters above is approximately 23,200 lbs, which represents 3.0 percent of the estimated total DNAPL mass of 780,000 lbs presented in Appendix C. The vertical extent of the target zone is shown on Figure 4.14. Soil above -4 ft NGVD that has TCVOC concentrations greater than 100 mg/kg would be excavated and consolidated into piles set up for treatment to reduce VOC concentrations. Excavated soil that is saturated would require dewatering/drying before treatment. The excess water from the piles would drain back into the excavations. Soil that has TCVOC concentrations less than 100 mg/kg overlying the soil targeted for on-Site treatment would be temporarily stockpiled separately for GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 37 reuse. The on-Site treatment would involve ex situ soil vapor extraction (SVE) to remove VOC from the soil followed by treatment of the extracted vapors by a portable thermal oxidizer system and/or activated carbon. SVE is typically an in situ remedial technology that may be applied to stockpiles of excavated soil. There are various types of vapor extraction methods including vertical and horizontal pipes, gravel beds, and trenches. Synthetic membranes are often placed over the soil surface to prevent short-circuiting and to increase the radius of influence of the extraction pipes. Thermal oxidation would involve transferring extracted soil vapors through a vessel that uses thermal processes (e.g., exposure to flame) to oxidize VOC into innocuous compounds before being released to the atmosphere. Activated carbon treatment would involve transferring extracted soil vapors through filtrate vessels, which promote adsorption of VOC via contact with filter material. Following completion of the SVE, the treated soil and soil suitable for reuse would be backfilled on the 605 Alexander Avenue property within and around the excavations and ultimately would be under a PDCE barrier (see Subsection 4.3.2). Excavations beyond the 605 Alexander Avenue property would be backfilled with soil suitable for reuse and/or imported clean material. The surfaces would be returned to the same or better conditions that were present prior to the excavation. 4.4.5 VOC Mass Removal Alternative M4 Mass Removal Alternative M4 includes the same excavation element as Mass Removal Alternative M3, but with off-Site transportation, treatment, and disposal of the excavated material containing TCVOC concentrations greater than 100 mg/kg. Figure 4.13 presents the layout and Figure 4.14 presents cross-sections related to the M4 alternative. The mass of TCVOC targeted for this alternative is the same as the M3 alternative described above in Subsection 4.4.4. Soil above -4 ft NGVD that has TCVOC concentrations greater than 100 mg/kg would be excavated. Unsaturated soil would be consolidated directly into licensed trucks that would transport the material to an appropriate facility licensed to accept, treat, and dispose of the material. Saturated soil would be consolidated into temporary piles adjacent to the excavations to allow for some drying. The excess water from the piles would be permitted to drain back into the excavations. Once appropriate moisture content levels were achieved to allow proper transport, this soil would be consolidated into licensed trucks that would transport the material to an appropriate facility licensed to accept, treat, and dispose of the material. Soil that has TCVOC concentrations less than 100 mg/kg overlying the soil targeted for off-Site disposal would be temporarily stockpiled separately for reuse. Excavations would be backfilled with the soil suitable for reuse and imported clean material to replace the soil that was removed and transported off Site for treatment and disposal. The surfaces would be returned to the same or better conditions that were present prior to the excavation. 4.4.6 VOC Mass Reduction Alternative M5 Mass Reduction Alternative M5 was designed to further reduce, compared to the M3 and M4 alternatives, TCVOC concentrations in shallow soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M5 alternative includes in situ treatment with the following elements:  Treatment using in situ electrical resistance heating (ERH) of shallow saturated soil below 2.5 ft NGVD and above -21 ft NGVD containing TCVOC concentrations greater than 500 mg/kg. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 38  Treatment using in situ SVE of shallow unsaturated (vadose zone) soil above 2.5 ft NGVD containing TCVOC concentrations greater than 500 mg/kg. The TCVOC concentration of 500 mg/kg represents the lower limit to identify areas with potential DNAPL for potential remediation based on a significantly declining benefit (i.e., diminishing returns) analysis presented in Appendix D. As shown in Appendix D, shallow soil down to -21 ft NGVD contains this potential DNAPL mass in the shallow zone. It is also considered PTW as presented in Appendix B. The M5 alternative layout is presented on Figure 4.15. Figure 4.15 shows the areas above 2.5 ft NGVD and between 2.5 ft NGVD and above -21 ft NGVD that have TCVOC concentrations greater than 500 mg/kg. Figure 4.16 presents north/south and east/west cross-sections showing the TCVOC plume developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.15. The mass of TCVOC within the volume of soil defined by the parameters above is approximately 62,200 lbs, which represents 8.0 percent of the estimated total mass of DNAPL of 780,000 lbs presented in Appendix C. The vertical extent of the target zones are shown on Figure 4.16. ERH is a thermal treatment technology that increases the temperature of the saturated zone and allows contaminants to be more easily volatilized, mobilized, and extracted from the subsurface. ERH involves the installation of electrodes in the ground and passing an alternating current through the electrodes, thereby heating the soil. Steam is generated when the subsurface temperature is raised to the boiling point of the saturated media. The steam strips the contaminants from the subsurface and enables extraction through liquid or vapor recovery wells. SVE is an in situ remedial technology where a vacuum is applied through extraction wells located near the source of elevated chemical concentrations in the unsaturated soil zone. Volatile constituents of the chemical mass volatilize and the vapors are drawn toward the extraction wells thus reducing the concentrations of VOC sorbed to the soil in the vadose zone. The extracted vapors are then typically treated as necessary using thermal oxidation or activated carbon before being released to the atmosphere. Synthetic membranes are often placed over the soil surface to prevent short-circuiting and to increase the radius of influence of the extraction wells. As shown on Figure 4.15, the area designated for treatment by SVE is within the area designated for treatment by ERH. Since SVE is necessary over the ERH treatment area to collect VOC migrating to the surface during the ERH process, the in situ ERH treatment (with in situ SVE) will cover the smaller area shown on Figure 4.15 designated for SVE treatment alone. 4.4.7 VOC Mass Removal/Reduction Alternative M6 Mass Removal/Reduction Alternative M6 was designed to remove near-surface impacted soil and to further reduce TCVOC concentrations in shallow soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M6 alternative is a combination of the excavation and in situ ERH treatment elements from the M3 and M5 alternatives, respectively, and includes the following elements:  Excavation of shallow soil above -4 ft NGVD containing TCVOC concentrations greater than 100 mg/kg.  Removal of VOC from the excavated soil by on-Site treatment. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 39  Backfill on Site of treated excavated soil.  Treatment using in situ ERH (with SVE) of shallow soil below -4 ft NGVD and above -21 ft NGVD containing TCVOC concentrations greater than 500 mg/kg. The M6 alternative layout is presented on Figure 4.17, which shows the areas above -4 ft NGVD that have TCVOC concentrations greater than 100 mg/kg and between -4 ft NGVD and above -21 ft NGVD that have TCVOC concentrations greater than 500 mg/kg. Figure 4.18 presents north/south and east/west cross-sections showing the TCVOC plume developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.17. The mass of TCVOC within the volume of soil defined by the parameters above is approximately 66,200 lbs, which represents 8.5 percent of the estimated total mass of DNAPL of 780,000 lbs presented in Appendix C. The vertical extent of the target zones are shown on Figure 4.17. Descriptions of excavation, on-Site treatment, and backfilling are provided in Subsection 4.4.4. Descriptions of ERH and SVE technologies are provided in Subsection 4.4.6 above. 4.4.8 VOC Mass Removal/Reduction Alternative M7 Mass Removal/Reduction Alternative M7 includes the same elements as Mass Removal/Reduction Alternative M6, but with off-Site transportation, treatment, and disposal of the excavated material containing TCVOC concentrations greater than 100 mg/kg. It is a combination of the excavation and in situ ERH treatment elements from the M4 and M5 alternatives, respectively. Figure 4.17 presents the layout and Figure 4.18 presents cross-sections related to the M7 alternative. The mass of TCVOC targeted for this alternative is the same as the M6 alternative described above in Subsection 4.4.7. 4.4.9 VOC Mass Removal/Reduction Alternative M8 Mass Reduction Alternative M8 was designed to further reduce TCVOC concentrations in shallow groundwater and in shallow soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M8 alternative includes elements from the M5 alternative (ERH and SVE) plus elements for in situ treatment of shallow groundwater as follows:  Treatment using in situ chemical oxidation (ISCO) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u.  Treatment using enhanced in situ bioremediation (ISB) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is less than 10 s.u. The TCVOC concentration of 10 mg/L was selected because in situ groundwater treatment is usually applied to concentrated source areas and not to widely-dispersed, low-concentration plumes. The M8 alternative layout is presented on Figure 4.19. Figure 4.19 shows the areas above 2.5 ft NGVD and between 2.5 ft NGVD and above -21 ft NGVD that have TCVOC concentrations greater than 500 mg/kg. It also shows areas above -60 ft NGVD that have TCVOC concentrations greater than 10 mg/L within the zones where pH is between 10 s.u. and 12.5 s.u. and less than 10 s.u. Figure 4.20 presents north/south and east/west cross-sections showing the TCVOC plume GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 40 developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.19. The mass of TCVOC within the volume of soil defined by the parameters above is the same as the M5 alternative (approximately 62,200 lbs, which represents 8.0 percent of the estimated total mass of DNAPL of 780,000 lbs presented in Appendix C). The vertical extent of the target zone is shown on Figure 4.20. Descriptions of ERH and SVE technologies are provided in Subsection 4.4.6 above. The mass of TCVOC within the volume of shallow groundwater defined by the parameters above is approximately 19,400 lbs, which represents 12.4 percent of the estimated total mass of TCVOC in groundwater of 156,960 lbs. The total mass of TCVOC within the volume of soil and groundwater defined above represents 10.5 percent of the estimated total DNAPL mass of 780,000 lbs presented in Appendix C. ISCO by injection would be used to introduce chemical oxidant into groundwater to react with and destroy organic contaminants. Multiple injections of the oxidant are usually required and for this site would be completed using installed wells because of the depth of the target zone. Alkaline persulfate would be used as the oxidant because it would take advantage of the synergistic effects of the elevated pH in groundwater between 10 s.u. and 12.5 s.u. to activate the alkaline persulfate. This technology is non-selective meaning that other organic material present in the target zone would be oxidized along with the targeted organic material. Therefore, overdosing would be required to effectively treat the groundwater. ISCO was successfully demonstrated to reduce contaminants to carbon dioxide (CO2) and water at small sites in permeable material (McGuire et al., 2013, 2014). ISB by injection in wells would be used to establish vertical "curtains" of biological activity where impacted groundwater would flow through treating (degrading) VOC. Multiple injections of the substrate (emulsified vegetable oil), Dehalococoides spp. (DHC) and enhancements are usually required to maintain suitable conditions for biological activity. Additionally, an electron donor would be released into groundwater and would be transported downgradient of each "curtain." The electron donor would promote further contaminant biodegradation in the aquifer. The target zone for this technology would be within areas of pH that are less than 10 s.u., since it is not effective in higher pH. 4.4.10 VOC Mass Removal/Reduction Alternative M9 Mass Reduction Alternative M9 was designed to further reduce TCVOC concentrations in shallow and deep groundwater and in shallow and deep soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M9 alternative includes elements from the M8 alternative plus elements for in situ treatment of deep groundwater and soil as follows:  Treatment using ISCO of deep soil below -60 ft NGVD containing TCVOC concentrations greater than 500 mg/kg within the zone where pH is between 10 s.u. and 12.5 s.u.  Treatment using ISB of deep soil below -60 ft NGVD containing TCVOC concentrations greater than 500 mg/kg within the zone where pH is less than 10 s.u.  Treatment using ISCO of deep groundwater below -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 41  Treatment using ISB of deep groundwater below -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is less than 10 s.u. The M9 alternative layout is presented on Figure 4.21. Figure 4.21 shows the areas above 2.5 ft NGVD, between 2.5 ft NGVD and above -21 ft NGVD, and below -60 ft NGVD that have TCVOC concentrations greater than 500 mg/kg. It also shows areas that have TCVOC concentrations greater than 10 mg/L within the zones where pH is between 10 s.u. and 12.5 s.u. and less than 10 s.u through the full depth of the Site. Figure 4.22 presents north/south and east/west cross-sections showing the TCVOC plume developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.21. The mass of TCVOC within the volume of soil defined by the parameters above is approximately 525,800 lbs, which represents 67.4 percent of the estimated total mass of DNAPL of 780,000 lbs presented in Appendix C. The vertical extent of the target zones are shown on Figure 4.22. The mass of TCVOC within the volume of groundwater defined by the parameters above is approximately 87,500 lbs, which represents 55.7 percent of the estimated total mass of TCVOC in groundwater of 156,960 lbs. The total mass of TCVOC within the volume of soil and groundwater defined above represents 78.6 percent of the estimated total DNAPL mass of 780,000 lbs presented in Appendix C Descriptions of the technologies are provided in Subsections 4.4.6 and 4.4.9. 4.5 pH Reduction/Enhanced Containment Alternatives The pH Reduction/Enhanced Containment Alternatives were determined based on the 2015 Draft FS report and Agencies' review of and comments on that report. The alternatives are focused on evaluating selected potential technologies and process options for reducing or enhancing containment of pH in soil and groundwater. The seven reduction/enhanced containment alternatives include: 1. No Additional Action (i.e., only a containment alternative from Subsection 4.3 is implemented). 2. pH2: pH >12.5 s.u. reduction by shallow soil and groundwater in situ treatment. 3. pH3: pH >12.5 s.u. enhanced containment by shallow soil and groundwater in situ treatment. 4. pH4: pH >12.5 s.u. enhanced containment of shallow soil and groundwater by vertical barrier. 5. pH5: pH >12.5 s.u. reduction by shallow and deep soil and groundwater in situ treatment. 6. pH6: pH >12.5 s.u. enhanced containment by shallow and deep soil and groundwater in situ treatment. 7. pH7: pH >12.5 s.u. enhanced containment of shallow and deep soil and groundwater by vertical barrier. The pH targeted by the above alternatives includes pH in shallow (ground surface to -60 ft NGVD) and/or deep (-60 ft NGVD to the bottom of the impacted aquifer) zones within portions of the upland areas. The estimated total soil volumes and quantity of pH >12.5 s.u. (quantified as acid-neutralizing capacity [ANC] as presented in Appendix F) in the shallow and deep target zones GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 42 based on the estimated total ANC of 200 Megaequivalents (Meq) acid presented in Appendix F are shown on Figure 4.23 and summarized in the table below. Table 4.3 Summary of Estimated Soil Volumes and Quantity of pH within Target Zones Targeted Zone Shallow Deep Not Targeted Estimated Impacted Soil Volume 3 (yd ) 78,068 85,690 10,560 Estimated Quantity of pH (ANC) (Meq acid) 91 97 12 Table 4.3 and Figure 4.23 also include the small portion that is not targeted. The following subsections describe the seven reduction/enhanced containment pH alternatives designated as No Additional Action and pH2 through pH7 selected for inclusion in this FS Report, which are listed in Table 4.1 along with other grouped alternatives. 4.5.1 No Additional Action pH Reduction/Enhanced Containment Alternative Under the No Additional Action alternative, only a containment alternative (see Subsection 4.3) would be implemented with no additional remedial action performed. This pH reduction/enhanced containment alternative is the baseline alternative against which the effectiveness of the other pH reduction/enhanced containment alternatives is compared. 4.5.2 pH Reduction Alternative pH2 The pH Reduction Alternative pH2 was designed to reduce, by in situ treatment, pH >12.5 s.u. (i.e., PTW) in shallow soil and groundwater that could be a future source of contamination in soil and groundwater. The pH2 alternative includes the following elements:  Treatment using in situ mixing of sodium persulfate with shallow soil and groundwater above -60 ft NGVD containing pH greater than 12.5 s.u. The 12.5 s.u. target treatment level was selected because material with pH greater than 12.5 s.u. would be characteristically hazardous for corrosivity in accordance with the Code of Federal Regulations (40 CFR 261.22) and is considered PTW as presented in Appendix B. The pH2 alternative layout is presented on Figure 4.24 and includes contours for pH of 10 s.u. and 12.5 s.u. As shown on Figure 4.24, pH greater than 12.5 s.u. is mostly within the east side of the 605 Alexander Avenue property. Figure 4.24 also shows the areas above -60 ft NGVD that have pH greater than 12.5 s.u. Figure 4.25 presents north/south and east/west cross-sections showing the pH developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.24. The volume of aquifer defined by the parameters above have an ANC that is approximately 11.2 percent of the estimated ANC in the aquifer with pH greater than 7 s.u. (pH neutral) as presented in Appendix F. The vertical extent of the target zone is shown on Figure 4.25. In situ reagent mixing would involve mixing a chemical reagent vertically into the unsaturated and saturated subsurface using either a single auger or multiple augers equipped with mixing paddles. The augers would penetrate the ground and mix the soil and groundwater as they rotate. The reagent would be simultaneously injected through the hollow drill stem as the augers retreat back to GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 43 the surface. Each treated soil column would be typically 3 to 5 ft in diameter after mixing. The treatment process would be repeated over the treatment area, overlapping each soil column to ensure complete mixing. Sodium persulfate would be used. The pH pilot studies (CRA, 2011) conducted for the Site, indicate that it would be expected that pH values would rebound after treatment and therefore would require over treatment to initially reduce the pH below the target treatment level of 12.5 s.u. (e.g., 10-11 s.u.). 4.5.3 pH Enhanced Containment Alternative pH3 The pH Enhanced Containment Alternative pH3 was designed to contain, by in situ treatment, pH >12.5 s.u. (i.e., PTW) in shallow soil and groundwater that could be a future source of contamination in soil and groundwater. The pH3 alternative includes the following elements:  Treatment using in situ mixing of cement with shallow soil and groundwater above -60 ft NGVD containing pH greater than 12.5 s.u. The pH3 alternative layout is the same as the pH2 alternative and is presented on Figure 4.24. Figure 4.24 shows the areas above -60 ft NGVD that have pH greater than 12.5 s.u. Figure 4.25 presents north/south and east/west cross-sections showing the pH developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.24. The ANC within the volume of aquifer defined by the parameters above is the same as the pH2 alternative, approximately 11.2 percent. A description of the mixing technology is provided in Subsection 4.5.2. Cement would be used to contain the pH greater than 12.5 s.u by stabilization. The technology would involve the mixing of a binding agent (cement) into soil to greatly reduce the potential ability of contaminants to migrate with groundwater. It will also reduce the permeability of the soil, which reduces groundwater flow through the area. 4.5.4 pH Enhanced Containment Alternative pH4 The pH Enhanced Containment Alternative pH4 was designed to contain, by in situ vertical barrier, pH >12.5 s.u. (i.e., PTW) in shallow soil and groundwater that could be a future source of contamination in soil and groundwater. The pH3 alternative includes the following elements:  Construction of a vertical slurry barrier wall around shallow soil and groundwater above -60 ft NGVD containing pH greater than 12.5 s.u. The pH4 alternative layout is presented on Figure 4.26 that includes the conceptual potential location of a vertical slurry barrier wall around the areas above -60 ft NGVD that have pH greater than 12.5 s.u. Figure 4.25 presents north/south and east/west cross-sections showing the pH developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.24. The ANC within the volume of aquifer defined by the parameters above is the same as the pH2 and pH3 alternatives, approximately 11.2 percent. A vertical slurry barrier wall would be used to enhance the containment of groundwater with high pH and prevent it from reaching environmental receptors and potential extraction wells related to the containment alternatives. (See Subsection 4.3). The vertical slurry barrier wall would also contain other contaminants preventing horizontal migration but also limiting contaminant extraction by pumping groundwater related to the containment alternatives and the Mass Reduction Alternatives, GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 44 M100, M150, M200, and MSP. (See Subsection 4.4.2). Extraction of contaminants would be limited to groundwater movement under the vertical slurry barrier wall due to pumping. The alignment shown on Figure 4.26 would result in a vertical slurry barrier wall approximately 1,650 ft long and approximately 70 to 75 ft bgs. The vertical slurry barrier wall would be installed to ground surface, at a top elevation of approximately 12 ft NGVD and base elevation of approximately -60 ft NGVD. The spoils would be placed within the contained area and under the proposed PDCE barrier. (See Subsection 4.3). 4.5.5 pH Reduction Alternative pH5 The pH Reduction Alternative pH5 was designed to reduce, by in situ treatment, pH >12.5 s.u (i.e., PTW) in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH5 alternative includes the following elements:  Treatment using in situ mixing of sodium persulfate with shallow and deep soil and groundwater containing pH greater than 12.5 s.u. The pH5 alternative layout is presented on Figure 4.27. Figure 4.27 shows the areas that have pH greater than 12.5 s.u. Figure 4.28 presents north/south and east/west cross-sections showing the pH developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.24. The volume of aquifer defined by the parameters above have an ANC that is approximately 23.3 percent of the estimated ANC in the aquifer with pH greater than 7 s.u. (pH neutral) as presented in Appendix F. The vertical extent of the target zones are shown on Figure 4.28. A description of the technology is provided in Subsection 4.5.2. 4.5.6 pH Enhanced Containment Alternative pH6 The pH Enhanced Containment Alternative pH6 was designed to contain, by in situ treatment, pH >12.5 s.u (i.e., PTW) in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH6 alternative includes the following elements:  Treatment using in situ mixing of cement with shallow and deep soil and groundwater containing pH greater than 12.5 s.u. The pH6 alternative layout is the same as the pH6 alternative and is presented on Figure 4.27. Figure 4.27 shows the areas that have pH greater than 12.5 s.u. Figure 4.28 presents north/south and east/west cross-sections showing the pH developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.24. The ANC within the volume of aquifer defined by the parameters above is the same as the pH5 alternative, approximately 23.3 percent. A description of the technology is provided in Subsection 4.5.3. 4.5.7 pH Enhanced Containment Alternative pH7 The pH Enhanced Containment Alternative pH7 was designed to contain, by in situ vertical barrier, pH >12.5 s.u (i.e., PTW) in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH7 alternative includes the following elements: GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 45  Construction of a vertical slurry barrier wall around shallow and deep soil and groundwater containing pH greater than 12.5 s.u. The pH7 alternative layout is presented on Figure 4.29 that includes the conceptual potential location of vertical slurry barrier walls around the areas that have pH greater than 12.5 s.u. Figure 4.28 presents north/south and east/west cross-sections showing the pH developed from the MVS/EVS through some of these areas. The cross-section locations are shown on Figure 4.24. The ANC within the volume of aquifer defined by the parameters above is the same as the pH5 and pH6 alternatives, approximately 23.3 percent. A description of the technology is provided in Subsection 4.5.4. The alignment shown on Figure 4.29 would result in vertical slurry barrier walls including: approximately 970 ft long and approximately 70 to 75 ft bgs for shallow pH enhanced containment (see Subsection 4.5.4); approximately 2,235 ft long and approximately 110 to 115 ft bgs for deep pH enhanced containment within the 605 Alexander Avenue property; and approximately 625 ft long and approximately 150 to 155 ft bgs for deep pH enhanced containment outside of the 605 Alexander Avenue property. The vertical slurry barrier walls would be installed to ground surface, at a top elevation of approximately 12 ft NGVD and base elevations of approximately -60 ft NGVD, -100 ft NGVD, and -140 ft NGVD. The spoils would be placed within the contained area and under the proposed PDCE barrier. (See Subsection 4.3). 5. Containment Alternatives Initial Screening and Detailed Evaluation 5.1 Initial Screening The purpose of an initial screening of alternatives is to potentially reduce the number of alternatives for the detailed evaluation, if appropriate. Cleanup action alternatives or components may be eliminated from further consideration if: (i) it is determined (by the Agencies) based on a preliminary analysis that an alternative or a component so clearly does not meet the minimum requirements specified in WAC 173-340-360. This includes an alternative or a component for which costs are clearly disproportionate under WAC 173-340-360(3)(e). (ii) the alternative or component is not technically possible at the site. The minimum requirements in WAC 173-340-360 include threshold requirements as follows:  Protect human health and the environment  Comply with cleanup standards  Comply with applicable state and federal laws  Provide for compliance monitoring The threshold criteria in CERCLA and the NCP include overall protection of human health and the environment and compliance with Applicable or Relevant and Appropriate Requirements (ARARs). These are included in the WAC threshold requirements. Determining if an alternative is GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 46 administratively and technically possible is analogous to the NCP criterion of implementability (administrative and technical). The containment alternatives are described in Subsection 4.3. Except for the No Action alternative, it has been determined that the containment alternatives would meet the minimum requirements and are administratively and technically possible. The No Action alternative is retained for comparison with the other alternatives consistent with CERCLA and the NCP even though it does not meet the minimum/threshold requirements. It is recognized for this Site that a reasonable restoration time frame, which is meaningful and a reliable estimate, cannot be reasonably established because of inherent uncertainties in existing conditions and in the future response of those conditions to site remediation activities. This is a fundamental reason for including containment in all the alternatives described in Section 4., except the No Action Alternative. It is further recognized that a restoration time frame for this Site will likely exceed 100 years for all feasible remediation alternatives. Therefore, for the purpose of evaluating and comparing alternatives, a 100-year period of time is used for comparing the potential effectiveness over the long term in the disproportionate cost analyses. The following Subsections present the initial screening of the containment alternatives C100, C150, and C200 with respect to relative costs for alternatives that have similar technical implementability and potential effectiveness. 5.1.1 Containment Alternative C100 Alternative C100 is fully implementable and would be effective to protect human health and the environment by eliminating and managing potential exposure pathways. Proper maintenance and monitoring would ensure permanence and effectiveness of the containment alternative. The relative cost of this alternative would be lowest of the containment alternatives based on a lower groundwater extraction rate that would require, for example, smaller equipment, less consumables (e.g., less power and chemicals for ex situ treatment), and less solids disposal. The contingency pH treatment (see Subsection 4.3.2) would increase cost for pH treatment equipment and the operation and maintenance (O&M) costs for power consumption, chemical usage, and solids disposal, but would not increase the size of the treatment plant and other equipment that would be sufficiently sized to accommodate up to 50 percent more flow from adding dilution water. 5.1.2 Containment Alternative C150 Alternative C150 is fully implementable and would be effective to protect human health and the environment by eliminating and managing potential exposure pathways. Proper maintenance and monitoring would ensure permanence and effectiveness of the containment alternative. The relative cost of this alternative would be slightly higher than the containment alternative C100 based on a higher groundwater extraction rate that would require increased O&M, for example, more consumables (e.g., more power and chemicals for ex situ treatment) and more solids disposal. The treatment plant/equipment size would be relatively the same. However, when factoring in the contingency pH treatment (see Subsection 4.3.2), the treatment plant/equipment would need to be larger to accommodate up to 50 percent more flow from adding dilution water and therefore the capital costs would be slightly higher as well. Additionally, the O&M costs for consumables and solids disposal would further increase commensurate with the additional flow. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 47 5.1.3 Containment Alternative C200 Alternative C200 is fully implementable and would be effective to protect human health and the environment by eliminating and managing potential exposure pathways. Proper maintenance and monitoring would ensure permanence and effectiveness of the containment alternative. The relative cost of this alternative would be higher than the containment alternatives C100 and C150 based on a higher groundwater extraction rate that would require larger treatment plant equipment and more consumables (e.g., more power and chemicals for ex situ treatment) and more solids disposal. When factoring in the contingency pH treatment (see Subsection 4.3.2), the larger treatment plant equipment associated with the C150 alternative would be adequate to accommodate the up to 50 percent more flow from adding dilution water. The O&M costs for consumables and solids disposal would further increase commensurate with the additional flow. The relative O&M cost of the C200 alternative with the contingency pH treatment would be higher than the C150 alternative with the contingency pH treatment, but the treatment plant equipment would be the same as noted above. The higher O&M costs would be based on a higher groundwater extraction rate that would require, for example, more consumables (e.g., more power and chemicals for ex situ treatment) and more solids disposal. The relative cost of the C200 alternative with the contingency pH treatment would be greater than the C100 alternative with the contingency pH treatment since the treatment plant equipment would be larger and O&M costs would be greater. 5.1.4 Summary All three containment alternatives (C100, C150, and C200) are fully implementable and similar in O&M required. The effectiveness of the drawdown (a measure of containment; see Subsection 5.2) increases with increases in pumping rate, which in turn increases the costs to construct, operate, and maintain to some degree. The potential benefits of increasing the pumping rate do not appear to clearly add disproportionate costs (i.e., no large increase in costs). Therefore, the initial screening did not eliminate any of the alternatives based on the requirements presented above. 5.2 Detailed Evaluation Purpose and Evaluation Criteria The detailed evaluation of the Containment Alternatives involved using the calibrated groundwater flow model developed for the Site, as presented in Appendix E, to determine if the alternatives meet the model-based objectives provided by the Agencies. In general, the purpose and objectives of the modeling evaluation include:  Evaluate potential discharge of TCVOC mass to the surface water bodies that surround the Site peninsula.  Evaluate the degree of hydraulic containment achieved by groundwater extraction. The specific Model-Based Performance Objectives for the Containment Alternatives consist of: 1) Within the hydraulic control boundaries provided by the Agencies on March 30, 2016, there must be inward gradients and a target drawdown of at least 1 foot (See Appendix E). 2) The Site groundwater flow model must be used to estimate the future mass discharge to Commencement Bay and the Hylebos Waterway with the containment system in place. In GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 48 addition to needing to meet RAGs presented in Subsection 3.1, as a minimum, the containment system must result in an estimated TCVOC mass discharge of less than 0.2 percent of the current estimated total TCVOC mass in the aquifer. 3) Groundwater flow beneath the Waterway must be directed to the plant-west toward the containment system. Per MTCA and CERCLA, other factors to consider include:  Potential risks.  Practicability.  Current use of the site, surrounding areas, and associated resources that are, or might be, affected by releases from the site.  Potential future use of the site, surrounding areas, and associated resources that are, or might be, affected by releases from the site.  Availability of alternative water supplies.  Likely effectiveness and reliability of institutional controls.  Ability to control and monitor migration of hazardous substances from the site.  Toxicity of the hazardous substances at the site.  Natural processes that reduce concentrations of hazardous substances and have been documented to occur at the site or under similar site conditions. 5.2.1 Containment Alternative C100 Evaluation of Model-Based Performance Objectives Containment Alternative C100 includes a physical hydraulic barrier wall along the Site peninsula adjacent to the Waterway and upland groundwater extraction wells on the Site peninsula. The location and number of upland extraction wells were optimized using the groundwater flow model. The objective of optimization was to maximize TCVOC groundwater plume containment while not placing extraction wells where the pH was greater than 10 s.u. (to minimize fouling of extraction wells). For Containment Alternative C100, the optimization resulted in eleven extraction wells (including existing inactive extraction well EXT-9) at a total groundwater pumping rate of 157.5 gpm. The detailed modeling evaluation of Containment Alternative C100 is presented in Appendix E, and the results of the modeling evaluation are summarized below relative to meeting Model-Based Performance Objectives. Containment Alternative C100 achieves inward gradients and simulated drawdown of at least 1 foot where TCVOC concentrations are above 1,000 µg/L in the 15-ft zone (see Figure 1 of Appendix E). Containment Alternative C100 achieves inward gradients and simulated drawdown of at least 1 foot within the majority of the hydraulic control boundaries for the 25-ft to 75-ft zones (see Figures 2 to 4 in Appendix E), which essentially meets Model-Based Performance Objective 1). However, the simulated drawdown is less than 1 foot within a significant portion of the hydraulic control boundaries for the 100-ft and 130-ft zones (see Figures 5 and 6 in Appendix E), and this does not meet Model-Based Performance Objective 1), although inward gradients are simulated for these zones. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 49 Containment Alternative C100 results in an estimated TCVOC mass discharge of less than 0.2 percent of the total TCVOC mass in the aquifer, which meets Model-Based Performance Objective 2) (see Table 2 of Appendix E). The TCVOC mass discharge to the surface water bodies surrounding the Site peninsula is approximately 0.02 percent of the total TCVOC mass in the aquifer (188 lbs) after the 1,000-year simulation duration. Figures 4, 5, and 6 of Appendix E show that simulated groundwater flow directions under the Waterway in the 75-ft, 100-ft, and 130-ft zones, respectively, are directed toward the Site peninsula and the groundwater extraction system, which meets Model-Based Performance Objective 3). Since Containment Alternative C100 does not meet the required drawdown component of Model-Based Performance Objective 1), it is not evaluated further in the FS. 5.2.2 Containment Alternative C150 Evaluation of Model-Based Performance Objectives Containment Alternative C150 is based on Containment Alternative C100 but with increased extraction rates. Containment Alternative C150 applies the same extraction wells as Containment Alternative C100, but with pumping rates increased by up to 50 percent from that applied in Containment Alternative C100. The total groundwater pumping rate applied for Containment Alternative C150 corresponds to 226.25 gpm, which is approximately 44 percent higher than Alternative C100. The detailed modeling evaluation of Containment Alternative C150 is presented in Appendix E, and the results of the modeling evaluation are summarized below relative to meeting Model-Based Performance Objectives. Containment Alternative C150 achieves inward gradients and simulated drawdown of at least 1 foot where TCVOC concentrations are above 1,000 µg/L in the 15-ft zone (see Figure 8 in Appendix E). Containment Alternative C150 achieves inward gradients and simulated drawdown of at least 1 foot within the hydraulic control boundaries for the 25-ft and 50-ft zones (see Figures 9 and 10 in Appendix E), which meets Model-Based Performance Objective 1). Containment Alternative C150 achieves inward gradients and simulated drawdown of at least 1 foot within the vast majority of the hydraulic control boundaries for the 75-ft to 130-ft zones (see Figures 11 to 13 in Appendix E), The 1-foot simulated drawdown encompasses where TCVOC concentrations are above 1,000 µg/L in the 75-ft to 130-ft zones on the Site peninsula. The above in combination with simulating inward gradients for the 75-ft to 130-ft zone hydraulic control boundaries, satisfies the intent of Model-Based Performance Objective 1). Simulating significant drawdown (i.e., 1 ft or more) in the 160-ft zone is not expected since much of this zone lies below the zone of apparent confining effect where lower permeability is represented in the groundwater flow model (see Figure 14 of Appendix E). Containment Alternative C150 achieves Model-Based Performance Objective 2) (see Table 2 of Appendix E). The TCVOC mass discharge to the surface water bodies surrounding the Site peninsula is approximately 0.004 percent of the total TCVOC mass in the aquifer (35 lbs) after the 1,000-year simulation duration, which is 0.016 percent less than Alternative C100. Containment Alternative C150 achieves simulated groundwater flow directions under the Waterway in the 75-ft, 100-ft, and 130-ft zones that are directed toward the Site peninsula and the groundwater extraction system, which meets Model-Based Performance Objective 3) (see Figures 11, 12, and 13 of Appendix E). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 50 Other Factors to Consider Containment Alternative C150 is designed to eliminate, reduce, or otherwise control risks posed through potentially complete exposure pathways and migration routes. Therefore, a properly operated, maintained, and monitored C150 containment alternative would protect human health and the environment, including potential ecological receptors, by containing and preventing exposure to media with concentrations of COC above SSLs and by meeting the Site RAGs (see Subsection 3.1). The technologies proposed are common and practical for containing a large complex site such as this and could be effectively operated, maintained, and monitored. The C150 alternative components presented herein are administratively and technically possible at the Site. The applicable state and federal laws (see Subsection 3.3) would be complied with during the design and implementation phases by meeting the substantive requirements. Administratively, substantive requirements of permitting would be met in terms of the following: 1. Construction - storm water, potential air monitoring, and building. 2. Post Construction and Long-term operations - National Pollutant Discharge Elimination System (NPDES) (to include wastewater sampling, storm water sampling, air monitoring). Pre-Construction and Construction (including demolition and construction) - might include Washington State Environmental Policy Act (SEPA), Ecology construction storm water permitting requirements, Port of Tacoma tenant improvement requirements for off-property work, City of Tacoma construction permitting requirements, and Joint Aquatic Resources Permit Application (JARPA) working in water ways (US Army Corps Of Engineers - requirements for general permit, nationwide permit, standard individual permits, and letter of permission - as authorized under Section 10 and/or Section 404). It is most likely that a sheet pile vertical barrier wall would require the most effort and would take the longest time to meet the substantive requirements. Port of Tacoma officials report that recently observed permitting time frames in the Tacoma Tideflats area has taken up to 1.5 years to complete. Air monitoring might be required during construction if emissions are expected during construction. Post-construction, an impermeable barrier (PDCE barrier) over an area of approximately 34.5 acres would result in large quantities of runoff during storm events and would need to meet NPDES substantive requirements. Discharge from the GWETS would need to meet NPDES substantive requirements as well. Air discharge from the GWETS would need to meet the substantive requirements of applicable State and Federal air emissions regulations. ICs and compliance monitoring along with O&M are very reliable and effective means to ensure control of potential future migration of hazardous substances. Compliance monitoring would include performance monitoring, confirmation monitoring, and protection monitoring. The C150 containment alternative would include compliance monitoring in the forms of the Common Elements of ICs and monitoring (see Subsection 4.2), substantive requirements of permitting, five-year reviews, and field-based performance objectives. The existing network of monitoring wells is likely more than adequate to monitor the effectiveness and field-based performance objectives. The compliance monitoring would ensure that potential exposure to residual threats are eliminated or managed. The C150 alternative would be compatible with the current and anticipated future uses of the Site and surrounding areas, which are industrial with generally paved surfaces. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 51 This alternative would prevent future potential discharges into surface water that could potentially adversely impact ecological populations. The area is serviced by a municipal water supply and the groundwater beneath the Site has been determined to be non-potable (see Appendix A). Since the containment system would not significantly alter the geochemical conditions in the subsurface, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 5.2.3 Containment Alternative C200 Evaluation of Model-Based Performance Objectives Containment Alternative C200 is based on Containment Alternative C100 but with increased extraction rates, which are higher than the C150 alternative extraction rates as well. Containment Alternative C200 applies the same extraction wells as Containment Alternative C100, but with pumping rates increased by up to 100 percent from that applied in Containment Alternative C100. The total groundwater pumping rate applied for Containment Alternative C200 corresponds to 281.5 gpm, which is approximately 79 percent higher than Alternative C100 and 24 percent higher than Alternative C150. The detailed modeling evaluation of Containment Alternative C200 is presented in Appendix E, and the results of the modeling evaluation are summarized below relative to meeting Model-Based Performance Objectives. Containment Alternative C200 achieves inward gradients and simulated drawdown of at least 1 foot where TCVOC concentrations are above 1,000 µg/L in the 15-ft zone (see Figure 15 in Appendix E). Containment Alternative C200 achieves inward gradients and simulated drawdown of at least 1 foot within the hydraulic control boundaries for the 25-ft and 50-ft zones (see Figures 16 and 17 in Appendix E), which meets Model-Based Performance Objective 1). Similar to Containment Alternative C150, Containment Alternative C200 achieves inward gradients and simulated drawdown of at least 1 foot within the vast majority of the hydraulic control boundaries for the 75-ft to 130-ft zones (see Figures 18 to 20 in Appendix E), The 1-foot simulated drawdown encompasses where TCVOC concentrations are above 1,000 µg/L in the 75-ft to 130-ft zones on the Site peninsula. The above in combination with simulating inward gradients for the 75-ft to 130-ft zone hydraulic control boundaries, satisfies the intent of Model-Based Performance Objective 1). Simulating significant drawdown (i.e., 1 ft or more) in the 160-ft zone is not expected since much of this zone lies below the zone of apparent confining effect where lower permeability is represented in the groundwater flow model (see Figure 21 of Appendix E). Containment Alternative C200 achieves Model-Based Performance Objective 2) (see Table 2 of Appendix E). The TCVOC mass discharge to the surface water bodies surrounding the Site peninsula is approximately 0.004 percent of the total TCVOC mass in the aquifer (30 lbs) after the 1,000-year simulation duration, which is 0.016 percent less than Alternative C100 and essentially the same as Alternative C150. Containment Alternative C200 achieves simulated groundwater flow directions under the Waterway in the 75-ft, 100-ft, and 130-ft zones that are directed toward the Site peninsula and the groundwater extraction system, which meets Model-Based Performance Objective 3) (see Figures 18, 19, and 20 of Appendix E). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 52 Other Factors to Consider The consideration of other factors for Containment Alternative C200 is consistent with the evaluation for Containment Alternative C150. The Containment Alternative C200 meets the Model-Based Performance Objectives similar to Containment Alternative C150. 5.2.4 Disproportionate Cost Analysis A disproportionate cost analysis (DCA) is designed to evaluate if the incremental costs of an alternative over that of a lower cost alternative exceed the incremental degree of benefits potentially achieved by the more costly alternative. As presented in WAC 173-340-360(3)(f), the evaluation criteria are as follows: (i) Protectiveness (ii) Permanence (iii) Effectiveness over the long term (iv) Management of short-term risks (v) Technical and administrative implementability (vi) Consideration of public concerns (vii) Cost These MTCA evaluation criteria are analogous to the NCP evaluation criteria under CERCLA. In the DCA process, each alternative is assigned a rank (score) for each criterion using a scale of 1 to 10 (10 being the best) that represent a judgement of how well an alternative satisfies a criterion. Since each criterion is not considered equal by the Agencies, each rank is multiplied by a weighting factor or percentage representative of the criterion before the ranks are added up to produce a total that is referred to as an 'overall benefit score.' The overall benefit score is divided by the relative cost (normalized by dividing the actual costs by the order of magnitude of the lowest cost alternative [e.g., 10,000,000]) to come up with a relative benefit score to cost ratio. These ratios are compared and the higher the ratio the more beneficial the alternative is. Table 5.1 presents the weighting percentages developed for this Site and the rationale for each, which are summarized below: (i) Protectiveness - 30% (ii) Permanence - 20% (iii) Effectiveness over the long term - 20% (iv) Management of short term risks - 10% (v) Technical and administrative implementability - 10% (vi) Consideration of public concerns - 10% The following presents an evaluation of Containment Alternatives C150 and C200 with respect to the above DCA process. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 53 Protectiveness Both Containment Alternatives C150 and C200 would provide similar protectiveness. The required protection for human health and the environment would be met through access restrictions, ICs, and engineered barriers (i.e., PDCE and sheet pile vertical barrier wall). The PDCE would protect against incidental ingestion, inhalation, and dermal contact with impacted soil and shallow DNAPL. It would prevent runoff of potentially impacted surface water. Additionally, the PDCE might reduce infiltration/percolation through impacted soil in the vadose zone, potentially reducing migration. The sheet pile vertical barrier wall along the Waterway would isolate the impacted embankment material preventing direct contact by human and ecological receptors. The sheet pile vertical barrier wall would also prevent flushing of shallow soil by tidal fluctuations and prevent shallow groundwater discharge to surface water and aquatic receptors. The treatment of impacted groundwater would prevent discharge of impacted water to surface water bodies. Potential risks associated with the Site would be reduced within the construction time frame and would continue to be reduced over time as contaminated groundwater is extracted and treated. Overall environmental quality would improve by preventing direct contact with, incidental ingestion of and inhalation of hazardous substances, and potential discharge of groundwater with concentrations above SSLs to surface water. Permanence Both Containment Alternatives C150 and C200 would offer essentially the same practical solution and equal permanence. Groundwater extraction under this alternative would contain the impacted groundwater plumes, thus reducing contaminant mobility. The treatment of the extracted groundwater would destroy contaminants, resulting in a reduction of their toxicity and volume. Migration and potential release of hazardous substances would be mitigated by maintaining inward hydraulic gradients and demonstrating containment using existing monitoring wells to achieve field-based performance objectives that would be determined during the design phase. The treatment process would result in the generation of solids that would require off-Site transportation and disposal. Effectiveness Over the Long Term Containment Alternatives C150 and C200 would be equally effective over the long term since they equally meet the Model-Based Performance Objectives and are anticipated to equally meet the field-based performance objective. Containment Alternative C200 has an increased risk of drawing in groundwater with higher pH since the pumping rates are higher. As discussed in Subsection 4.3.2, pumping groundwater with high pH should be avoided in order to minimize/prevent: potential fouling of the treatment system; the need for treatment of high pH water; and disposal of additional solids associated with this high pH groundwater. Therefore, a lower groundwater pumping rate would be preferred to minimize this potential risk. Both Containment Alternatives C150 and C200 would include technologies that are common and practical for containing a large complex site, could be effectively operated, maintained, and monitored, and are proven to be successful and reliable over time. Both alternatives reduce risk by eliminating or managing potential exposure pathways and containing hazardous substances remaining at the Site. Long-term effectiveness would require ongoing operation and/or maintenance of the components, monitoring, and maintenance of ICs. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 54 The installation of the PDCE barrier would be an effective and reliable solution to eliminate exposure to the impacted soil, impacted embankment material, and shallow DNAPL. The asphalt cover would need to be maintained and periodically repaired or replaced. The long-term integrity and effectiveness of well-designed and constructed PDCE barriers is well documented. PDCE barrier technology must be used in combination with ICs to protect the integrity of the barrier material, and other technologies to address potential migration of subsurface impacts under the PDCE barrier. The installation of the sheet pile vertical barrier wall is an effective and reliable solution to provide isolation of the impacted embankment material and to prevent discharge of impacted shallow groundwater to the Hylebos. The installation of sheet pile vertical barrier wall to the depths anticipated is commonly done in both upland and marine settings. The GWETS would be effective in maintaining containment and would reduce mass over time through extraction and treatment of contaminated groundwater. Management of Short-term Risks The short-term risks during construction and implementation of both alternatives would be the same and would be managed through standard safety and health procedures that would be documented in a Site-specific health and safety plan (HASP). The types of procedures that would be required are those regularly practiced for the types of construction anticipated. In addition to the HASP, other plans for activities such as soil management, traffic control, and air monitoring would be developed to protect human health and the environment during construction and implementation. Technical and Administrative Implementability As discussed in Subsection 5.1, both alternatives are equally implementable. The technical implementability of a PDCE barrier is high as PDCE barrier is a proven technology that was used successfully at many sites and PDCE barrier materials (e.g., asphalt and granular bedding materials) are readily available. The technical implementability of sheet pile vertical barrier wall technology is high as well as this technology is widely used for containment in upland and marine applications, and materials and equipment to install sheet pile vertical barrier walls are widely available. A barrier wall could be easily installed to the depths anticipated. Groundwater extraction wells are commonly used, and are generally simple to maintain. Experience at the Site has shown that extraction wells could be operated for long periods of time outside of the zone where groundwater pH is greater than 10 s.u. Wells could be maintained and rehabilitated using standard techniques. Well construction contractors and materials are readily available. Since the engineered barriers and groundwater extraction technology are proven technologies and typically applied at many sites; services, capabilities, equipment, specialists, and materials should be readily available for implementation of these remedial technologies. Permitting of these remedial technologies is also expected to be obtained without significant difficulties. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 55 Consideration of Public Concerns Ecology held a public comment period from October 23, 2015 through February 1, 2016 for the approved SCR (CRA, 2014c), during which, Ecology received a total of 14 letters and emails. The following four common significant themes were apparent in the public comments: 1) Several comments were largely unrelated to the Site, and focused more on the CB/NT site, sediment cleanup standards, and uses of the Hylebos. 2) Some comments believed that the Exposure Pathway Assessment (sediment and shallow groundwater discharge assessment) is incomplete. 3) A few comments believed that the full extent of the biological receptors has not been assessed. 4) A couple of comments believed that the northern boundary of the plume extent has not been fully defined. As the comments in Item 1 above were largely unrelated to the Site, they are outside the scope of this FS. The comments in Items 2, 3, and 4 above were addressed through the 2016 Anchor QEA investigation sediment and porewater sampling in the Hylebos as discussed in Subsection 2.4.5 and 2.4.6. To the extent that the comments were related to Upland Areas of the Site, they would be addressed by a containment system. Public notice and participation is an integral part of the remedy selection process. The public notice and participation requirements for cleanups conducted are set forth in MTCA (WAC 173-340-600), NCP 40 CFR 300.430(f)(3)(i), and CERCLA §117. The public will have an opportunity to voice any concerns regarding the FS during a public comment period. It is expected that the public will be supportive of a reliable containment system that protects human health and the environment by eliminating all potential exposure pathways. Containment systems, which could be effectively operated, maintained, and monitored, are common and have proven to be reliable and effective solutions for large complex sites like this one. Mobility of mass within the containment system would be of minimal concern as long as there is hydraulic control of the target zones. A containment alternative is the foundation of any other measures that are deemed appropriate to address Site conditions. Cost The estimated costs for Containment Alternatives C150 and C200 are presented in Appendix G and were developed in accordance with guidance (USEPA, 2000) specified by the Agencies. The costs include a placeholder for potential mitigation for the loss of intertidal zone along the embankment to comply with the Clean Water Act. The cost estimates include periods of 30 years (yrs), in accordance with the guidance (USEPA, 2000), and 100 years, at the request of the Agencies. Discount factors for O&M and periodic costs include 7 percent, in accordance with the guidance (USEPA, 2000), and 1.5 percent (2016 Discount Rate for OMB Circular No. A-94 for the 30-Year Real Interest Rate on Treasury Notes and Bonds of Specific Maturities), at the request of the Agencies. A summary of the capital, O&M, and periodic costs is as follows: GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 56 Table 5.2 Summary of Containment Alternatives Estimated Costs Cost Type Capital O&M/Periodic (30yrs;7%) O&M/Periodic (30yrs;1.5%) O&M/Periodic (100yrs;7%) O&M/Periodic (100yrs;1.5%) Alternative C150 $38,700,240 $15,656,240 $30,652,600 $18,469,760 $70,539,760 Alternative C200 $38,700,240 $16,490,000 $32,266,220 $19,429,760 $74,009,760 As shown in the above table, the estimated capital costs are the same since the same plant would be constructed for either extraction system. The O&M/Periodic costs for the C200 alternative are higher than the C150 alterative due to requirements for treating the additional flow such as increased power consumption, chemical usage for solids removal and pH adjustment, and production of solids requiring off-Site disposal. Disproportionate Cost Analysis Summary Table 5.3 presents a DCA summary table that provides relative benefit score to cost ratios for the Containment Alternatives C150 and C200 using weighting percentages from Table 5.1 and the scoring from Table 5.3. As shown in Table 5.3, the C150 alternative has a benefit score to cost ratio of 1.36 that is slightly greater than the benefit score to cost ratio for the C200 alternative of 1.34. The following provides additional discussion regarding the common elements costs, cash flow projections, and alternative durations. Figure 5.1 presents the common elements capital cost distribution for Containment Alternatives C150 and C200. As shown on this figure, the costs are the same. Figure 5.2 presents the alternatives anticipated 30-year cash flow projections. As shown on this figure, the costs are similar; however, they are higher for C200 alternative. Figure 5.3 shows the anticipated durations for the different components of the alternatives, which are the same. Since Containment Alternatives C150 and C200 are essentially equivalent based on the evaluation criteria other than cost, there is no tangible degree of incremental benefit of the higher cost alternative. This is substantiated by C150 alternative having a higher benefit score to cost ratio than C200 alternative in Table 5.3. 5.2.5 Summary Containment Alternatives C150 and C200 both meet the Model-Based Performance Objectives and Containment Alternative C100 does not. Containment Alternatives C150 and C200 would be equally implementable, effective, and permanent. Since Containment Alternatives C150 and C200 are essentially equivalent based on the evaluation criteria and the C150 alternative has a higher benefit score to cost ratio, there is no tangible degree of incremental benefit to justify selecting the higher cost alternative. Therefore, the identified preferred alternative is Containment Alternative C150. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 57 6. VOC Mass Removal/Reduction Alternatives Initial Screening and Detailed Evaluation 6.1 Initial Screening The VOC mass removal/reduction alternatives are described in Subsection 4.4. The initial screening criteria are described in Subsection 5.1. The VOC mass removal/reduction alternatives are designed to remove or reduce concentrations of contaminants, primarily TCVOC, in groundwater and soil. The VOC mass removal/reduction alternatives would not protect human health and the environment, including potential ecological receptors, at the Site by themselves. Therefore, they would not meet all the minimum/threshold requirements. However, in combination with containment technologies they would meet the minimum/threshold requirements (see Subsection 5.1). Accordingly, the VOC mass removal/reduction alternatives all assume that appropriate containment technologies are implemented at the Site. Therefore, none of the VOC mass removal/reduction alternatives were removed from further evaluation based on this initial screening. The VOC mass removal alternatives M3 and M4 (see Subsection 4.4 for descriptions) would include excavation of the same quantity of shallow soil containing concentrations of TCVOC greater than 100 mg/kg. Therefore, these two alternatives would be equally effective in removing VOC mass from the Site. The difference between these alternatives would be the method of treatment/disposal after the soil is excavated. The M3 alternative includes on-Site treatment and backfilling whereas the M4 alternative includes off-Site transportation, treatment, and disposal. Based on discussions with vendors the cost would be approximately $720 per ton of soil for transportation, treatment, and disposal at an off-Site hazardous waste facility. On-Site treatment via ex situ SVE and backfilling is expected to be significantly less, on the order of $150 per ton, since there would not be any transportation or disposal costs. There would be some additional cost for backfilling under the M3 alternative but this would not be a significant cost and would be less than the cost to import clean backfill for excavated areas under the M4 alternative. Therefore, the costs for the M4 alternative would be clearly disproportionate compared to the M3 alternative, which would be equally as effective in removing concentrations of TCVOC greater than 100 mg/kg in shallow soil. Similarly, the M6 and M7 alternatives (see Subsection 4.4 for descriptions) would be equally as effective because they would include the same technologies for treating and removing soils and the only difference would be the method of treatment/disposal for excavated soil, which is the same as the M3 and M4 alternatives. Therefore, the costs for the M7 alternative would be clearly disproportionate compared to the M6 alternative, which would be equally as effective. The remaining VOC mass removal/reduction alternatives would be sufficiently different because of the technologies used and/or areas targeted that determining which alternatives' costs would be clearly disproportionate under WAC 173-340-360(3)(e) and/or have the lowest relative benefit score to cost ratio in the initial screening is not evident. Therefore, no additional VOC mass removal/reduction alternatives were removed from further evaluation based on this initial screening criterion. The VOC mass removal/reduction alternatives and components presented herein are administratively and technically possible at the Site and therefore none of the VOC mass removal/reduction alternatives were removed from further evaluation based on this initial screening GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 58 criterion. However, the M8 and M9 alternatives effective implementation might not be feasible because of the depth and size of the targeted zones and other activities on the peninsula. These alternatives include in situ treatment of VOC in deep soil and groundwater north of the 605 Alexander Avenue property. This is discussed further in the following detailed evaluation subsection. Based on the above, the initial screening eliminated the M4 and M7 alternatives from further evaluation. 6.2 Detailed Evaluation Purpose and Evaluation Criteria The purpose of the detailed evaluation is to select an alternative, retained following the initial screening, which does not have an incremental cost that exceeds the incremental degree of benefits potentially achieved. The detailed evaluation of the VOC mass removal/reduction alternatives involved assessing MTCA and CERCLA factors to be considered (see Subsection 5.2) and conducting a disproportionate cost analysis per WAC 173-340-360(3)(f). The detailed evaluation assumes that containment is part of the selected remedy for the Site, which is consistent with the initial screening of the VOC mass removal/reduction alternatives. 6.2.1 No Additional Action VOC Mass Removal/Reduction Alternative The No Additional Action VOC Mass Removal/Reduction Alternative would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment. It would not alter or undermine the practicality and effectiveness of a containment alternative and therefore would be compatible with the use at the Site. This alternative would not reduce/remove or enhance containment of VOC mass in media at the Site and thus would not increase permanence or long-term effectiveness. However, VOC mass would be reliably contained by containment technologies. There are no short-term risks and it is fully implementable. Since this alternative would not alter the geochemical conditions in the subsurface, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 6.2.2 VOC Mass Reduction Alternatives M100, M150, and M200 The detailed evaluation of the VOC Mass Reduction Alternatives M100, M150, and M200 involved using the calibrated groundwater flow model developed for the Site, as presented in Appendix E, to determine TCVOC mass reduction that might be achieved by groundwater extraction. The simulated TCVOC mass removal by groundwater extraction is evaluated relative to the total TCVOC mass in the aquifer beneath the Site calculated from TCVOC concentrations in soil (above a threshold soil concentration of 100 mg/kg) equal to approximately 780,000 lbs presented in Appendix C. Soil concentrations represent mass in the dissolved, sorbed, and DNAPL phases. 6.2.2.1 VOC Mass Reduction Alternative M100 VOC Mass Reduction Alternative M100 includes a physical hydraulic barrier wall along the Site peninsula adjacent to the Waterway and two upland mass removal groundwater extraction wells on the Site peninsula. Groundwater extraction was represented in the model only from areas of elevated concentrations in the shallow and deep TCVOC groundwater plume to yield reduction in GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 59 TCVOC mass. Two extraction wells were simulated to pump from shallow and deep groundwater with high dissolved concentrations of TCVOC outside the areas of elevated pH (i.e., greater than [>]10 s.u.). Figure 22 of Appendix E shows the locations and depths of two proposed mass reduction extraction wells, one shallow and one deep. A total groundwater pumping rate of 35 gpm was applied for VOC Mass Reduction Alternative M100. The rationale for this pumping rate is discussed in Appendix E. Simulated mass-weighted particle capture for VOC Mass Reduction Alternative M100 was completed for 30 years and 100 years, as requested by the Agencies. VOC Mass Reduction Alternative M100 would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands VOC would already be reliably contained. However, it would increase the rate of VOC removal from the subsurface in the short term and the total quantity of VOC removed in the long term in combination with a containment alternative, and thus would significantly increase permanence and long-term effectiveness. The technology proposed is common and practical for extracting contaminated groundwater from a large complex site such as this and could be effectively operated, maintained, and monitored. There are some manageable short-term risks related to construction and it is implementable. The M100 alternative is not expected to alter or undermine the practicality of a containment alternative and could be easily incorporated into the design of the GWETS. It would enhance the drawdown and gradients within the containment system, which would require optimization if the M100 alternative was selected to be combined with a containment alternative. The alternative would be compatible with the current and anticipated future uses of the Site and surrounding areas, which are industrial with generally paved surfaces. Since the M100 alternative would not significantly alter the geochemical conditions in the subsurface, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 6.2.2.2 VOC Mass Reduction Alternative M150 VOC Mass Reduction Alternative M150 is based on VOC Mass Reduction Alternative M100. VOC Mass Reduction Alternative M150 applies the same extraction wells as VOC Mass Reduction Alternative M100, but with pumping rates increased by 50 percent from that applied in VOC Mass Reduction Alternative M100. A total groundwater pumping rate of 52.5 gpm was applied for VOC Mass Reduction Alternative M150. VOC Mass Reduction Alternative M150 would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands VOC would already be reliably contained. However, it would increase the rate of VOC removal from the subsurface in the short term and the total quantity of VOC removed in the long term in combination with a containment alternative, and thus would significantly increase permanence and long-term effectiveness. The rate of removal and quantity of VOC removed would be greater than the M100 alternative as shown on Figures 30 and 31 in Appendix E. The technology proposed is common and practical for extracting contaminated groundwater from a large complex site such as this and could be effectively operated, maintained, and monitored. There are some manageable short-term risks related to construction and it is implementable. The M150 alternative is not expected to alter or undermine the practicality of a containment alternative and could be easily incorporated into the design of the GWETS. It would enhance the drawdown and gradients within the containment system, which would require optimization if the M150 alternative was selected to be combined with a containment alternative. The alternative would be compatible with the current and anticipated future uses of the Site and surrounding areas, which are industrial with generally paved surfaces. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 60 Since the M150 alternative would not significantly alter the geochemical conditions in the subsurface, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 6.2.2.3 VOC Mass Reduction Alternative M200 VOC Mass Reduction Alternative M200 is based on VOC Mass Reduction Alternative M100. VOC Mass Reduction Alternative M200 applies the same extraction wells as VOC Mass Reduction Alternative M100, but with pumping rates increased by 100 percent from that applied in VOC Mass Reduction Alternative M100. A total groundwater pumping rate of 70 gpm was applied for VOC Mass Reduction Alternative M200. VOC Mass Reduction Alternative M200 would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands VOC would already be reliably contained. However, it would increase the rate of VOC removal from the subsurface in the short term and the total quantity of VOC removed in the long term in combination with a containment alternative, and thus would significantly increase permanence and long-term effectiveness. The rate of removal and quantity of VOC removed would be greater than the M100 and M150 alternatives as shown on Figures 30 and 31 in Appendix E. The technology proposed is common and practical for extracting contaminated groundwater from a large complex site such as this and could be effectively operated, maintained, and monitored. There are some manageable short-term risks related to construction and it is implementable. The M200 alternative is not expected to alter or undermine the practicality of a containment alternative and could be easily incorporated into the design of the GWETS. It would enhance the drawdown and gradients within the containment system, which would require optimization if the M200 alternative was selected to be combined with a containment alternative. The alternative would be compatible with the current and anticipated future uses of the Site and surrounding areas, which are industrial with generally paved surfaces. Since the M200 alternative would not significantly alter the geochemical conditions in the subsurface, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 6.2.3 VOC Mass Reduction Alternative MSP The detailed evaluation of the VOC Mass Reduction Alternatives MSP involved using the calibrated groundwater flow model developed for the Site, as presented in Appendix E, to determine TCVOC mass reduction that might be achieved by groundwater extraction in areas of higher mass in soil below the water table and outside areas of high pH (i.e., >10 s.u.). The simulated TCVOC mass removal by groundwater extraction is evaluated relative to the total TCVOC mass in the aquifer beneath the Site calculated from TCVOC concentrations in soil (above a threshold soil concentration of 100 mg/kg) equal to approximately 780,000 lbs presented in Appendix C. The soil concentrations represent mass in the dissolved, sorbed, and DNAPL phases. VOC Mass Reduction Alternative MSP includes a physical hydraulic barrier wall along the Site peninsula adjacent to the Waterway and eleven upland groundwater mass removal and containment extraction wells strategically positioned on the Site peninsula. Groundwater extraction was represented in the model from areas of elevated concentrations of TCVOC in the shallow and deep soil below the water table to reduce TCVOC mass (i.e., strategic pumping). Nine extraction wells were simulated to pump from shallow and deep groundwater with high concentrations of TCVOC outside the areas of elevated pH (i.e., pump in areas where pH is less than [<]10 s.u.). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 61 Additionally, two extraction wells were simulated to pump from shallow groundwater to supplement the groundwater containment achieved by pumping in zones of high TCVOC concentrations. Figure 23 of Appendix E shows the strategic locations of the eleven proposed groundwater mass reduction and containment extraction wells, four shallow and seven deep. A total groundwater pumping rate of 210 gpm was applied for VOC Mass Reduction Alternative MSP. The rationale for this pumping rate is discussed in Appendix E. Simulated mass-weighted particle capture for VOC Mass Reduction Alternative MSP was completed for 30 years and 100 years, as requested by the Agencies. VOC Mass Reduction Alternative MSP would replace the components related to groundwater pumping of a containment alternative because it satisfies the model-based containment objectives for the Site (see Appendix E). It would minimize potential risks to human health and the environment because the uplands VOC would be reliably contained. It would increase the rate of VOC removal from the subsurface in the short term and the total quantity of VOC removed in the long term by strategic pumping, and thus would significantly increase permanence and long-term effectiveness. The technology proposed is common and practical for extracting contaminated groundwater from a large complex site such as this and could be effectively operated, maintained, and monitored. There are some manageable short-term risks related to construction and it is implementable. The MSP alternative could be easily incorporated into the design of a treatment system presented for the containment alternatives. The parts other than the extraction wells of a containment alternative would need to be included with the MSP alternative to protect human health and environment as discussed above. The alternative would be compatible with the current and anticipated future uses of the Site and surrounding areas, which are industrial with generally paved surfaces. Since the MSP alternative would not significantly alter the geochemical conditions in the subsurface, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 6.2.4 VOC Mass Removal Alternative M3 The VOC Mass Removal Alternative M3 includes removing elevated concentrations of TCVOC in shallow (-4 ft NGVD) soil by excavation, on-Site treatment of the soil, and on-Site backfilling of the treated soil. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands TCVOC mass would already be reliably contained. It would reduce very little potential for migration of TCVOC via leaching to groundwater and volatilization, adding a small degree of permanence and long-term effectiveness. Excavation of shallow soil would be practical and implementable with some short-term risks for construction and added effort to manage saturated soil and potential release of VOC to ambient air during material handling. The M3 alternative is not expected to alter or undermine the practicality of a containment alternative or its effectiveness. The alternative would be compatible with the current and anticipated future uses of the Site and surrounding areas, which are industrial with generally paved surfaces. Since the M3 alternative would not significantly alter the geochemical conditions in the subsurface, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 6.2.5 VOC Mass Reduction Alternative M5 The VOC Mass Reduction Alternative M5 includes treating elevated concentrations of TCVOC in shallow (-21 ft NGVD) soil by in situ ERH and in situ SVE. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 62 the uplands TCVOC mass would already be reliably contained. It would reduce some potential for migration of TCVOC via leaching to groundwater and volatilization compared to the M3 alternative, but still adding a very small degree of permanence and long-term effectiveness. In situ treatment of shallow soils by ERH and SVE would be practical and implementable as these technologies have proven to be successful at reducing VOC concentrations in unsaturated (SVE) and saturated (ERH) soils at other sites. There would be some short-term risks for construction and operation of the technologies. The M5 alternative is not expected to alter or undermine the practicality of a containment alternative or its effectiveness. The alternative would be compatible with the current and anticipated future uses of the Site and surrounding areas, which are industrial with generally paved surfaces. Since the M5 alternative would not significantly alter the geochemical conditions in the subsurface outside the immediate target zone, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 6.2.6 VOC Mass Removal/Reduction Alternative M6 The M6 alternative is a combination of the excavation and in situ ERH treatment elements from the M3 and M5 alternatives, respectively. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands TCVOC mass would already be reliably contained. It would further reduce some potential for migration of TCVOC via leaching to groundwater and volatilization compared to the M3 and M5 alternatives, but still adding a very small degree of permanence and long-term effectiveness. As noted previously the technologies would be practical and implementable at the Site. There would be some short-term risks for construction, operation of the technologies, and added effort to manage saturated soil and potential release of VOC to ambient air during material handling. The M6 alternative is not expected to alter or undermine the practicality of a containment alternative or its effectiveness. The alternative would be compatible with the current and anticipated future uses of the Site and surrounding areas, which are industrial with generally paved surfaces. Since the M6 alternative would not significantly alter the geochemical conditions in the subsurface outside the immediate target zone, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 6.2.7 VOC Mass Removal/Reduction Alternative M8 The M8 alternative includes the shallow soil treatment from the M5 alternative (ERH and SVE) and treatment of elevated concentrations of TCVOC in shallow (-60 ft NGVD) groundwater (and soil) by ISCO and ISB. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands TCVOC mass would already be reliably contained. It would further reduce some potential for migration of TCVOC via leaching to groundwater, groundwater flow, and volatilization compared to the M3, M5, and M6 alternatives, but adding a very small degree of permanence and long-term effectiveness. As noted previously the technologies from the M5 alternative would be practical and implementable at the Site. The ISCO technology would be practical and implementable, as this technology has proven to be successful at reducing VOC concentrations in saturated soils at other sites. The ISB technology would also be practical and implementable for similar reasons; however, the treatment relies on maintaining optimal conditions for biological activity and contaminated groundwater passing through/near the treatment curtains. Therefore the effectiveness might be limited if the optimal conditions cannot be maintained because of Site-specific subsurface conditions (e.g., pH above 10 s.u., low dissolved oxygen content [DOC], high salt content) and/or if impacted groundwater does not pass GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 63 through/near the treatment curtains under natural flow or groundwater pumping conditions. There would be some short-term risks for construction, operation of the technologies, and protection of the injection wells from traffic on the Port of Tacoma properties. The M8 alternative is not expected to alter or undermine the practicality of a containment alternative, but it might alter the effectiveness by altering the groundwater flow patterns in the target zone. For example, ISCO might alter the hydraulic conductivity if significant quantities of solids are precipitated out of solution. This could potentially impact drawdown and gradients within the containment system and might reduce the quantity of TCVOC mass that would be extracted from the subsurface over time. However, the M8 alternative would reduce concentrations of TCVOC in the target zones in a shorter time frame, which otherwise would be extracted by the containment system. Despite the concern of impacting the containment alternative, it would still be compatible with the use at the Site since the target zone would still be reliably contained. It would alter the geochemical conditions in the subsurface and therefore natural processes (e.g., biodegradation) documented to occur at the Site that reduce concentrations of hazardous substances might be affected. 6.2.8 VOC Mass Removal/Reduction Alternative M9 The M9 alternative includes the shallow soil and groundwater treatment from the M8 alternative and treatment of elevated concentrations of TCVOC in deep (below -60 ft NGVD) groundwater and soil by ISCO and ISB. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands TCVOC mass would already be reliably contained. It would significantly reduce the potential for migration of TCVOC via leaching to groundwater, groundwater flow, and volatilization compared to the M3, M5, M6, and M8 alternatives, adding significant additional permanence and long-term effectiveness. As noted previously the technologies from the M8 alternative would be practical and implementable at the Site. The ISCO technology would be practical and implementable in the deeper target zones, as this technology has proven to be successful at reducing VOC concentrations in deep saturated soils at other sites. The ISB technology would also be practical and implementable for similar reasons; however, the treatment relies on maintaining optimal conditions for biological activity and contaminated groundwater passing through/near the treatment curtains. Therefore, the effectiveness might be limited. Another potential difficulty is with potential overlapping of technologies that might impact the effectiveness. For example, applying ISCO near ISB might cause loss of optimal conditions for biological activity in the short-term and inhibit native microbial populations in the long-term. This might delay implementation of a technology that is not compatible with another. There would be some short-term risks for construction and operation of the technologies. There would be significant short-term risks for protection of the injection wells from traffic on the Port of Tacoma properties because of the large area required to implement the technologies. The M9 alternative is not expected to alter or undermine the practicality of a containment alternative, but it might alter the effectiveness by changing the groundwater flow (i.e., hydraulic conductivity) in the target zone. This could potentially impact drawdown and gradients within the containment system and might reduce the quantity of TCVOC mass that would be extracted from the subsurface over time. However, the M9 alternative would reduce concentrations of TCVOC in the target zones in a shorter time frame, which otherwise would be extracted by the containment system. Despite the concern of impacting the containment alternative, it would still be compatible with the use at the Site since the target zones would still be reliably contained. It would alter the geochemical conditions in the subsurface and therefore natural processes (e.g., biodegradation) documented to occur at the Site that reduce concentrations of hazardous substances might be affected. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 64 6.2.9 Disproportionate Cost Analysis A DCA of the VOC mass removal/reduction alternatives was conducted using the same process described in Subsection 5.2.4. The following presents an evaluation of VOC Mass Removal/Reduction Alternatives M100, M150, M200, MSP, M3, M5, M6, M8, and M9, and the No Additional Action alternative with respect to the DCA process. Protectiveness The VOC mass removal/reduction alternatives would not protect human health and the environment, including potential ecological receptors, at the Site by themselves. Therefore, they would not meet all the minimum/threshold requirements. However, they would in combination with a containment alternative, each of which meet the minimum/threshold requirements (see Subsection 5.1) or parts of a containment alternative in the case of the MSP alternative. Accordingly, the VOC mass removal/reduction alternatives assume that all or part of a containment alternative is implemented at the Site to meet the minimum/threshold requirements. Permanence The No Additional Action alternative would not add any permanence to a Site remedy. Alternatives M100, M150, and M200 would each add a significant degree of permanence since concentrations of TCVOC in the subsurface would be reduced over time via extraction of impacted groundwater that would remove TCVOC mass. The added degree of permanence would be significant because between approximately 305 and 326 thousand lbs of TCVOC (dissolved, sorbed, and DNAPL phases) outside areas of pH >10 s.u. would be extracted over 100 years as shown in Table 4 in Appendix E. The M200 alternative would add the highest degree of permanence since it would remove a greater quantity of TCVOC mass over time compared to the M100 and M150 mass removal/reduction alternatives as shown in Table 4 in Appendix E. Alternative MSP would add a significant degree of permanence since concentrations of TCVOC in the subsurface would be reduced over time via targeted extraction of impacted groundwater (i.e., strategic pumping) that would remove TCVOC mass. In comparison to the M100, M150, and M200 alternatives, the added degree of permanence would be significant in the short term (i.e., 324 thousand lbs [dissolved, sorbed, and DNAPL phases] compared to less than 292 thousand lbs [dissolved, sorbed, and DNAPL phases] extracted outside areas of pH >10 s.u. in 20 years). The added degree of permanence would be greater in the long term (i.e., 329 thousand lbs [dissolved, sorbed, and DNAPL phases]) as shown in Table 4 in Appendix E. Alternative M3 would add a very small degree of permanence since up to 23 thousand lbs of TCVOC mass (dissolved, sorbed, and DNAPL phases) would be excavated, treated on Site, and backfilled on Site. The added degree of permanence would be very small in comparison to the M100, M150, M200, and MSP alternatives. Alternative M5 would add a very small degree of permanence since up to 62 thousand lbs of TCVOC mass (dissolved, sorbed, and DNAPL phases) would be removed from the subsurface by in situ treatment. The added degree of permanence would be much less than the M100, M150, M200, and MSP alternatives, but more than the M3 alternative. Alternative M6 would add a very small degree of permanence similar to the M5 alternative since up to 66 thousand lbs of TCVOC mass (dissolved, sorbed, and DNAPL phases) would be removed GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 65 from the subsurface by a combination of excavation, treatment on Site and backfilling on Site, and in situ treatment. The added degree of permanence would be much less than the M100, M150, M200, and MSP alternatives, but more than the M3 alternative and slightly more than the M5 alternative. Alternative M8 would add a very small degree of permanence since up to 82 thousand lbs of TCVOC mass (dissolved, sorbed, and DNAPL phases) would be removed from the subsurface by in situ treatment. The added degree of permanence would be less than the M100, M150, M200, and MSP alternatives, but more than the M3, M5, and M6 alternatives. Alternative M9 would add a significant degree of permanence since up to 613 thousand lbs of TCVOC mass (dissolved, sorbed, and DNAPL phases) would be removed from the subsurface by in situ treatment. The added degree of permanence would be greater than the other mass reduction/removal alternatives. It is noted that for all mass removal/reduction alternatives, the areas outside the target zones would still contain elevated TCVOC concentrations that would require containment to maintain long-term permanence. Effectiveness Over the Long Term The No Additional Action alternative would not have any effectiveness over the long term. Alternatives M100, M150, and M200 would have effectiveness over the long term since outside the areas of pH >10 s.u. they would remove approximately 39.1 to 41.7 percent of the total TCVOC mass (dissolved, sorbed, and DNAPL phases) and enhance a containment system. These alternatives might shorten the length of time of O&M for some parts of the Site since they remove a significant amount of mass. However, there may still be areas that would require long-term containment. Alternative MSP would have the greatest effectiveness over the long term with the exception of Alternative M9 since outside the areas of pH >10 s.u. it would remove the most mass (approximately 42.1 percent of dissolved, sorbed, and DNAPL phases) and meet the model-based containment objectives. It might shorten the length of time of O&M for some parts of the Site since it removes the second most mass of all the alternatives. However, there may still be areas that would require long-term containment. Alternatives M3, M5, M6, and M8 would have less effectiveness over the long term compared to the M100, M150, M200, and MSP alternatives since they would remove much less mass. These alternatives would not affect the length of time for O&M of a containment alternative that was modeled for 100 years and would be required to contain the remaining mass outside the targeted areas. Additionally for the M8 alternative, the effectiveness of ISB might be limited as discussed in Subsection 6.2.7. Alternative M9 would have the most effectiveness over the long term compared to the other alternatives since it would remove the most VOC mass. Similar to MSP alternative, it might affect the length of time for O&M of a containment alternative for some parts of the Site. However, there may still be areas that would require long-term containment. Additionally, the effectiveness of ISB might be limited as discussed in Subsection 6.2.8. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 66 Management of Short-Term Risks The short-term risks during construction and implementation of the alternatives would be managed through standard safety and health procedures that would be documented in a Site-specific HASP. The types of procedures that would be required are those regularly practiced for the types of construction anticipated. The M9 alternative would present more short-term risks because the scope extends to greater depths, covers a greater area outside of the 605 Alexander Avenue property, and would require up to 20 years to maintain/protect injection points in areas of active business and traffic. The M100, M150, M200, and MSP alternatives would present the lowest short-term risks, excluding the No Additional Action alternative, because they could be implemented relatively quickly, would involve the least amount of equipment and smallest areal footprint (e.g., less noise impact, construction-related risks, and potential for fugitive emissions), the infrastructure would be underground, and would have the lowest potential for human/ecological exposure. Soil excavation with on-Site treatment would include additional short-term risks such as exposure to high concentration of VOC in soil, water, and air (from vitalization), managing access to large open holes, managing stockpiles hazardous materials including saturated soils, and managing potential water run-off from stockpiled materials. ERH and SVE would include additional short-term risks such as hazards related to high temperatures, high-voltage electricity, controlling and treating VOC, and vapor migration through existing utilities. ISCO and ISB would include additional short-term risks such as chemical transport, mixing, and handling, chemical daylighting (i.e., chemicals flowing to and over ground surface), and managing soils (drill cuttings) and equipment over a large footprint. Additionally, ERH, ISCO, and ISB might delay startup of parts of the containment system to permit implementation of these technologies. In addition to the HASP, other plans for activities such as soil management, traffic control, and air monitoring would be developed to protect human health and the environment during construction and implementation. Technical and Administrative Implementability As discussed in Subsection 6.1, all of the VOC mass removal/reduction alternatives are implementable. The technical implementability of the M100, M150, M200, MSP, M3, M5, and M6 alternatives are considered good since these technologies have been successful at similar depths at other sites. Additionally, the target zones are within the 605 Alexander Avenue property or in areas outside building envelopes and therefore access to the target zones would be relatively easy since the area would be either void of any operations or in manageable areas. The technical implementability of the M8 alternative is considered fair to good since these technologies have been successful at similar depths at other sites; however, some of the target zones would be below building envelopes and in roadways. This would make access to these target zones more difficult. The remainder of the target zones would be within the 605 Alexander Avenue property or in areas outside building envelopes and roadways where access would be relatively easy. The technical implementability of the M9 alternative is considered fair since the additional depth of target zones in some areas might present difficulties, some of the target zones would be below building envelopes and roadways making access more difficult, and overlapping target zones require different technologies that might affect each other or delay implementation. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 67 Since the technologies selected are proven and typically applied at many sites; services, capabilities, equipment, specialists, and materials should be available for implementation of these remedial alternatives. Permitting of these remedial alternatives is also expected to be obtained without significant difficulties. Consideration of Public Concerns As noted in Subsection 5.2.4, under Consideration of Public Concerns, a containment system alone would be protective of human health and the environment by eliminating all potential exposure pathways and is a common, reliable, and effective solution for large complex sites like this one, which could be effectively operated, maintained, and monitored. Additionally, public concerns regarding the Hylebos documented during a public comment period from October 23, 2015 through February 1, 2016 for the approved SCR (CRA, 2014c) are addressed through the 2016 Anchor QEA investigation sediment and porewater sampling in the Hylebos. (See Subsection 2.4.5 and 2.4.6). Mobility of mass within the containment system would be of minimal concern as long as there is hydraulic control of the target zones. Therefore, the mass removal/reduction alternatives do not materially enhance protectiveness, would add minimal long-term effectiveness and permanence in terms of containment, and none would provide any incremental benefit to mitigating potential impacts from the Site and overall potential impacts from other sites adjacent to the Waterways and Commencement Bay. Short-term risks for some of the alternatives might be of concern, but could be managed. Any other potential measures in addition to a containment alternative to address Site conditions are not necessary but rather augmentations to a system that reliably contains contaminants at the Site. For these reasons, it is expected that the public would be supportive of any overall remedy for the Site that includes containment. Public notice and participation is an integral part of the remedy selection process. The public notice and participation requirements for cleanups conducted are set forth in MTCA (WAC 173-340-600), NCP 40 CFR 300.430(f)(3)(i), and CERCLA §117. The public will have an opportunity to voice any concerns regarding the FS during a public comment period. Cost The estimated costs for VOC Mass Removal/Reduction Alternatives M100, M150, M200, MSP, M3, M5, M6, M8, and M9, and the No Additional Action alternative are presented in Appendix G and were developed in accordance with guidance (USEPA, 2000) specified by the Agencies. The cost estimates include periods of 30 years, in accordance with the guidance (USEPA, 2000), and 100 years, at the request of the Agencies. Discount factors for O&M and periodic costs include 7 percent, in accordance with the guidance (USEPA, 2000), and 1.5 percent (2016 Discount Rate for OMB Circular No. A-94 for the 30-Year Real Interest Rate on Treasury Notes and Bonds of Specific Maturities), at the request of the Agencies. A summary of the capital, O&M, and periodic costs, which include costs for containment required to meet the threshold criteria discussed previously, is provided in Table 6.1 below. The alternatives are listed/ranked from most to least added degree of permanence (i.e., most to least lbs of TCVOC mass removed/reduced [see Table 6.3]) in accordance with WAC 173-340-360(3)(e)(ii)(A). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 68 Table 6.1 Summary of VOC Mass Removal/Reduction Alternatives Estimated Costs Alternative Capital M9 MSP M200 M150 M100 M8 M6 M5 M3 No Additional Action* $35,480,940 $38,854,780 $38,903,190 $38,903,190 $38,903,190 $114,264,240 $52,488,140 $50,712,040 $41,366,240 $38,700,240 Capital plus O&M/Periodic (30yrs;7%) $401,254,360 $54,877,530 $56,232,640 $55,838,770 $55,442,430 $142,006,010 $68,144,380 $66,368,280 $57,022,480 $54,356,480 Capital plus O&M/Periodic (30yrs;1.5%) $442,991,030 $70,216,710 $72,794,730 $72,032,470 $71,265,400 $167,471,640 $83,140,740 $81,364,640 $72,018,840 $69,352,840 Capital plus O&M/Periodic (100yrs;7%) $405,747,880 $57,750,000 $59,300,000 $58,850,000 $58,390,000 $146,499,530 $72,637,900 $70,861,800 $61,516,000 $57,170,000 Capital plus O&M/Periodic (100yrs;1.5%) $488,428,190 $110,920,000 $116,430,000 $114,790,000 $113,140,000 $212,908,800 $128,577,900 $126,801,800 $117,456,000 $109,240,000 Notes: Costs for compliance monitoring are assumed to be included in a selected containment alternative. * meaning no additional action will be conducted beyond implementing a containment alternative. As shown in Table 6.1 the MSP alternative ranked the second highest for added degree of permanence would have a cost that is similar to or less than alternatives with lesser degrees of permanence. The M9 alternative ranked highest for added degree of permanence would have the highest cost, which is much higher than the other VOC mass removal/reduction alternatives. The M200 alternative ranked third for added degree of permanence has a cost that is slightly higher compared to the MSP, M150 and M100 alternatives over 30 years using a discount rate of 7 percent and lower in costs compared to the M8, M6, M5, and M3 alternatives that are ranked lower for added degree of permanence. Disproportionate Cost Analysis Summary Table 6.2 presents a DCA summary table that provides relative benefit score to cost ratios for the VOC mass reduction/removal alternatives using weighting percentages from Table 5.1. As shown in Table 6.2, the MSP alternative has a benefit score to cost ratio of 1.37 that is greater than the benefit score to cost ratios for the other alternatives. The next highest ratios are 1.32, 1.31, and 1.30 for the M100, M150, and M200 alternatives, respectively. The M3 alternative had the next highest ratio of 1.17 followed by 1.03 for the No Additional Action alternative. The benefit score to cost ratios for the remaining alternatives are less than No Additional Action alternative, which indicate that the costs exceed the benefits of these alternatives. The benefit score to cost ratios for M9 of 0.18 and M8 of 0.46 are the lowest and are clearly disproportionate in cost compared to the other alternative ratios. The following provides additional discussion regarding the relationship between costs and TCVOC mass potentially addressed, cash flow projections, and alternative durations. The table below summarizes the quantity of TCVOC mass (dissolved, sorbed, and DNAPL phases) potentially addressed by each alternative in 20 years as presented in Subsection 4.4 and Appendix E. Figure 6.1 presents the information graphically. A 20-year time frame was selected GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 69 because all the non-pumping mass removal alternatives (M3, M5, M6, M8, and M9) are estimated to be completed after 20 years. An estimated quantity of TCVOC mass potentially addressed by Containment Alternative C150 to represent the No Additional Action VOC Mass Removal/Reduction Alternative is included in the table for comparison purposes. Table 6.3 Summary of Estimated Quantity of VOC Mass Potentially Addressed by each VOC Mass Removal/Reduction Alternative Alternative M9 MSP M200 M150 M100 M8 M6 M5 M3 No Additional Action Estimated Quantity of TCVOC Mass Potentially Addressed (lbs) 613,300 323,883* 291,648* 285,394* 275,132* 81,600 66,200 62,200 23,200 151,735* Estimated Percent of Total Estimated TCVOC Mass (%) 78.6 41.5 37.4 36.6 35.3 10.5 8.5 8.0 3.0 19.5 Estimated Cost (30yrs;7%) per Pound of TCVOC Potentially Addressed ($/lb) 654 169 193 196 202 1,740 1,029 1,067 2,458 358 Note: *Represents mass outside areas of pH >10 s.u. only. Note that estimated quantity of TCVOC mass potentially addressed for the alternatives that incorporate groundwater extraction (i.e., MSP, M200, M150, M100, and No Additional Action [equivalent to C150]) were determined using the three-dimensional (3D) groundwater flow model that was specifically constructed and calibrated for the Site. The Site groundwater flow model provides a useful tool to evaluate the potential effectiveness of the groundwater mass reduction remedial alternatives that incorporate groundwater extraction. It is noted that the model assumes idealized mass transport controlled by advection and equilibrium sorption and all mass is assumed to be either dissolved in the groundwater or sorbed onto the aquifer matrix. Potential effects of non-aqueous phase liquids are not included. The potential effects of diffusion into low-permeability units or areas are not included. Additionally, the estimates do not include potential effects of high pH potentially reaching extraction wells, all contributing to the uncertainty of the mass estimates. However, the evaluation approach was applied consistently for all alternatives. The MSP alternative adds the second greatest degree of permanence over the other alternatives and has the highest benefit score to cost ratio, addresses up to 41.5 percent of the estimated total TCVOC mass for a cost of approximately $54.9M (capital plus 30 years O&M at a discount rate of 7 percent). This is equivalent to approximately $169/lb. Additionally, the MSP alternative is predicted to remove a significant quantity of TCVOC mass (dissolved, sorbed, and DNAPL phases) in the short term (i.e., 324 thousand lbs in 20 years) The M200 alternative, which is ranked third in adding degree of permanence and has the fourth highest benefit score to cost ratio, addresses less than the MSP alternative achieves (37.4 percent) for a similar cost of approximately $56.2M, which is equivalent to approximately $193/lb. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 70 The M150 and M100 alternatives are ranked lower in adding degree of permanence since they remove less mass and cost more per pound of TCVOC mass addressed. However, their benefit score to cost ratios are slightly greater than the M200 alternative. The M9 alternative adds the greatest degree of permanence, but has a very low benefit score to cost ratio (i.e., disproportionate cost) that is less than the ratio for the No Additional Action alternative. It addresses up to 78.6 percent of the estimated total TCVOC mass for a cost of approximately $401M. This is equivalent to approximately $654/lb. assuming all the targeted mass is removed. As noted above, the effectiveness of the M9 alternative is less certain than the other alternatives and is expected to be more difficult to implement. It would also present more short-term risks than any other alternative. The remaining alternatives including No Additional Action remove less mass for significantly greater cost per pound. The benefit score to cost ratios for the M3 alternative is above the ratio for the No Additional Action alternative and the remaining ratios are below. Figure 6.2 presents the relationship between estimated cost and estimated quantity of TCVOC mass potentially addressed by the alternatives. As shown on the figure the MSP, M100, M150, and M200 alternatives remove the largest quantity of TCVOC mass for the lowest costs. The figure also shows that the M9 alternative, which addresses the most mass, is disproportionate in cost since it is approximately seven times greater in cost than the above noted alternatives. Figure 6.3 presents the alternatives anticipated 30-year cash flow projections. As shown on this figure, the costs are lowest for the MSP alternative. The M8 and M9 alternatives costs are much greater in comparison to the other alternatives. Figure 6.4 shows the anticipated durations for the different components of the alternatives. The MSP, M100, M150, and M200 alternatives require a short time (6 months to 1 year) to construct and include operation and maintenance over the entire time frame of 100 years. The duration for ISB for Alternatives M8 and M9 including construction is approximately 19 years. The remaining alternatives are shown to be completed within 2 years. Figure 6.5 presents the relationship between estimated time and estimated quantity of TCVOC mass potentially addressed by the alternatives. As shown on the figure, after approximately 2 years of operation the quantity of TCVOC mass removed for the MSP alternative is the greatest. After approximately 20 years, only the M9 alternative potentially addresses more mass than the MSP alternative. After 100 years, the MSP alternative still removes the most mass of all the alternatives that include groundwater extraction (i.e., MSP, M100, M150, and M200). 6.2.10 Summary Each of the alternatives, except the No Additional Action alternative, would simply augment a containment system that is reliably operated and maintained. The Mass Reduction/Removal Alternatives in addition to a containment alternative to address Site conditions are not necessary to protect human health and the environment and would provide minimal additional protectiveness. However, it is recognized that there might be a desire to achieve some additional mass removal to augment the mass reduction expected from a containment system. The disproportionate cost analysis indicates that a point of diminishing returns is quickly reached after the mass reduction alternatives that include groundwater extraction (i.e., less or similar benefit for more cost). The MSP alternative has the lowest cost, the highest benefit score to cost ratio, and includes the hydraulic component of a containment alternative since it meets the model-based containment objectives. The MSP alternative potentially addresses the most mass in the short term and the second most mass in the long term. The M9 alternative potentially addresses the most mass in the GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 71 long term, but was shown to be disproportionate in cost. The M100, M150, and M200 alternatives have the next highest benefit score to cost ratios, but remove less mass than the MSP alternative. The M100, M150, and M200 alternatives would require higher sustainable individual and collective groundwater pumping rates when combined with a containment alternative as would be required to meet all the minimum/threshold requirements. The M8 alternative was shown to be disproportionate in cost. The remaining VOC Mass Reduction/Removal Alternatives (M3, M5, and M6) remove less mass and have lower benefit score to cost ratios. The No Additional Action alternative does not remove any additional mass. Based on the above evaluation, the identified preferred alternative is VOC Mass Reduction Alternative MSP since it has the highest benefit score to cost ratio, removes the highest quantity of mass in the short term, and has the lowest per pound cost. The MSP alternative is a cost-effective means to remove additional mass from the subsurface and meet the model-based containment objectives and can be reliably operated and maintained. 7. pH Reduction/Enhanced Containment Alternatives Initial Screening and Detailed Evaluation 7.1 Initial Screening The pH reduction/enhanced containment alternatives are described in Subsection 4.5. The initial screening criteria are described in Subsection 5.1. The pH reduction/enhanced containment alternatives are designed to reduce or otherwise enhance containment of high pH in groundwater and soil. The pH reduction/enhanced containment alternatives would not protect human health and the environment, including potential ecological receptors, at the Site by themselves. Therefore, they would not meet all the minimum/threshold requirements. However, in combination with containment technologies they would meet the minimum/threshold requirements (see Subsection 5.1). Accordingly, the pH alternatives all assume that appropriate containment technologies are implemented at the Site. Therefore, none of the pH alternatives were removed from further evaluation based on this initial screening. The pH alternatives are sufficiently different because of the technologies used and/or areas targeted that determining which alternatives' costs would be clearly disproportionate under WAC 173-340-360(3)(e) in the initial screening is not evident. Therefore, none of the pH alternatives were removed from further evaluation based on this initial screening criterion. The pH alternatives and components presented herein are administratively and technically possible at the Site and therefore none of the pH alternatives were removed from further evaluation based on this initial screening criterion. Based on the above, the initial screening did not eliminate any of the pH alternatives. 7.2 Detailed Evaluation Purpose and Evaluation Criteria The purpose of the detailed evaluation is to select an alternative, retained following the initial screening, which does not have an incremental cost that exceeds the incremental degree of GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 72 benefits potentially achieved. The detailed evaluation of the pH Reduction/Enhanced Containment Alternatives involved assessing MTCA and CERCLA factors to be considered (see Subsection 5.2) and conducting a disproportionate cost analysis per WAC 173-340-360(3)(f). The detailed evaluation assumes that containment is part of the selected remedy for the Site, which is consistent with the initial screening of the pH alternatives. 7.2.1 No Additional Action pH Reduction/Enhanced Containment Alternative The No Additional Action pH Reduction/Enhanced Containment Alternative would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment. It would not alter or undermine the practicality and effectiveness of a containment alternative and therefore would be compatible with the use at the Site. This alternative would not reduce or enhance containment of high pH in media at the Site and thus would not increase permanence or long-term effectiveness. However, the high pH would be reliably contained by containment technologies. There are no short-term risks and it is fully implementable. Since this alternative would not alter the geochemical conditions in the subsurface, natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 7.2.2 pH Reduction Alternative pH2 The pH Reduction Alternative pH2 includes reducing high pH in shallow groundwater and soil by in situ mixing of sodium persulfate. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands high pH would already be reliably contained. It would reduce a little pH. Therefore, the pH2 alternative would add a very small degree of permanence and limited long-term effectiveness. It would prevent the potential for migration of a little high pH water to extraction wells; however, the extraction wells would be positioned to minimize this potential already. Additionally, the containment alternatives include a contingency for pH treatment. The pH2 alternative would not reduce the time for O&M of a containment alternative. Based on discussions with an experienced contractor, in situ mixing to a depth of -60 ft NGVD (approximately 75 ft below grade) would be practical and implementable with some difficulty if the subsurface contains deleterious material and/or non-cohesive soil that could bind the mixing equipment. There would be short-term risks for construction and managing the sodium persulfate. The pH2 alternative is not expected to alter or undermine the practicality of a containment alternative, but it might alter the effectiveness by changing the groundwater flow (i.e., hydraulic conductivity) in the target zone. This could potentially impact drawdown and gradients within the containment system and might reduce the quantity of TCVOC mass that would be extracted from the subsurface over time. Despite this concern, it would still be compatible with the use at the Site since the target zone would still be reliably contained. It would alter the geochemical conditions in the subsurface and therefore natural processes (e.g., biodegradation) documented to occur at the Site that reduce concentrations of hazardous substances might be affected. However, since sodium persulfate is an oxidant and would be introduced into zones of TCVOC mass and high pH, it would be expected that concentrations of TCVOC within the target zone would decrease since the high pH is likely to activate the sodium persulfate, which in theory will oxidize CVOC. It should be noted that only a small percentage (i.e., less than one percent) of the TCVOC mass is present within the zones of pH greater than or equal to 12.5 s.u. Therefore, this added benefit is not expected to be significant with respect to reducing the quantity of TCVOC mass. There are safety concerns while GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 73 handling sodium persulfate since the dust can be hazardous primarily if inhaled; however, these concerns would be minimized with handling and storage in accordance with the manufacturer's guidelines and a health and safety program. 7.2.3 pH Enhanced Containment Alternative pH3 The pH Enhanced Containment Alternative pH3 includes containment of high pH in shallow groundwater and soil by in situ mixing of cement. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands high pH would already be reliably contained. It would not reduce pH. Therefore, the pH3 alternative would not add any permanence and long-term effectiveness. It would prevent the potential for migration of a little high pH water to extraction wells; however, the extraction wells would be positioned to minimize this potential already. Additionally, the containment alternatives include a contingency for pH treatment. The pH3 alternative would not reduce the time for O&M of a containment alternative. Based on discussions with an experienced contractor, in situ mixing to a depth of -60 ft NGVD (approximately 75 ft below grade) would be practical and implementable with some difficulty if the subsurface contains deleterious material and/or low permeability soil that could bind the mixing equipment. There would be short-term risks for construction and managing the cement. The pH3 alternative is not expected to alter or undermine the practicality of a containment alternative, but it might alter the effectiveness by changing the groundwater flow (i.e., hydraulic conductivity) in the target zone. This could potentially impact drawdown and gradients within the containment system and might reduce the quantity of TCVOC mass that would be extracted from the subsurface over time. Despite this concern, it would still be compatible with the use at the Site since the target zone would still be reliably contained. It would alter the geochemical conditions in the subsurface and therefore natural processes (e.g., biodegradation) documented to occur at the Site that reduce concentrations of hazardous substances might be affected. The introduction of cement would not decrease concentrations of TCVOC within the target zone. It should be noted that only a small percentage (i.e., less than one percent) of the TCVOC mass is present within the zones of pH greater than or equal to 12.5 s.u. There are safety concerns while handling cement since it is caustic (high pH); however, these concerns would be minimized with handling and storage in accordance with the manufacturer's guidelines and a health and safety program. Another concern would be due to the exothermic cementitious reactions that produce heat that could increase vitalization of VOC near the ground surface. Air collection and treatment devices might be needed to capture VOC that volatilize during the mixing process. This might also slow the mixing process in order to control the reaction. 7.2.4 pH Enhanced Containment Alternative pH4 The pH Enhanced Containment Alternative pH4 includes containment of high pH in shallow groundwater and soil by construction of a vertical slurry wall north, south, and west of the high pH. The eastern extent of the high pH would be contained by a sheet pile vertical barrier wall that is part of the containment alternatives. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands high pH would already be reliably contained. It would not reduce pH. Therefore, the pH4 alternative would not add any permanence and long-term effectiveness. It would prevent the potential for migration of a little high pH water to shallow extraction wells; however, the extraction wells would be positioned to GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 74 minimize this potential already. Additionally, the containment alternatives include a contingency for pH treatment. The pH4 alternative would not reduce the time for O&M of a containment alternative. Based on discussions with an experienced contractor, construction of the slurry wall to a depth of -60 ft NGVD (approximately 75 ft below grade) would be practical and implementable with some difficulty if the subsurface contains deleterious material. There would be short-term risks for construction and managing the slurry. The pH4 alternative is not expected to alter or undermine the practicality of a containment alternative, but it might alter the effectiveness by changing the groundwater flow (i.e., hydraulic conductivity) in the target zone. This could potentially impact drawdown and gradients within the containment system and might reduce the quantity of TCVOC mass that would be extracted from the subsurface over time. Despite this concern, it would still be compatible with the use at the Site since the target zone would still be reliably contained. Additionally, it should be noted that only a small percentage (i.e., less than one percent) of the TCVOC mass is present within the zones of pH greater than or equal to 12.5 s.u. It would not alter the geochemical conditions in the subsurface except in the immediate vicinity of the wall and therefore natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 7.2.5 pH Reduction Alternative pH5 The pH Reduction Alternative pH5 includes reducing high pH in shallow and deep groundwater and soil by in situ mixing of sodium persulfate. This alternative would involve the same processes as the pH2 alternative, but the mixing would extend to greater depths. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands high pH would already be reliably contained. It would further reduce pH compared to the pH2 alternative. Therefore, the pH5 alternative would add a small degree of permanence and long-term effectiveness compared to the pH2 alternative. It would prevent the potential for migration of some high pH water to extraction wells; however, the extraction wells would be positioned to minimize this potential already. Additionally, the containment alternatives include a contingency for pH treatment. The pH5 alternative would not reduce the time for O&M of a containment alternative. Based on discussions with an experienced contractor, in situ mixing to depths below -60 ft NGVD (approximately 75 ft below grade) would be implementable but not with conventional equipment resulting in increased costs. There would be additional difficulties if the subsurface contains deleterious material and/or non-cohesive soil that could bind the mixing equipment, which would increase with depth. There would be short-term risks for construction and managing the sodium persulfate. The pH5 alternative is not expected to alter or undermine the practicality of a containment alternative, but it might further alter the effectiveness by changing the groundwater flow (i.e., hydraulic conductivity) in the target zone. This could potentially impact drawdown and gradients within the containment system and might further reduce the quantity of TCVOC mass that would be extracted from the subsurface over time. Despite this concern, it would still be compatible with the use at the Site since the target zone would still be reliably contained. It would further alter the geochemical conditions in the subsurface and therefore natural processes (e.g., biodegradation) documented to occur at the Site that reduce concentrations of hazardous substances might be further affected. However, since sodium persulfate is an oxidant and would be introduced into zones of TCVOC mass and high pH, it is expected that concentrations of TCVOC within the target zone would decrease since the high pH is likely to activate the sodium persulfate, which in theory will oxidize CVOC. It should be noted that only a small percentage (i.e., less than one percent) of the TCVOC mass is present within the zones of pH greater than or equal to 12.5 s.u. Therefore, this GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 75 added benefit is not expected to be significant with respect to reducing the quantity of TCVOC mass. There are safety concerns while handling sodium persulfate since the dust can be hazardous primarily if inhaled; however, these concerns would be minimized with handling and storage in accordance with the manufacturer's guidelines and a health and safety program. 7.2.6 pH Enhanced Containment Alternative pH6 The pH Enhanced Containment Alternative pH6 includes containment of high pH in shallow and deep groundwater and soil by in situ mixing of cement. This alternative would involve the same processes as the pH3 alternative, but the mixing would extend to greater depths. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands high pH would already be reliably contained. It would not reduce pH. Therefore, the pH6 alternative would not add any permanence and long-term effectiveness. It would prevent the potential for migration of some high pH water to extraction wells; however, the extraction wells would be positioned to minimize this potential already. Additionally, the containment alternatives include a contingency for pH treatment. The pH6 alternative would not reduce the time for O&M of a containment alternative. The pH6 alternative would have the same difficulties with mixing at depth as the pH5 alternative. There would be short-term risks for construction and managing the cement. The pH6 alternative is not expected to alter or undermine the practicality of a containment alternative, but it might further alter the effectiveness by changing the groundwater flow (i.e., hydraulic conductivity) in the target zone. This could potentially impact drawdown and gradients within the containment system and might reduce the quantity of TCVOC mass that would be extracted from the subsurface over time. Despite this concern, it would still be compatible with the use at the Site since the target zone would still be reliably contained. It would further alter the geochemical conditions in the subsurface and therefore natural processes (e.g., biodegradation) documented to occur at the Site that reduce concentrations of hazardous substances might be further affected. The introduction of cement would not decrease concentrations of TCVOC within the target zone. It should be noted that only a small percentage (i.e., less than one percent) of the TCVOC mass is present within the zones of pH greater than or equal to 12.5 s.u. There are safety concerns while handling cement since it is caustic (high pH); however, these concerns would be minimized with handling and storage in accordance with the manufacturer's guidelines and a health and safety program. Another concern would be due to the exothermic cementitious reactions that produce heat and would vaporize the VOC in the subsurface. Air collection and treatment devices might be needed to capture VOC that volatilize during the mixing process. This might also slow the mixing process in order to control the reaction. 7.2.7 pH Enhanced Containment Alternative pH7 The pH Enhanced Containment Alternative pH7 includes containment of high pH in shallow and deep groundwater and soil by construction of vertical slurry walls north, south, and west of the shallow high pH and in all directions around the deep high pH. The eastern extent of the shallow high pH would be contained by a sheet pile vertical barrier wall that is part of the containment alternatives. It would not enhance a containment alternative with respect to minimizing potential risks to human health and the environment because the uplands high pH would already be reliably contained. It would not reduce pH. Therefore, the pH7 alternative would not add any permanence and long-term effectiveness. It would prevent the potential for migration of some high pH water to extraction wells; however, the extraction wells would be positioned to minimize this potential GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 76 already. Additionally, the containment alternatives include a contingency for pH treatment. The pH7 alternative would not reduce the time for O&M of a containment alternative. Based on discussions with an experienced contractor, construction of slurry walls to depths greater than -60 ft NGVD (approximately 75 ft below grade) would be practical and implementable with some difficulty if the subsurface contains deleterious material and depending on the subsurface soil types at depth. The contractor indicated that the slurry walls would be constructed to ground surface because the construction technique relies on an established slope to prevent segregation and permit the backfill material to slide down through the slurry. There would be short-term risks for construction and managing the slurry. The pH7 alternative is not expected to alter or undermine the practicality of a containment alternative, but it might further alter the effectiveness by changing the groundwater flow (i.e., hydraulic conductivity) in the target zone. This could potentially impact drawdown and gradients within the containment system and might reduce the quantity of TCVOC mass that would be extracted from the subsurface over time. This would be most significant in the shallow zone above the deeper high pH target zone, where high concentrations of TCVOC exist. The deeper slurry wall would effectively prevent groundwater flow in this area and therefore prevent extraction of higher concentrations of TCVOC within parts of the shallow zone. Despite this concern, it would still be compatible with the use at the Site since the target zone would still be reliably contained. It would not alter the geochemical conditions in the subsurface except in the immediate vicinity of the wall and therefore natural processes (e.g., biodegradation) documented to occur at the Site would also continue to reduce concentrations of hazardous substances. 7.2.8 Disproportionate Cost Analysis A DCA of the pH Reduction/Enhanced Containment Alternatives was conducted using the same process described in Subsection 5.2.4. The following presents an evaluation of pH Reduction/Enhanced Containment Alternatives pH2 through pH7 and the No Additional Action alternative with respect to the DCA process. Protectiveness The pH Reduction/Enhanced Containment Alternatives would not protect human health and the environment, including potential ecological receptors, at the Site by themselves. Therefore, they would not meet all the minimum/threshold requirements. However, they would in combination with a containment alternative, each of which meet the minimum/threshold requirements (see Subsection 5.1). Accordingly, the pH alternatives all assume that one of the containment alternatives is implemented at the Site to meet the minimum/threshold requirements. Permanence The No Additional Action alternative would not add any permanence to a Site remedy. Alternative pH2 would add a very small degree of permanence since the high pH in the shallow zone would be reduced to less than 12.5 s.u. However, the targeted zone and areas outside the target zone would still contain elevated pH, including pH greater than 12.5 s.u. in the deep zone. This residual high pH would require O&M of a containment alternative for long-term permanence. Alternatives pH3 and pH4 would not add any degree of permanence since enhanced containment of the high pH within the cemented aquifer or within slurry walls in the shallow zone would not affect the length of time for O&M of a containment alternative. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 77 Alternative pH5 would add a small degree of permanence greater than the pH2 alternative since the high pH in the shallow and deep zones would be reduced to less than 12.5 s.u. However, the targeted zones and areas outside the target zones would still contain elevated pH that would require O&M of a containment alternative for long-term permanence. Alternatives pH6 and pH7 would not add any degree of permanence since enhanced containment of the high pH within the cemented aquifer or within slurry walls in the shallow zone would not affect the length of time for O&M of a containment alternative. Alternative pH7 might decrease the degree of permanence of a containment alternative since the deeper slurry wall would effectively prevent groundwater flow in the parts of the shallow zone where higher concentrations of TCVOC are and therefore prevent extraction of groundwater with these higher concentrations of TCVOC. Effectiveness Over the Long Term The No Additional Action alternative would not have any effectiveness over the long term. Alternative pH2 would have very little effectiveness over the long term since it does not treat all groundwater and soil with elevated pH, including groundwater and soil at depth with pH greater than 12.5 s.u. Additionally, there is a possibility that pH values could rebound in the targeted zone based on the results of the extensive pH studies conducted for the Site. This alternative would not affect the length of time for O&M of a containment alternative. Alternatives pH3 and pH4 would have limited overall effectiveness over the long term since they do not enhance containment of all groundwater and soil with elevated pH, including groundwater and soil at depth with pH greater than 12.5 s.u. The limited effectiveness in the target zone would be in terms of preventing migration of high pH to a containment alternative extraction wells. However, this is considered a low risk since the extraction wells would be located away from the high pH. Additionally, the containment alternatives include a contingency for pH treatment. These two alternatives would not affect the length of time for O&M of a containment alternative. Additionally for the pH4 alternative, groundwater with elevated pH might migrate below the vertical slurry wall and/or the sheet pile vertical barrier wall since hydraulic containment within the target zone is not expected because none of the wells from a containment alternative would be within the area surrounded by the walls. Alternative pH5 would have a little effectiveness over the long term since it treats all of the groundwater and soil with pH greater than 12.5 s.u. However, it does not treat all groundwater and soil with elevated pH and there is a possibility that pH values could rebound in the targeted zone based on the results of the extensive pH studies conducted for the Site. This alternative would not affect the length of time for O&M of a containment alternative. Alternatives pH6 and pH7 would have limited overall effectiveness over the long term since they do not enhance containment of all groundwater and soil with elevated pH. The limited effectiveness in the target zone would be in terms of preventing migration of high pH to a containment alternative extraction wells. However, this is considered a low risk since the extraction wells would be located away from the high pH. Additionally, the containment alternatives include a contingency for pH treatment. These two alternatives would not affect the length of time for O&M of a containment alternative. Additionally for the pH7 alternative, groundwater with elevated pH might migrate below the shallower vertical slurry wall and/or the sheet pile vertical barrier wall since hydraulic containment within the target zone is not expected because none of the wells from a containment GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 78 alternative would be within the area surrounded by the walls. For the pH in the deeper zone, the deeper vertical slurry walls surround the pH greater than 12.5 s.u. Management of Short-term Risks The short-term risks during construction and implementation of the alternatives would be managed through standard safety and health procedures that would be documented in a Site-specific HASP. The types of procedures that would be required are those regularly practiced for the types of construction anticipated. The pH6 and pH7 alternatives might present more short-term risks because their scopes extend to greater depths compared to the pH3 and pH4 alternatives. The pH4 and pH7 alternatives that include a slurry wall would present the lowest short-term risks, excluding the No Additional Action alternative, because they involve the smallest areal footprint (e.g., less noise impact, construction-related risks, and potential for fugitive emissions), and less sub-surface disturbance for potential exposure to hazardous materials. The pH2, pH3, pH5, and pH6 alternatives that involve mixing of subsurface soils would include additional short-term risks such as chemical transport, mixing, and handling, managing soil stability and chemical daylighting (i.e., chemicals flowing to and over ground surface), and managing equipment over a large footprint. In addition to the HASP, other plans for activities such as soil management, traffic control, and air monitoring would be developed to protect human health and the environment during construction and implementation. Technical and Administrative Implementability As discussed in Subsection 7.1, all of the pH alternatives are implementable. The technical implementability of the pH2 and pH3 alternatives involving in situ mixing and pH4 alternative involving construction of vertical slurry walls is considered good since these technologies have been successful at similar depths at other sites. Additionally, the target zone is within the 605 Alexander Avenue property and therefore access to the target zone would be relatively easy since the area would be void of any operations. The pH2 and pH3 alternatives would be less implementable because they involve disturbance of large areas and depths of soil, which might affect surface stability. The technical implementability of the pH5 and pH6 alternatives involving in situ mixing and pH7 alternative involving construction of vertical slurry walls is considered fair to good since the additional depth of target zones in some areas might present difficulties and require more specialized equipment as discussed previously in Subsection 7.2.5. Additionally, the targeted area on the Port of Tacoma property is under an existing building that further complicates implementation. The pH5 and pH6 alternatives would be the least implementable because they involve disturbance of even large areas and greater depths of soil, which might affect surface stability. Since the in situ mixing and vertical slurry walls are proven technologies and typically applied at many sites; services, capabilities, equipment, specialists, and materials should be available for implementation of these remedial alternatives. Permitting of these remedial alternatives is also expected to be obtained without significant difficulties. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 79 Consideration of Public Concerns As noted in Subsection 5.2.4, under Consideration of Public Concerns, a containment system alone would be protective of human health and the environment by eliminating all potential exposure pathways and is a common, reliable, and effective solution for large complex sites like this one, which could be effectively operated, maintained, and monitored. Additionally, public concerns regarding the Hylebos documented during a public comment period from October 23, 2015 through February 1, 2016 for the approved SCR (CRA, 2014c) are addressed through the 2016 Anchor QEA investigation sediment and porewater sampling in the Hylebos. (See Subsection 2.4.5 and 2.4.6). Mobility of pH within the containment system would be of minimal concern as long as there is hydraulic control of the target zones. Therefore, the pH reduction/enhanced containment alternatives do not materially enhance protectiveness, would add minimal or no long-term effectiveness and permanence in terms of containment, might negatively impact a containment system that would reliably contain all high pH, and none would provide any incremental benefit to mitigating potential impacts from the Site and overall potential impacts from other sites adjacent to the Waterways and Commencement Bay. Short-term risks for some of the alternatives might be of concern, but could be managed. Any other potential measures in addition to a containment alternative to address Site conditions are not necessary but rather augmentations to a system that reliably contains contaminants at the Site. For these reasons, it is expected that the public will be supportive of any overall remedy for the Site that includes containment. Public notice and participation is an integral part of the remedy selection process. The public notice and participation requirements for cleanups conducted are set forth in MTCA (WAC 173-340-600), NCP 40 CFR 300.430(f)(3)(i), and CERCLA §117. The public will have an opportunity to voice any concerns regarding the FS during a public comment period. Cost The estimated costs for pH Reduction/Enhanced Containment Alternatives pH2 through pH7 and the No Additional Action alternative are presented in Appendix G and were developed in accordance with guidance (USEPA, 2000) specified by the Agencies. The cost estimates include periods of 30 years, in accordance with the guidance (USEPA, 2000), and 100 years, at the request of the Agencies. Discount factors for O&M and periodic costs include 7 percent, in accordance with the guidance (USEPA, 2000), and 1.5 percent (2016 Discount Rate for OMB Circular No. A-94 for the 30-Year Real Interest Rate on Treasury Notes and Bonds of Specific Maturities), at the request of the Agencies. There are no O&M costs associated with the pH alternatives. A summary of the capital costs for the pH alternatives and capital, O&M, and periodic costs for containment required to meet the minimum/threshold requirements discussed previously, is provided in Table 7.1 below. The alternatives are listed/ranked from most to least for added degree of permanence (i.e., most to least pH reduced [see Table 7.3]) in accordance with WAC 173-340-360(3)(e)(ii)(A), and thereafter from highest to lowest cost for alternatives that would not add any degree of permanence to a containment alternative (i.e., no pH reduction). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 80 Table 7.1 Summary of pH Reduction/Enhanced Containment Alternatives Estimated Costs Alternative Capital pH5 pH2 pH6 pH3 pH7 pH4 No Additional Action* $174,488,040 $91,895,240 $101,386,040 $55,682,540 $50,548,440 $41,086,040 $38,700,240 O&M/Periodic (30yrs;7%) $15,656,240 $15,656,240 $15,656,240 $15,656,240 $15,656,240 $15,656,240 $15,656,240 O&M/Periodic (30yrs;1.5%) $30,652,600 $30,652,600 $30,652,600 $30,652,600 $30,652,600 $30,652,600 $30,652,600 O&M/Periodic (100yrs;7%) $18,469,760 $18,469,760 $18,469,760 $18,469,760 $18,469,760 $18,469,760 $18,469,760 O&M/Periodic (100yrs;1.5%) $70,539,760 $70,539,760 $70,539,760 $70,539,760 $70,539,760 $70,539,760 $70,539,760 Notes: Costs for compliance monitoring are assumed to be included in a selected containment alternative. * meaning no additional action will be conducted beyond implementing a containment alternative. As shown in Table 7.1, the pH5 alternative ranked highest for adding a small degree of permanence would have the highest cost. The pH2 alternative ranked second for adding degree of permanence has a relatively high cost for the very small added degree of permanence. The lowest cost alternatives, pH4 and pH7, do not add any degree of permanence and might negatively impact a containment system that is the foundation of a successful remedy for the Site in terms of effectiveness and degree of permanence with respect to mitigating VOC. Disproportionate Cost Analysis Summary Table 7.2 presents a DCA summary table that provides relative benefit score to cost ratios for the pH Reduction/Enhanced Containment Alternatives using weighting percentages from Table 5.1. As shown in Table 7.2, the No Additional Action alternative has a benefit score to cost ratio of 1.03 that is greater than the benefit score to cost ratios for the other alternatives. The next highest ratio is 0.88 for the pH4 alternative, which is considerably lower than the ratio for the No Additional Action alternative. The benefit score to cost ratios for the remaining alternatives are less than No Additional Action alternative as well, which indicate that the costs exceed the benefits of these alternatives. The benefit score to cost ratios for pH2 of 0.47, pH5 of 0.28, and pH6 of 0.38 are the lowest and are disproportionate in cost compared to the other alternatives. The following provides additional discussion regarding the relationship between costs and quantity of pH (ANC) potentially addressed, cash flow projections, and alternative durations. The following table summarizes the quantity of pH (ANC) potentially addressed by each alternative as presented in Subsection 4.5 and based on the analysis in Appendix F. Figure 7.1 presents the information graphically. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 81 Table 7.3 Summary of Estimated Quantity of pH (ANC) Potentially Addressed by each pH Alternative Alternative pH5 pH2 pH6 pH3 pH7 pH4 No Additional Action Estimated Quantity of pH (ANC) Potentially Addressed (Meq acid) 188 91 188 91 188 91 0 Estimated Percent of Total pH (ANC) (%) 23.3 11.2 23.3 11.2 23.3 11.2 0 Note: Estimated quantity of pH (ANC) in units of Megaequivalents acid. (See Appendix F) The pH5 alternative adds a small degree of permanence greater than the other alternatives, would address up to 23.3 percent of the estimated total pH (ANC) for a cost of approximately $190M (capital plus 30 years O&M at a discount rate of 7 percent). The pH2 alternative that is ranked second for adding degree of permanence would address about half of the ANC (11.2 percent) that the pH5 alternative would achieve, but for about 57 percent of the cost of approximately $108M. As noted above, the remaining alternatives would not add any degree of permanence and would not address any additional pH compared to the pH2 and pH5 alternatives at costs ranging from $54M to $117M. The two lowest cost enhanced containment alternatives, pH4 (approximately $54M) and pH7 (approximately $66M), might negatively impact a containment system that is the foundation of a successful remedy for the Site in terms of effectiveness and degree of permanence with respect to mitigating VOC. Additionally, the containment alternatives include a contingency for pH treatment that would cost approximately $27,000 (plus additional O&M) and might not be needed at all. Figure 7.2 presents the relationship between estimated cost and estimated quantity of pH (ANC) potentially addressed by the alternatives. As shown on the figure the pH2 and pH5 alternatives would reduce relatively small quantities of pH for high costs. In terms of the other alternatives that would enhance containment, but not reduce pH, the slurry walls are more cost effective; however, they might affect the containment system negatively, as noted previously. Figure 7.3 presents the alternatives anticipated 30-year cash flow projections. As shown on this figure, there are no operation and maintenance costs anticipated (excluding O&M for containment) and therefore only capital costs are graphed. The conclusions that may be determined from this graph are the same as stated above for Figure 7.2. Figure 7.4 shows the anticipated durations for the different components of the alternatives. It is anticipated that all the pH alternatives could be completed within 4 years. 7.2.9 Summary Each of the alternatives, except the No Additional Action alternative, would augment a reliable containment system. The most aggressive pH alternative would potentially address 23.3 percent of the pH (ANC), leaving a minimum of 76.7 percent to be contained at the Site. Therefore, any potential concerns regarding migration of groundwater with elevated pH and/or extraction of groundwater with elevated pH would still exist. The potential benefits of some alternatives are minor and come at relatively high costs as indicated by their benefit score to cost ratios, which are all less than the No Additional Action alternative. In some cases (e.g., slurry walls), there might be negative GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 82 effects to a containment system that is the foundation of a successful remedy for the Site in terms of effectiveness and degree of permanence with respect to mitigating VOC. The pH5 alternative that would potentially add a small degree of permanence to a containment alternative, greater than the other pH alternatives, is estimated to cost $136M in additional to the cost of containment. The pH Reduction/Enhanced Containment Alternatives in addition to a containment alternative to address Site conditions are not necessary to protect human health and the environment and would provide minimal additional protectiveness. Based on the above evaluation, the identified preferred alternative is the No Additional Action pH Reduction/Enhanced Containment Alternative since the benefit score to cost ratios for the pH2 through pH7 pH alternatives are less than the No Additional Action alternative. Meaning, there would be no tangible degree of incremental benefit to justify selecting one of the pH2 through pH7 pH alternatives. Additionally, none of the pH alternatives would address more than 23.3 percent of the pH (ANC) and therefore elevated pH would still need to be reliably contained. 8. Select Preferred Remedy Based on the evaluation presented in this FS, the preferred remedy consists of VOC Mass Reduction Alternative MSP combined with appropriate containment technologies from Containment Alternative C150. This alternative includes Common Elements (Subsection 4.2), containment, and VOC mass reduction as follows:  Institutional Controls (ICs) - fence, use restrictions, soil management and Site-specific health and safety plans  Groundwater Quality Monitoring  Soil Vapor Monitoring  PDCE Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area  Sheet pile vertical barrier wall between the Site and the Hylebos  VOC source area mass reduction by strategic groundwater pumping from nine extraction wells  Hydraulic containment by groundwater pumping from eleven extraction wells (the nine for VOC source area mass reduction by strategic groundwater pumping plus two additional wells)  Ex situ treatment of extracted groundwater through a newly constructed conveyance and treatment system The MSP alternative would reliably contain Site impacts while significantly reducing mass in the shortest time of all the alternatives for a reasonable cost, making it the most cost effective combination of containment and mass reduction/removal alternatives. This combination alternative is estimated to reduce the TCVOC mass outside areas of pH >10 s.u. by approximately 98 percent over 20 years while reliably achieving containment of Site impacts. If the above is selected as the preferred remedy for the Site, then it is recommended that the well locations and groundwater pumping rates be further optimized with the model developed for the Site during the design phase of the preferred remedy. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 83 The recommended performance objective for TCVOC mass removal would be based on achieving 90 percent removal of the estimated mass of TCVOC outside of the pH >10 s.u. at the site within 15 years. Based on current estimates derived using the site groundwater flow model, the TCVOC mass outside the high pH (pH >10 s.u.) is approximately 331 thousand lbs. The expected rates of mass removal are as follows:  25 percent of the estimated TCVOC mass outside the high pH (pH >10 s.u.) will be removed by 2 years (approximately 12.5 percent per year for 2 years). This is equivalent to approximately 82,750 lbs  An additional 20 percent of the estimated TCVOC mass outside high pH will be removed by 5 years (approximately 6.66 percent per year for 3 years). This is equivalent to approximately 66,200 lbs  An additional 25 percent of the estimated TCVOC mass outside of the high pH will be removed by 10 years (approximately 5 percent per year for 5 years). This is equivalent to approximately 82,750 lbs  An additional 20 percent of the estimated TCVOC mass outside of the high pH will be removed by 15 years (approximately 4 percent per year for 5 years). This is equivalent to approximately 66,200 lbs Note that estimated rates of mass removal were determined using the three-dimensional (3D) groundwater flow model that was specifically constructed and calibrated for the Site. The Site groundwater flow model provides a useful tool to evaluate the potential effectiveness of the groundwater mass reduction remedial alternatives that incorporate groundwater extraction. It is noted that the model assumes idealized mass transport controlled by advection and equilibrium sorption and all mass is assumed to be either dissolved in the groundwater or sorbed onto the aquifer matrix. Potential effects of non-aqueous phase liquids are not included. The potential effects of diffusion into low-permeability units or areas are not included. Additionally, the estimates do not include potential effects of high pH potentially reaching extraction wells, all contributing to the uncertainty of the mass estimates. However, the evaluation approach was applied consistently for all alternatives. The recommended preferred remedy would protect human health and the environment in the short term and long term. It would provide both VOC mass reduction/removal at a relatively quick rate by strategic groundwater pumping and hydraulic containment reliably and effectively by pumping sufficient groundwater to achieve the Site model-based containment objectives. 9. References Anchor QEA, 2016. Data Summary Report, Occidental Chemical Corporation, Tacoma Groundwater Site, November. CRA, 2015. Draft Feasibility Study, Occidental Chemical Corporation, Tacoma, Washington, May. CRA, 2014a. Final Conceptual Site Model Report, Groundwater and Sediment Remediation, Occidental Chemical Corporation, Tacoma, Washington, April. CRA, 2014b. Draft Evaluation of Remedial Technologies Report, Occidental Chemical Corporation, Tacoma, Washington, June. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 84 CRA, 2014c. Site Characterization Report, Groundwater and Sediment Remediation, Occidental Chemical Corporation, Tacoma, Washington, August. (Also known as the Remedial Investigation Report [RI Report]) CRA, 2011. pH Pilot Study Report, Groundwater and Sediment Remediation, Occidental Chemical Corporation, Tacoma, Washington, January. CRA, 2005. Statement of Work for the Administrative Order on Consent, Groundwater and Sediment Remediation, Occidental Chemical Corporation, Tacoma, Washington, January. C Tech, 2007. Mining Visualization System/Environmental Visualization System (MVS/EVS) software package, developed by C Tech Development Corporation. Ecology, 2016a. Agencies Comments on the Draft Feasibility Study, Occidental Chemical Corporation, Tacoma, Washington, EPA ID Number WAD009242314 and EPA Docket No. 10-97-0011 CERCLA, January 5, 2016. Ecology, 2016b. Occidental Chemical Corporation, Tacoma, Washington, EPA ID Number WAD009242314 and EPA Docket No. 10-97-0011 CERCLA, Conditional Approval of the Remedial Investigation Report, October 11, 2016. (RI Report approval letter) Ecology, 2015. Groundwater Non-Potability Designation, former Occidental Chemical (OCC) Site, Tacoma, March 30, 2015. Ecology, 2013. Model Toxics Control Act Regulation and Statute: MTCA Cleanup Regulation Chapter 173-340 WAC, Model Toxics Control Act Chapter 70.105D RCW, Uniform Environmental Covenants Act Chapter 64.70 RCW. Hart Crowser, 2013. Final Remedial Action Construction Report. Piers 24 and 25 Embankment Remediation Project E1934. Mouth of the Hylebos Waterway Problem Area, Tacoma, Washington. Kueper, B.H. and K. Davies, 2009. Assessment and Delineation of DNAPL Source Zones at Hazardous Waste Sites. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/119, 2009. September. McGuire, T. and C. Newell, 2013. Development of an Expanded, High-Reliability Cost And Performance Database for In-Situ Remediation Technologies, ESTCP In-Progress Review Meeting, Arlington Virginia, May 2013. McGuire, T.M., J.M. McDade, P.R. Kulkarni, D.T. Adamson, and C.J. Newell, 2014. "Data Mining to Evaluate Performance and Cost of DNAPL Source Zone Depletion" in preparation for submittal to Ground Water. USEPA, 2005a. Amendment, Administrative Order on Consent for Removal Activities Embankment and Area 5106, USEPA Docket No. 10 97 0011 CERCLA, as Amended February 1, 2005. USEPA, 2005b. RD/RA Consent Decree for the Mouth of Hylebos Waterway, C 05 5103 FDB, February. USEPA, 2000. A Guide to Developing and Documenting Cost Estimates During the Feasibility Study, EPA 540-R-00-002, OSWER 9355.0-75. July 2000. USEPA, 1994. United States Environmental Protection Agency, 40 Code of Federal Regulations Part 300, National Oil and Hazardous Substances Pollution Contingency Plan: Final Rule, Federal Register, Washington, DC. September 1994. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 85 USEPA, 1991. A Guide to Principal Threat and Low Level Threat Wastes, Office of Solid Waste and Emergency Response, November. USEPA, 1989. Record of Decision: Commencement Bay, Near Shore/Tide Flats, USEPA ID: WAD980726368, September. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report 007843 (139) 86 LEGEND APPROXIMATE MAXIMUM EXTENT OF OCCIDENTAL SITE GROUNDWATER PLUME See Plan View Below IVE VIEW DR MARINE PUYALLUP TRIBE S TR EI C H MARI NE VI EW DRIVE NE SEGMENT 3 SEGMENT 2 SEGMENT 1 721 ALEXANDER AVE. VI EW MURRAY PACIFIC DR IV 709 ALEXANDER AVE. E SE COMMENCEMENT BAY MARINA LONE STAR NW USG INTERIORS LOUSIANA PACIFIC TAYLOR WAY OLE & CHARLIE'S MARINA PUYALLUP TRIBE / MARINA HYLEBOS SEGMENT 5 PIER 25 PIER 24 G 4 NT ME PORT OF TACOMA INDUSTRIAL YARD CITY OF TACOMA PORT OF TACOMA TA YL OR WA Y FORMER OCC FACILITY 605 ALEXANDER AVE. PIER 23 LI NCOLN AVENUE RI NORDLUN PROPERT PORT OF TACOM FORMER US NAVY MA B TACOMA RO S. SEATTLE TACOMA/ COMMENCEMENT BAY ALEXANDER AVENUE ALEXANDER AVENUE 2000ft 2 1 1000 ER PI ER PI 0 0.0005 SOURCE: ELECTRONIC FILE PROVIDED BY ANCHOR ENVIRONMENTAL LLC, JUNE 01, 2004. 07843-C2D2(139)GN-WA014 APR 29, 2016 S T E L E V E N T H ST. SLIP 1 NCD FACILITY P ORT OF T A COM A ROAD figure 2.1 VICINITY MAP TRUE NORTH A COM CIT CITY OF TACOMA F TA YO PLANT NORTH 0 100 300ft 45 00 FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 40 00 35 00 30 00 15 00 20 00 25 00 PUYALLUP TRIBE OF INDIANS PORT OF TACOMA 709 ALEXANDER AVENUE EMBANKMENT FILL AREA NAVY TODD DUMP PIER 25 SHOPS BUILDING AREA DOCK 1 DOCK 2 AREA USED BY SHIPYARD OPERATIONS FROM 1917-1937 AND 1939-1945 MAINTENANCE DISPOSAL INCINERATION SEWERAGE MATERIAL CONTROL WAREHOUSE AREA PAINT SHOP AREA FORMER US NAVY PROPERTY OF TACOMA) BY PORT (OWNED PORT OF TACOMA RIGGING BUILDING AREA BLACKSMITHING SHOP AREA FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) MOLD LOFT AREA STEEL SHED BUILDING AREA 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) PETROLEUM STORAGE/ HANDLING 1930s-1980s PETROLEUM STORAGE/ HANDLING 1930s-1980s CITY OF TACOMA LEGEND SHIPWAY CONSTRUCTION AREA TACOMA FORMER USPORT NAVYOF PROPERTY (OWNED BY PORT OF TACOMA) STEEL SHED BUILDING AREA SHIPYARD OPERATIONS UNDER SUPERVISION OF U.S.NAVY FROM 1917-1958 SHIP CONSTRUCTION PAINTING MAINTENANCE ABRASIVE BLASTING BERTHING BILGE-DUMPING SHIP DECOMMISSIONING/MOTHBALLING DEMOLITION PROPERTY LINE APPROXIMATE SHORELINE 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) APPROXIMATE PROPERTY LINE OF 401 ALEXANDER AVENUE PROMINENT SHIPYARD OPERATION AREAS CIRCA 1941 APPROXIMATE BOUNDARY OF AREA REFERRED TO AS THE "NORTH TEN ACRES" AND INCLUDES THE NAVY TODD DUMP figure 2.2 PROPERTY OWNERSHIP AND OTHER HISTORICAL OPERATIONS 07843-C2D2(139)GN-WA015 DEC 5, 2016 PLANT NORTH TRUE NORTH COMMENCEMENT BAY PUY A LLU P RIVE R VA LLE Y NOT TO SCALE figure 2.3 REGIONAL GEOLOGY Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 2.3.srf) DEC 9, 2016 PLANT WEST PLANT EAST I BLUFFS BLAIR WATERWAY DELTAIC DEPOSITS GLACIAL DEPOSITS GLACIAL DEPOSITS LOWER PERMEABILITY LENSES BURIED VALLEY WALL SAND AND GRAVEL SILT AND CLAY PUYALLUP RIVER VALLEY PLANT NORTH PLANT SOUTH II COMMENCEMENT BAY 0 DELTAIC DEPOSITS -50 -100 -150 GLACIAL DEPOSITS -200 -250 -300 NOTES: (1) DARK BROWN INDICATES WHERE MUD FLATS ARE OBSERVED TO PROVIDE HYDRAULIC SEPARATION BETWEEN THE FILL AND DELTAIC DEPOSITS; BROWN DOT PATTERN INDICATES WHERE HYDRAULIC SEPARATION BY THE MUD FLATS IS NOT CONFIRMED figure 2.4 CONCEPTUAL SITE GEOLOGIC CONDITIONS Occidental Chemical Corporation, Tacoma, Washington PLANT WEST PLANT EAST I RECHARGE CONFINING UNIT B (1) BLAIR WATERWAY AQUIFER UNIT C (1) ? CONFINING UNIT D (1) ? ? AQUIFER UNIT E (1) ? GLACIAL DEPOSITS LOWER PERMEABILITY LENSES ? BURIED VALLEY WALL SAND AND GRAVEL SILT AND CLAY RECHARGE PLANT NORTH PLANT SOUTH II COMMENCEMENT BAY 0 -50 -100 ? -150 ? -200 ? -250 figure 2.5 -300 NOTES: (1) SAVOCA ET AL. (2010) (2) DARK BROWN INDICATES WHERE MUD FLATS ARE OBSERVED TO PROVIDE HYDRAULIC SEPARATION BETWEEN THE FILL AND DELTAIC DEPOSITS; BROWN DOT PATTERN INDICATES WHERE HYDRAULIC SEPARATION BY THE MUD FLATS IS NOT CONFIRMED ? FRESH GROUNDWATER/SALT WATER TRANSITION ZONE AND SALT WATER DISTRIBUTION ASSUMED CONCEPTUAL SITE MODEL OF FRESH GROUNDWATER/SALT WATER DISTRIBUTION Occidental Chemical Corporation, Tacoma, Washington LOCATION S1 S2 S3 S4 S5 S6 S7 DESCRIPTION FORMER SOLVENT PRODUCTION PLANT (1947-1973) FORMER EFFLUENT SETTLING BARGE (WMU F) (1950-1972) FORMER EFFLUENT SETTLING PONDS (WMU A) (1972-1978) FORMER EFFLUENT SETTLING PONDS (WMU G) (1949-1952) FORMER EFFLUENT SETTLING PONDS (WMU H) (1949-1952) FORMER DRAINAGE POND (WMU D) (1948-1973) FORMER PCE/TCE STORAGE Y CI T CITY OF TACOMA TRUE NORTH A OM TAC OF PLANT NORTH 0 100 300ft S5 FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 45 00 40 00 35 00 30 00 25 00 15 00 20 00 PUYALLUP TRIBE OF INDIANS PORT OF TACOMA NAVY TODD DUMP S2 PIER 25 DOCK 2 DOCK 1 S7 PORT OF TACOMA S4 S1 S6 FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) S3 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) TANK 13 SOLVENT CITY OF TACOMA PORT OF TACOMA LEGEND PROPERTY LINE APPROXIMATE SHORELINE 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) POTENTIAL CVOC SOURCE POTENTIAL CVOC SOURCE AREA FORMER FUEL-RELATED STRUCTURES AREA AREA 5106 VOC IMPACTED EMBANKMENT FILL AREA 07843-C2D2(139)GN-WA016 MAY 24, 2016 figure 2.6 POTENTIAL SOURCES OF VOC LOCATION S8 S9 S10 S11 S12 S13 TRUE NORTH DESCRIPTION FORMER CAUSTIC PROCESSING/STORAGE (CAUSTIC HOUSE) FORMER CAUSTIC STORAGE FORMER CAUSTIC PRODUCTION/STORAGE FORMER CAUSTIC STORAGE FORMER CAUSTIC STORAGE FORMER AMMONIUM HYDROXIDE PRODUCTION/CAUSTIC STORAGE YO CI T MA ACO FT PLANT NORTH 0 100 300ft 45 00 PORT OF TACOMA DOCK 2 DOCK 1 PIER 25 FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 40 00 S9 35 00 30 00 15 00 20 00 25 00 PUYALLUP TRIBE OF INDIANS S11 S12 S8 S13 PORT OF TACOMA S10 FORMER OCC OCCFACILITY FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) CITY OF TACOMA PORT OF TACOMA LEGEND PROPERTY LINE POTENTIAL CAUSTIC SOURCE APPROXIMATE SHORELINE POTENTIAL CAUSTIC SOURCE AREA 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) 07843-C2D2(139)GN-WA017 APR 29, 2016 figure 2.7 POTENTIAL SOURCES OF CAUSTIC Y CI T CITY OF TACOMA O TRUE NORTH MA ACO FT PLANT NORTH 0 100 300ft FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 45 00 40 00 35 00 30 00 25 00 20 00 15 00 PUYALLUP TRIBE OF INDIANS PORT OF TACOMA PIER 25 DOCK 1 DOCK 2 SALT PAD PORT OF TACOMA FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) CITY OF TACOMA PORT OF TACOMA LEGEND PROPERTY LINE APPROXIMATE SHORELINE 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) SALT PAD 07843-C2D2(139)GN-WA018 APR 29, 2016 figure 2.8 POTENTIAL SOURCE OF SALT Y CI T CITY OF TACOMA O TRUE NORTH MA ACO FT PLANT NORTH 0 100 300ft FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 45 00 40 00 35 00 30 00 25 00 15 00 20 00 PUYALLUP TRIBE OF INDIANS PORT OF TACOMA NAVY TODD DUMP DOCK 1 PIER 25 DOCK 2 N LANDFILL PORT OF TACOMA FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) CITY OF TACOMA PORT OF TACOMA LEGEND PROPERTY LINE POTENTIAL METALS SOURCE AREA APPROXIMATE SHORELINE METALS IN EMBANKMENT FILL 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) 07843-C2D2(139)GN-WA019 APR 29, 2016 figure 2.9 POTENTIAL SOURCES OF METALS LOCATION FORMER WASTE MANAGEMENT UNIT A FORMER WASTE MANAGEMENT UNIT F FORMER WASTE MANAGEMENT UNIT G FORMER WASTE MANAGEMENT UNIT H NAVY TODD DUMP DESCRIPTION PONDS (1972-1978) LIME BARGE (1950-1972) PONDS (1949-1952) PONDS (1949-1952) 1945 Y CI T CITY OF TACOMA O TRUE NORTH MA ACO FT PLANT NORTH 0 100 300ft FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 45 00 40 00 35 00 30 00 25 00 15 00 20 00 PUYALLUP TRIBE OF INDIANS PORT OF TACOMA AREA 5106 DOCK 2 DOCK 1 PIER 25 NAVY TODD DUMP WMU F WMU H WMU G PORT OF TACOMA FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) WMU A CITY OF TACOMA PORT OF TACOMA LEGEND PROPERTY LINE POTENTIAL SVOC SOURCE AREA APPROXIMATE SHORELINE SVOC IMPACTED EMBANKMENT FILL AREA 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) 07843-C2D2(139)GN-WA020 MAY 24, 2016 figure 2.10 POTENTIAL SOURCES OF SVOC LOCATION CHEMICAL ACTIVITY AREA 16 FORMER WASTE MANAGEMENT UNIT L FORMER WASTE MANAGEMENT UNIT M FORMER WASTE MANAGEMENT UNIT N FORMER WASTE MANAGEMENT UNIT P FORMER WASTE MANAGEMENT UNIT Q NAVY TODD DUMP DESCRIPTION CELL RENEWAL, TRANSFORMER GRAPHITE PILE (1978-1980) CITY OF TACOMA INTERMITTENT GRAPHITE PILE (1950-1978) LANDFILL (1929-1971) WASTE PILE AREA DRUM STORAGE (1980-2002) 1945 Y CI T O TRUE NORTH MA ACO FT PLANT NORTH 0 100 300ft FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 45 00 40 00 35 00 30 00 25 00 15 00 20 00 PUYALLUP TRIBE OF INDIANS PORT OF TACOMA DOCK 1 PIER 25 DOCK 2 NAVY TODD DUMP N LANDFILL PORT OF TACOMA FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) CHEMICAL ACTIVITY AREA 16 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) CITY OF TACOMA PORT OF TACOMA NOTE: ADDITIONAL POTENTIAL SOURCES OF PCBs AND DIOXINS/FURANS WERE IDENTIFIED AT 401 ALEXANDER AVENUE AS DESCRIBED IN SECTION 5.2.6. OF THE SCR. THE EXTENT OF 401 ALEXANDER AVENUE IS ILLUSTRATED ON FIGURE 2.2. LEGEND PROPERTY LINE POTENTIAL SOURCE OF PCBs AND DIOXINS/FURANS APPROXIMATE SHORELINE PCBs IN EMBANKMENT FILL 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) FORMER WASTE MANAGEMENT UNIT 07843-C2D2(139)GN-WA021 APR 29, 2016 figure 2.11 POTENTIAL SOURCES OF PCBs AND DIOXINS/FURANS I' PLANT WEST PLANT EAST I POTENTIAL CAUSTIC SOURCE AREA BLAIR WATERWAY F H C SALT PAD POTENTIAL CAUSTIC SOURCE AREA COMMENCEMENT BAY G BLAIR WATERWAY GLACIAL DEPOSITS LOWER PERMEABILITY LENSES PLANT NORTH II POTENTIAL CAUSTIC SOURCE AREA BURIED VALLEY WALL COMMENCEMENT BAY SAND AND GRAVEL SILT AND CLAY Location Former Waste Management Unit C Former Waste Management Unit F Former Waste Management Unit G Former Waste Management Unit H Description Landfill (1949-1971) Lime Barge (1950-1972) Ponds (1949-1952) Ponds (1949-1952) figure 2.12 NOTES: (1) DARK BROWN INDICATES WHERE MUD FLATS ARE OBSERVED TO PROVIDE HYDRAULIC SEPARATION BETWEEN THE FILL AND DELTAIC DEPOSITS; BROWN DOT PATTERN INDICATES WHERE HYDRAULIC SEPARATION BY THE MUD FLATS IS NOT CONFIRMED EARLY TIME ANTHROPOGENIC DENSITY PLUME Occidental Chemical Corporation, Tacoma, Washington I' PLANT WEST PLANT EAST I POTENTIAL CAUSTIC SOURCE AREA BLAIR WATERWAY COMMENCEMENT BAY POTENTIAL CVOC SOURCE AREA SALT PAD POTENTIAL CAUSTIC SOURCE AREA BLAIR WATERWAY PLANT NORTH II POTENTIAL CAUSTIC SOURCE AREA COMMENCEMENT BAY GLACIAL DEPOSITS LOWER PERMEABILITY LENSES BURIED VALLEY WALL SAND AND GRAVEL SILT AND CLAY figure 2.13 NOTES: (1) DARK BROWN INDICATES WHERE MUD FLATS ARE OBSERVED TO PROVIDE HYDRAULIC SEPARATION BETWEEN THE FILL AND DELTAIC DEPOSITS; BROWN DOT PATTERN INDICATES WHERE HYDRAULIC SEPARATION BY THE MUD FLATS IS NOT CONFIRMED EARLY TIME ANTHROPOGENIC DENSITY PLUME INFLUENCE ON TOTAL CVOC PLUME MIGRATION Occidental Chemical Corporation, Tacoma, Washington I' PLANT WEST PLANT EAST I POTENTIAL CAUSTIC SOURCE AREA BLAIR WATERWAY F H C SALT PAD POTENTIAL CAUSTIC SOURCE AREA COMMENCEMENT BAY G BLAIR WATERWAY GLACIAL DEPOSITS LOWER PERMEABILITY LENSES PLANT NORTH II POTENTIAL CAUSTIC SOURCE AREA BURIED VALLEY WALL COMMENCEMENT BAY SAND AND GRAVEL SILT AND CLAY Location Former Waste Management Unit C Former Waste Management Unit F Former Waste Management Unit G Former Waste Management Unit H Description Landfill (1949-1971) Lime Barge (1950-1972) Ponds (1949-1952) Ponds (1949-1952) figure 2.14 NOTES: (1) DARK BROWN INDICATES WHERE MUD FLATS ARE OBSERVED TO PROVIDE HYDRAULIC SEPARATION BETWEEN THE FILL AND DELTAIC DEPOSITS; BROWN DOT PATTERN INDICATES WHERE HYDRAULIC SEPARATION BY THE MUD FLATS IS NOT CONFIRMED CURRENT ANTHROPOGENIC DENSITY PLUME Occidental Chemical Corporation, Tacoma, Washington I' PLANT WEST PLANT EAST I POTENTIAL CAUSTIC SOURCE AREA BLAIR WATERWAY COMMENCEMENT BAY POTENTIAL CAUSTIC SOURCE AREA BLAIR WATERWAY PLANT NORTH II POTENTIAL CAUSTIC SOURCE AREA COMMENCEMENT BAY GLACIAL DEPOSITS LOWER PERMEABILITY LENSES BURIED VALLEY WALL SAND AND GRAVEL SILT AND CLAY figure 2.15 NOTES: (1) DARK BROWN INDICATES WHERE MUD FLATS ARE OBSERVED TO PROVIDE HYDRAULIC SEPARATION BETWEEN THE FILL AND DELTAIC DEPOSITS; BROWN DOT PATTERN INDICATES WHERE HYDRAULIC SEPARATION BY THE MUD FLATS IS NOT CONFIRMED pH PLUME Occidental Chemical Corporation, Tacoma, Washington I' PLANT WEST PLANT EAST I BLAIR WATERWAY COMMENCEMENT BAY POTENTIAL CVOC SOURCE AREA BLAIR WATERWAY PLANT NORTH II COMMENCEMENT BAY GLACIAL DEPOSITS LOWER PERMEABILITY LENSES BURIED VALLEY WALL SAND AND GRAVEL SILT AND CLAY figure 2.16 NOTES: (1) DARK BROWN INDICATES WHERE MUD FLATS ARE OBSERVED TO PROVIDE HYDRAULIC SEPARATION BETWEEN THE FILL AND DELTAIC DEPOSITS; BROWN DOT PATTERN INDICATES WHERE HYDRAULIC SEPARATION BY THE MUD FLATS IS NOT CONFIRMED DNAPL DISTRIBUTION Occidental Chemical Corporation, Tacoma, Washington I' PLANT WEST PLANT EAST I BLAIR WATERWAY ? ? ? ? ? BLAIR WATERWAY PLANT NORTH II COMMENCEMENT BAY GLACIAL DEPOSITS LOWER PERMEABILITY LENSES ? BURIED VALLEY WALL ? SAND AND GRAVEL ? SILT AND CLAY ? COMMENCEMENT BAY ? POTENTIAL CVOC SOURCE AREA figure 2.17 NOTES: (1) DARK BROWN INDICATES WHERE MUD FLATS ARE OBSERVED TO PROVIDE HYDRAULIC SEPARATION BETWEEN THE FILL AND DELTAIC DEPOSITS; BROWN DOT PATTERN INDICATES WHERE HYDRAULIC SEPARATION BY THE MUD FLATS IS NOT CONFIRMED TOTAL CVOC PLUME IN GROUNDWATER Occidental Chemical Corporation, Tacoma, Washington VAPOR AND PARTICULATE CARRIED BY WIND TRESSPASSER INGESTION INCIDENTAL INGESTION AND DIRECT/ DERMAL CONTACT HYLEBOS WATERWAY SOIL INVERTEBRATE AND BURROWING ANIMALS INGESTION INHALATION AQUATIC INSECTS INHALATION T EC KE TA UP CONTAMINANT LEACHING FROM UNSATURATED SOIL S LANT ES TIC P T AQUA ERTEBRA INV AND DI R DIRECT CONTACT INGESTION CLEAN FRESH GROUNDWATER FROM BLUFFS DISCHARGING TO PUYALLUP RIVER VALLEY CONTAMINATED GROUNDWATER MIGRATION TO SEDIMENTS AND WATERWAY ADP AND COMINGLED CONTAMINATED GROUNDWATER DENSITY-DRIVEN DISCHARGE TO WATERWAY THROUGH SALT WATER DRAWING NOT TO SCALE figure 2.18 SCHEMATIC OF EXPOSURE PATHWAYS AND RECEPTORS Occidental Chemical Corporation, Tacoma, Washington TRUE NORTH PLANT NORTH 100 0 300ft CHANNEL LINE CHANNEL LINE X X X M-1 H25 EXT-4(s) EXT-3(d) 20 10 EXT-1(s) 15 X G-2 TREATMENT PLANT X EXT-10(s) 15 EXT-8(s) 15 X STN-06+00 D-9 LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) C-2 B-9 C-28 PARKING LOT X X BARRIER WALL EAST B-3 B-21 M-4 X X D-2 EXT-15(s) 7.5 F-9A E-1 EXT-9(d) 20 F-9 F-2 E24 PORT OF TACOMA X X F-24 X X SALT PAD 12 .5 10 10 D OCK X EXT-18(s) 15 1 0. DOCK 2 DOCK 1 PIER 25 CRANE RAIL CROSS-SECTION LOCATION X PHYSICAL DIRECT CONTACT EXPOSURE BARRIER PARKING LOT EXT-16(s) 20 ALEXANDER AVENUE X EXT-5(s) 15 X PORT OF TACOMA EXT-1 15 ALTERNATIVE C100 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) EXT-9 20 EXISTING ALTERNATIVE C100 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) (s) SHALLOW EXTRACTION WELL (d) DEEP EXTRACTION WELL 0.1 mg/L TCVOC IN GROUNDWATER X 10 mg/L TCVOC IN GROUNDWATER EXT-21(s) 5 pH 10 s.u. IN GROUNDWATER pH 12.5 s.u. IN GROUNDWATER X X STN-33+00 07843-C2D2(139)GN-WA032 JUN 13, 2016 X figure 4.1 CONTAINMENT ALTERNATIVE C100 DRAFT NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA ELEVATION (FT NGVD) -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) ELEVATION (FT NGVD) -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 TCVOC (µg/L) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 100000 10000 1000 100 2.4 figure 4.2a CONTAINMENT ALTERNATIVES CROSS-SECTIONS - TCVOC CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\007843-C2D2-RPT139-Fig 4.2a.srf) MAY 24/2016 DRAFT NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA ELEVATION (FT NGVD) -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) ELEVATION (FT NGVD) -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 pH (s.u.) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 13 12 11 10 8.5 figure 4.2b CONTAINMENT ALTERNATIVES CROSS-SECTIONS - pH CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\007843-C2D2-RPT139-Fig 4.2b.srf) MAY 11/2016 PROPOSED BARRIER WALL EAST SITE 20 14' MLLW PRE-DREDGE BASE OF HYLEBOS (JULY 2002) 10 -3' MLLW POST-5106 (PRE-SEGMENT 5) DREDGE BASE OF HYLEBOS (JUNE 2003) -10 -20 (FT MLLW) 0 POST-SEGMENT 5 DREDGE BASE OF HYLEBOS (MARCH 2004) AREA 5106 -30 -40 NOTES: 1. PRE-DREDGE BASE OF HYLEBOS (JULY 2002) PROVIDED BY DAVID EVANS AND ASSOCIATES INC., SURVEY JULY 24, 2002. 2. DREDGING, TREATMENT, AND DEWATERING OF AREA 5106 SEDIMENT BEGAN ON OCTOBER 15, 2002 AND CONTINUED UNTIL FEBRUARY 28, 2003. 3. POST-5106 (PRE-SEGMENT 5) DREDGE BASE OF HYLEBOS (JUNE 2003) PROVIDED BY PETERSON CONSULTING ENGINEERS, SURVEY JUNE 2003. 4. POST-SEGMENT 5 DREDGE BASE OF HYLEBOS (MARCH 2004) TAKEN FROM "FIGURE 8B SEGMENT 5 POST DREDGE SURVEY" OF THE "REMEDIAL ACTION CONSTRUCTION REPORT - SEGMENT 5 AND SLIP 1" (CRA, MARCH 25, 2015) BASED ON MARCH 2004 BATHYMETRY. CROSS-SECTION SCALES: HORIZONTAL 1"=60' (ROTATION C) 2.5X VERTICAL EXAGGERATION TRUE NORTH CHANNEL LINE PLANT EAST CHANNEL LINE AREA 5106 DOCK 2 DOCK 1 PIER 25 CRANE RAIL PLANT NORTH DOCK M-1 H25 STN-33+00 G-2 F-24 SALT PAD F-9 F-9A SITE E-1 E24 PORT OF TACOMA F-2 TREATMENT PLANT D-9 D-2 C-2 B-9 C-28 PARKING LOT B-3 B-21 M-4 PARKING LOT X ALEXANDER AVENUE CROSS-SECTION LOCATION SCALE: 1" = 800' figure 4.3 SCHEMATIC CROSS-SECTION ALONG EMBANKMENT WITHIN AREA 5106 07843-C2D2(139)GN-WA058 DEC 5, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE X X X M-1 H25 EXT-4(s) EXT-3(d) 30 15 EXT-1(s) 16.5 X G-2 D-9 X EXT-10(s) 22.5 EXT-15(s) 11.25 EXT-8(s) 22.5 LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) C-2 B-9 C-28 PARKING LOT X X BARRIER WALL EAST B-3 B-21 M-4 X PHYSICAL DIRECT CONTACT EXPOSURE BARRIER X X D-2 X TREATMENT PLANT F-9A E-1 EXT-9(d) 30 F-9 F-2 E24 PORT OF TACOMA X X F-24 X X SALT PAD 12 .5 10 10 D OCK X EXT-18(s) 22.5 1 0. DOCK 2 DOCK 1 PIER 25 CRANE RAIL PARKING LOT EXT-16(s) 30 EXT-1 15 ALTERNATIVE C150 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) EXT-9 20 EXISTING ALTERNATIVE C150 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) ALEXANDER AVENUE X EXT-5(s) 18.5 (d) X PORT OF TACOMA (s) SHALLOW EXTRACTION WELL DEEP EXTRACTION WELL 0.1 mg/L TCVOC IN GROUNDWATER 10 mg/L TCVOC IN GROUNDWATER X EXT-21(s) 7.5 pH 10 s.u. IN GROUNDWATER pH 12.5 s.u. IN GROUNDWATER X X X figure 4.4 CONTAINMENT ALTERNATIVE C150 07843-C2D2(139)GN-WA033 MAY 24, 2016 TRUE NORTH PLANT NORTH 100 0 300ft CHANNEL LINE CHANNEL LINE X X X H25 EXT-4(s) EXT-3(d) 40 20 EXT-1(s) 15 X G-2 D-9 X EXT-10(s) 30 EXT-15(s) 12 EXT-8(s) 30 LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) C-2 B-9 C-28 PARKING LOT X X BARRIER WALL EAST B-3 B-21 M-4 X PHYSICAL DIRECT CONTACT EXPOSURE BARRIER X X D-2 X TREATMENT PLANT F-9A E-1 EXT-9(d) 40 F-9 F-2 E24 PORT OF TACOMA X X F-24 X X SALT PAD 12 .5 10 10 D OCK M-1 X EXT-18(s) 29 1 0. DOCK 2 DOCK 1 PIER 25 CRANE RAIL PARKING LOT EXT-16(s) 40 EXT-1 15 ALTERNATIVE C200 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) EXT-9 20 EXISTING ALTERNATIVE C200 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) ALEXANDER AVENUE X EXT-5(s) 17.5 X PORT OF TACOMA (s) SHALLOW EXTRACTION WELL (d) DEEP EXTRACTION WELL 0.1 mg/L TCVOC IN GROUNDWATER 10 mg/L TCVOC IN GROUNDWATER X EXT-21(s) 8 pH 10 s.u. IN GROUNDWATER pH 12.5 s.u. IN GROUNDWATER X X X figure 4.5 CONTAINMENT ALTERNATIVE C200 07843-C2D2(139)GN-WA034 JUN 13, 2016 Estimated Total TCVOC Impacted Soil Volume (cubic yards [cy]) Impacted Soil Volume (cy) 600,000 500,000 400,000 300,000 472,590 200,000 100,000 98,229 16,230 0 Deep (-60 ft NGVD to Bottom) Shallow (Ground Surface to -60 ft NGVD) Not Targeted (Incidental) Targeted Zones Shallow Zone Deep Zone Not Targeted Quantity of TCVOC (pounds [lbs]) Quantity of TCVOC (lbs) 700,000 600,000 500,000 400,000 669,430 300,000 200,000 100,000 107,260 3,310 0 Deep (-60 ft NGVD to Bottom) Shallow (Ground Surface to -60 ft NGVD) Not Targeted (Incidental) Target Zones Shallow Zone Deep Zone Not Targeted figure 4.6 TCVOC Mass Target Zones Occidental Chemical Corporation, Tacoma, Washington 007843 (139) LEGEND TRUE NORTH 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) PLANT NORTH BARRIER WALL EAST CROSS-SECTION LOCATION 0 100 EXT-1 15 300ft ALTERNATIVE M100 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) (s) SHALLOW EXTRACTION WELL (d) DEEP EXTRACTION WELL 0.1 mg/L TCVOC IN GROUNDWATER 10 mg/L TCVOC IN GROUNDWATER TARGET AREAS CHANNEL LINE 500 mg/kg TCVOC IN SOIL GROUND SURFACE TO 2.5 FT NGVD 2.5 FT NGVD TO -21 FT NGVD 10 mg/L TCVOC IN GROUNDWATER WITHIN pH 10 - 12.5 s.u. CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK 500 mg/kg TCVOC IN SOIL WITHIN pH 10 - 12.5 s.u. BELOW -60 FT NGVD X M-1 H25 X X G-2 10 X EXT-23(s) 15 F-9 F-2 E-1 F-9A STN-06+00 D-9 D-2 X X X E24 X PORT OF TACOMA TREATMENT PLANT X F-24 SALT PAD X 1 0. EXT-22(d) 20 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA X X X STN-33+00 07843-C2D2(139)GN-WA035 DEC 5, 2016 X figure 4.7 VOC MASS REDUCTION ALTERNATIVE M100 ELEVATION (FT NGVD) NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA -15 -40 TARGET ZONE -65 -90 -115 -140 TARGET ZONE -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) ELEVATION (FT NGVD) -15 -40 TARGET ZONE -65 -90 -115 -140 -165 -190 -215 -240 TCVOC (µg/L) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 100000 10000 1000 100 2.4 figure 4.8 VOC MASS REDUCTION ALTERNATIVES M100, M150, AND M200 CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.8.srf) DEC 9, 2016 TRUE NORTH PLANT NORTH 100 0 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 X PIER 25 CRANE RAIL X D OCK X M-1 H25 X X 10 G-2 F-9A D-9 D-2 EXT-22(d) 30 X X X TREATMENT PLANT F-9 F-2 E-1 X PORT OF TACOMA EXT-23(s) 22.5 X F-24 X X SALT PAD E24 1 0. LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) C-2 B-9 C-28 PARKING LOT X M-4 EXT-1 15 X X BARRIER WALL EAST B-3 B-21 X ALTERNATIVE M150 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) PARKING LOT ALEXANDER AVENUE (s) SHALLOW EXTRACTION WELL (d) DEEP EXTRACTION WELL 0.1 mg/L TCVOC IN GROUNDWATER X 10 mg/L TCVOC IN GROUNDWATER TARGET AREAS X PORT OF TACOMA 500 mg/kg TCVOC IN SOIL GROUND SURFACE TO 2.5 FT NGVD 2.5 FT NGVD TO -21 FT NGVD X 10 mg/L TCVOC IN GROUNDWATER WITHIN pH 10 - 12.5 s.u. 10 s.u. X 500 mg/kg TCVOC IN SOIL WITHIN pH 10 - 12.5 s.u. BELOW -60 FT NGVD 10 s.u. BELOW -60 FT NGVD X X figure 4.9 VOC MASS REDUCTION ALTERNATIVE M150 07843-C2D2(139)GN-WA036 JUN 13, 2016 TRUE NORTH PLANT NORTH 100 0 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 X PIER 25 CRANE RAIL X D OCK X M-1 H25 X X 10 G-2 F-9A D-9 D-2 EXT-22(d) 40 X X X TREATMENT PLANT F-9 F-2 E-1 X PORT OF TACOMA EXT-23(s) 30 X F-24 X X SALT PAD E24 1 0. LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) C-2 B-9 C-28 PARKING LOT X M-4 EXT-1 15 X X BARRIER WALL EAST B-3 B-21 X ALTERNATIVE M200 EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) PARKING LOT ALEXANDER AVENUE (s) SHALLOW EXTRACTION WELL (d) DEEP EXTRACTION WELL 0.1 mg/L TCVOC IN GROUNDWATER X 10 mg/L TCVOC IN GROUNDWATER TARGET AREAS X PORT OF TACOMA 500 mg/kg TCVOC IN SOIL GROUND SURFACE TO 2.5 FT NGVD 2.5 FT NGVD TO -21 FT NGVD X 10 mg/L TCVOC IN GROUNDWATER WITHIN pH 10 - 12.5 s.u. 10 s.u. X 500 mg/kg TCVOC IN SOIL WITHIN pH 10 - 12.5 s.u. BELOW -60 FT NGVD 10 s.u. BELOW -60 FT NGVD X X figure 4.10 VOC MASS REDUCTION ALTERNATIVE M200 07843-C2D2(139)GN-WA037 JUN 13, 2016 LEGEND TRUE NORTH 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) PLANT NORTH BARRIER WALL EAST CROSS-SECTION LOCATION 0 100 MR1 20 300ft ALTERNATIVE MSP EXTRACTION WELL AND ESTIMATED PUMPING RATE (GPM) (s) SHALLOW EXTRACTION WELL (d) DEEP EXTRACTION WELL 0.1 mg/L TCVOC IN GROUNDWATER 10 mg/L TCVOC IN GROUNDWATER TARGET AREAS CHANNEL LINE 500 mg/kg TCVOC IN SOIL GROUND SURFACE TO 2.5 FT NGVD 2.5 FT NGVD TO -21 FT NGVD CHANNEL LINE 10 mg/L TCVOC IN GROUNDWATER WITHIN pH 10 - 12.5 s.u. DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK 500 mg/kg TCVOC IN SOIL WITHIN pH 10 - 12.5 s.u. BELOW -60 FT NGVD X M-1 H25 X X G-2 X NW5(d) 20 X MR3(d) 20 NW4(d) 20 NW3(d) 20 F-9 F-2 F-9A STN-06+00 D-9 D-2 X X PORT OF TACOMA NW6(d) 20 NW1(s) TREATMENT 20 NW2(s) PLANT 20 X SALT PAD E-1 X MR2(d) 20 X MR1(d) 20 F-24 10 E24 1 0. C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA NW7(s) 20 X NW8(s) 10 X figure 4.11 X STN-33+00 07843-C2D2(139)GN-WA063 DEC 5, 2016 X VOC MASS REDUCTION ALTERNATIVE MASS REDUCTION BY STRATEGIC GROUNDWATER PUMPING (MSP) ELEVATION (FT NGVD) NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA -15 -40 TARGET ZONE -65 -90 -115 -140 TARGET ZONE -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) ELEVATION (FT NGVD) -15 -40 TARGET ZONE -65 -90 -115 -140 -165 -190 -215 -240 TCVOC (µg/L) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 100000 10000 1000 100 2.4 figure 4.12 VOC MASS REDUCTION ALTERNATIVE MSP CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.12.srf) December 9/2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X 1 G-2 10 F-9A X TREATMENT PLANT E-1 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD E24 0. X X STN-06+00 D-9 D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) PARKING LOT ALEXANDER AVENUE CROSS-SECTION LOCATION 0.1 mg/L TCVOC IN GROUNDWATER X 10 mg/L TCVOC IN GROUNDWATER TARGET AREAS X PORT OF TACOMA 100 mg/kg TCVOC IN SOIL TO -4 FT NGVD X X X STN-33+00 07843-C2D2(139)GN-WA038 DEC 5, 2016 X figure 4.13 VOC MASS REMOVAL ALTERNATIVES M3 AND M4 NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA ELEVATION (FT NGVD) TARGET ZONE -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) TARGET ZONE ELEVATION (FT NGVD) -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 TCVOC (µg/L) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 100000 10000 1000 100 2.4 figure 4.14 VOC MASS REMOVAL ALTERNATIVES M3 AND M4 CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.14.srf) DEC 9, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X 1 G-2 10 X F-9A TREATMENT PLANT E-1 E24 X X PORT OF TACOMA F-9 F-2 X F-24 SALT PAD X 0. D-2 X X STN-06+00 D-9 C-2 LEGEND B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X CROSS-SECTION LOCATION PARKING LOT 0.1 mg/L TCVOC IN GROUNDWATER ALEXANDER AVENUE 10 mg/L TCVOC IN GROUNDWATER X TARGET AREAS 500 mg/kg TCVOC IN SOIL GROUND SURFACE TO 2.5 FT NGVD (SVE) X PORT OF TACOMA 2.5 FT NGVD TO -21 FT NGVD (ERH) X X X STN-33+00 07843-C2D2(139)GN-WA039 DEC 5, 2016 X figure 4.15 VOC MASS REDUCTION ALTERNATIVE M5 ELEVATION (FT NGVD) NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA TARGET ZONE -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) TARGET ZONE ELEVATION (FT NGVD) -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 TCVOC (µg/L) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 100000 10000 1000 100 2.4 figure 4.16 VOC MASS REDUCTION ALTERNATIVE M5 CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.16.srf) DEC 9, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X G-2 10 X F-9A TREATMENT PLANT E-1 E24 X X PORT OF TACOMA F-9 F-2 X F-24 SALT PAD X 1 0. X X STN-06+00 D-9 D-2 C-2 B-9 C-28 PARKING LOT X X X B-3 B-21 M-4 X LEGEND PARKING LOT ALEXANDER AVENUE 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) CROSS-SECTION LOCATION X 0.1 mg/L TCVOC IN GROUNDWATER 10 mg/L TCVOC IN GROUNDWATER X PORT OF TACOMA TARGET AREAS 100 mg/kg TCVOC IN SOIL GROUND SURFACE TO -4 FT NGVD (EXCAVATION) X 500 mg/kg TCVOC IN SOIL -4 FT NGVD TO -21 FT NGVD) (ERH) X X STN-33+00 07843-C2D2(139)GN-WA040 DEC 5, 2016 X figure 4.17 VOC MASS REMOVAL/REDUCTION ALTERNATIVES M6 AND M7 NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA ELEVATION (FT NGVD) TARGET ZONE -15 TARGET ZONE -40 -65 -90 -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) TARGET ZONE ELEVATION (FT NGVD) -15 TARGET ZONE -40 -65 -90 -115 -140 -165 -190 -215 -240 TCVOC (µg/L) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 100000 10000 1000 100 2.4 figure 4.18 VOC MASS REMOVAL/REDUCTION ALTERNATIVES M6 AND M7 CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.18.srf) DEC 9, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X G-2 10 X F-9A E-1 X TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X F-24 SALT PAD X 1 0. X X STN-06+00 D-9 D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X LEGEND PARKING LOT ALEXANDER AVENUE 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) CROSS-SECTION LOCATION X 0.1 mg/L TCVOC IN GROUNDWATER 10 mg/L TCVOC IN GROUNDWATER TARGET AREAS X PORT OF TACOMA 500 mg/kg TCVOC IN SOIL GROUND SURFACE TO 2.5 FT NGVD (SVE) 2.5 FT NGVD TO -21 FT NGVD (ERH) X 10 mg/L TCVOC IN GROUNDWATER WITHIN pH TO -60 FT NGVD 10 - 12.5 s.u. (ISCO) X X STN-33+00 07843-C2D2(139)GN-WA041 DEC 5, 2016 X figure 4.19 VOC MASS REMOVAL/REDUCTION ALTERNATIVE M8 ELEVATION (FT NGVD) NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA -15 TARGET ZONE -40 -65 -90 -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) TARGET ZONE ELEVATION (FT NGVD) -15 -40 -65 -90 -115 -140 -165 -190 -215 -240 TCVOC (µg/L) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 100000 10000 1000 100 2.4 figure 4.20 VOC MASS REMOVAL/REDUCTION ALTERNATIVE M8 CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.20.srf) DEC 9, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X 1 G-2 10 X F-9A E-1 X TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X F-24 SALT PAD X 0. X X STN-06+00 D-9 D-2 C-2 PARKING LOT LEGEND B-9 C-28 M-4 X X X B-3 B-21 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X CROSS-SECTION LOCATION PARKING LOT 0.1 mg/L TCVOC IN GROUNDWATER ALEXANDER AVENUE 10 mg/L TCVOC IN GROUNDWATER X TARGET AREAS 500 mg/kg TCVOC IN SOIL GROUND SURFACE TO 2.5 FT NGVD (SVE) X PORT OF TACOMA 2.5 FT NGVD TO -21 FT NGVD (ERH) 10 mg/L TCVOC IN GROUNDWATER WITHIN pH 10 - 12.5 s.u. (ISCO) X 500 mg/kg TCVOC IN SOIL WITHIN pH 10 - 12.5 s.u. BELOW -60 FT NGVD (ISCO) X X STN-33+00 07843-C2D2(139)GN-WA042 DEC 5, 2016 X figure 4.21 VOC MASS REMOVAL/REDUCTION ALTERNATIVE M9 ELEVATION (FT NGVD) NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA -15 TARGET ZONE -40 -65 -90 TARGET ZONE -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) ELEVATION (FT NGVD) -15 TARGET ZONE -40 -65 -90 -115 -140 -165 -190 -215 -240 TCVOC (µg/L) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 100000 10000 1000 100 2.4 figure 4.22 VOC MASS REMOVAL/REDUCTION ALTERNATIVE M9 CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.22.srf) DEC 9, 2016 Estimated Total pH (ANC) ≥12.5 s.u. Impacted Soil Volume (cubic yards [cy]) Impacted Soil Volume (cy) 175,000 155,000 135,000 115,000 95,000 75,000 55,000 35,000 85,690 78,068 15,000 -5,000 10,560 Deep (-60 ft NGVD to Bottom) Shallow (Ground Surface to -60 ft NGVD) Not Targeted (Incidental) Targeted Zones Shallow Zone Deep Zone Not Targeted Quantity of pH (ANC) ≥12.5 s.u. (Megaequivalents acid [Meq acid]) 200 Quantity of ANC (Meq acid) 180 160 140 120 100 80 60 40 97 91 20 0 12 Not Targeted (Incidental) Deep (-60 ft NGVD to Bottom) Shallow (Ground Surface to -60 ft NGVD) Target Zones Shallow Zone Deep Zone Not Targeted figure 4.23 pH Target Zones Occidental Chemical Corporation, Tacoma, Washington 007843 (139) TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X F-9A X F-9 F-2 X X E-1 PORT OF TACOMA TREATMENT PLANT E24 12 .5 X X F-24 10 G-2 SALT PAD X X STN-06+00 D-9 D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X PORT OF TACOMA CROSS-SECTION LOCATION X TARGET AREAS X TO -60 FT NGVD X STN-33+00 07843-C2D2(139)GN-WA045 DEC 5, 2016 X figure 4.24 pH REDUCTION AND ENHANCED CONTAINMENT ALTERNATIVES pH2 AND pH3 ELEVATION (FT NGVD) NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA -15 TARGET ZONE -40 -65 -90 -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) ELEVATION (FT NGVD) -15 TARGET ZONE -40 -65 -90 -115 -140 -165 -190 -215 -240 pH (s.u.) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 13 12 11 10 figure 4.25 8.5 pH REDUCTION/ENHANCED CONTAINMENT ALTERNATIVES pH2, pH3, AND pH4 CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.25.srf) DEC 9, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X F-9A X D-9 X F-9 F-2 X X X TREATMENT PLANT E-1 PORT OF TACOMA E24 12 .5 X X F-24 10 G-2 SALT PAD D-2 LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) C-2 B-9 C-28 PARKING LOT M-4 X X X BARRIER WALL EAST B-3 B-21 X PARKING LOT SLURRY WALL TO -60 FT NGVD ALEXANDER AVENUE TARGET AREAS X TO -60 FT NGVD X PORT OF TACOMA X X X X figure 4.26 pH ENHANCED CONTAINMENT ALTERNATIVE pH4 07843-C2D2(139)GN-WA046 DEC 5, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X F-9A X D-9 X F-9 F-2 X X X TREATMENT PLANT E-1 PORT OF TACOMA E24 12 .5 X X F-24 10 G-2 SALT PAD D-2 LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X TARGET AREAS PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA X X X X figure 4.27 pH REDUCTION AND ENHANCED CONTAINMENT ALTERNATIVES pH5 AND pH6 07843-C2D2(139)GN-WA047 DEC 5, 2016 ELEVATION (FT NGVD) NORTH V' SOUTH V SITE COMMENCEMENT BAY HYLEBOS/BLAIR PENINSULA -15 TARGET ZONES -40 -65 -90 -115 -140 -165 -190 -215 -240 10,000 9,500 9,000 8,500 8,000 7,500 7,000 6,500 6,000 5,500 5,000 4,500 4,000 3,500 DISTANCE ALONG CROSS-SECTION (FT) ELEVATION (FT NGVD) -15 TARGET ZONE -40 -65 -90 -115 -140 -165 -190 -215 -240 pH (s.u.) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 DISTANCE ALONG CROSS-SECTION (FT) 13 12 11 10 figure 4.28 8.5 pH REDUCTION/ENHANCED CONTAINMENT ALTERNATIVES pH5, pH6, AND pH7 CROSS-SECTIONS CROSS-SECTIONS IV-IV' AND V-V' Occidental Chemical Corporation, Tacoma, Washington 07843-C2D2(139)GN-WA-HYD (N:\HEG\07843\RPT139\Figures-Current\07843-C2D2(139)HEG-Fig 4.28.srf) DEC 9, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X F-9A X D-9 X F-9 F-2 X X X TREATMENT PLANT E-1 PORT OF TACOMA E24 12 . 5 X X F-24 10 G-2 SALT PAD D-2 LEGEND 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) C-2 B-9 C-28 PARKING LOT M-4 X X X BARRIER WALL EAST B-3 B-21 X PARKING LOT SLURRY WALL TO -60 FT NGVD ALEXANDER AVENUE SLURRY WALL TO -150 FT NGVD X TARGET AREAS X PORT OF TACOMA X X X X figure 4.29 pH ENHANCED CONTAINMENT ALTERNATIVE pH7 07843-C2D2(139)GN-WA048 DEC 5, 2016 $30,000,000 $25,000,000 Off-Site Treatment / Disposal Capital Cost ($) $20,000,000 Groundwater Treatment Plant Groundwater Extraction System Physical Direct Contact Exposure Barrier Sheet Pile Vertical Barrier Wall East $15,000,000 Demolition of Docks and Existing Buildings Mobilization/Demobilization $10,000,000 $5,000,000 $Containment Alternative C150 Containment Alternative C200 figure 5.1 Containment Alternatives Common Elements Capital Cost Distribution Occidental Chemical Corporation, Tacoma, Washington 007843 (139) $45,000 Year 0 Year 2 Year 4 Year 6 Year 8 Year 10 Year 12 Year 14 Year 16 Year 18 Year 20 Year 22 Year 24 Year 26 Year 28 Year 30 $40,000 $35,000 Annual Amount ($1,000) $30,000 $25,000 $20,000 Year 1 Year 3 Year 5 Year 7 Year 9 Year 11 Year 13 Year 15 Year 17 Year 19 Year 21 Year 23 Year 25 Year 27 Year 29 $15,000 $10,000 $5,000 $0 Containment Alternative C150 Containment Alternative C200 figure 5.2 Containment Alternatives 30-Year Cash Flow Projections Occidental Chemical Corporation, Tacoma, Washington 007843 (139) C150/C200 Groundwater Containment Common Elements Site Work (Demolition) Sheet Pile Vertical Barrier Wall Installation of GWETS PDCE Barrier O&M 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 92 96 100 Years LEGEND CONSTRUCTION/INSTALLATION ACTIVITIES COMMON ELEMENTS INCLUDING INSTITUTIONAL CONTROLS AND MONITORING NOTES: GWETS PDCE OPERATION AND MAINTENANCE ACTIVITIES GROUNDWATER EXTRACTION AND TREATMENT SYSTEM PHYSICAL DIRECT CONTACT EXPOSURE OCCIDENTAL CHEMICAL CORPORATION TACOMA, WASHINGTON CONTAINMENT ALTERNATIVES TECHNOLOGIES ESTIMATED DURATIONS JOB NUMBER 007843-C2D2-403 DATE December 9, 2016 FIGURE 5.3 900,000 Estimated Total TCVOC Mass (Pounds [lbs]) 800,000 700,000 78.6% 600,000 TCVOC Mass (lbs) 500,000 400,000 41.5% 37.4% 300,000 36.6% 35.3% 200,000 100,000 10.5% 8.5% 8.0% 3.0% 0 M9 - ERH, SVE, ISCO, ISB MSP - Groundwater Extraction M200 - Groundwater Extraction M150 - Groundwater Extraction M8 - Shallow ERH, SVE, ISCO, ISB M100 - Groundwater Extraction M6 - Shallow Excavation, ERH, SVE M5 - Shallow ERH, SVE M3 - Shallow Excavation VOC Mass Reduction/Removal Alternative TCVOC Mass Reduced/Removed After 20 Years Remaining TCVOC Mass figure 6.1 TCVOC Mass Reduced/Removed by Alternatives Comparison Occidental Chemical Corporation, Tacoma, Washington 007843 (139) $400 Estimated Total TCVOC Mass (lbs) M9 Alternative Estimated Cost (millions of dollars) $350 $300 $250 $200 $150 M8 Alternative $100 M6 Alternative $50 M5 Alternative M3 Alternative M100 Alternative M200 Alternative MSP Alternative M150 Alternative $0 0 100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 Estimated Quantity of TCVOC Mass Potentially Addressed (lbs) MSP Alternative M200 Alternative M150 Alternative M100 Alternative M8 Alternative M6 Alternative M5 Alternative M3 Alternative M9 Alternative figure 6.2 Relationship Between Estimated Cost and Estimated Quantity of TCVOC Mass Potentially Addressed Occidental Chemical Corporation, Tacoma, Washington 007843 (139) $65,000,000 $60,000,000 $55,000,000 Annual Amount (dollars) $50,000,000 $45,000,000 $40,000,000 $35,000,000 $30,000,000 $25,000,000 $246M $70,000,000 Year 0 Year 2 Year 4 Year 6 Year 8 Year 10 Year 12 Year 14 Year 16 Year 18 Year 20 Year 22 Year 24 Year 26 Year 28 Year 30 Year 1 Year 3 Year 5 Year 7 Year 9 Year 11 Year 13 Year 15 Year 17 Year 19 Year 21 Year 23 Year 25 Year 27 Year 29 $20,000,000 $15,000,000 $10,000,000 $5,000,000 $0 Alternative M100 ($55,442,430) Alternative M150 ($55,838,770) Alternative M200 ($56,232,640) Alternative MSP ($54,877,530) Alternative M3 ($57,022,480) Alternative M5 ($66,368,280) Alternative M6 ($68,144,380) Alternative M8 ($142,006,010) Alternative M9 ($401,254,360) figure 6.3 VOC Mass Alternatives 30-Year Cash Flow Projections Occidental Chemical Corporation, Tacoma, Washington 007843 (139) M100/M150/M200 Groundwater Extraction Installation of Wells and Conveyance O&M MSP Strategic Groundwater Pumping M3 Excavation of shallow soil and on-site treatment Installation of System O&M Excavation to -4 ft NGVD LEGEND Ex Situ SVE CONSTRUCTION/INSTALLATION ACTIVITIES M5 In Situ Treatment of TCVOC in shallow soil and groundwater M6 Combination of M3 and M5 O&M ACTIVITIES SOIL EXCAVATION In Situ ERH and SVE EX SITU SOIL VAPOR EXTRACTION (SVE) IN SITU ELECTRICAL RESISTENCE HEATING (ERH) WITH SOIL VAPOR EXTRACTION (SVE) Excavation to -4 ft NGVD IN SITU CHEMICAL OXIDATION (ISCO) ENHANCED IN SITU BIOREMEDIATION (ISB) Ex Situ SVE In Situ ERH and SVE M8 ISCO and ISB Treatment of shallow groundwater plus M5 In Situ ERH and SVE M9 ISCO and ISB Treatment of shallow and deep groundwater and soil plus M5 In Situ ERH and SVE NOTES: SVE ERH ISCO ISB ISCO - Shallow ISB - Shallow ISCO - Shallow and Deep ISB - Shallow and Deep SOIL VAPOR EXTRACTION ELECTRICAL RESISTANCE HEATING IN SITU CHEMICAL OXIDATION ENHANCED IN SITU BIOREMEDIAITON 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 92 96 100 Years OCCIDENTAL CHEMICAL CORPORATION TACOMA, WASHINGTON VOC MASS ALTERNATIVES TECHNOLOGIES ESTIMATED DURATIONS 007843-C2D2-403 January 17, 2017 FIGURE 6.4 Estimated Quantity of TCVOC Mass Potentially Addressed (lbs) 700,000 M9 Alt. at 20yrs. 600,000 500,000 400,000 300,000 MSP Alt. at 100yrs. M200 Alt. at 100yrs. M150 Alt. at 100yrs. M100 Alt. at 100yrs. MSP Alt. at 20yrs. M200 Alt. at 20yrs. M150 Alt. at 20yrs. M100 Alt. at 20yrs. MSP Alt. at 2yrs. 200,000 M200 Alt. at 2yrs. 100,000 M150 Alt. at 2yrs. M6 Alt. at 2yrs. M5 Alt. at 2yrs. M100 Alt. at 2yrs. M3 Alt. at 2yrs. 0 0 10 M8 Alt. at 20yrs. 20 30 40 50 60 70 80 90 100 Years M9 Alt. at 20yrs. M8 Alt. at 20yrs. M6 Alt. at 2yrs. M5 Alt. at 2yrs. M3 Alt. at 2yrs. M200 Alt. at 2yrs. M200 Alt. at 20yrs. M200 Alt. at 100yrs. M150 Alt. at 2yrs. M150 Alt. at 20yrs. M150 Alt. at 100yrs. M100 Alt. at 2yrs. M100 Alt. at 20yrs. M100 Alt. at 100yrs. MSP Alt. at 2yrs. MSP Alt. at 20yrs. MSP Alt. at 100yrs. figure 6.5 Relationship Between Estimated Time and Estimated Quantity of TCVOC Mass Potentially Addressed Occidental Chemical Corporation, Tacoma, Washington 007843 (139) 900 Estimated Total ANC (Megaequivalents [Meq] acid) 800 700 600 ANC (Meq acid) 500 400 300 200 23.3% 23.3% 11.2% 11.2% 100 23.3% 11.2% 0 pH5 - Shallow and Deep pH Reduction pH2 - Shallow pH Reduction pH6 - Shallow and Deep Enhanced Containment - Treatment pH3 - Shallow Enhanced Containment - Treatment pH7 - Shallow and Deep Enhanced Containment - Vertical Barrier pH4 - Shallow Enhanced Containment - Vertical Barrier pH Reduction/Enhance Containment Alternative pH (ANC) Targeted Remaining pH (ANC) figure 7.1 pH (ANC) Targeted by Alternatives Comparison Occidental Chemical Corporation, Tacoma, Washington 007843 (139) $200,000,000 pH5 Alternative Estimated Total ANC (Megaequivalents [Meq] acid) $180,000,000 $160,000,000 Estimated Cost (dollars) $140,000,000 $120,000,000 pH6 Alternative pH2 Alternative $100,000,000 $80,000,000 pH3 Alternative pH7 Alternative $60,000,000 pH4 Alternative $40,000,000 $20,000,000 $0 0 100 200 300 400 500 600 700 800 Estimated Quantity of pH (ANC) Potentially Addressed (Meq acid) pH5 Alternative pH2 Alternative pH6 Alternative pH3 Alternative pH7 Alternative pH4 Alternative figure 7.2 Relationship Between Estimated Cost and Estimated Quantity of pH (ANC) Potentially Addressed Occidental Chemical Corporation, Tacoma, Washington 007843 (139) $180,000,000 Year 0 Year 2 Year 4 Year 6 Year 8 Year 10 Year 12 Year 14 Year 16 Year 18 Year 20 Year 22 Year 24 Year 26 Year 28 Year 30 $160,000,000 Annual Amount (dollars) $140,000,000 $120,000,000 $100,000,000 $80,000,000 Year 1 Year 3 Year 5 Year 7 Year 9 Year 11 Year 13 Year 15 Year 17 Year 19 Year 21 Year 23 Year 25 Year 27 Year 29 $60,000,000 $40,000,000 $20,000,000 $0 Alternative pH2 ($107,551,480) Alternative pH3 ($71,338,780) Alternative pH4 ($56,742,280) Alternative pH5 ($190,144,280) Alternative pH6 ($117,042,280) Alternative pH7 ($66,204,680) figure 7.3 pH Alternatives 30-Year Cash Flow Projections Occidental Chemical Corporation, Tacoma, Washington 007843 (139) pH2/pH3 Reduction/Enhanced Containment of pH in shallow soil and groundwater Soil Mixing LEGEND SOIL MIXING ACTIVITIES SLURRY WALL INSTALLATION pH4 Enhanced Containment of pH in shallow soil and groundwater Slurry Wall pH5/pH6 Reduction/Enhanced Containment of pH in shallow Soil Mixing and deep soil and groundwater pH7 Enhanced Containment of pH in shallow and deep soil and groundwater Slurry Wall 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 92 96 100 Years OCCIDENTAL CHEMICAL CORPORATION TACOMA, WASHINGTON pH ALTERNATIVES TECHNOLOGIES ESTIMATED DURATIONS JOB NUMBER 007843-C2D2-403 DATE December 9, 2016 FIGURE 7.4 Page 1 of 2 Table 2.1 Sitewide COC and Media Occidental Chemical Corporation Tacoma, Washington Contaminant of Concern Groundwater (COC) VOCs 1,1,2,2-Tetrachloroethane √ 1,1,2-Trichloroethane √ 1,1-Dichloroethene √ Carbon tetrachloride √ Chloroform (Trichloromethane √ Ethylbenzene √ Methylene chloride √ Tetrachloroethene √ cis-1,2-Dichloroethene √ trans-1,2-Dichloroethene Trichloroethene √ Vinyl chloride √ 1,1,1-Trichloroethane NA 1,2,4-Trimethylbenzene NA 1,4-Dichlorobenzene NA Benzene m & p-Xylenes Naphthalene o-Xylene Styrene NA Toluene SVOCs 1,2,4-Trichlorobenzene NA bis(2-Ethylhexly) phthalate NA Hexachlorobutadiene √ Hexachlorobenzene √ Pentachlorophenol √ Acenaphthene Acenaphthylene NA Anthracene Benz(a)anthracene Benzo(a)pyrene Benzo(b)fluoranthene Benzo(k)fluoranthene Chrysene Dibenz(a,h)anthracene Fluoranthene Fluorene Indeno(1,2,3-cd)pyrene 2-Methylnaphthalene Naphthalene Phenanthrene NA Pyrene - GHD 007843 (139) Porewater Unsaturated Soil Saturated Soil Sediment Indoor Air NA √ NA NA NA NA - √ √ NA √ NA √ √ NA NA NA NA - √ √ √ √ √ NA √ √ NA √ √ √ NA NA NA √ NA - NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA √ √ √ √ NA √ √ √ √ √ √ √ - NA NA - NA NA √ √ √ NA √ √ √ √ √ √ √ NA - NA NA √ √ √ NA √ √ √ √ √ √ √ √ NA - NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA √ √ √ NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Page 2 of 2 Table 2.1 Sitewide COC and Media Occidental Chemical Corporation Tacoma, Washington Contaminant of Concern (COC) Pesticides/PCBs 4,4'-DDD 4,4'-DDE 4,4'-DDT Total PCBs Dioxin-Furan (2,3,7,8 TCDD) Metals Antimony Arsenic Cadmium Chromium, total Copper Lead Mercury Nickel Silver Thallium Zinc Other pH Groundwater Porewater Unsaturated Soil Saturated Soil Sediment Indoor Air √ √ NA - √ √ NA √ √ √ √ NA NA NA NA NA NA NA NA √ NA √ √ √ √ √ NA √ √ - NA √ NA √ √ √ √ √ NA √ NA √ NA √ √ √ √ √ NA √ √ NA NA - NA NA NA NA NA NA NA NA NA NA √ - NA NA NA NA Notes: √ NA COC exceeds criterion in media indicated. COC does not exceed criterion in media. COC does not apply to the media or there is no established criteria. GHD 007843 (139) Page 1 of 2 Table 3.3 Remedial Action Goals and General Response Actions Occidental Chemical Corporation Tacoma, Washington Environmental Medium Groundwater Surface Water GHD 007843 (139) General Response Remedial Action Objectives (1) 1. Prevent discharge of contaminated groundwater to Hylebos Waterway and Commencement Bay resulting in surface water contaminant concentrations exceeding AWQC and applicable health based standards for aquatic life and human consumption of resident fish and shellfish. 2. Prevent discharge of contaminated groundwater to sediments in the Hylebos Waterway and Commencement Bay at concentrations that will re-contaminate the sediments above sediment quality standards for Site contaminants and applicable health based standards for aquatic life and human consumption of resident fish. 3. Prevent use of aquifer groundwater for drinking water, irrigation, or industrial purposes which would result in unacceptable risks to human health. 4. Prevent further migration of the contaminant plume and high pH plume to prevent the spread of contaminated groundwater to the Hylebos waterway, Commencement Bay, and non-impacted portions of the aquifer. 1. Prevent marine ecological receptors from contacting surface waters that have contaminant concentrations that exceed surface water cleanup levels. 2. Prevent migration of hazardous substances, pollutants or contaminants to the surface waters at concentrations that exceed surface water cleanup levels. 3. Control bioaccumulation exposures to human receptors associated with releases to surface water from the Site. Actions No Action Institutional Controls Containment/Extraction In-Situ Treatment Ex-Situ Treatment General Response Actions for groundwater, sediment, and soil are protective of surface water Page 2 of 2 Table 3.3 Remedial Action Goals and General Response Actions Occidental Chemical Corporation Tacoma, Washington Environmental Medium Soil General Response Remedial Action Objectives (1) 1. Prevent human health risks associated with direct contact, ingestion or inhalation of shallow soil contaminated above levels for industrial use 2. Prevent terrestrial ecological receptors from contacting soils that have contaminant concentrations that exceed industrial soil cleanup levels. 3. Prevent migration of hazardous substances, pollutants or contaminants from soil to the surface waters at concentrations that exceed surface water cleanup levels Indoor Air 1. Prevent human exposure to hazardous substances, pollutants, or contaminants from subsurface soil vapor at concentrations in excess of applicable standards and risk based cleanup levels. Actions No Action Institutional Controls Containment In-Situ Treatment Ex-Situ Treatment Removal Disposal No Action Institutional Controls Containment/Extraction In-Situ Treatment Ex-Situ Treatment Note: (1) Remedial Action Objectives (RAOs) for groundwater, sediment, soil, and indoor air are based on revisions captured in a February 10, 2015 email communication from Kevin Rochlin (USEPA Project Manager) in consultation with Ecology. GHD 007843 (139) Table 3.4 Page 1 of 3 Potential Applicable Local, State, and Federal Laws and Relevant and Appropriate Requirements Occidental Chemical Corporation Tacoma, Washington Regulatory Citation Topic Standard or Requirement Hazardous Substance Cleanup Washington State Cleanup Standards; Cleanup Screening Levels (CSL) Surface Water Quality Surface water quality standards. National Recommended Water Quality Criteria (WQC); National Toxics Rule (NTR); State Water Quality Standards (WQS); Clean Water Act and NPDES Requirements Model Toxics Control Act (MTCA) Federal State and Local Project-Specific Comments Model Toxics Control Act (MTCA) (RCW 70.105D; WAC 173-340) Applicable to determining cleanup of hazardous waste sites to protect human health and the environment. WQC per Clean Water Act Section 304(a) (33 USC § 1314) NTR at 40 CFR 131.36(b)(1) as applied to Washington, 40 CFR 131.36(d)(14) 40 CFR 122-125 Water Pollution Control Act (RCW 90.46); WQS (WAC 173201A); Aquatic Life Criteria (ALC) numerical criteria (WAC 173201A-240) Relevant to remedial actions impacting contaminant migration to surface water and groundwater. Applicable to remedial actions involving discharge to a POTW. Substantive requirements will be applicable to any alternative that discharges effluent to surface water. State Waste Discharge Program; Clean Water Act Pretreatment Requirements 40 CFR Part 403 and 405-471 WAC-173-216 Applicable if the option of discharge to the sanitary sewer (POTW) is part of a remedy. Substantive requirements must be met. Solid Waste Disposal Requirements for solid waste handling management and disposal Solid Waste Disposal Act (42 U.S.C 6901-6992K; 40 CFR 257-258) Solid Waste Management (RCW 70.95; WAC 173-350) Substantive requirements for non-dangerous or non-hazardous waste generated during remedial activities unless wastes meet recycling or other exemptions will be complied with. Waste Treatment, Storage, and Disposal Dangerous or Hazardous Waste Management Ecology Dangerous Waste Regulations Resource Conservation and Recovery Act, Hazardous Waste (42 U.S.C §§ 69016992K, 40 CFR 260-279) Dangerous Waste Management (RCW 70.105; WAC 173-303) Applicable if remedial activities include land disposal of RCRA hazardous waste, such as that generated from excavation of waste that is characterized as hazardous. Transportation of Hazardous Waste 49 CFR 170-189 Land Disposal of Waste Management and disposal of materials containing polychlorinated biphenyls (PCBs) Hazardous Waste Land Disposal Restrictions Dredge/Fill and Other In-Water Construction Work Discharge of dredged/fill material into navigable waters or wetlands Navigation and Commerce GHD 007843 (139) Toxic Substances Control Act (15 U.S.C § 2605; 40 CFR 761.61(c )) Resource Conservation and Recovery Act Land Disposal Restrictions (42 U.S.C §§ 6901-6992K; 40 CFR 268) Clean Water Act Sections 401, 404 (33 U.S.C §§ 1341, 1344; 40 CFR 121.2 (content of 401 certifications), 230 (disposal sites/mitigation), 232 (definitions/exemptions); 33 CFR 320, 322-3, 328-30 (Army Corps of Engineers 404 Permitting)) Rivers and Harbor Act Section 10 (33 U.S.C. § 403) Applicable to remedial activities that involve the off-Site transportation of hazardous waste Dangerous Waste Management (RCW 70.105; WAC 173-303- 140, 141) Any dangerous or hazardous waste land disposal shall meet substantive land disposal requirements. Hydraulic Code Rules (RCW 77.65; WAC 220-110) Dredged Materials Management Program (DMMP) (RCW 79.105.500; WAC 332-30166 (3)) Applicable to construction of barrier wall east. Unauthorized obstruction or alteration of navigable waterways is prohibited. In-water dredging and disposal are not anticipated. Table 3.4 Page 2 of 3 Potential Applicable Local, State, and Federal Laws and Relevant and Appropriate Requirements Occidental Chemical Corporation Tacoma, Washington Regulatory Citation Topic Standard or Requirement Federal State and Local Project-Specific Comments Endangered Species and Critical Habitat Taking or jeopardy to endangered or threatened species; adverse modification of critical habitat Endangered Species Act (16 U.S.C.§§ 1531-1544; 50 CFR 17 (listings, prohibitions), 402 (interagency consultations), 222-224 (endangered and threatened marine species), 226.212 (critical habitat for Northwest salmon and steelhead)) It is unlawful to take (or possess, deliver, carry, transport or ship) any endangered species, or violate any regulation re-endangered or threatened species. EPA in consultation with the Services shall insure any authorized action is not likely to jeopardize endangered or threatened species or adversely modify critical habitat, absent an exemption. Migratory Birds Taking or adversely affecting migratory birds Migratory Bird Treaty Act, (16 U.S.C §§ 703-712; 50 CFR 10 and 21) Applicable to avoid adversely affecting migratory bird species as defined in federal regulations, including individual birds and their nests. Eagles Taking or harming eagles Bald and Golden Eagle Protection Act (16 U.S.C. § 668, 50 CFR 22) Floodplain Protection Adverse impacts; potential harm Floodplain Management Procedures (40 CFR 6, Appendix A, Section 6, see also Executive Order 11988) Shoreline Management Construction and development Air Emissions Taking or harming of eagles, their eggs, nests or young is prohibited; substantive requirements for the protection of bald eagle habitat including nesting, perching and roosting at the site will be met. Applicable to avoid potential adverse impacts and to minimize impacts for which no practical alternative exists. Shoreline Management Act RCW 90.58; WAC 173-26; City of Tacoma Shoreline Master Program; Pierce County Shoreline Master Program (18S.10.010 Title.21) Master plans within their jurisdiction apply within 200 feet of the shoreline to the extent they impose or establish more stringent requirements. Washington Clean Air Act (RCW 70.94; WAC 173-400) Some treatment alternatives may impact ambient air quality. Substantive requirements will be applicable if alternative results in emission from treatment processes. Ambient air quality standards; fugitive emission/fugitive dust Clean Air Act (42 U.S.C. §§ 7401-7671q; 40 CFR 50) National Ambient Air Quality Standards (NAAQS) 40 CFR Part 50 Applicable to treatment alternatives that may emit pollutants to the air, establishes standards to protect health and welfare. National Emission Standards for Hazardous Air Pollutants (NESHAPs) 40 CFR Part 261 Applicable to treatment alternatives that my emit toxic pollutants to the air. State Environmental Policy Act (SEPA) Native American Graves Protections and Sacred Sites GHD 007843 (139) Bald Eagle Protection Rules (RCW 77.12.655; WAC 232-12-292) WAC 192-11 Native American Graves Protection and Repatriation Act (25 U.S.C. §§ 3001 et seq.); American Indian Religious Freedom Act (42 U.S.C. §§ 1196 et seq.) SEPA checklist may be required prior to construction of the remediation system. Requirements for the protection of Native American remains, funerary objects and associated cultural artifacts when burial sites are encountered; and protection of tribal exercise of traditional tribal religions, including traditional cultural properties, sites and archeological resources. See also Executive Order 13007 which requires federal agencies to avoid physical damage to tribal sacred sites, and interfering with access of tribes thereto. Table 3.4 Page 3 of 3 Potential Applicable Local, State, and Federal Laws and Relevant and Appropriate Requirements Occidental Chemical Corporation Tacoma, Washington Regulatory Citation Topic Noise Standard or Requirement Federal Permissible noise levels Historic Preservation State and Local Noise Control Act (RCW 70.107;WAC 173-60-040-050) Project-Specific Comments Maximum levels at specified times for specified durations are WAC 173-60-040, subject to exemptions in WAC 173-60-050, including 050(3) (a) ( sounds originating from temporary construction sites as a result of construction activity) and (3)(f) (sounds created by emergency equipment and work necessary in the interests of law enforcement or for health, safety or welfare of the community). National Historic Preservation Act Section 106 (16 U.S.C. § 470; 36 CFR 800) Potentially applicable if potential remedial activity on the site, building, structure, or object included or eligible for inclusion in the National Register of Historic Places. 40 CFR 144 and 146 To be considered for any in situ remediation technologies that involve injection into an aquifer. Groundwater Quality EPA Underground Injection Control (UIC) Program Regulations Construction City of Tacoma requirements Establishes criteria for review and analysis of all development, including grading, erosion control, and property development. Requires permits for excavation of soil in excess of 50 cubic yards and construction and demolition activities. SEPA checklist required if soil excavation is greater than 500 cubic yards. Permit required for connection if effluent water from the treatment system to the storm drain system. Even though it is necessary to meet the substantive provisions of these permits, appropriate permits should be obtained from the City for future site work in the spirit of cooperation. Tacoma Power Permits required for power connections and wiring for remediation systems. GHD 007843 (139) Table 4.1 Page 1 of 1 Identified Alternatives and Groupings Occidental Chemical Corporation Tacoma, Washington Group Containment Identification Nomenclature Technology/ Process Options Included No action C100 Barrier wall east, physical direct contact exposure (PDCE) barrier, hydraulic containment C150 Barrier wall east, physical direct contact exposure (PDCE) barrier, hydraulic containment with up to 50 percent more pumping C200 Barrier wall east, physical direct contact exposure (PDCE) barrier, hydraulic containment with up to 100 percent more pumping No additional action VOC Mass Removal / Reduction M100 M150 M200 VOC source area groundwater (gw) extraction VOC source area gw extraction with up to 50 percent more pumping VOC source area gw extraction with up to 100 percent more pumping MSP VOC source area mass reduction by strategic groundwater pumping M3 VOC source area shallow soil excavation (TCVOC≥100mg/kg) to -4 ft. NGVD with on-site treatment M4 VOC source area shallow soil excavation (TCVOC≥100mg/kg) to -4 ft. NGVD with off-site treatment/ disposal M5 VOC source area shallow soil treatment (TCVOC≥500mg/kg) using ERH in saturated zone 2.5 ft. to -21 ft. NGVD and SVE in vadose zone M6 VOC source area shallow soil treatment (TCVOC≥500mg/kg) using ERH from -4 ft. to -21 ft. NGVD with SVE to collect soil gas from ERH, and soil excavation to -4 ft. NGVD with on-site treatment M7 VOC source area shallow soil treatment (TCVOC≥500mg/kg) using ERH from -4 ft. to -21 ft. NGVD with SVE to collect soil gas from ERH, and soil excavation to -4 ft. NGVD with off-site treatment/ disposal M8 VOC shallow gw treatment (TCVOC≥10,000µg/L) using ISCO within pH 10-12.5s.u. and ISB within pH <10s.u. to -60 ft. NGVD, VOC source area shallow soil treatment (TCVOC≥500mg/kg) using SVE in vadose zone and ERH in saturated zone 2.5 ft.to -21 ft. NGVD M9 VOC shallow and deep gw treatment (TCVOC≥10,000µg/L) using ISCO within pH 10-12.5s.u. and ISB within pH <10s.u., VOC source area shallow and deep soil treatment (TCVOC≥500mg/kg) using SVE in vadose zone, ERH in saturated zone 2.5 ft. to -21 ft. NGVD, and ISCO/ ISB below -60 ft. NGVD pH2 pH ≥12.5s.u. in shallow soil and gw treatment using in situ mixing (persulfate) to -60 ft. NGVD pH3 pH ≥12.5s.u. in shallow soil and gw treatment using in situ mixing (cement) to -60 ft. NGVD No additional action pH ≥12.5s.u. Reduction / Enhanced Containment Notes: ERH ISCO ISB TCVOC ft. NGVD mg/kg µg/L s.u. pH4 Enhance containment of pH ≥12.5s.u. in shallow gw using slurry walls to -60 ft. NGVD pH5 pH ≥12.5s.u. in shallow and deep soil and gw treatment using in situ mixing (persulfate) pH6 pH ≥12.5s.u. in shallow and deep soil and gw treatment using in situ mixing (cement) pH7 Enhance containment of pH ≥12.5s.u. in shallow and deep gw using slurry walls electrical resistance heating in situ chemical oxidation in situ bioremediation total chlorinated volatile organic compounds feet above/below National Geodetic Vertical Datum milligrams per kilogram micrograms per liter standard units of pH GHD 007843 (139) Page 1 of 1 Table 5.1 Disproportionate Cost Analysis Criteria Site-Specific Weighting Percentages and Rationale Occidental Chemical Corporation Tacoma, Washington Evaluation Criteria and WAC Citations Weighting Percentages and Rationales Considerations Protectiveness: WAC 173-340-360(3)(f)(i) 30%: highest weighting percentage because it is a minimum or threshold requirement Permanence: WAC 173-340-360(3)(f)(ii) 20%: higher weighting percentage because of MTCA requirement to use permanent solutions to maximum extent practicable 20%: higher weighting percentage because of MTCA requirement to try and achieve a reasonable restoration time frame 10%: Weighting percentage assigned because the short-term risks for the proposed alternatives are manageable with standard industry practice 10%: Weighting percentage assigned because the technologies are all considered to be readily implementable 10%: Weighting percentage assigned because 2016 porewater / sediment data alleviates the main issues raised by public in during Public Comment Period from October 23, 2015 to February 1, 2016 Protection of human health and environment; Comply with clean up standards; Comply with applicable state and federal laws; Provide compliance monitoring Reduction in quantity of hazardous substances Effectiveness Over the Long Term: WAC 173-340-360(3)(f)(iv) Management of Short-term Risks: WAC 173-340-360(3)(f)(v) Technical and Administrative Implementability: WAC 173-340-360(3)(f)(vi) Consideration of Public Concerns: WAC 173-340-360(3)(f)(vii) Degree of certainty that the remedial alternative will be effective over the long term; Reliability of institutional and engineering controls Ease of managing short-tem risks Technical complexity of technologies; Administrative (legal, regulatory, and monitoring) requirements Consider potential public support for each alternative Notes: The Cost criterion [WAC 173-340-360(3)(f)(iii)] is not listed above because it is not weighted or ranked in the disproportionate cost analysis (DCA). WAC - Washington Administrative Code. MTCA - Model Toxics Control Act Regulation and Statute. GHD 007843 (139) Page 1 of 1 Table 5.3 Disproportional Cost Analysis (DCA) - Containment Alternatives Occidental Chemical Corporation Tacoma, Washington Alternative C150 Alternative C200 Yes Yes Yes Yes Yes Yes Yes Yes Benefit Scoring 9 5 8 8 8 5 Benefit Scoring 9 5 8 8 8 5 7.4 7.4 Threshold Criteria Protection of Human Health and the Environment Compliance with Cleanup Standards Compliance with Applicable State and Federal Laws Provision for Compliance Monitoring Weighted Benefits Rankings/Scores for DCA (1 [lowest] to 10 [highest]) 1 Weighted Criteria (refer to Table 5.1 for explanation of weighting) 30% Overall Protectiveness 20% Permanence 20% Long-Term Effectiveness 10% Management of Short-Term Risk 10% Implementability 10% Consideration of Public Concerns Total Benefit Score (weighted)2 Alternatives Costs3 Estimated Costs (-30% to +50%; 30-years at 7% discount rate) Capital Operation and Maintenance/Periodic Total Estimated Alternative Cost Unit Benefit per Cost Ratio4 (multiplied by 10,000,000) $ $ $ 38,700,240 15,656,240 54,356,480 1.36 $ $ $ 38,700,240 16,490,000 55,190,240 1.34 Notes: GHD 007843 (139) 1 Higher scores equate to a higher level of relative benefit. 2 The Total Benefit Score (weighted) was calculated by multiplying each Benefit Score by multiplying each Benefit Score by the corresponding Weighted Criteria percent, then summing the weighted values. 3 Alternative costs in Appendix G. 4 Unit Benefit per Cost Ratio calculated by dividing the Total Benefit Score (weighted) by the total alternative cost (in 10 millions). A higher ratio indicates the most benefit for the associated cost. Page 1 of 1 Table 6.2 Disproportional Cost Analysis (DCA) - VOC Mass Reduction/Removal Alternatives Occidental Chemical Corporation Tacoma, Washington Threshold Criteria1 Protection of Human Health and the Environment Compliance with Cleanup Standards Compliance with Applicable State and Federal Laws Provision for Compliance Monitoring Weighted Benefits Rankings/Scores for DCA (1 [lowest] to 10 [highest])2 Weighted Criteria (refer to Table 5.1 for explanation of weighting) 30% Overall Protectiveness 20% Permanence 20% Long-Term Effectiveness 10% Management of Short-Term Risk 10% Implementability 10% Consideration of Public Concerns Total Benefit Score (weighted)3 Alternatives Costs4 Estimated Costs (-30% to +50%; 30-years at 7% discount rate) Capital Operation and Maintenance/Periodic Total Estimated Alternative Cost Unit Benefit per Cost Ratio5 (multiplied by 10,000,000) Alternative MSP Alternative M9 Alternative M200 Alternative M150 Alternative M100 Alternative M8 Alternative M6 Alternative M5 Alternative M3 Alternative No Additional Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Action Yes Yes Yes Yes 9 6 7 8 9 5 9 8 7 5 6 5 9 5 7 8 9 5 9 5 7 8 9 5 9 5 7 8 9 5 9 4 7 5 7 5 9 3 7 7 9 5 9 3 7 7 9 5 9 2 7 8 9 5 9 1 1 10 10 5 7.5 7.3 7.3 7.3 7.3 6.6 6.8 6.8 6.7 5.6 $ 38,854,780 $ 16,022,750 $ 54,877,530 $ 354,880,940 $ 46,373,420 $ 401,254,360 $ 38,903,190 $ 17,329,450 $ 56,232,640 $ 38,903,190 $ 16,935,580 $ 55,838,770 $ 38,903,190 $ 16,539,240 $ 55,442,430 $ 114,264,240 $ 27,741,770 $ 142,006,010 $ 52,488,140 $ 15,656,240 $ 68,144,380 $ 50,712,040 $ 15,656,240 $ 66,368,280 $ 41,366,240 $ 15,656,240 $ 57,022,480 $ 38,700,240 $ 15,656,240 $ 54,356,480 1.37 0.18 1.30 1.31 1.32 0.46 1.00 1.02 1.17 1.03 Notes: 1 Meeting threshold criteria assumes containment technologies are part of an overall remedy. 2 Higher scores equate to a higher level of relative benefit. 3 The Total Benefit Score (weighted) was calculated by multiplying each Benefit Score by multiplying each Benefit Score by the corresponding Weighted Criteria percent, then summing the weighted values. 4 Alternative costs in Appendix G. 5 Unit Benefit per Cost Ratio calculated by dividing the Total Benefit Score (weighted) by the total alternative cost (in 10 millions). A higher ratio indicates the most benefit for the associated cost. GHD 007843 (139) Page 1 of 1 Table 7.2 Disproportional Cost Analysis (DCA) - pH Reduction/Enhanced Containment Alternatives Occidental Chemical Corporation Tacoma, Washington Threshold Criteria1 Protection of Human Health and the Environment Compliance with Cleanup Standards Compliance with Applicable State and Federal Laws Provision for Compliance Monitoring Weighted Benefits Rankings/Scores for DCA (1 [lowest] to 10 [highest])2 Weighted Criteria (refer to Table 5.1 for explanation of weighting) 30% Overall Protectiveness 20% Permanence 20% Long-Term Effectiveness 10% Management of Short-Term Risk 10% Implementability 10% Consideration of Public Concerns Total Benefit Score (weighted)3 Alternative pH5 Alternative pH2 Alternative pH6 Alternative pH3 Alternative pH7 Alternative pH4 Alternative No Additional Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Action Yes Yes Yes Yes 9 3 3 5 4 5 9 2 2 5 6 5 9 1 1 4 4 5 9 1 1 5 6 5 9 1 1 6 5 5 9 1 1 7 7 5 9 1 1 10 10 5 5.3 5.1 4.4 4.7 4.7 5 5.6 $ 174,488,040 $ 15,656,240 $ 190,144,280 $ 91,895,240 $ 15,656,240 $ 107,551,480 $ 101,386,040 $ 15,656,240 $ 117,042,280 $ 55,682,540 $ 15,656,240 $ 71,338,780 $ 50,548,440 $ 15,656,240 $ 66,204,680 $ 41,086,040 $ 15,656,240 $ 56,742,280 $ 38,700,240 $ 15,656,240 $ 54,356,480 0.28 0.47 0.38 0.66 0.71 0.88 1.03 4 Alternatives Costs Estimated Costs (-30% to +50%; 30-years at 7% discount rate) Capital Operation and Maintenance/Periodic Total Estimated Alternative Cost Unit Benefit per Cost Ratio5 (multiplied by 10,000,000) Notes: 1 Meeting threshold criteria assumes containment technologies are part of an overall remedy. 2 Higher scores equate to a higher level of relative benefit. 3 The Total Benefit Score (weighted) was calculated by multiplying each Benefit Score by multiplying each Benefit Score by the corresponding Weighted Criteria percent, then summing the weighted values. 4 Alternative costs in Appendix G. 5 Unit Benefit per Cost Ratio calculated by dividing the Total Benefit Score (weighted) by the total alternative cost (in 10 millions). A higher ratio indicates the most benefit for the associated cost. GHD 007843 (139) Appendices GHD Report for Glenn Springs Holdings, Inc. Feasibility Study 007843 (139) Appendix A State of Washington Department of Ecology Groundwater Non-Potable Determination GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) STATE OF WASHINGTON DEPARTMENT OF ECOLOGY Lacey HQ ● 300 Desmond Dr. ● Lacey, Washington 98503 ● (360) 407-6000 March 30th, 2015 TO: Kerry Graber, HWTR FROM: Charles San Juan, LHG, TCP-HQ Charles San Juan SUBJECT: Groundwater Non-Potability Designation, former Occidental Chemical (OCC) Site, Tacoma. Summary This transmittal provides both the legal framework and technical justification for designating the Occidental site groundwater as non-potable (unfit for human consumption). Briefly, this non-potability designation is based on two components within MTCA Section 720. First, Ecology has determined that site groundwater is not a current source or future source of drinking water. Second, Ecology, as well as CRA (2014), have determined that site groundwater contains naturally occurring saltwater levels, which renders it unfit for human consumption. Lastly, Ecology (1995) has completed a Comprehensive Ground Water Protection Program (CGWPP). If a state has completed a CGWPP, then the EPA remediation program may defer to the state for groundwater current / future use designations (EPA, 1997). This means that Ecology now has jurisdiction for this current / future use designation, per prior agreement with EPA. Conceptual Site Model The groundwater non-potability designation means the human ingestion of groundwater exposure pathway does not apply to this site. Therefore, the final cleanup remedy for this site will be based on two exposure pathways: 1) groundwater discharge to surface water, which includes marine sediments /aquatic life and 2) vapor intrusion (human inhalation of indoor air). Organization of this Transmittal There are four parts to this document. A brief synopsis of each part is as follows: • Part I contains background information (site description, land use, geology / hydrogeology, etc). • Part II provides information on the MTCA Section 720 criteria for designating non-potable groundwater. Part II also contains an analysis of current fresh / saltwater conditions. • Part III provides information on the EPA guidelines / criteria for groundwater non-potability. 1 • Part IV provides a conclusion and summary observations. Part I – Background Information Site Description The Occidental Chemical (OCC) property (605 and 709 Alexander Avenue) is located within a man-made peninsula of land that extends roughly 0.8 miles northwest into Commencement Bay (Figure 1). The Port of Tacoma (POT) is the primary owner / operator for this area. The Occidental “site” (where hazardous substances are located, MTCA Section 200) is part of the EPA Commencement Bay Nearshore/Tideflats (CB/NT) Superfund Site. An affiliate of OCC (Mariana Properties), now owns the 605 Alexander Avenue parcel. The 709 Alexander parcel has also been conveyed to Mariana Properties (CRA, 2014). Historical OCC Operations Chlorinated solvents (TCE / PCE), were manufactured at the OCC facility from approximately 1947 – 1973. Historical solvent releases from former OCC operations have impacted the peninsula soil, groundwater and adjoining Hylebos Waterway sediment (CRA, 2014). Land Use / History Historical transcontinental railroad traffic to Commencement Bay resulted in the need for rail to sea transport. However, the flat tidal mud flats were not suitable for deep draft vessels. Consequently, to accommodate shipping traffic, five man-made peninsulas were constructed (from tidal mud flats dredge / fill). The former OCC site is located on the peninsula that intersects both the Blair and Hylebos waterways. Site Geology / Hydrogeology The former OCC site is located at the mouth of the Puyallup River valley, which empties to Commencement Bay. Several creeks also discharge to Commencement Bay (Ruston, Mason, Asarco, Puget, Hylebos and Wapato). Historically, the hydrogeology of this area was tidal marsh / estuary, as well as Puyallup River deltaic deposits. A key point is that the OCC site is located on land reclaimed from the sea. Therefore, the natural state (or occurrence) of underlying groundwater has probably always been more of a fresh / saltwater mix (brackish). Part II – MTCA Section 720 Criteria Groundwater Non-Potability Criteria Non-potable groundwater is defined in MTCA Section 720 (Chapter 173-340 WAC). Groundwater may be deemed non-potable if it is demonstrated that it is not a current or future drinking water source. There are several criteria for non-potability. A brief description of key criteria as well as whether it applies to this OCC site is provided herein. 2 Yield If the groundwater yield is less than 0.5 gpm on a “sustainable” basis, then it can be assumed that the groundwater is non-potable. This criteria is not met at the Occidental Site because yields greater than 0.5 are routinely observed in groundwater extraction wells and in groundwater monitoring wells. Natural Background Concentrations If there are naturally occurring substances that render groundwater non-potable, then the aquifer can be designated as non-potable. The OCC site groundwater has been impacted by salinity intrusion from the surrounding waterways. Therefore, this site does qualify for the natural background (salinity) nonpotability designation. The remainder of this section speaks to two substances that were used to quantify naturally occurring salinity levels: total dissolved solids (TDS) and bromide. Total Dissolved Solids Per the Section 720 regulations, groundwater with naturally occurring total dissolved solids (TDS) levels > 10,000 mg/L may be deemed non-potable. TDS measures minerals and salts dissolved in water. TDS are typically those compounds that cannot be removed by traditional water filters. The EPA secondary drinking water standard for TDS is 500 mg/L. As part of a salinity intrusion study (CRA, 2013), groundwater TDS levels were measured. Most of the groundwater TDS data is from the 2012-13 sampling events, however, some of the wells have historical TDS levels as well (CRA “e-dat” database). A query of the 2012-13 groundwater TDS data resulted in 361 records, from wells with depths from 0 to -175 ft elevation. However, OCC did use salt (sodium chloride) to produce chlorine gas and caustic soda (CRA, 2014). This salt was stored on a 1.6 acre salt pad (land surface). This historical chlorine gas / soda production has resulted in a significant groundwater caustic plume, with pH levels in the 11-12 range. This in turn has resulted in what has come to be known as the anthropogenic density plume (ADP). This ADP is a mixture of caustic soda, lime sludge and solvent residue (CRA, 2014). Therefore, given that sodium chloride was used in historical OCC operations, TDS may not be a reliable measure of what is truly “naturally occurring”. However, for 2012-13, there are wells with higher TDS levels (> 10,000 mg/L) that are located outside the pH / ADP footprint. As a footnote, OCC’s manufacturing operations were from 1929 – 2002 (CRA, 2014). Therefore, the 2012-13 groundwater TDS data was collected ten years after OCC ceased operations. Consequently, some fraction of the 2012-13 groundwater TDS data set is thought to be suitable for a non-potability designation. Thus, data from what is thought to be non-impacted (i.e. background) wells was used to assess salinity (from TDS). The following methods were used to filter / process the 2012-13 groundwater TDS data: • Reduce the data to those wells west and south of the former OCC plant. This results in 100 data records, from wells ranging in depth from 0 to -150 ft elevation. • Subdivide the data into 25 ft thick intervals (layers) and sort the data by elevation (e.g. 0 to -25, 25 to -50 ft, etc). The was done to accommodate various wells screened over different depths (elevations). • Calculate the average groundwater TDS level for each 25 ft interval. 3 The resulting overall average groundwater TDS level is 10,600 mg/L (100 records). Spatially, it appeared that there were higher TDS levels more to the west (along the Blair Waterway; Figure 2). TDS levels did increase over depth (elevation). Specifically, the average groundwater TDS level from 0 to -50 ft elevation was < 5,000 mg/L. However, the average TDS level from -50 to -150 ft elevation was between ~20,000 and 25,000 mg/L (Table 1; Figure 3 TDS v. depth plot; Figure 4 interval / box plots). This suggests that there is a freshwater lens from roughly 0 to -50 ft elevation, with denser seawater from -50 to -150 ft elevation. A conclusion that can be derived from this evaluation is that peninsula groundwater contains naturally high TDS levels (> 10,000 mg/L), which makes it unfit for human consumption. Ideal drinking water has 0 – 50 mg/L TDS and hard to marginally-acceptable water has 200 – 400 mg/L TDS. For this data set (2012-13), about 80% of the levels exceeded the EPA secondary MCL of 500 mg/L. Likewise, 40% of the data set was greater than 10,000 mg/L TDS. Historical OCC operations (pH / ADP plume) may have biased some of these TDS levels. However, again, this data set was filtered / reduced to account for potential anthropogenic impacts. Therefore, the weight of evidence points to groundwater with naturally occurring salinity levels that are unfit for human consumption. Percent Seawater In 2013, a site salt / freshwater equilibrium study was conducted (CRA, 2013). The objective of this study was to determine natural saltwater / freshwater equilibrium conditions. For this study, ten common seawater ions (boron, bromide, calcium, chloride, iodide, magnesium, potassium, sodium, strontium, and sulfate) were measured. Of these ten, it was determined that several were used in historical OCC operations (e.g. calcium, iodide and magnesium) and were therefore unsuitable for the salinity intrusion analysis. In the end, bromide was used to assess fresh / saltwater equilibrium. Percent seawater levels were calculated using a mixing equation with estimated background concentrations for bromide in freshwater and in saltwater. As with the TDS data, average percent seawater levels were calculated from 25 ft elevation intervals (from 0 to -175 ft). Average saltwater levels based on the observed bromide concentrations range from roughly 10 to 50% over depth (Table 2). Like TDS, average percent seawater levels increased over depth and again, like TDS, percent seawater levels peaked at -50 to -75 ft (Figure 5). The -50 to -75 elevation peak was then followed by a gradual decline in percent levels to -175 ft elevation. Percent seawater interval and box plots are also provided in Figure 6. To better understand percent seawater levels over depth (elevation), the data were spatially mapped (using kernel smoothing and filled contours; Figure 7). Results are as follows: • 0 to -25 ft – predominantly freshwater across the peninsula, with smaller seawater lenses both northeast and southeast of the former OCC property. • -25 to -50 ft – more salinity intrusion along the northeast tip of the peninsula as well as a freshwater lens that sort of centers (or follows) Alexander Avenue. • -50 to -75 ft – most of the peninsula is now predominantly seawater, however, there is freshwater lens that centers beneath the former OCC property. • -75 to -100 ft – most of the peninsula is predominantly seawater, however, there is freshwater lens more to the west (towards the Blair Waterway). 4 • -100 to -125 ft – most of the peninsula is predominantly seawater, however, there is a freshwater from the OCC property trending northwest. • -125 to -150 ft – most of the peninsula is predominantly seawater, however, the northwest trending freshwater lens (from the OCC property) is more pronounced. • -150 to -175 ft – there’s really not enough data points (only 5) to draw any meaningful conclusion. However, what you observe is a freshwater lens along the north tip of the peninsula. In summary, as with the TDS data, it appears that there is a freshwater lens within the middle of the peninsula, from about 0 to -50 ft elevation. However, below -50 ft elevation, saltwater levels gradually increased and then declined. From this evaluation, it can be concluded that in its natural state, the peninsula groundwater is a mix of both fresh / seawater. There are higher freshwater levels near land surface, however, seawater levels increase over depth. Consequently, in its natural state (high salinity), this groundwater is unfit for human consumption. Effect of Pumping on the Distribution of Saltwater The distribution of saltwater and freshwater at the Occidental site inferred from the TDS and bromide data consists of a relatively thin freshwater lens that is underlain and surrounded laterally by saltwater. The lateral extent of the shallow freshwater lens is constrained by saltwater from Commencement Bay to the north, the Blair Waterway to the west, and the Hylebos Waterway to the east. The aquifer that contains the freshwater lens is an unconfined aquifer comprised of fluvial and deltaic deposits. There are no stratigraphic layers or boundaries to separate the freshwater lens from the surrounding saltwater. Pumping fresh groundwater at the site will cause additional saltwater intrusion from both lateral boundaries and from underlying saltwater zones. Zones of freshwater that might be considered for water supply would be highly susceptible to saltwater contamination from surrounding and underlying areas. Fresh / Saltwater Equilibrium Summary Both TDS and percent seawater increase significantly at elevations below roughly -50 ft. This is consistent with the site conceptual model for fresh / saltwater conditions. Specifically, CRA (2014) has previously defined fresh / saltwater conditions as follows: less dense freshwater (from precipitation recharge) near land surface, followed by denser seawater over depth. Prior tidal studies (CRA, 2014) have found that peninsula groundwater at depths greater than 25 ft is tidally influenced. However, groundwater at depths less than15 ft is not generally tidally influenced. Again, this points to a freshwater lens near land surface, with denser seawater over depth. Also, the bottom of the Hylebos Waterway is -35 ft MLLW (-47 ft NGVD;. The bottom of the Hylebos is at approximately -50 ft elevation (CRA, 2014), which is where TDS and percent seawater levels generally increase. However, there is deeper submarine groundwater discharge, from the east side of the Hylebos Waterway (i.e. the “bluffs” area, CRA, 2014). This deeper recharge is fresh groundwater, from upland areas at higher elevations. Prior to the peninsula construction, the natural state of the discharging groundwater was likely brackish. The increased TDS and percent seawater levels over depth support this historical model. Other MTCA Non-Potability Criteria Aside from yield and naturally occurring substances, there are several other criteria that may be used to designate groundwater non-potable. A brief discussion is as follows: 5 • Groundwater is located at a depth that makes it technically impracticable for use. This criteria would not apply as the groundwater table is < 25 ft from land surface. A groundwater treatment / extraction system has also been operating for nearly 20 years now. • It is unlikely that hazardous substances will be transported from the site to a drinking water source. This criteria would apply as the peninsula is bounded by marine water. The closest public supply well (City of Tacoma tideflats well ACN703; 775 feet deep) is roughly 0.6 miles southeast (and up-gradient) of the former OCC property. • The site is located near or within close proximity to surface water, i.e. the “Harbor Island” rule exemption. If a site is near or abuts a marine waterway, then you may conclude that there is an “extremely low probability” of future human consumption of groundwater. As a footnote, the rule does not provide any criteria as to how this decision is made. However, Harbor Island (Duwamish River estuary) is used as an example and this OCC site matches that type of scenario. Therefore, this OCC site does qualify for the Harbor Island rule exemption. Part III – EPA Criteria Underground Source of Drinking Water (USDW) Like Ecology, EPA also uses the TDS 10,000 mg/L threshold to define what is an “underground source of drinking water” (USDW; 40 CFR) Section 144.3). Per federal regulations, you may also create or designate “exempted aquifers” (40 CFR Section 146.4). The criteria for exempted aquifers is similar to Ecology’s MTCA Section 720. As a footnote, EPA’s criteria for exempted aquifers is groundwater with TDS levels > 3,000 and < 10,000 mg/L (“freshwater” is TDS < 3,000 mg/L). Lastly, the USDW criteria has also been incorporated into EPA’s Underground Injection Control (UIC) program. For example, EPA Region V has published guidance on how to apply USDW criteria to states with UIC programs (e.g. Michigan, Indiana, etc.). Comprehensive State Groundwater Protection Program (CGWPP) Both Ecology / EPA have jurisdiction for this former OCC site cleanup. This is a federal EPA superfund site; therefore, the CERCLA provisions do apply. However, if a state has a Comprehensive State Groundwater Protection Plan (CGWPP), then EPA may defer to the state for determinations of current / future groundwater use (EPA, 1997). A State of Washington CGWPP was completed by Ecology (1995). This CGWPP was endorsed by EPA (2002).Therefore, per these directives, Ecology now has the authority to determine groundwater current / future use. In this case, Ecology has decided that the former OCC site groundwater is not a current or potential source of drinking water. Part IV – Conclusion Based on the weight of evidence, this peninsula groundwater (former OCC plant) is unfit for human consumption. Although there is a freshwater lens near land surface, the underlying and surrounding groundwater has much higher salinity levels. These salinity levels do vary over depth. However, for the most part, levels exceed drinking water standards (e.g. TDS > 500 mg/L). From a practical standpoint, no one would ever drill a well and use this peninsula groundwater for drinking water. If this were to occur, then the groundwater would have to be treated (desalinization). This would be very costly and seems impracticable from a future use standpoint. For that matter, the historical natural state of groundwater entering (or discharging to) Commencement Bay was likely always brackish. Therefore, this peninsula groundwater does meet the MTCA Section 720 non-potability criteria. 6 .References CRA (2013). Salt Water / Freshwater Evaluation Results. CRA technical memorandum (Michael Mateyk and Jody Vaillancourt, CRA to Clint Babcock; March 8th, 2013. CRA (2014). Site Characterization Report (SCR). Groundwater and Sediment Remediation, Occidental Chemical Corporation, Tacoma, Washington. August-2014, 007843, Report No. 128 Ecology (1995). Washington State Ground Water Protection Program Core Program Assessment Document (July, 1995). Note: this document published prior to advent (or use) of Ecology publication numbers. EPA (1997). The Role of CSGWPPs in EPA Remediation Programs (memorandum from Timothy Fields to Region I – X administrators; April 4th, 1997). OSWER Directive 9283.1-09 EPA (2002). Endorsement of State of Washington Core Comprehensive Ground Water Protection Program (letter from John Iani, EPA Region X to Kirk Cook, Ecology; February 1st, 2002). 7 Table 1 – Average Groundwater TDS Levels (2012-13) Over Depth (Elevation). Layer Elevation Elevation 1 2 3 4 5 6 ft ft 0 -25 -50 -75 -100 -125 -25 -50 -75 -100 -125 -150 n Average TDS mg/L 36 26 11 11 8 8 1,481 4,656 22,873 22,214 25,050 23,684 100 Table 2 – Average Percent Seawater (2012-13) Over Depth (Elevation). Layer Elevation Elevation 1 2 3 4 5 6 7 ft ft 0 -25 -50 -75 -100 -125 -150 -25 -50 -75 -100 -125 -150 -175 n Average Percent Seawater % 79 76 40 45 32 26 6 304 8 8.5% 26.1% 53.9% 48.7% 42.0% 45.2% 38.1% Hylebos Waterway Former OCC Plant Tacoma Commencement Bay Blair Waterway Figure 1 – 3D Land Surface and Bathymetry (Commencement Bay, Tacoma). 9 f" Occidental Chemical .14 0t . Groundwater TDS ar(2012-1 3) up" Legend .- . Marine Shoreline - Former Salt Pad 000 Propeny TDS (mglL) a 112 ?2,130 0 2,131 ?10,000 . 10,001 ?14,600 . 14,601 24,300 . Will-mm. II il'l Lljfull I . 24,301 ?29,400 1, 1? WI .. (null230 460 690 920 Feet DEPARTMENT OF ECOLOGY State :31 \I?un'amingr'on Figure 2 Groundwater TDS Levels (2012-13). 10 Average Groundwater TDS (mg/L) 0 5,000 10,000 15,000 20,000 0 Elevation (Ft) -25 -50 -75 -100 -125 -150 10,000 Figure 3 – Groundwater TDS Levels v. Depth (Elevation). 11 25,000 30,000 Interval Plot (with Average Values Labeled) 95% CI for the Mean 30000 TDS (mg/L) 25000 25,050 22,873 23,684 22,214 20000 15000 10000 10000 5000 4,656 1,481 0 0 to 5 -2 5 -2 to 0 -5 0 -5 to 5 -7 5 -7 to 0 -1 0 - 0 10 to 25 -1 25 -1 to 50 -1 Elevation (Ft) Box Plot (with Median Values Labeled) 30000 23800 22300 TDS (mg/L) 25950 25450 25000 20000 15000 10000 10000 5000 3390 602 0 0 to 5 -2 5 -2 to 0 -5 0 -5 to 5 -7 5 -7 to 00 -1 00 -1 to 25 -1 25 -1 to 50 -1 Elevation (Ft) Figure 4 – Groundwater TDS Histogram and Box Plot (2012-13 Data). 12 Average Percent Seawater 0% 10% 20% 30% 40% 0.0 Elevation (Ft) -25.0 -50.0 -75.0 -100.0 -125.0 -150.0 -175.0 Figure 5 – Average Percent Seawater v. Depth (Elevation). 13 50% 60% Interval Plot (with Average Values Labeled) 95% CI for the Mean 70 Percent Seawater 60 53.9 50 48.7 45.2 42.0 40 30 38.1 26.1 20 10 8.5 0 0 to 5 -2 5 -2 to 0 -5 -5 0 to 5 -7 5 -7 to -1 00 00 -1 to 2 -1 5 25 -1 to -1 50 50 -1 to 7 -1 5 Elevation (Ft) Box Plot (with Median Values Labeled) 100 Percent Seawater 80 64.262 60 49.5854 40 31.4262 20 29.2703 26.3682 14.7595 0 0.0995025 0 to 5 -2 5 -2 to 0 -5 0 -5 to 5 -7 5 -7 to 00 -1 00 -1 to 25 -1 25 -1 to 50 -1 Elevation (Ft) Figure 6 – Percent Seawater Interval and Box Plots. 14 50 -1 to 75 -1 0 to -25 Ft Elevation -50 to -75 Ft Elevation -25 to -50 Ft Elevation -75 to -100 Ft Elevation Figure 7 – Percent Seawater Levels Over Depth (Elevation, Ft). 15 -100 to -125 Ft Elevation -150 to -175 Ft Elevation -125 to -150 Ft Elevation Figure 7 (Cont.) 16 Appendix B Delineation of Areas of Potential Principal Threat Waste (PTW) GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) Appendix B 1. Delineation of Areas of Potential Principal Threat Waste Former Occidental Petroleum Site - Tacoma, Washington Introduction This appendix presents the rationale used for identification and delineation of areas of potential principal threat waste (PTW) at the former Occidental Chemical Facility (Site) located in Tacoma, Washington. The concept of PTW originally developed by United States Environmental Protection Agency (USEPA) was 1 applied to potential "source material" at a site. "Source material" is defined in USEPA, 1991 as "…material that includes or contains hazardous substances, pollutants or contaminants that act as a reservoir for migration of contaminants to ground water, to surface water, to air, or acts as a source for direct exposure." The Site characterization identified two major potential source materials that have impacted groundwater. They are: dense non-aqueous phase liquids (DNAPLs) resulting from solvent production; and caustic-impacts that have resulted in elevated pH in the soil and groundwater. The following sections of this Appendix present the regulatory framework for the determination of potential PTW and the evaluation of the potential "source material" at the Site with respect to this framework. Finally, the areas of potential PTW are identified. 2. Regulatory Framework The regulatory framework regarding the identification and remediation of source materials and PTW includes WAC 173-340-350, WAC 173-340-370, and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) [40 CFR 300.430 (a) (1) (iii)]. The concept of PTW and low-level threat waste was initially developed by USEPA in the NCP. While MTCA does not specifically call out PTW, it does identify in WAC 173-340-350 and WAC 173-340-370 the requirements for dealing with source materials (hazardous substances) with the same characteristics attribute to PTW by USEPA. The concept of PTW is to be applied on a site-specific basis when characterizing "source material" (as defined above). Considerations that should be taken into account when categorizing waste are presented in USEPA, 1991. Some examples of source materials provided in USEPA, 1991 are: drummed waste, contaminated soil and debris, pooled DNAPL, LNAPL, etc. Contaminated groundwater is generally not considered source material. In general, MTCA and the NCP consider hazardous substances/PTW to be those source materials that are: • Highly toxic • Highly mobile that generally cannot be reliably contained • Would present a significant risk to human health or the environment should exposure occur 1 USEPA, 1991. A Guide to Principal Threat Waste and Low Level Waste, OSWER Superfund Publication 9380.3-06FS, November, 1991. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report Appendix B 007843 (139) 1 Both MTCA and the NCP establish an expectation that treatment will be used to address hazardous substances/PTW at a site wherever practicable. This is clearly stated in WAC 173-340-370 (1) as follows: "The department expects that treatment technologies will be emphasized at sites containing liquid wastes, areas contaminated with high concentrations of hazardous substances, highly mobile materials, and/or discrete areas of hazardous substances that lend themselves to treatment." However, both MTCA and the NCP also acknowledge that hazardous substances/PTW may be contained rather than treated due to difficulties in treating the source material. Ecology's position is stated in Focus No. 94-130 as follows: "Protecting Human Health and the Environment. The cleanup action selected must either remove or destroy the contamination, restoring the site to cleanup levels, or contain the contamination in such a way that will minimize future exposure of humans and ecological receptors (plants 2 and animals)." As stated in the preamble to the NCP (55 FR at 8703, March 8, 1990), there may be situations where PTW may be contained rather than treated due to difficulties in treating the wastes. Specific situations that may limit the use of treatment are summarized in USEPA (1991) as follows: • Treatment technologies are not technically feasible or are not available within a reasonable timeframe. • The extraordinary volume of materials or complexity of the site make implementation of treatment technologies impracticable. • Implementation of a treatment-based remedy would result in a greater overall risk to human health and the environment due to risks posed to workers or the surrounding community during implementation. • Severe effects across environmental media resulting from implementation would occur. The decision to treat or contain hazardous substances/PTW is made on a site-specific basis through the remedy selection process (USEPA, 1991 and WAC 173-340-360). 3. Evaluation of Potential DNAPL Source Material Chlorinated solvents were produced at the Site from 1947 to 1973. Trichloroethene (TCE) was produced over this entire period, while tetrachloroethene (PCE) was produced from 1960 to 1973. The former solvent production plant and associated waste management units (WMUs) are shown on Figure 1. A single area around the former solvent production plant and associated WMUs is also shown on Figure 1 and described as the "CVOC Source Area." The chlorinated solvents were present in the solvent residue released to the environment and would have behaved as a DNAPL. The distribution of DNAPL in the subsurface is shown on Figure 2. As described in Section 4.8 and Appendix S of the draft SCR, confirmed DNAPL source zones were identified in the 15-, 25-, 100-, 130-, and 160-foot depth zones. Free-phase DNAPL was not encountered during Site investigations. The DNAPL composition was determined from soil analyses and found to be primarily PCE and TCE. Therefore, the DNAPL source material would be considered toxic. None of the DNAPL source zones are highly mobile. This conclusion is reached for two reasons. Firstly, no free-phase or pooled DNAPL was encountered at the Site. Secondly, solvent production at the Site 2 Ecology, Focus No. 94-130, page 4, November 2007 (revised 2013). GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report Appendix B 007843 (139) 2 ceased in 1973 (41 years ago). TCE and PCE DNAPLs have high density (compared to groundwater), low viscosity and high mobility, so that migration in relatively permeable media would cease within a few 3 months to a few years following the time of release (USEPA, 2009) . As a result, the current DNAPL distribution is likely stable and is already reliably contained naturally by the local geology. Exposure to the confirmed DNAPL source zones is unlikely, especially for the zones located within the 100-, 130-, and 160-foot depth zones. However, should exposure occur it could result in an unacceptable risk or hazard. Based on the facts that the confirmed DNAPL source zones contain toxic material and that exposure to these zones, if it was to occur, could result in significant risk to human and environmental receptors, they potentially could be considered PTW. The areas where DNAPL source material potentially could be considered PTW are shown on Figures 3a (15- and 25-foot depth zones) and 3b (100-, 130- and 160-foot depth zones). 4. Evaluation of Caustic Source Material Caustic soda (sodium hydroxide) was produced at the Site over the period of 1929 to 2002. Locations of historical production and handling of caustic soda are shown on Figure 4. A single area around these production and handing areas is shown on Figure 4 as the "Caustic Source Area." The caustic soda released to the subsurface resulted in elevated soil alkalinity. Elevated soil alkalinity in the Caustic Source Area is an on-going source of elevated groundwater pH and is considered source material. In order to determine which portion of the elevated caustic soil is potential PTW, an examination of the soil and groundwater pH was undertaken. In order to define potential PTW with respect to caustic waste, pH greater than and equal to 12.5 s.u. was selected. A pH of 12.5 s.u. is the lower limit that defines a caustic waste as being characteristic for corrosivity (40 CFR 261.22). During the Comprehensive Site Investigation (CSI), the pH source area was evaluated through the installation of 10 soil borings to a depth of 50 feet below ground surface. The area of investigation was selected because of the elevated groundwater pH found at shallow depths. The locations of the soil borings are shown on Figure 5. Soil pH was measured at regular intervals as drilling progressed. The soil pH data were presented in Table 4.14 of the draft SCR. These data were used to create a soil pH 4DIM with Mining Visualization System/Environmental Visualization System software package (MVS/EVS). The EVS domain was limited to the pH source area of investigation, as this is the area with adequate soil data for kriging. The extent of soil with pH greater than and equal to 12.5 s.u. is shown on Figure 5. There is limited soil pH data within the entire Caustic Source Area depicted on Figure 4, e.g., in the area of the Caustic House (S8 on Figure 4). As a result, it was necessary to also examine the groundwater pH plume to see where pH above 12.5 s.u. occurs in the groundwater. Although contaminated groundwater is generally not considered to be source material, the soil that the groundwater is in contact with could be considered source material. The extent of the groundwater pH plume at 12.5 s.u. as determined from EVS is shown in plain view on Figure 6. A north-south elevation view from EVS of soil and the groundwater with pH greater than and equal to 12.5 s.u. is shown on Figure 7. The soil co-located with the groundwater plume that is equal or greater than 12.5 s.u. potentially could be considered PTW. Based on historical knowledge of caustic production, soil pH data, and groundwater pH data, the areas of caustic impacted soil that potentially could be considered PTW are shown on Figure 8. 3 USEPA, 2009. Assessment and Delineation of DNAPL Source Zones at Hazardous Waste Sites. Publication EPA. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report Appendix B 007843 (139) 3 5. Summary The DNAPL and caustic source material that could potentially be considered hazardous substances/PTW were identified following the guidance presented in MTCA, the NCP, and USEPA, 1991. All confirmed DNAPL source zones were considered to be potential PTW because of their toxic composition and the significant risk that could result should exposure occur. All unsaturated and saturated soil where the soil or groundwater pH was equal to or greater than 12.5 s.u. was considered potential PTW because they are considered to be characteristically hazardous for corrosivity (40 CFR 261.22). Both MTCA and the NCP have an expectation for treatment of hazardous substance/PTW, wherever practicable. At this Site, the complete treatment of hazardous substance/PTW may be considered impracticable for the following reasons: • Feasible treatment technologies are not available • Very large volumes of hazardous substances/PTW • Complex geologic and geochemical conditions • Potential for increased risks during implementation of treatment GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report Appendix B 007843 (139) 4 LOCATION S1 S2 S3 S4 S5 S6 S7 DESCRIPTION FORMER SOLVENT PRODUCTION PLANT (1947-1973) FORMER EFFLUENT SETTLING BARGE (WMU F) (1950-1972) FORMER EFFLUENT SETTLING PONDS (WMU A) (1972-1978) FORMER EFFLUENT SETTLING PONDS (WMU G) (1949-1952) FORMER EFFLUENT SETTLING PONDS (WMU H) (1949-1952) FORMER DRAINAGE POND (WMU D) (1948-1973) FORMER PCE/TCE STORAGE Y CI T CITY OF TACOMA TRUE NORTH A OM TAC OF PLANT NORTH 0 100 300ft S5 FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 45 00 40 00 35 00 30 00 25 00 15 00 20 00 PUYALLUP TRIBE OF INDIANS PORT OF TACOMA NAVY TODD DUMP S2 PIER 25 DOCK 2 DOCK 1 S7 PORT OF TACOMA S4 S1 S6 FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) S3 CITY OF TACOMA PORT OF TACOMA LEGEND PROPERTY LINE AREA 5106 APPROXIMATE SHORELINE POTENTIAL CVOC SOURCE 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) POTENTIAL CVOC SOURCE AREA 07843-C2D2(139)GN-WA049 MAY 24, 2016 figure 1 POTENTIAL SOURCES OF VOC 15(? 1 PLANT I 1 EAST HYLEBOS BLAIR WATERWM - It - I'm?Ems WATEHWM -1oo It a; 1-: -1 50 In an. I'll?r nu .. hr -200 ?250 I ?300 605 AND T09 FILL BLAIR I ALEXANDER AVENUE OWNED BY 33:3 MUD FLAT MARIANA - SALT SURFACE WATER DELTAIC DEPOSITS PLANT :le . MT FRESH SRou GLACIAL DEPOSITS NORTH 11 - I scum SALT WATER TRANSITION - LOWER CDMMENCEMEMT BAY 4L I ZONE IN LENSES .. - - - SALT WATER IN AQU IFER BLU FFS - - BURIED VALLEY -50 3.3.3.3.3.3.. HDTE5: DARK BROWN INDICATES WHERE MUD FLAT-5 ARE DBSERVED TD PROVIDE HYD RAULIC SEPARATION BETWEEN THE FILL AND DELTAIC BROWN DDT INDICATES WHERE I-WDRAULIC SEPARATICIN BY THE MUD FLATS IS NDT GONFIRMED ??150 ?00 600 FT NGVD DNAPL PLUME SAND AND GRAVEL SILT AND CLAY - CONFIRMED DNAPL SUSPECTED DNAPL figure 2 DNAPL DISTRIBUTION Oocidantai Chamioai Corporation, Tacoma, Washington UTB43-CEDEHSQIGN-WA-HYD 29i2016 TRUE NORTH PLANT NORTH 0 150 300ft 0 CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 X X X X X X X SALT PAD X X X X X X X X X X X X LEGEND POSITIVE DYE TEST CONFIRMED NAPL (15-FT ZONE) CONFIRMED NAPL (25-FT ZONE) PTW (POTENTIAL PRINCIPAL THREAT WASTE) figure 3a CONFIRMED DNAPL SOURCE ZONES - 15-FT AND 25-FT ZONES 07843-C2D2(139)GN-WA050 APR 27, 2016 TRUE NORTH PLANT NORTH 0 150 300ft 0 CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 X X X X X X X SALT PAD X X X X X X X X X X X X LEGEND POSITIVE DYE TEST CONFIRMED NAPL (100-FT ZONE) CONFIRMED NAPL (130-FT ZONE) CONFIRMED NAPL (160-FT ZONE) PTW (POTENTIAL PRINCIPAL THREAT WASTE) figure 3b CONFIRMED DNAPL SOURCE ZONES - 100-FT, 130-FT AND 160-FT ZONES 07843-C2D2(139)GN-WA051 APR 27, 2016 LOCATION S8 S9 S10 S11 S12 S13 TRUE NORTH DESCRIPTION FORMER CAUSTIC PROCESSING/STORAGE (CAUSTIC HOUSE) FORMER CAUSTIC STORAGE FORMER CAUSTIC PRODUCTION/STORAGE FORMER CAUSTIC STORAGE FORMER CAUSTIC STORAGE FORMER AMMONIUM HYDROXIDE PRODUCTION/CAUSTIC STORAGE YO CI T MA ACO FT PLANT NORTH 0 100 300ft 45 00 PORT OF TACOMA DOCK 2 DOCK 1 PIER 25 FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 40 00 S9 35 00 30 00 15 00 20 00 25 00 PUYALLUP TRIBE OF INDIANS S11 S12 S8 S13 PORT OF TACOMA S10 FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) CITY OF TACOMA PORT OF TACOMA LEGEND PROPERTY LINE POTENTIAL CAUSTIC SOURCE APPROXIMATE SHORELINE POTENTIAL CAUSTIC SOURCE AREA 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) 07843-C2D2(139)GN-WA052 APR 29, 2016 figure 4 POTENTIAL SOURCES OF CAUSTIC LOCATION S8 S9 S10 S11 S12 S13 TRUE NORTH DESCRIPTION FORMER CAUSTIC PROCESSING/STORAGE (CAUSTIC HOUSE) FORMER CAUSTIC STORAGE FORMER CAUSTIC PRODUCTION/STORAGE FORMER CAUSTIC STORAGE FORMER CAUSTIC STORAGE FORMER AMMONIUM HYDROXIDE PRODUCTION/CAUSTIC STORAGE YO CI T MA ACO FT PLANT NORTH 0 100 300ft 45 00 FORMER US NAVY PROPERTY (OWNED BY PORT OF TACOMA) 40 00 S9 35 00 30 00 25 00 20 00 15 00 PUYALLUP TRIBE OF INDIANS PORT OF TACOMA S11 PIER 25 DOCK 2 DOCK 1 PH-01 S8 PH-04 PH-07 PH-10 PH-03 PH-02 PH-05 PH-08 PH-06 S12 PH-09 S13 PORT OF TACOMA S10 FORMER OCC FACILITY 605 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 709 ALEXANDER AVE. (OWNED BY MARIANA PROPERTIES) 721 ALEXANDER AVE. (OWNED BY PORT OF TACOMA) CITY OF TACOMA LEGEND PORT OF TACOMA PROPERTY LINE APPROXIMATE SHORELINE 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) figure 5 POTENTIAL CAUSTIC SOURCE POTENTIAL CAUSTIC SOURCE AREA EXTENT OF SHALLOW SOIL WITH pH SOIL SAMPLING LOCATION 07843-C2D2(139)GN-WA053 APR 29, 2016 12.5 s.u. EXTENT OF SHALLOW SOIL WITH pH GREATER THAN AND EQUAL TO 12.5 s.u. LOCATION S8 S9 S10 S11 S12 S13 TRUE NORTH DESCRIPTION FORMER CAUSTIC PROCESSING/STORAGE (CAUSTIC HOUSE) FORMER CAUSTIC STORAGE FORMER CAUSTIC PRODUCTION/STORAGE FORMER CAUSTIC STORAGE FORMER CAUSTIC STORAGE FORMER AMMONIUM HYDROXIDE PRODUCTION/CAUSTIC STORAGE PLANT NORTH 0 100 300ft S9 S11 S12 S8 S13 S10 LEGEND PROPERTY LINE POTENTIAL CAUSTIC SOURCE AREA APPROXIMATE SHORELINE EXTENT OF GROUNDWATER WITH pH 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) POTENTIAL CAUSTIC SOURCE 07843-C2D2(139)GN-WA054 APR 29, 2016 12.5 s.u. figure 6 EXTENT OF GROUNDWATER PLUME WITH pH GREATER THAN AND EQUAL TO 12.5 s.u. LEGEND pH GROUNDWATER PLUME pH SOIL PLUME figure 7 NORTH-SOUTH ELEVATION VIEW OF SOIL AND GROUNDWATER WITH pH GREATER THAN AND EQUAL TO 12.5 s.u. 07843-C2D2(139)GN-WA055 APR 20, 2016 TRUE NORTH PLANT NORTH 0 150 300ft 0 CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 X X X X X X X SALT PAD X X X X X X X X X X X X LEGEND EXTENT OF SHALLOW SOIL WITH pH > 12.5 s.u. EXTENT OF GROUNDWATER WITH pH > 12.5 s.u. figure 8 POTENTIAL PTW RELATED TO CAUSTIC SOURCE MATERIAL 07843-C2D2(139)GN-WA056 APR 27, 2016 Appendix C Technical Memorandum Revised DNAPL Mass Estimates GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) . 651 Colby Drive. Waterloo, Ontario, Canada N2V Telephone: (519) 884-0510 Fax: (519) 884-0525 on . .. -- TECHNICAL MEM ORAN DU - T0: Clint Babcock REF. No.: 007843 FROM: Mike Matevk/kf/75 DATE: November 11, 2014 CC: Ian Richardson RE: Revised DNAPL Mass Estimates Former Occidental Chemical Corporation Facility - Tacoma, Washington 1.0 Introduction This Technical Memorandum (TM) presents revised dense non?aqueous phase liquid (DNAPL) mass estimates for the former Occidental Chemical Facility (Site) located in Tacoma, Washington. DNAPL mass estimates were originally provided in the August 2014 Draft Site Characterization Report (SCR). Two methods were used to estimate DNAPL mass. The first method used the NAPL source zones developed by the procedures described in Kueper?Daviesl. The second method used NAPL source zones developed through the kriging of NAPL saturations calculated using an analytical model called NAPL Calculator (NAPLCALC). There was a large variation in the estimated confirmed DNAPL mass between the two methods. At the October 1, 2014 Technical Team meeting, the DNAPL mass estimates were discussed. It was decided that a range in DNAPL mass could be provided; but a best estimate was required for future reference. It was agreed to develop a DNAPL mass estimate by calculating the mass of total chlorinated volatile organic compounds (TCVOCs) in soil using the model. In addition, the assumptions used in the Kueper?Davies method were re?visited to determine if any revisions were required The following sections of this TM present the procedures and results for the revised Kueper?Davies method and the EVS method. 2.0 Revised Kueper-Davies Calculations The Kueper?Davies method is a qualitative procedure used to delineate DNAPL source zone areas. In order to estimate DNAPL mass based on these areas, a thickness must be assigned to each delineated DNAPL source zone; as well as a NAPL saturation. For the estimate provided in the draft SCR, the DNAPL source 1 USEPA, 2009. Assessment and Delineation of DNAPL Source Zones at Hazardous Waste Sites. Publication H33 CRA MEMORANDUM  Page 2      zone thickness was assigned the total thickness of the zone grouping plan in which it was located.  This was  considered conservative (i.e., maximizes the DNAPL mass).  A DNAPL saturation of 1 percent was then  applied to the total source zone volume.    The application of a 1 percent NAPL saturation to the entire source zone volume is the equivalent of  applying a DNAPL saturation of approximately 2.3 percent of the pore volume (based on a total porosity of  0.43)2.  A review of the calculated DNAPL saturations determined using NAPLCALC indicates that the  application of 2.3 percent DNAPL saturation over the entire source zone pore volume would result in an  overestimate of the DNAPL mass.  Therefore, it was decided to revise the Kueper‐Davies mass estimate to  factor in the soil porosity and apply a DNAPL saturation of 1 percent of the pore volume.  This revision  results in a total confirmed NAPL mass of approximately 2.7 million pounds.  A summary of the distribution  of confirmed DNAPL mass by zone grouping plan is provided in Table 1.      3.0  EVS Method  A third method was used to estimate DNAPL mass which was based on the mass of total chlorinated VOCs  (TCVOCs) in the soil/porous media.  This mass was calculated using the EVS/MVS model for the Site.  The  data set used in the development of the TCVOC soil model included all available soil data.  However, there  were 11 locations where a positive dye test confirmed the presence of DNAPL, but there was no co‐located  soil sample.  There were also 8 locations where there was a positive dye test result, but the co‐located soil  sample had concentrations of TCVOCs below the portioning threshold (Kueper‐Davies calculation #4).   Neglecting to take into account the positive dye test results from these 19 samples would result in a DNAPL  mass estimate that is biased low.  These locations, along with their associated CVOC concentrations, where  present, are presented in Table 2.    To include these 19 locations in the DNAPL mass calculation using EVS, TCVOC values must be entered at  each location.  The average TCVOC value at the remaining 47 locations with positive dye test results and  co‐located soil samples was used for the 19 locations.  Table 3 presents the locations with positive dye test  results and CVOC concentrations above the NAPL portioning threshold.  The average TCVOC value for these  samples is 12,436 milligrams per kilogram (mg/kg).  This average CVOC value from locations in Table 3 was  used to complete the data set for the EVS/MVS program so that each location with a positive dye test result  had an appropriate TCVOC concentration.    This new, complete, data set was then used to create a 3‐D model of the soil TCVOC concentrations using  EVS/MVS.  The model conventions and settings used in the development of this TCVOC 4DIM were identical  to those used in the generation of 4DIMs in the SCR (see Appendix O of the SCR).  In order to calculate the  mass within EVS, a threshold concentration must be established.  The 4DIM was reviewed to examine the  size and shape of the volume under different concentrations.  At a threshold concentration of 100 mg/kg  the size and shape of the TCVOC volume roughly corresponded to the areal extent of the potential DNAPL  zones determined using by the Kueper‐Davies method (see Figure 1).  The calculated mass of TCVOCs above  this threshold of 100 mg/kg was 780,000 lbs.                                                            2     Conestoga‐Rovers & Associates, 2014.  Draft Site Characterization Report.  Ref. No.7843 (128), August.  CRA MEMORANDUM  Page 3        4.0  Summary  A summary of the estimated confirmed DNAPL mass obtained by each method is presented below:    Method  NAPL Mass (pounds)  NAPLCALC  606,000  EVS  780,000  Kueper‐Davies  2,770,000    The mass of confirmed DNAPL is likely within the ranged of values determined by the NAPLCALC and  Kueper‐Davies methods.  However, the mass determined using the EVS method is considered the "best"  estimate and should be used going forward.    It is important to note, that a precise determination of the NAPL mass is not required for the evaluation of  treatment alternatives in the Feasibility Study (FS).  It is the volume of impacted soil/porous media which  contains the NAPL that determines the practicability and cost of any treatment alternatives.    TRUE NORTH PLANT NORTH 0 150 300ft 0 CHANNEL LINE CHANNEL LINE DOCK 1 DOCK 1 PIER 25 X X PIER 25 X X X X SALT PAD X X SALT PAD X X X X X X X X X X X X X X X X X X EXTENT OF POTENTIAL NAPL (KUEPER-DAVIES) TCVOC IN SOIL @ 100 mg/kg figure 1 TCVOC AND NAPL EXTENTS 07843-A6(MEMO075)GN-WA001 OCT 28/2014 Page 1 of 1 TABLE 1 REVISED DNAPL MASS IN EACH DEPTH ZONE KUEPER-DAVIES METHOD WITH POROSITY OCCIDENTAL CHEMICAL CORPORATION TACOMA, WASHINGTON Depth Zone 15-foot 25-foot 50-foot 75-foot 100-foot 130-foot 160-foot TOTAL CRA 007843Memo75-Tables-rh.xlsx Calculated DNAPL Mass (lbs) 503,889 225,496 none none 164,413 1,602,655 271,777 2,768,231 Page 1 of 1 TABLE 2 POSITIVE DYE TEST NAPL INVESTIGATION - VAS AND SOIL SAMPLING OCCIDENTAL CHEMICAL CORPORATION TACOMA, WASHINGTON Location Name MW-EXT-9-INT MW-EXT-9-INT SB-A WMUA-34 WMUA-40 WMUA-41 WMUG-12 WMUR-01 WMUR-01 WMUR-09 WMUR-06 WMUA-41 WMUA-41 WMUG-14 WMUR-09 WMUR-09 WMUR-09 WMUR-10 WMUR-10 (1) Mid-screen Total CVOC (Comprehensive 2013 ) (ft NGVD) (mg/kg) Threshold Chemical Concentration Calculated (unitless) -126.19 -131.19 1.63 -2.62 -2.23 -4.65 -3.46 -4.67 -13.17 -7.12 -125.81 3.35 -10.65 -12.01 1.88 -0.12 -1.12 -108.31 -136.11 No Soil Sampled No Soil Sampled No Soil Sampled No Soil Sampled No Soil Sampled No Soil Sampled No Soil Sampled No Soil Sampled No Soil Sampled No Soil Sampled No Soil Sampled 11 43.27 0.097 13.056 86.3 65.2 120.5 171.9 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.10 0.02 0.00 0.12 0.79 0.60 0.85 0.08 Note: (1) Reported concentration and Kueper-Davies calculation #4 is for soil sample collected at -137.61 CRA 007843Memo75-Tables-rh.xlsx Page 1 of 1 TABLE 3 TCVOC AND NAPL THRESHOLD VALUES FOR POSITIVE DYE TEST SAMPLES NAPL INVESTIGATION OCCIDENTAL CHEMICAL CORPORATION TACOMA, WASHINGTON Threshold Chemical Trichloroethene Vinyl chloride Concentration Calculation (unitless) (ug/kg) (ug/kg) Location Name Mid-screen Soil Sample Mid-screen Dye Test (ft NGVD) 1,1-Dichloroethene (ug/kg) cis-1,2-Dichloroethene (ug/kg) Tetrachloroethene (ug/kg) trans-1,2-Dichloroethene (ug/kg) SB-B-DEEP SB-B-DEEP SB-B-DEEP SB-B-DEEP SB-B-DEEP WMUA-34 WMUA-34 WMUA-40 WMUA-40 WMUA-41 WMUA-41 WMUA-41 WMUG-01 WMUG-03 WMUG-03 WMUG-03 WMUG-06 WMUG-06 WMUG-06 WMUG-10 WMUG-10 WMUG-10 WMUG-12 WMUR-01 WMUR-01 WMUR-01 WMUR-01 WMUR-01 WMUR-01 WMUR-01 WMUR-03 WMUR-03 WMUR-04 -134.95 -138.95 -133.45 -130.45 -140.45 -3.12 -3.12 -1.13 -1.13 -3.65 -6.15 -3.65 -6.23 -6.92 -17.42 -5.92 -8.07 -4.07 -6.07 -9.07 -4.57 -7.07 -5.46 -12.17 -12.17 -2.67 -10.17 -7.67 -4.17 -87.67 -100.02 -100.02 -99.14 -135.70 * -138.20 * -133.20 * -130.70 * -140.70 * -3.12 -3.62 -0.23 * -1.23 * -2.65 * -6.15 -3.65 -6.23 -6.92 -17.42 -5.92 -7.07 * -5.07 * -6.07 -8.07 * -4.57 -7.07 -5.46 -11.17 * -11.67 * -2.67 -10.17 -7.67 -4.17 -87.67 -99.72 * -100.22 * -99.14 960 1,100 1,600 5,200 2,000 ---------350 260 250 180 68 ----------1,900 9,100 9,100 -- 6,400 9,800 13,000 34,000 23,000 38,000 38,000 3,000 3,000 -22,000 --69 370 150 1,400 2,200 370 ----------300,000 460,000 460,000 26,000 120,000 210,000 340,000 1,100,000 2,100,000 6,400,000 6,400,000 130,000 130,000 3,300,000 180,000 3,300,000 10,000,000 270,000 280,000 1,400,000 400,000 1,200,000 190,000 98,000 120,000 32,000,000 450,000 210,000 210,000 340,000 810,000 2,000,000 3,100,000 5,600,000 7,400,000 7,400,000 5,900,000 780 770 770 2,600 ----------160 ---23 ----------2,400 11,000 11,000 -- 290,000 350,000 490,000 1,500,000 1,700,000 8,400,000 8,400,000 16,000 16,000 77,000 100,000 77,000 120,000 57,000 320,000 170,000 830,000 250,000 200,000 470,000 160,000 58,000,000 89,000 21,000 21,000 -98,000 1,200,000 88,000 2,500,000 11,000,000 11,000,000 5,000,000 --910 ----28 28 -------3,600 1,600 180 -310 --520 520 ----18,000 7,800 7,800 -- 1.63 2.57 4.02 12.83 22.37 73.96 73.96 1.22 1.22 30.47 1.84 30.47 92.13 2.58 3.15 13.17 5.17 11.48 2.11 1.75 1.39 398.52 4.30 1.97 1.97 3.12 7.62 20.54 28.65 56.10 88.03 88.03 63.24 416,400 569,800 843,910 2,634,000 3,823,000 14,838,000 14,838,000 149,028 149,028 3,377,000 302,000 3,377,000 10,120,000 327,069 600,370 1,570,150 1,235,000 1,453,800 390,550 568,000 280,310 90,000,000 539,000 231,520 231,520 340,000 908,000 3,200,000 3,188,000 8,418,000 18,867,800 18,867,800 10,926,000 WMUR-05/83C -11.54 -11.54 31 18,000 93,000 210 100,000 220 1.04 WMUR-06/94C WMUR-07 WMUR-07 WMUR-08 WMUR-09 WMUR-09 WMUR-09 WMUR-09 WMUR-09 WMUR-09 WMUR-10 WMUR-10 WMUR-10 -126.21 -112.14 -109.04 -99.07 -12.82 -17.62 -9.62 -79.62 -7.62 -82.12 -135.91 -114.61 -126.11 -126.21 -112.14 -109.14 -99.17 * -12.62 * -17.62 -9.62 -79.62 -7.62 -82.12 -135.61 * -114.61 -126.11 690,000 --18,000 -------1,400 180,000 580,000 760 8,600 --1,900 1,300 9,100 1,300 39,000 180,000 4,100 530,000 120,000,000 320,000 15,000,000 15,000,000 180,000 400,000 530,000 540,000 960,000 7,700,000 1,800,000 170,000 61,000,000 140,000 -7,900 250,000 ---------- 53,000,000 330,000 17,000,000 7,200,000 13,000 390,000 690,000 1,100,000 450,000 12,000,000 300,000 280,000 49,000,000 -------------- 1199.45 3.54 168.47 150.99 1.68 4.38 6.11 6.95 9.63 92.39 17.16 2.07 649.28 209,022 173,580,000 650,760 32,008,600 22,200,000 193,000 791,900 1,221,300 1,649,100 1,411,300 19,739,000 2,280,000 454,100 110,530,000 Average CVOC Note: * Vertical separation between dye test results and soil sample ≤ 1 ft CRA 007843Memo75-Tables-rh.xlsx Total CVOC (ug/kg) 12,436,131 Appendix D Technical Memorandum - Analysis of TCVOCs Concentrations in Soil to Determine Zones for Potential Targeted Remediation GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) To: Clint Babcock Ref. No.: 007843 From: Robert Harris/wg/79  Date: June 13, 2016 CC: Ian Richardson Re: Analysis of TCVOC Concentrations in Soil to Determine Zones for Potential Targeted Remediation The technical memorandum (TM) presents the analysis of total chlorinated volatile organic compounds (TCVOC) in soil to identify zones for potential targeted remediation at the Occidental Chemical Corporation (OCC) Site in Tacoma, Washington. The purpose of the analysis is to determine the concentration threshold below which the benefit of additional mass removal declines significantly (i.e., diminishing returns), which would result in escalating effort and time to target limited additional mass. Selecting a concentration threshold of TCVOC for potential targeted remediation requires determining a point at which the benefit of treating additional mass diminishes significantly because of a large increase of soil volume (containing the mass) to remediate. Therefore, this analysis is focused on the relationship between masses of TCVOC in soil and the estimated remediation soil volumes containing the corresponding TCVOC masses. Concentration Thresholds Evaluated The following concentration thresholds were evaluated in the analysis. 1. 10,000 milligrams per kilogram (mg/kg) 2. 7,500 mg/kg 3. 5,000 mg/kg 4. 2,500 mg/kg 5. 1,000 mg/kg 6. 500 mg/kg 7. 250 mg/kg 8. 100 mg/kg The above provides a wide range and sufficient number of concentrations to study the relationship between mass and estimated remediation soil volume. The 10,000 mg/kg threshold was selected as the upper bound because a small number and size of volumes appear at this concentration. The 100 mg/kg threshold was selected as the lower bound consistent with Revised DNAPL Mass Estimates (CRA memorandum, GHD Limited 651 Colby Drive Waterloo Ontario N2V 1C2 Canada T 519 884 0510 F 519 884 0525 W www.ghd.com November 11, 2014). The calculated mass of TCVOC above the threshold of 100 mg/kg was 780,000 pounds (lbs). Determining Chemical Masses and Estimated Soil Remediation Volumes The EVS software was used to determine chemical masses and soil volumes at each concentration threshold based on a porosity of 0.43, soil density of 1.61 grams per cubic centimeter (gm/cc), and chemical density of 1.623 gm/cc. These parameters are those within the current EVS plume models. Furthermore, the volumes were segregated into shallow and deep zones, the cut off being -60 feet (ft) National Geodetic Vertical Datum (NGVD) consistent with the feasibility study agreed approach for evaluation. The shallow zone was further segregated into elevations above -21 feet (ft) NGVD and elevations between -21 and -60 ft NGVD. This segregation was done because there is no mass between -21 and -60 ft NGVD for thresholds from 10,000 mg/kg to 1,000 mg/kg and insignificant mass when compared to the total mass for thresholds from 500 mg/kg to 100 mg/kg. At the 100 mg/kg threshold, approximately 11 percent of the total mass (780,000 lbs) is located above -21 ft NGVD in the shallow zone and 85 percent of the mass is located in the deep zone (below -60 ft NGVD). The remaining approximately 3 percent is located between -21 and -60 ft NGVD. Estimated remediation soil volumes were calculated by multiplying the plan view area of the soil volumes produced from EVS by the plume volume thickness (difference of top and bottom elevations) and adding ten percent, accounting for a factor of safety for remedial implementation. The plan view areas were determined TM using the calculation tool in AutoCAD . The shallow zone is discussed below, followed by discussion of the deep zone. Shallow Zone (≥ -21 ft NGVD) TCVOC ≥ 10,000 mg/kg Threshold One volume was identified in the shallow zone (≥ -21 ft NGVD) for TCVOC ≥ 10,000 mg/kg concentration threshold as shown in plan view on Figure 1. The calculated values for this threshold are summarized in the following table. Area [square feet(sf)] Soil volume [cubic yards (cy)] Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) Total 1,390 138 4,262 0 -7 396 The shallow zone estimated remediation volume for the 10,000 mg/kg threshold is 396 cy. TCVOC ≥ 7,500 mg/kg Threshold 007843Memo-79 2 Two volumes were identified in the shallow zone for TCVOC ≥ 7,500 mg/kg concentration threshold as shown in plan view on Figure 2. The difference from the 10,000 mg/kg threshold is that one additional volume was identified. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 2,703 360.5 9,452 1 -8 991 239 4.5 99 -6 -8 19.5 Total 2,942 365 9,551 1,011 The shallow zone estimated remediation volume for the 7,500 mg/kg threshold is 1,011 cy. TCVOC ≥ 5,000 mg/kg Threshold Three volumes were identified in the shallow zone for TCVOC ≥ 5,000 mg/kg concentration threshold as shown in plan view on Figure 3. The difference from the 7,500 mg/kg threshold is that one additional volume was identified. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 5,654 884 18,040 1 -9 2,303 819 34 581 -6 -9 100 19 0.3 4 3 1 1.5 Total 6,492 918 18,625 2,405 The shallow zone estimated remediation volume for the 5,000 mg/kg threshold is 2,405 cy. TCVOC ≥ 2,500 mg/kg Threshold Four volumes were identified in the shallow zone for TCVOC ≥ 2,500 mg/kg concentration threshold as shown in plan view on Figure 4. The difference from the 5,000 mg/kg threshold is that one additional volume was identified. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) 007843Memo-79 9,552 2,160 30,391 2 2,377 173 1,865 -5 280 15 137 3 23 0.2 1.5 -9 Total 12,232 2,348 32,395 - 3 Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) -11 5,059 -9 387 0.5 29 Total 5,477 -11 2 The shallow zone estimated remediation volume for the 2,500 mg/kg threshold is 5,477 cy. TCVOC ≥ 1,000 mg/kg Threshold Nine volumes were identified in the shallow zone for TCVOC ≥ 1,000 mg/kg concentration threshold as shown in plan view on Figure 5. The difference from the 2,500 mg/kg threshold is that additional volumes were identified. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 14,456 4,855 41,992 2 8,746 1,222 5,953 -3 1,427 130 628.4 5 1,225 158 541.4 -3 473 19.6 65.4 -2 360 8 26.1 -9 243 4.7 14.2 -17 163 3.8 12 -6 4 0.3 1 -2 Total 27,097 6,401 49,234 - -16 -12 -1 -12 -5 -12 -20 -7 -3 - 10,601 3,207 349 449 57.8 44 29.7 6.6 0.2 14,744 The shallow zone estimated remediation volume for the 1,000 mg/kg threshold is 14,744 cy. TCVOC ≥ 500 mg/kg Threshold Six volumes were identified in the -21 ft NGVD shallow zone for TCVOC ≥ 500 mg/kg concentration threshold as shown in plan view on Figure 6. There was three less volume than at the 1,000 mg/kg threshold because volumes combined. An additional three volumes were identified between -21 and -60 ft NGVD and make up less than 0.01 percent of the total DNAPL mass of 780,000 mg/kg. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 007843Memo-79 21,713 4,034 11,218 -3 -21 19,870 8,111 48,327 3 -17 2,996 412 1,201 5 -1 2,943 549 1,284 -2 -12 1,034 102 219 -2 -7 249 10.2 17 -1 -4 Total 48,805 13,218 62,266 - 12,827 16,190 732.4 1,199 211 30.4 31,190 4 The area of 21,713 sf is a combination of four areas previously identified for the TCVOC ≥ 1,000 mg/kg concentration threshold. These combined areas have varying depths and thicknesses. Therefore the thickness of the total area was adjusted to 14.5 ft based on averaging thicknesses of 18 ft (maximum thickness) and 11 ft (thickness of the largest of the combined areas). The shallow zone estimated remediation volume for the 500 mg/kg threshold is 31,190 cy. TCVOC ≥ 250 mg/kg Threshold Five volumes were identified in the -21 ft NGVD shallow zone for TCVOC ≥ 250 mg/kg concentration threshold as shown in plan view on Figure 7. There was one less volume than at the 500 mg/kg threshold because volumes combined. An additional ten small volumes were identified between -21 and -60 ft NGVD that make up less than 0.5 percent of the total DNAPL mass of 780,000 mg/kg. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 61,775 24,174 71,235 3 -21 60,402 6,808 1,263.7 1,941 -1 -12 3,100 5,126 959.4 1,701 5 -2 1,462 1,948 266 364 -1 -7 476 58 2.9 2 -9 -11 4.7 Total 75,715 26,666 75,243 65,445 The shallow zone estimated remediation volume for the 250 mg/kg threshold is 65,445 cy. TCVOC ≥ 100 mg/kg Threshold Six volumes were identified in the -21 ft NGVD shallow zone for TCVOC ≥ 100 mg/kg concentration threshold as shown in plan view on Figure 8. The difference from the 250 mg/kg threshold is that some volumes combined and additional volumes were identified. At this threshold, the largest volume in the -21 ft NGVD shallow zone is connected to the largest volume in the deep zone (< -60 ft NGVD). The volume between -21 ft NGVD and -60 ft NGVD represents approximately 3 percent of the total mass of 780,000 mg/kg. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 109,166 47,307 82,479 7 -21 10,198 2,531 2,503 5 -13 8,588 1,319 777 -1 -10 2,822 226 67 -2 -8 1,430 159.8 53 -3 -11 559 21.6 6.7 -5 -8 Total 132,763 51,564 85,886 - 124,530 7,479 3,149 690 466 68 136,382 The shallow zone estimated remediation volume for the 100 mg/kg threshold is 136,382 cy. 007843Memo-79 5 The following table summarizes the findings from the above analysis. Potential Concentration Threshold (mg/kg) DNAPL Mass from EVS (lbs) Percent of Total DNAPL Mass Soil Volume from EVS (cy) Plan View Area (sf) Estimated Remediation Volume (cy) 10,000 4,262 0.5% 138 1,390 396 7,500 9,551 1.2% 365 2,942 1,011 5,000 18,625 2.4% 918 6,492 2,405 2,500 32,395 4.2% 2,348 12,232 5,477 1,000 49,234 6.3% 6,401 27,097 14,744 500 62,266 8.0% 13,218 48,805 31,190 250 75,243 9.6% 26,666 75,715 65,445 100 85,886 11.0% 51,564 132,763 136,382 A review of the estimated remediation volumes for all the thresholds in comparison to the related soil volumes determined from the EVS software was completed. The comparison indicates that the average percent increase from the EVS volumes to the estimated remediation volumes is 254 percent, with a range of 230 to 287 percent. Determining Concentration Threshold in the Shallow Zone To evaluate the threshold of optimum remediation volume/mass ratio, total mass was plotted versus the estimated remediation volume for each of the potential concentration thresholds as shown below. 007843Memo-79 6 As shown on the graph, initially the mass of TCVOC in soil increases with minimum increases in the estimated remediation volume. The plotted line then begins to arc between the TCVOC ≥ 1,000 mg/kg and TCVOC ≥ 500 mg/kg concentration thresholds, indicating that the estimated remediation volumes are increasing more significantly with lower concentration thresholds. Between the TCVOC ≥ 500 mg/kg concentration threshold and the TCVOC ≥ 100 mg/kg concentration threshold, the graph becomes increasingly flat, indicating that the estimated remediation volumes are increasing at a greater rate than the masses. The benefit of additional mass removal declines significantly at thresholds below 500 mg/kg. Therefore, the lower limit to identify DNAPL areas for potential remediation should be 500 mg/kg. As discussed previously, at the TCVOC ≥ 500 mg/kg concentration threshold, there are three small areas between -21 and -60 ft NGVD as shown on Figure 9 that make up less than 0.01 percent of the total DNAPL mass of 780,000 mg/kg. The benefit of attempting to remove these masses is insignificant and not practical. Deep Zone (< -60 ft NGVD) The estimated remediation soil volumes for the deep zone were calculated using the average percent increase from the EVS volumes to the estimated remediation volumes for the shallow zone of 254 percent. This is based on the assumption that the procedure used for the shallow zone would yield similar results for the deep zone. TCVOC ≥ 10,000 mg/kg Threshold Three volumes were identified in the deep zone for TCVOC ≥ 10,000 mg/kg concentration threshold as shown in plan view on Figure 10. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 1,458 117.2 4,649 -125 -129 297 644 35.2 1,111.7 -100 -103 89 180 5.1 210.6 -125 -127 13 Total 2,282 158 5,971 400 The deep zone estimated remediation volume for the 10,000 mg/kg threshold is 400 cy. TCVOC ≥ 7,500 mg/kg Threshold Four volumes were identified in the deep zone for TCVOC ≥ 7,500 mg/kg concentration threshold as shown in plan view on Figure 11. The difference from the 10,000 mg/kg threshold is that one additional volume was identified. 007843Memo-79 7 The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 2,215 203 6,689 -125 -129 516 1,131 106 2,762 -98 -104 269 257 8.6 293 -125 -127 22 Total 3,663 320 9,778 812 60 2 34 -133 -135 5 The deep zone estimated remediation volume for the 7,500 mg/kg threshold is 812 cy. TCVOC ≥ 5,000 mg/kg Threshold Six volumes were identified in the deep zone for TCVOC ≥ 5,000 mg/kg concentration threshold as shown in plan view on Figure 12. The difference from the 7,500 mg/kg threshold is that additional volumes were identified. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 4,320 884 11,655 -130 -140 2,245 3,796 437 10,782 -124 -130 1,110 2,399 257 5,290 -98 -104 653 398 16.4 428 -125 -128 42 327 6.6 92 -132 -134 17 52 2.1 30 -81 -83 5.3 Total 11,292 1,603 28,277 4,072 The deep zone estimated remediation volume for the 5,000 mg/kg threshold is 4,072 cy. TCVOC ≥ 2,500 mg/kg Threshold Six volumes were identified in the deep zone for TCVOC ≥ 2,500 mg/kg concentration threshold as shown in plan view on Figure 13. The difference from the 5,000 mg/kg threshold is that two volumes combined and one additional volume was identified. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 007843Memo-79 35,150 12,449 116,370 -123 -145 9,687 1,585 21,281 -124 -131 4,896 747 9,962 -97 -105 877 37 627 -125 -128 658 65 597 -80 -84 346 18 141 -98 -101 Total 51,614 14,901 148,978 - 31,620 4,026 1,897 94 165 46 37,848 8 The deep zone estimated remediation volume for the 2,500 mg/kg threshold is 37,848 cy. TCVOC ≥ 1,000 mg/kg Threshold Six volumes were identified in the deep zone for TCVOC ≥ 1,000 mg/kg concentration threshold as shown in plan view on Figure 14. The difference from the 2,500 mg/kg threshold is that two volumes combined and one additional volume was identified. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 76,120 45,107 255,160 -117 32,052 8,926 51,053 -122 10,529 2,331 16,379 -95 6,194 674.5 2,344 -85 4,706 629 2,886 -78 1,283 141 642 -97 Total 130,884 57,809 328,464 - -152 -137 -108 -113 -90 -102 - 114,572 22,672 5,921 1,713 1,598 358 146,834 The deep zone estimated remediation volume for the 1,000 mg/kg threshold is 146,834 cy. TCVOC ≥ 500 mg/kg Threshold Three volumes were identified in the deep zone for TCVOC ≥ 500 mg/kg concentration threshold as shown in plan view on Figure 15. The difference from the 1,000 mg/kg threshold is that some volumes combined. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 229,768 126,920 455,610 -94 -156 322,377 8,543 2,756 6,906 -76 -92 7,000 2,232 341 1,038 -96 -103 866 Total 240,543 130,017 463,554 330,243 The deep zone estimated remediation volume for the 500 mg/kg threshold is 330,243 cy. TCVOC ≥ 250 mg/kg Threshold Three volumes were identified in the deep zone for TCVOC ≥ 250 mg/kg concentration threshold as shown in plan view on Figure 16. The difference from the 500 mg/kg threshold is that two volumes combined and one additional volume was identified. 007843Memo-79 9 The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 330,617 242,611 571,030 -60 -156 616,232 3,532 756 1,444 -95 -105 1,920 2,304 281 230 -73 -78 714 Total 336,453 243,648 572,704 618,866 The deep zone estimated remediation volume for the 250 mg/kg threshold is 618,866 cy. TCVOC ≥ 100 mg/kg Threshold Four volumes were identified in the deep zone for TCVOC ≥ 100 mg/kg concentration threshold as shown in plan view on Figure 17. The difference from the 250 mg/kg threshold is that some volumes combined and additional volumes were identified. The calculated values for this threshold are summarized in the following table. Area (sf) Soil volume (cy) Chemical mass (lbs) Elevation at top of volume (ft NGVD) Elevation at bottom of volume (ft NGVD) Estimated Remediation Soil Volume (cy) 507,342 492,049 663,028 -60 -156 1,249,805 15,260 4,239.4 1,739 -70 -83 10,768 833 95 27.7 -66 -72 241 162 6 1.7 -75 -77 15 Total 523,597 496,389 664,796 1,260,829 The deep zone estimated remediation volume for the 100 mg/kg threshold is 1,260,829 cy. The following table summarizes the findings from the above analysis. Potential Concentration Threshold (mg/kg) 10,000 7,500 5,000 2,500 1,000 500 250 100 007843Memo-79 DNAPL Mass from EVS (lbs) 5,971 9,778 28,277 148,978 328,464 463,554 572,704 664,796 Percent of Total DNAPL Mass 0.8% 1.3% 3.6% 19.1% 42.1% 59.4% 73.9% 85.2% Soil Volume from EVS (cy) 158 320 1,603 14,901 57,809 130,017 243,648 496,389 Plan View Area (sf) 2,282 3,663 11,292 51,614 130,884 240,543 336,453 523,597 Estimated Remediation Volume (cy) 400 812 4,072 37,848 146,834 330,243 618,866 1,260,829 10 Determining Concentration Threshold in the Deep Zone To evaluate the threshold of optimum remediation volume/mass ratio, total mass was plotted versus the estimated remediation volume for each of the potential concentration thresholds as shown below. Similar to the shallow zone, initially the mass of TCVOC in soil increases with minimum increases in the estimated remediation volume. The plotted line then begins to arc between the TCVOC ≥ 1,000 mg/kg and TCVOC ≥ 500 mg/kg concentration thresholds, indicating that the estimated remediation volumes are increasing more significantly with lower concentration thresholds. Between the TCVOC ≥ 500 mg/kg concentration threshold and the TCVOC ≥ 100 mg/kg concentration threshold, the graph becomes increasingly flat, indicating that the estimated remediation volumes are increasing at a greater rate than the masses. The benefit of additional mass removal declines significantly at thresholds below 500 mg/kg. Therefore, the lower limit to identify DNAPL areas for potential remediation should be 500 mg/kg. Conclusion The analysis presented herein determined that the lower limit to identify DNAPL areas for potential remediation should be 500 mg/kg. At this threshold concentration, the total masses targeted will be approximately 62,000 lbs in the shallow zone (-21 ft NGVD) and 464,000 lbs in the deep zone (< -60 ft NGVD). These masses represent approximately 8 percent and 59.4 percent of the total mass calculated at the 100 mg/kg concentration, respectively. The estimated remediation volumes containing these masses were calculated to be approximately 31,000 cy in the shallow zone and 330,000 cy in the deep zone. 007843Memo-79 11 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X G-2 AREA = 1,390 SQ.FT. X D-9 E-1 X X F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF SHALLOW TCVOC TOTAL = 1,390 SQ. FT. X 07843-C2D2(MEMO079)GN-WA001 JUN 13, 2016 X figure 1 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X AREA = 239 SQ.FT. AREA = 2,703 SQ. FT. G-2 X D-9 E-1 X X F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF SHALLOW TCVOC TOTAL = 2,942 SQ. FT. X 07843-C2D2(MEMO079)GN-WA002 JUN 13, 2016 X figure 2 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X AREA = 819 SQ. FT. G-2 AREA = 19 SQ. FT. X X D-9 E-1 X F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD AREA = 5,654 SQ. FT. D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF SHALLOW TCVOC TOTAL = 6,492 SQ. FT. X 07843-C2D2(MEMO079)GN-WA003 JUN 13, 2016 X figure 3 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X G-2 AREA = 280 SQ. FT. X D-9 E-1 X F-9A AREA = 2,377 SQ. FT. TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD X AREA = 9,552 SQ. FT. D-2 AREA = 23 SQ. FT. C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF SHALLOW TCVOC TOTAL = 12,232 SQ. FT. X 07843-C2D2(MEMO079)GN-WA004 JUN 13, 2016 X figure 4 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 X PIER 25 CRANE RAIL X DOCK X M-1 H25 X AREA = 360 SQ. FT. X AREA = 1,427 SQ. FT. G-2 F-9 F-2 F-9A TREATMENT PLANT E-1 E24 X X PORT OF TACOMA X F-24 X X AREA = 8,746 SQ. FT. SALT PAD D-9 D-2 AREA = 163 SQ. FT. AREA = 4 SQ. FT. X X AREA = 243 SQ. FT. AREA = 14,456 SQ. FT. C-2 PARKING LOT B-9 AREA = 1,225C-28SQ. FT. M-4 X X X B-3 B-21 X PARKING LOT AREA = 473 SQ. FT. ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF SHALLOW TCVOC TOTAL = 27,097 SQ. FT. X X figure 5 AREAS OF SHALLOW ( -21 FT NGVD) TCVOC 1,000 mg/kg 07843-C2D2(MEMO079)GN-WA005 JUN 13, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X AREA = 21,713 SQ. FT. AREA = 2,996 SQ. FT. G-2 X D-9 E-1 X F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD X AREA = 19,870 SQ. FT. D-2 AREA = 2,943 SQ. FT. AREA = 249 SQ.FT. C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT AREA =1,034 SQ.FT. ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF SHALLOW TCVOC TOTAL = 48,805 SQ. FT. X 07843-C2D2(MEMO079)GN-WA006 JUN 13, 2016 X figure 6 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 X AREA = 58 SQ. FT. DOCK X PIER 25 CRANE RAIL X M-1 H25 X X AREAG-2= 61,775 SQ. FT. AREA = 5,126 SQ. FT. X D-9 E-1 X X F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD D-2 AREA = 6,808 SQ. FT. C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE AREA = 1,948 SQ. FT. X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF SHALLOW TCVOC TOTAL = 75,715 SQ. FT. X 07843-C2D2(MEMO079)GN-WA007 JUN 13, 2016 X figure 7 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 X DOCK AREA = 559 SQ. FT. X PIER 25 CRANE RAIL X M-1 H25 X X AREA = 109,166 SQ. FT. G-2 F-9 F-2 F-9A E-1 E24 TREATMENT PLANT X D-9 D-2 X X X PORT OF TACOMA X F-24 X X SALT PAD AREA = 10,198 SQ. FT. C-2 B-9 C-28 PARKING LOT AREA = 1,430 SQ. FT. M-4 X X X AREA = 2,822 SQ. FT. B-3 B-21 X PARKING LOT ALEXANDER AVENUE AREA = 8,588 SQ. FT. X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF SHALLOW TCVOC TOTAL = 132,764 SQ. FT. X X figure 8 AREAS OF SHALLOW ( -21 FT NGVD) TCVOC 100 mg/kg 07843-C2D2(MEMO079)GN-WA008 JUN 13, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE AREA = 186 SQ. FT. DOCK 2 DOCK 1 PIER 25 AREA = 15 SQ. FT. X CRANE RAIL X DOCK X M-1 H25 X X G-2 D-9 E-1 X X F-9A X F-9 F-2 TREATMENT PLANT E24 X PORT OF TACOMA AREA = 545 SQ. FT. X X X F-24 SALT PAD D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF INTERMEDIATE TCVOC TOTAL = 746 SQ. FT. X 07843-C2D2(MEMO079)GN-WA009 JUN 13, 2016 X figure 9 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE AREA = 180 SQ. FT. DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X G-2 AREA = 1,458 SQ. FT. X D-9 E-1 X X F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD D-2 AREA = 644 SQ. FT. C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF DEEP TCVOC TOTAL = 2,282 SQ. FT. X 07843-C2D2(MEMO079)GN-WA010 JUN 13, 2016 X figure 10 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE AREA = 257 SQ. FT. DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK AREA = 2,215 SQ. FT. X M-1 H25 X X AREA = 60 SQ. FT. G-2 X D-9 E-1 X X F-9A AREA = 1,131 SQ. FT. TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF DEEP TCVOC TOTAL = 3,663 SQ. FT. X 07843-C2D2(MEMO079)GN-WA011 JUN 13, 2016 X figure 11 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE AREA = 3,796 SQ. FT. AREA = 398 SQ. FT. DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X AREA = 2,399 SQ. FT. AREA = 4,320 SQ. FT. G-2 X D-9 E-1 X F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD X AREA = 327 SQ. FT. AREA = 52 SQ. FT. D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF DEEP TCVOC TOTAL = 11,292 SQ. FT. X 07843-C2D2(MEMO079)GN-WA012 JUN 13, 2016 X figure 12 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE AREA = 658 SQ. FT. AREA = 346 SQ. FT. DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X AREA = 9,687 SQ. FT. AREA = 4,896 SQ. FT. G-2 X D-9 E-1 X AREA = 877 SQ. FT. X AREA = 35,150 SQ. FT. F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF DEEP TCVOC TOTAL = 51,614 SQ. FT. X 07843-C2D2(MEMO079)GN-WA013 JUN 13, 2016 X figure 13 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE AREA = 6,194 SQ. FT. AREA = 32,052 SQ. FT. DOCK 2 DOCK 1 X PIER 25 CRANE RAIL X DOCK X AREA = 1,283 SQ. FT. M-1 H25 X X AREA = 10,529 SQ. FT. G-2 F-9A X D-9 E-1 TREATMENT PLANT F-9 F-2 E24 X X PORT OF TACOMA X F-24 X X SALT PAD X AREA = 4,706 SQ. FT. D-2 AREA = 76,120 SQ. FT. C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF DEEP TCVOC TOTAL = 130,884 SQ. FT. X X figure 14 AREAS OF DEEP (<-60 FT NGVD) TCVOC ≥1,000 mg/kg 07843-C2D2(MEMO079)GN-WA014 JUN 13, 2016 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE CHANNEL LINE DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X AREA = 2,232 SQ. FT. M-1 H25 X X AREA = 229,768 SQ. FT. G-2 X D-9 E-1 X X F-9A AREA = 8,543 SQ. FT. TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X X F-24 SALT PAD D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF DEEP TCVOC TOTAL = 240,543 SQ. FT. X 07843-C2D2(MEMO079)GN-WA015 JUN 13, 2016 X figure 15 TRUE NORTH PLANT NORTH 0 100 300ft CHANNEL LINE AREA = 2,304 SQ. FT. CHANNEL LINE DOCK 2 DOCK AREA = 3,532 1SQ. FT. X PIER 25 CRANE RAIL X DOCK X M-1 H25 X X G-2 F-9 F-2 F-9A E-1 E24 TREATMENT PLANT X D-9 D-2 X X X PORT OF TACOMA X F-24 X X SALT PAD C-2 B-9 C-28 PARKING LOT M-4 AREA = 330,617 SQ. FT. X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF DEEP TCVOC TOTAL = 336,453 SQ. FT. X X figure 16 AREAS OF DEEP (<-60 FT NGVD) TCVOC 250 mg/kg 07843-C2D2(MEMO079)GN-WA016 JUN 13, 2016 TRUE NORTH PLANT NORTH 0 100 300ft AREA = 833 SQ. FT. CHANNEL LINE AREA = 15,260 SQ. FT. CHANNEL LINE AREA = 162 SQ. FT. DOCK 2 DOCK 1 PIER 25 CRANE RAIL X X DOCK X M-1 H25 X X G-2 X D-9 E-1 X X F-9A TREATMENT PLANT E24 X PORT OF TACOMA F-9 F-2 X X AREA = 507,342 SQ. FT. X F-24 SALT PAD D-2 C-2 B-9 C-28 PARKING LOT M-4 X X X B-3 B-21 X PARKING LOT ALEXANDER AVENUE X X PORT OF TACOMA LEGEND X 605 & 709 ALEXANDER AVENUE (BOTH OWNED BY MARIANA PROPERTIES) X AREA OF DEEP TCVOC TOTAL = 523,597 SQ. FT. X 07843-C2D2(MEMO079)GN-WA017 JUN 13, 2016 X figure 17 Appendix E Groundwater Flow Modeling for Remedial Alternatives that Incorporate Groundwater Extraction GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) Table of Contents 1. Introduction ................................................................................................................................... 1 2. Modeling Approach ...................................................................................................................... 2 3. 4. 5. 2.1 Remedial Alternatives Evaluation Approach...................................................................... 3 2.2 Remedial Alternatives Model Set-Up ................................................................................. 5 Containment Alternatives ............................................................................................................. 5 3.1 Containment Alternative C100 ........................................................................................... 5 3.2 Containment Alternative C150 ........................................................................................... 7 3.3 Containment Alternative C200 ........................................................................................... 8 3.4 Summary of Containment Alternatives Modeling Results ................................................. 9 VOC Mass Reduction Alternatives ............................................................................................. 10 4.1 VOC Mass Reduction Alternative M100 .......................................................................... 10 4.2 VOC Mass Reduction Alternative M150 .......................................................................... 10 4.3 VOC Mass Reduction Alternative M200 .......................................................................... 11 4.4 VOC Mass Reduction Alternative MSP ........................................................................... 11 4.5 Summary of VOC Mass Reduction Alternatives .............................................................. 13 References ................................................................................................................................. 13 Figure Index Figure 1 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C100 - 15 ft Zone Figure 2 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C100 - 25 ft Zone Figure 3 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C100 - 50 ft Zone Figure 4 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C100 - 75 ft Zone Figure 5 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C100 - 100 ft Zone Figure 6 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C100 - 130 ft Zone Figure 7 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C100 - 160 ft Zone Figure 8 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C150 - 15 ft Zone Figure 9 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C150 - 25 ft Zone GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) i Figure Index Figure 10 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C150 - 50 ft Zone Figure 11 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C150 - 75 ft Zone Figure 12 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C150 - 100 ft Zone Figure 13 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C150 - 130 ft Zone Figure 14 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C150 - 160 ft Zone Figure 15 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C200 - 15 ft Zone Figure 16 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C200 - 25 ft Zone Figure 17 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C200 - 50 ft Zone Figure 18 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C200 - 75 ft Zone Figure 19 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C200 - 100 ft Zone Figure 20 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C200 - 130 ft Zone Figure 21 Simulated Drawdown and Groundwater Flow Directions For Containment Alternative C200 - 160 ft Zone Figure 22 Extraction Well Locations for VOC Mass Reduction Alternatives M100, M150, and M200 Figure 23 Simulated Drawdown and Groundwater Flow Directions For VOC Mass Reduction Alternative MSP – 15 ft Zone Figure 24 Simulated Drawdown and Groundwater Flow Directions For VOC Mass Reduction Alternative MSP – 25 ft Zone Figure 25 Simulated Drawdown and Groundwater Flow Directions For VOC Mass Reduction Alternative MSP – 50 ft Zone Figure 26 Simulated Drawdown and Groundwater Flow Directions For VOC Mass Reduction Alternative MSP – 75 ft Zone Figure 27 Simulated Drawdown and Groundwater Flow Directions For VOC Mass Reduction Alternative MSP – 100 ft Zone Figure 28 Simulated Drawdown and Groundwater Flow Directions For VOC Mass Reduction Alternative MSP – 130 ft Zone Figure 29 Simulated Drawdown and Groundwater Flow Directions For VOC Mass Reduction Alternative MSP – 160 ft Zone Figure 30 Cumulative Total TCVOC Mass-Weighted Particle Capture Over 100 Years GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) ii Table Index Table 1 Remedial Alternative Summary and Initial Chemistry Table 2 Summary of Aqueous Phase TCVOC Mass-Weighted Particle Capture Table 3 Summary of Total TCVOC Mass-Weighted Particle Capture Table 4 Summary of Total TCVOC Mass-Weighted Particle Capture Outside pH >10 s.u. GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) iii 1. Introduction This Appendix presents the evaluation of containment and mass reduction using the project's groundwater flow model as part of the Feasibility Study (FS) Report prepared on behalf of Occidental Chemical Corporation (OCC) at the "Occidental" Site associated in part with the former OCC facility located in Tacoma, Washington (Site). The groundwater modeling evaluation was conducted for the remedial alternatives considered in the FS that incorporate groundwater extraction. A three-dimensional (3D) groundwater flow model was constructed and calibrated for the Site. The details of the calibrated groundwater model are presented in the Draft Model Calibration Report (MCR) (CRA, 2014a). The calibrated model was used to evaluate and compare the remedial alternatives that incorporate groundwater extraction using particle tracking methods. The modeling evaluation was conducted assuming the shut-down of the current groundwater extraction system. The groundwater extraction remedial alternatives include a sheet pile vertical barrier wall along the Site peninsula adjacent to the Hylebos Waterway (Waterway) and upland groundwater extraction wells as part of the containment system for the Site. The modeling evaluation was conducted to evaluate levels of containment, migration, and mass reduction of the Total Chlorinated Volatile Organic Compounds (TCVOC) plume for the remedial alternatives that incorporate groundwater extraction. Reduction of the TCVOC plume was evaluated in terms of both reduction of aqueous phase TCVOC concentrations dissolved in groundwater (aqueous phase or dissolved TCVOC mass) and total TCVOC concentrations in soil (total TCVOC mass). The remedial alternatives evaluated using the calibrated model include:  Containment Alternatives C100, C150, and C200  VOC Mass Reduction Alternatives M100, M150, and M200  VOC Mass Reduction Alternative MSP (Mass Reduction by Strategic Groundwater Pumping), referred to herein as VOC Mass Reduction Alternative MSP In general, the purpose and objectives of the modeling evaluation include:  Evaluate the degree of hydraulic containment achieved by groundwater extraction for Containment Alternatives C100, C150, and C200, and VOC Mass Reduction Alternative MSP  Evaluate potential discharge of TCVOC mass to the surface water bodies that surround the Site peninsula for Containment Alternatives C100, C150, and C200, and VOC Mass Reduction Alternative MSP  Evaluate aqueous phase and total TCVOC mass reduction achieved by groundwater extraction for Containment Alternatives C100, C150, and C200, VOC Mass Reduction Alternatives M100, M150, and M200, and VOC Mass Reduction Alternative MSP The simulated aqueous phase TCVOC mass reduction by groundwater extraction is calculated from TCVOC concentrations in groundwater above a threshold concentration of 2.4 µg/L (equal to approximately 157,000 pounds [lbs]). The simulated total TCVOC mass reduction is calculated from TCVOC concentrations in soil above a threshold soil concentration of 100 mg/kg (equal to approximately 787,000 lbs). The total TCVOC mass represents mass in the dissolved, sorbed, and dense non-aqueous phase liquid (DNAPL) phases. GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 1 In addition to having to meet Remedial Action Goals (RAGs) presented in Section 3.1 of the main report, the specific Model-Based Performance Objectives for the Containment Alternatives and VOC Mass Reduction Alternative MSP consist of: 1 1) Within the hydraulic control boundaries provided by the Agencies on March 30, 2016 , there 2 must be inward gradients and a target drawdown of at least 1 foot . 2) The containment system must result in an estimated TCVOC mass discharge of less than 0.2 percent of the current estimated total TCVOC mass in the aquifer (i.e., 0.2 percent of 787,000 lbs). 3) Groundwater flow beneath the Waterway must be directed to the plant-west toward the containment system. The model also is used to predict and compare the amount of TCVOC mass reduction for the VOC Mass Reduction Alternatives independent of hydraulic containment. This Appendix is organized as follows: i) Section 1 – Introduction: provides the purpose and objectives of the modeling evaluation, and organization of this Appendix. ii) Section 2 – Modeling Approach: presents the approach and methodology taken to complete the modeling evaluation. iii) Section 3 – Containment Alternatives: presents the modeling results for the Containment Alternatives C100, C150, and C200. iv) Section 4 – VOC Mass Reduction Alternatives: presents the modeling results for the VOC Mass Reduction Alternatives M100, M150, and M200 as well as VOC Mass Reduction Alternative MSP. References cited in this Appendix are listed in Section 5. 2. Modeling Approach The 3D groundwater flow model developed for the Site and presented in the MCR provides a useful tool to evaluate the effectiveness of potential groundwater extraction remedial alternatives that could be implemented to address the TCVOC groundwater plume at the Site. Refinements of extraction well locations, pumping rates, and remedial alternative performance can and would be completed during the detailed design. Section 2.1 describes the approaches taken to evaluate the performance of the remedial alternatives using the groundwater flow model. Section 2.2 describes the groundwater flow model set-up for the remedial alternatives. 1 2 The hydraulic control boundaries were provided by the Agencies for the 25-foot (ft), 50-ft, 75-ft, 100-ft, 130-ft, and 160-ft zone on Figures 1 to 6, respectively, of the Agencies' email correspondence to OCC dated March 30, 2016. The target drawdown of 1 foot corresponds to lowering average groundwater elevations measured under pumping conditions by a minimum of 1 foot from the average groundwater elevations measured under non-pumping conditions. GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 2 2.1 Remedial Alternatives Evaluation Approach The remedial alternatives were evaluated using the groundwater flow model based on the following two approaches: a) Using simulated drawdown and groundwater flow directions to evaluate Model-Based Performance Objectives 1) and 3). b) Using simulated aqueous phase TCVOC mass-weighted particle capture to evaluate Model-Based Performance Objective 2). c) Using simulated total TCVOC mass-weighted particle capture to evaluate overall remedial alternative performance. Simulated Drawdown and Groundwater Flow Direction A field-based performance objective will be used to evaluate the remedial action once installed, which will entail measuring drawdown in the field to demonstrate actual remedial action performance. Since drawdown is equivalent to recovery, water levels would be measured, continuously at a selected time interval, at a select number of locations while the groundwater extraction and treatment system (GWETS) is running and during a temporarily shut-down of the GWETS. The temporary shut-down would take place following continuous GWETS operation for a time period sufficiently long to approach approximate steady-state groundwater flow conditions. The temporary shut-down would continue until approximate steady-state groundwater flow conditions were achieved. This would provide measurements of the groundwater level recovery occurring at select monitoring well locations on the Site peninsula and along the embankment adjacent to the Waterway after a temporary shut-down of the GWETS. The difference in the water levels (pre- and post-shut-down) in a well would be the measured drawdown at the well. Consistent with the field-based evaluation of drawdown, simulated drawdown was determined using the following steps:  Simulate the steady-state groundwater flow field under the operation of the remedial alternative, where the remedial action consists of extraction wells and a sheet pile vertical barrier wall along the embankment adjacent to the Waterway (pumping simulation).  Simulate the steady-state groundwater flow field with the extraction wells shut-off and the sheet pile vertical barrier wall in place (non-pumping simulation).  Determine the simulated drawdown by subtracting the fresh-water equivalent heads (FEHs) for the pumping simulation from the FEHs for the non-pumping simulation. Simulated drawdown is used to evaluate Model-Based Performance Objective 1) by determining the ability of a remedial alternative to achieve simulated drawdown of least 1 foot within the hydraulic control boundaries on the Site peninsula, which typically correspond to where the groundwater TCVOC concentrations are greater than 1,000 µg/L. In addition to simulated drawdown, simulated groundwater flow directions for each remedial alternative were determined by plotting groundwater flow velocity vectors predicted by the groundwater flow model under the influence of operating the remedial alternative. Model-Based Performance Objective 3) was further evaluated by determining whether groundwater flow under the Waterway is directed to the plant-west toward the containment system. GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 3 The two evaluation approaches are described below. Simulated Mass-Weighted Particle Capture Two approaches were used to simulate mass-weighted particle capture; one is based on aqueous phase TCVOC mass capture; and the other is based on total TCVOC mass capture. The simulated aqueous phase TCVOC mass-weighted particle capture approach released particles in each model cell with aqueous phase (i.e., groundwater) TCVOC concentrations above 2.4 µg/L, as presented in the Draft Site Characterization Report (SCR) (CRA, 2014b). The total TCVOC mass-weighted particle capture approach released particles in each model cell with soil TCVOC concentrations above 100 mg/kg. The ability of the remedial alternatives to contain each particle was evaluated by simulating particle pathways forward-in-time within the groundwater flow field simulated under the influence of the remedial alternatives for a duration of 1,000 years. Particle pathways were simulated considering retarded advective migration using a retardation factor value of 5 based on TCVOC mass in the aquifer calculated from soil concentrations (that represent mass in the aqueous, sorbed, and DNAPL phases) and aqueous phase TCVOC mass calculated from groundwater concentrations. Specifically, the retardation factor is determined using the relationship: R  1 MTotal  MAqueous MAqueous Where: R = Retardation factor MTotal = Total mass in aquifer calculated from soil TCVOC concentrations (above a threshold soil concentration of 100 mg/kg) equal to approximately 787,000 lbs MAqueous = Dissolved mass in aquifer calculated from groundwater TCVOC concentrations (above a threshold concentration of 2.4 µg/L) equal to approximately 157,000 lbs Particle tracking represents how particles move through a simulated groundwater flow field by advective migration processes only (i.e., migration with the linear groundwater flow velocity). To represent retardation in the particle tracking simulations, the effective porosity used to calculate groundwater flow velocities is multiplied by the retardation factor value. In this way, the particle movement through the simulated groundwater flow field occurs at the retarded groundwater flow velocity. The retarded groundwater flow velocity represents how TCVOC migration in groundwater is slowed by TCVOC adsorption onto soil particles. Aqueous phase and total TCVOC mass-weighted particle capture approaches were taken to evaluate the remedial alternatives. For the aqueous phase TCVOC mass-weighted particle capture approach, a TCVOC mass was determined for each particle based on the groundwater TCVOC concentration for the model cell where the particle was released and the volume of groundwater in the model cell. For the total TCVOC mass-weighted particle capture approach, a total TCVOC mass was determined for each particle based on the soil TCVOC concentration for the model cell where the particle was released and the volume of the model cell combined with the soil bulk density. The TCVOC concentrations per model cell were obtained from the 3D interpolated groundwater and soil TCVOC concentrations presented in the Draft SCR (CRA, 2014b). GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 4 The mass-weighted particle capture is used to evaluate Model-Based Performance Objective 2) by determining the ability of a remedial alternative to contain the TCVOC groundwater plume and limit the TCVOC mass-weighted particle discharge to the surface water bodies surrounding the Site peninsula to less than 0.2 percent of the estimated total TCVOC mass in the aquifer (i.e., 0.2 percent of 787,000 lbs). Particle tracking does not account for the natural attenuation of the groundwater plumes (i.e., biodegradation, dispersion, dilution, etc.) that can reduce plume concentrations, particularly at the plume limits, and alleviate the need for containment. Consequently, the particle tracking method provides a conservative assessment of the TCVOC groundwater plume containment. 2.2 Remedial Alternatives Model Set-Up The remedial alternatives were simulated using the Event 3A calibrated model presented in the MCR. Aqueous phase and total TCVOC mass-weighted particle capture was simulated under steady-state groundwater flow conditions for each alternative. Event 3A has an average Waterway surface water elevation of 0.71 feet (ft) National Geodetic Vertical Datum (NGVD), which was measured after dry conditions occurring from July to October 2012, and thus reflects a lower average surface water elevation in the Waterway. A lower average Waterway elevation increases hydraulic gradients towards, or groundwater discharge to, the Waterway, which increases the pumping required to achieve containment and is a conservative approach for evaluating containment. The groundwater pumping associated with the current groundwater extraction system implemented in the Event 3A calibrated model was turned off. Further details regarding the model set-up applied for each remedial alternative are presented in the following sections. 3. Containment Alternatives The modeling evaluation conducted for each of Containment Alternatives C100, C150, and C200 is presented in Sections 3.1, 3.2, and 3.3, respectively. Section 3.4 presents a summary of the modeling evaluation results for the Containment Alternatives. 3.1 Containment Alternative C100 Containment Alternative C100 represents a physical hydraulic sheet pile vertical barrier wall along the Site peninsula adjacent to the Waterway and upland groundwater extraction wells on the Site peninsula. The Event 3A calibrated model was used to determine the sheet pile vertical barrier wall alignment/depth and number of extraction wells (location and pumping rate) to provide containment of the upland TCVOC groundwater plume and prevent plume expansion. Containment Alternative C100 includes the existing inactive extraction well EXT-9. Potential reduced precipitation infiltration due to the capping component (physical direct contact exposure [PDCE] barrier) of Containment Alternative C100 (i.e., 605 & 709 Alexander Avenue Properties, N Landfill, and 709 Embankment Fill Area) was not implemented in the modeling evaluation as a conservative approach. The sheet pile vertical barrier wall alignment/depth and number of extraction wells/pumping rates for Containment Alternative C100 were determined by making manual adjustments to the sheet pile vertical barrier wall and extraction wells combined with automatic optimization of extraction well GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 5 locations. The Dynamically Dimensioned Search Algorithm (DDS) was selected to optimize well locations. DDS was selected because it has been shown to be an effective optimizer for computationally intensive models (Tolson and Shoemaker, 2007). DDS is also available as a discrete optimization algorithm which identifies well locations based on model cell row/column indices rather than Cartesian coordinates, which is advantageous when working with a row/column/layer based model such as SEAWAT (Langevin et al., 2008) used to develop the calibrated model for the Site. The Optimization Software Toolkit for Research Involving Computation Heuristics (OSTRICH) (Matott, 2005) was used to interface between the groundwater flow model and the optimization algorithm DDS. Initially, the sheet pile vertical barrier wall length/depth and extraction well locations/pumping rates were manually adjusted to achieve containment of the upland TCVOC groundwater plume. The sheet pile vertical barrier wall alignment was set along the Waterway side of Docks 1 and 2. The sheet pile vertical barrier wall was represented in the model as a no-flow boundary condition consistent with constructing the sheet pile vertical barrier wall using steel sheet piling. Extraction well pumping rates were varied between 5 and 20 gallons per minute (gpm). A pumping rate of 5 gpm is approximately the average pumping for the existing active extraction wells after being redeveloped (i.e., Event 1), and a pumping rate of 20 gpm corresponds to the pumping rate sustained during the EXT-9 pumping test. An extraction well screen length of 20 ft was typically specified based on the 20 ft screen length installed for existing inactive extraction well EXT-9. Pumping rates specified for the extraction wells were weighted over the screen length based on the transmissivity of the model cells intersected by the well screens. Manual adjustments to the sheet pile vertical barrier wall length/depth and extraction well locations were conducted initially to develop an understanding of sheet pile vertical barrier wall/extraction well interaction and key areas requiring wells for containment. The manual adjustments provided an indication of the sheet pile vertical barrier wall length/depth, number of extraction wells, extraction well pumping rates, and extraction well locations required for plume containment, which were used to inform a starting condition to apply for automated optimization of well locations. For optimization, adjustment bounds were set around each extraction well based on the TCVOC plume location and containment results from manual adjustment. DDS was applied to optimize the horizontal locations (vertical locations and pumping rates were left as determined manually) within the adjustment bounds. For the optimization simulations, the sheet pile vertical barrier wall was left as determined using the manual adjustments. The objective of optimization was to maximize TCVOC groundwater plume containment while not placing extraction wells where the pH was greater than 10 standard units of pH (s.u.) (to minimize fouling of extraction wells). Following optimization, the extraction well locations were manually adjusted to a minimal degree to ensure that they were outside of building envelopes, and in some cases extraction wells were combined where the optimization resulted in extraction wells being placed adjacent to one another. For Containment Alternative C100, the optimization of the manually located extraction wells resulted in eleven extraction wells (including existing inactive extraction well EXT-9) at a total pumping rate of 157.5 gpm. The sheet pile vertical barrier wall and extraction well layout for Containment Alternative C100 is presented on Figure 1. Table 1 summarizes the extraction well depths and pumping rates, as well as the initial chemistry at each extraction well in terms of groundwater TCVOC concentrations, soil TCVOC concentrations, and groundwater pH. GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 6 Figures 1 to 7 present the simulated drawdown and groundwater flow directions (groundwater flow direction indicates hydraulic gradient direction) for Containment Alternative C100 in the 15-ft, 25-ft, 50-ft, 75-ft, 100-ft, 130-ft, and 160-ft zones, respectively. Containment Alternative C100 achieves inward gradients and simulated drawdown of at least 1 foot where TCVOC concentrations are above 1,000 µg/L in the 15-ft zone (see Figure 1). Containment Alternative C100 achieves inward gradients and simulated drawdown of at least 1 foot within the majority of the hydraulic control boundaries for the 25-ft to 75-ft zones (see Figures 2 to 4), which essentially meets Model-Based Performance Objective 1). However, the simulated drawdown is less than 1 foot within a significant portion of the hydraulic control boundaries for the 100-ft and 130-ft zones (see Figures 5 and 6), and this does not meet Model-Based Performance Objective 1), although inward gradients are simulated for these zones. The majority of the 160-ft zone on the Site peninsula lies below the zone of apparent confining effect where lower permeability is represented in the groundwater flow model. Thus, simulating significant drawdown (i.e., 1 foot or more) within the hydraulic control boundary for the 160-ft zone is not expected (see Figure 7). For the portion of the 160-ft zone hydraulic control boundary that lies above the zone of apparent confining effect, Containment Alternative C100 achieves drawdown of greater than 0.5 ft and gradients are inward from Commencement Bay. Table 2 and Table 3 summarize the simulated aqueous phase and total TCVOC mass-weighted particle capture, respectively, for Containment Alternative C100. Tables 2 and 3 are organized into two sections, as follows:  Section I: presents the mass-weighted particle capture over all aquifer depths in terms of pounds of either aqueous phase TCVOC (Table 2) or total TCVOC (Table 3) mass removed  Section II: presents mass-weighted particle capture over all aquifer depths in terms of percentage of either the total aqueous phase TCVOC mass based on groundwater concentrations (Table 2) or total TCVOC mass based on soil concentrations (Table 3). Table 2 shows that Containment Alternative C100 achieves Model-Based Performance Objective 2). The TCVOC mass discharge to the surface water bodies surrounding the Site peninsula is approximately 0.02 percent of the total TCVOC mass in the aquifer (188 lbs) after the 1,000-year simulation duration. Figures 4, 5, and 6 show that simulated groundwater flow directions under the Waterway in the 75-ft, 100-ft, and 130-ft zones, respectively, for Containment Alternative C100 are directed toward the Site peninsula and the groundwater extraction system, which meets Model-Based Performance Objective 3). The Waterway extends through the 15-ft to 50-ft zones (i.e., the Waterway consists of surface water for the 15-ft to 50-ft zones). As a result, groundwater flow directions are not simulated within the Waterway for these zones (see Figures 1 to 3). Under the Waterway, the 160-ft zone lies below the zone of apparent confining effect, which isolates this portion of the 160-ft zone from the overlying aquifer depth zones (see Figure 7). 3.2 Containment Alternative C150 Containment Alternative C150 is based on Containment Alternative C100 but with increased extraction rates. Containment Alternative C150 applies the same extraction wells as Containment Alternative C100, but with pumping rates increased by up to 50 percent from that applied in Containment Alternative C100. At some extraction well locations, the groundwater flow model would not sustain a 50 percent increase in pumping (i.e., the extraction well was simulated to go dry). This occurred at proposed extraction wells EXT-1(s) and EXT-5(s), and therefore, the maximum GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 7 pumping rate that the model could sustain was applied for these extraction wells. Table 1 shows the pumping rates applied for Containment Alternative C150. The total pumping rate corresponds to 226.25 gpm, which is approximately 44 percent greater than Containment Alternative C100. Figures 8 to 14 present the simulated drawdown and groundwater flow directions for Containment Alternative C150 in the 15-ft, 25-ft, 50-ft, 75-ft, 100-ft, 130-ft, and 160-ft zones, respectively. Containment Alternative C150 achieves inward gradients and simulated drawdown of at least 1 foot where TCVOC concentrations are above 1,000 µg/L in the 15-ft zone (see Figure 8). Containment Alternative C150 achieves inward gradients and simulated drawdown of at least 1 foot within the hydraulic control boundaries for the 25-ft and 50-ft zones (see Figures 9 and 10), which meets Model-Based Performance Objective 1). Containment Alternative C150 achieves inward gradients and simulated drawdown of at least 1 foot within the vast majority of the hydraulic control boundaries for the 75-ft to 130-ft zones (see Figures 11 to 13), which essentially meets Model-Based Performance Objective 1). The 1-foot simulated drawdown encompasses where TCVOC concentrations are above 1,000 µg/L in the 75-ft to 130-ft zones on the Site peninsula (see Figures 11 to 13). Also, expanding the simulated drawdown to 0.8 ft does encompass nearly all of the hydraulic control boundaries for the 75-ft to 130-ft zones. Simulating drawdown of 0.8 ft, or practically 1 foot of drawdown, to encompass the hydraulic control boundaries is within the level of uncertainty inherent in the groundwater flow model, and in combination with simulating inward gradients for the 75-ft to 130-ft zone hydraulic control boundaries, satisfies the intent of Model-Based Performance Objective 1). Simulating significant drawdown (i.e., 1 foot or more) in the 160-ft zone is not expected since the majority of this zone on the Site peninsula lies below the zone of apparent confining effect where lower permeability is represented in the groundwater flow model (see Figure 14). For the portion of the 160-ft zone hydraulic control boundary that lies above the zone of apparent confining effect, Containment Alternative C150 achieves drawdown of greater than 0.8 ft and gradients are inward from Commencement Bay. Table 2 summarizes the simulated aqueous phase mass-weighted particle capture for Containment Alternative C150 and shows that it achieves Model-Based Performance Objective 2). The aqueous phase TCVOC mass discharge to the surface water bodies surrounding the Site peninsula is approximately 0.004 percent of the total TCVOC mass (35 lbs) in the aquifer after the 1,000-year simulation duration. Figures 11, 12, and 13 show that simulated groundwater flow directions under the Waterway in the 75-ft, 100-ft, and 130-ft zones, respectively, for Containment Alternative C150 are directed toward the Site peninsula and the groundwater extraction system, which meets Model-Based Performance Objective 3). Under the Waterway, the 160-ft zone lies below the zone of apparent confining effect, which isolates this portion of the 160-ft zone from the overlying aquifer depth zones (see Figure 14). 3.3 Containment Alternative C200 Containment Alternative C200 is based on Containment Alternative C100 but with further increased extraction rates. Containment Alternative C200 applies the same extraction wells as Containment Alternative C100, but with pumping rates increased by up to 100 percent from that applied in Containment Alternative C100. At some extraction well locations, the groundwater flow model would not sustain a 100 percent increase in pumping (i.e., the extraction well was simulated to go dry). This occurred at proposed extraction wells EXT-1(s), EXT-5(s), EXT-15(s), EXT-18(s), and EXT-21(s). The maximum pumping rate that the model could sustain was applied for these extraction wells. For EXT-1(s), the increased pumping rate applied in Containment Alternative C150 GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 8 had to be decreased to the pumping rate originally applied in Containment Alternative C100. Table 1 shows the pumping rates applied for Containment Alternative C200. The total pumping rate corresponds to 281.5 gpm, which is approximately 79 percent greater than Containment Alternative C100 and 24 percent greater than Containment Alternative C150. Figures 15 to 21 present the simulated drawdown and groundwater flow directions for Containment Alternative C200 in the 15-ft, 25-ft, 50-ft, 75-ft, 100-ft, 130-ft, and 160-ft zones, respectively. Containment Alternative C200 achieves inward gradients and simulated drawdown of at least 1 foot where TCVOC concentrations are above 1,000 µg/L in the 15-ft zone (see Figure 15). Containment Alternative C200 achieves inward gradients and simulated drawdown of at least 1 foot within the hydraulic control boundaries for the 25-ft and 50-ft zones (see Figures 16 and 17), which meets Model-Based Performance Objective 1). Similar to Containment Alternative C150, Containment Alternative C200 achieves inward gradients and simulated drawdown of at least 1 foot within the vast majority of the hydraulic control boundaries for the 75-ft to 130-ft zones (see Figures 18 to 20), which essentially meets Model-Based Performance Objective 1). The 1-foot simulated drawdown encompasses where TCVOC concentrations are above 1,000 µg/L in the 75-ft to 130-ft zones on the Site peninsula (see Figures 18 to 20). The above in combination with simulating inward gradients for the 75-ft to 130-ft zone hydraulic control boundaries, satisfies the intent of Model-Based Performance Objective 1). Simulating significant drawdown (i.e., 1 foot or more) in the 160-ft zone is not expected since the majority of this zone on the Site peninsula lies below the zone of apparent confining effect where lower permeability is represented in the groundwater flow model (see Figure 21). For the portion of the 160-ft zone hydraulic control boundary that lies above the zone of apparent confining effect, Containment Alternative C200 achieves drawdown of greater than 1 foot and gradients are inward from Commencement Bay. Table 2 summarizes the simulated aqueous phase mass-weighted particle capture for Containment Alternative C200. Table 2 shows that Containment Alternative C200 achieves Model-Based Performance Objective 2). The aqueous phase TCVOC mass discharge to the surface water bodies surrounding the Site peninsula is approximately 0.004 percent of the total TCVOC mass (30 lbs) in the aquifer after the 1,000-year simulation duration. Figures 18, 19, and 20 show that simulated groundwater flow directions under the Waterway in the 75-ft, 100-ft, and 130-ft zones, respectively, for Containment Alternative C200 are directed toward the Site peninsula and the groundwater extraction system, which meets Model-Based Performance Objective 3). Under the Waterway, the 160-ft zone lies below the zone of apparent confining effect, which isolates this portion of the 160-ft zone from the overlying aquifer depth zones (see Figure 21). 3.4 Summary of Containment Alternatives Modeling Results The modeling evaluation results show that both Containment Alternatives C150 and C200 meet the Model-Based Performance Objectives 2) and 3), and meet the intent of Model-Based Performance Objective 1), equivalently. Containment Alternative C150 meets the Model-Based Performance Objectives more economically since a lower total flow rate would result in lower operation and maintenance costs for treatment as presented in Subsection 5.2 of the main report. For example, less power consumption, less chemical usage for solids removal and pH adjustment, and less production of solids requiring off-Site disposal would be expected for Containment Alternative C150 compared to Containment Alternative C200. Additionally, as stated in Section 2, refinements of extraction well locations and pumping rates can and would be completed during the detailed design GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 9 to further optimize the containment system with respect to the Model-Based Performance Objectives. 4. VOC Mass Reduction Alternatives The modeling evaluation conducted for each of VOC Mass Reduction Alternatives M100, M150, and M200, as well as VOC Mass Reduction Alternative MSP, is presented in Sections 4.1, 4.2, 4.3, and 4.4 respectively. Section 4.5 presents a summary of the modeling evaluation results for the VOC mass reduction alternatives. 4.1 VOC Mass Reduction Alternative M100 VOC Mass Reduction Alternative M100 represents a physical hydraulic sheet pile vertical barrier wall along the Site peninsula adjacent to the Waterway and two upland groundwater extraction wells on the Site peninsula. Groundwater extraction for VOC mass reduction is represented only from areas of elevated concentrations in the shallow and deep TCVOC groundwater plume outside the areas of elevated/high pH (i.e., greater than 10 s.u.). Direct pumping from areas of high pH is avoided in order to prevent: potential fouling of the extraction and treatment system; the need for treatment of high pH water; and disposal of additional solids associated with this groundwater. Figure 22 shows the locations and depths of two proposed mass reduction extraction wells; one shallow and one deep. Table 1 summarizes the mass reduction extraction well depths and pumping rates, as well as the initial chemistry at each extraction well in terms of groundwater TCVOC concentrations, soil TCVOC concentrations, and groundwater pH. A total pumping rate of 35 gpm is applied for VOC Mass Reduction Alternative M100, which corresponds to specified pumping rates of 15 gpm for the proposed shallow extraction well and 20 gpm for the proposed deep extraction well. These well-specific pumping rates were determined by varying pumping at the wells between 5 and 20 gpm in the model to optimize capture assuming a containment system (i.e., C100) was operating, while avoiding capture of water with high pH. A pumping rate of 5 gpm is approximately the average pumping for the existing active extraction wells after being redeveloped (i.e., Event 1 applied for model calibration in the MCR), and a pumping rate of 20 gpm corresponds to the pumping rate sustained during the existing inactive extraction well EXT-9 pumping test. VOC Mass Reduction Alternative M100 is not intended to provide complete containment of the TCVOC groundwater plume, and thus, is not evaluated against Model-Based Performance Objectives. Table 4 summarizes the simulated total TCVOC (dissolved, sorbed, and DNAPL phases) mass-weighted particle capture outside pH >10 s.u. for VOC Mass Reduction Alternative M100. After 20 years and 100 years, VOC Mass Reduction Alternative M100 achieves a total TCVOC mass-weighted particle capture of 35.0 percent (275,132 lbs) and 38.7 percent (304,597 lbs), respectively. 4.2 VOC Mass Reduction Alternative M150 VOC Mass Reduction Alternative M150 is based on VOC Mass Reduction Alternative M100 but with increased extraction rates. VOC Mass Reduction Alternative M150 applies the same extraction wells as VOC Mass Reduction Alternative M100, but with pumping rates increased by 50 percent from that applied in VOC Mass Reduction Alternative M100. Table 1 shows that a total pumping rate of 52.5 gpm is applied for VOC Mass Reduction Alternative M150. GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 10 Mass Reduction Alternative M150 is not evaluated against the Model-Based Performance Objectives since it is not intended to provide complete containment of the TCVOC groundwater plume. Table 4 summarizes the simulated total TCVOC mass-weighted particle capture outside pH >10 s.u. for VOC Mass Reduction Alternative M150. After 20 years and 100 years, VOC Mass Reduction Alternative M150 achieves a total TCVOC mass-weighted particle capture of 36.3 percent (285,394 lbs) and 40.2 percent (316,373 lbs), respectively. 4.3 VOC Mass Reduction Alternative M200 VOC Mass Reduction Alternative M200 is based on VOC Mass Reduction Alternative M100 but with further increased extraction rates. VOC Mass Reduction Alternative M200 applies the same extraction wells as VOC Mass Reduction Alternative M100, but with pumping rates increased by 100 percent from that applied in VOC Mass Reduction Alternative M100. Table 1 shows that a total pumping rate of 70 gpm is applied for VOC Mass Reduction Alternative M200. Mass Reduction Alternative M200 is not evaluated against the Model-Based Performance Objectives since it is not intended to provide complete containment of the TCVOC groundwater plume. Table 4 summarizes the simulated total TCVOC mass-weighted particle capture outside pH >10 s.u. for VOC Mass Reduction Alternative M200. After 20 years and 100 years, VOC Mass Reduction Alternative M200 achieves a total TCVOC mass-weighted particle capture of 37.1 percent (291,648 lbs) and 41.4 percent (325,595 lbs), respectively. 4.4 VOC Mass Reduction Alternative MSP To focus on total TCVOC reduction, VOC Mass Reduction Alternative MSP was developed to determine if total TCVOC could be further reduced and reduced more quickly in comparison to the reductions simulated for the other VOC Mass Reduction Alternatives (M100, M150, M200) by an alternative approach to extraction well placement. VOC Mass Reduction Alternative MSP is a combination of proposed extraction well placements by the Agencies provided to OCC in October 2016 as well as hand modified well placements (both in the horizontal and vertical in terms of screen depth and length) to maximize removal of total TCVOC mass. Like the Containment and other VOC Mass Reduction Alternatives, the VOC Mass Reduction Alternative MSP represents a physical hydraulic sheet pile vertical barrier wall along the Site peninsula adjacent to the Waterway and upland groundwater extraction wells on the Site peninsula. The location of the sheet pile vertical barrier wall determined through the optimization of the Containment Alternatives was applied to VOC Mass Reduction Alternative MSP and not further optimized. Unlike the Containment Alternatives, which utilized DDS, optimization was completed manually to adjust the number of extraction wells/pumping rates to achieve optimum mass extraction from Site areas and depths containing the highest soil TCVOC concentrations while avoiding areas of high pH (pH >10 s.u.). Optimization through DDS was not utilized because there were few extraction well location possibilities that overlapped the highest soil TCVOC concentrations/lower pH areas and depths. Extraction rates were initially set to 20 gpm and reduced if portions of the well were simulated to go dry in the groundwater flow model. The extraction well screen length was set based on the depth of elevated soil TCVOC concentrations in a particular area. Table 1 presents the proposed extraction well rates, screen depths and lengths, along with the initial groundwater TCVOC concentrations, soil TCVOC concentrations, and groundwater pH at the proposed extraction well locations. By strategically positioning extraction wells in areas of elevated soil TCVOC concentrations both horizontally and vertically, mass reduction can be maximized. Pumping GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 11 rates specified for the extraction wells were weighted over the screen length based on the transmissivity of the model cells intersected by the well screens. As presented in Table 1, the manual optimization of proposed extraction well locations for VOC Mass Reduction Alternative MSP resulted in eleven extraction wells (optimized well locations do not include any existing wells or wells identified in the Containment Alternatives) at a total pumping rate of 210 gpm. Nine of the proposed extraction wells are in areas of elevated soil TCVOC concentrations and two of the wells are positioned to enhance containment of the VOC Mass Reduction Alternative MSP. The proposed sheet pile vertical barrier wall and extraction well layout for the VOC Mass Reduction Alternative MSP is presented on Figure 23. Figures 23 to 29 present the simulated drawdown and groundwater flow directions for VOC Mass Reduction Alternative MSP in the 15-ft, 25-ft, 50-ft, 75-ft, 100-ft, 130-ft, and 160-ft zones, respectively. The VOC Mass Reduction Alternative MSP achieves inward gradients and simulated drawdown of at least 1 foot where TCVOC concentrations are above 1,000 µg/L in the 15-ft zone (see Figure 23). VOC Mass Reduction Alternative MSP achieves inward gradients and simulated drawdown of at least 1 foot within the hydraulic control boundaries for the 25-ft and 50-ft zones (see Figures 24 and 25), which meets Model-Based Performance Objective 1). The VOC Mass Reduction Alternative MSP achieves inward gradients and simulated drawdown of at least 1 foot within the vast majority of the hydraulic control boundaries for the 75-ft to 130-ft zones (see Figures 26 to 28), which essentially meets Model-Based Performance Objective 1). The 1-foot simulated drawdown encompasses where TCVOC concentrations are above 1,000 µg/L in the 75-ft to 130-ft zones on the Site peninsula (see Figures 26 to 28). Simulating significant drawdown (i.e., 1 foot or more) in the 160-ft zone is not expected since the majority of this zone on the Site peninsula lies below the zone of apparent confining effect where lower permeability is represented in the groundwater flow model (see Figure 29). For the portion of the 160-ft zone hydraulic control boundary that lies above the zone of apparent confining effect, VOC Mass Reduction Alternative MSP achieves drawdown of greater than 1 ft and gradients are inward from Commencement Bay. Table 2 summarizes the simulated aqueous phase mass-weighted particle capture for VOC Mass Reduction Alternative MSP. Table 2 shows that VOC Mass Reduction Alternative MSP achieves Model-Based Performance Objective 2). The aqueous phase TCVOC mass discharge to the surface water bodies surrounding the Site peninsula is approximately 0.01 percent of the total TCVOC mass (22 lbs) in the aquifer after the 1,000-year simulation duration. Figures 26, 27, and 28 show that simulated groundwater flow directions under the Waterway in the 75-ft, 100-ft, and 130-ft zones, respectively, for VOC Mass Reduction Alternative MSP are directed toward the Site peninsula and the groundwater extraction system, which meets Model-Based Performance Objective 3). Under the Waterway, the 160-ft zone lies below the zone of apparent confining effect, which isolates this portion of the 160-ft zone from the overlying aquifer depth zones (see Figure 29). Table 4 summarizes the simulated total TCVOC mass-weighted particle capture outside pH >10 s.u. for VOC Mass Reduction Alternative MSP. After 20 years and 100 years, VOC Mass Reduction Alternative MSP achieves a total TCVOC mass-weighted particle capture of 41.2 percent (323,883 lbs) and 41.7 percent (328,540 lbs), respectively. In comparison to the other VOC mass reduction alternatives, the VOC Mass Reduction Alternative MSP reduces more overall total mass and the rate of reduction is greatest in the short term. GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 12 4.5 Summary of VOC Mass Reduction Alternatives The modeling evaluation results show that VOC Mass Reduction Alternative MSP provides greater mass reduction of total TCVOC mass outside areas of high pH (pH >10 s.u.) and the rate of reduction is greatest in the short term when compared to the VOC Mass Reduction Alternatives M100, M150, and M200. Figures 30 shows the total TCVOC mass-weighted particle capture outside pH >10 s.u. over 100 years for VOC Mass Reduction Alternatives M100, M150, M200, and MSP. The significant improvement in the rate of total TCVOC mass removed in the short term provided by VOC Mass Reduction Alternative MSP is apparent on Figure 30. As presented in Sections 6.2 and 8 of the main report, VOC Mass Reduction Alternative MSP is the preferred alternative based on the detailed evaluation performed. VOC Mass Reduction Alternative MSP provides both VOC mass reduction/removal by strategic groundwater pumping and pumps sufficient groundwater to achieve the Site Model-Based Performance Objectives for containment. 5. References Conestoga-Rovers & Associates (CRA), 2014a. Model Calibration Report, Draft (Revised August 29, 2014), Groundwater and Sediment Remediation, Occidental Chemical Corporation, Tacoma, Washington, Ref. No. 007843 (135), August. CRA, 2014b. Site Characterization Report, Draft Report, Groundwater and Sediment Remediation, Occidental Chemical Corporation, Tacoma, Washington, Ref. No. 007843 (128), August. Langevin, C.D., D.T. Thorne, Jr., A.M. Dausman, M.C. Sukop, and W. Guo, 2008. SEAWAT Version 4: A Computer Program for Simulation of Multi-Species Solute and Heat Transport, Techniques and Methods Book 6, Chapter A22, U.S. Department of the Interior, U.S. Geological Survey, Reston, Virginia. Matott, L.S., 2005. OSTRICH: An Optimization Software Tool; Documentation and User's Guide, Version 1.6, State University of New York at Buffalo, Dept. of Civil, Structural and Environmental Engineering. Tolson, B.A., and C.A. Shoemaker, 2007. Dynamically Dimensioned Search Algorithm for Computationally Efficient Watershed Model Calibration, Water Resources Research, Vol. 43, W01413, doi:10.1029/2005WR004723. GHD Report for Glenn Springs Holdings, Inc. – Feasibility Study Report Appendix E 007843 (139) 13 TRUE NORTH PLANT NORTH 0 400ft 1 1 1 1 200 EXT-3(d) EXT-18(s) EXT-4(s) 1 EXT-1(s) EXT-9(d) EXT-10(s) EXT-8(s) 1 EXT-15(s) EXT-16(s) 1 EXT-5(s) (s) (d) EXT-21(s) 1 1 figure 1 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C100 - 15 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C100-DDN-15FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 1 400ft 1 1 1 200 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) EXT-9(d) 1 1 EXT-8(s) EXT-10(s) EXT-15(s) 1 EXT-16(s) 1 1 EXT-5(s) (s) (d) EXT-21(s) 1 figure 2 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C100 - 25 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C100-DDN-25FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 400ft 1 1 1 1 200 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) 1 EXT-9(d) 1 EXT-10(s) EXT-8(s) 1 EXT-15(s) EXT-16(s) 1 1 EXT-5(s) (s) (d) EXT-21(s) 1 figure 3 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C100 - 50 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C100-DDN-50FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 EXT-18(s) EXT-4(s) 400ft EXT-3(d) 1 EXT-1(s) 1 1 200 EXT-9(d) EXT-10(s) EXT-8(s) 1 EXT-15(s) 1 EXT-16(s) 1 EXT-5(s) (s) (d) EXT-21(s) 1 figure 4 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C100 - 75 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C100-DDN-75FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft EXT-3(d) 1EXT-18(s) EXT-4(s) EXT-1(s) 1 EXT-9(d) EXT-10(s) EXT-8(s) EXT-15(s) EXT-16(s) 1 EXT-5(s) (s) (d) EXT-21(s) 1 figure 5 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C100 - 100 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C100-DDN-100FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft EXT-3(d) EXT-18(s) EXT-4(s) 1 EXT-1(s) EXT-9(d) EXT-10(s) EXT-8(s) EXT-15(s) EXT-16(s) 1 EXT-5(s) (s) (d) EXT-21(s) 1 figure 6 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C100 - 130 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C100-DDN-130FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 200 400ft 0.2 5 5 0.2 0 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) 0. 25 25 0. EXT-8(s) EXT-10(s) 0. 25 0.2 5 EXT-15(s) 0.25 EXT-9(d) 0.25 EXT-16(s) 0.5 0.5 EXT-5(s) 0.5 (s) (d) 0.2 EXT-21(s) 5 0.5 5 0.2 1 0.5 0.2 0.25 0.25 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C100-DDN-160FT.srf) JAN 18/2017 5 figure 7 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C100 - 160 FT ZONE Occidental Chemical Corporation, Tacoma, Washington TRUE NORTH PLANT NORTH 0 400ft 1 1 1 1 200 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) EXT-9(d) EXT-10(s) EXT-8(s) 1 EXT-15(s) 1 EXT-16(s) EXT-5(s) (s) (d) EXT-21(s) 1 1 1 1 figure 8 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C150 - 15 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C150-DDN-15FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 1 400ft 1 1 1 200 EXT-3(d) EXT-18(s) EXT-4(s) 1 EXT-1(s) 1 EXT-9(d) EXT-10(s) EXT-8(s) EXT-15(s) 1 EXT-16(s) EXT-5(s) 1 (s) (d) EXT-21(s) 1 1 1 figure 9 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C150 - 25 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C150-DDN-25FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 1 1 400ft 1 1 1 200 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) EXT-9(d) EXT-8(s) EXT-10(s) EXT-15(s) 1 1 EXT-16(s) EXT-5(s) 1 (s) (d) 1EXT-21(s) 1 1 figure 10 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C150 - 50 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C150-DDN-50FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 1 1 0.8 0.8 0.8 1 0.8 1 200 400ft 0.8 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) 1 EXT-9(d) EXT-10(s) EXT-8(s) EXT-15(s) 0.8 1 1 EXT-16(s) 0.8 EXT-5(s) 1 1 0.8 EXT-21(s) 0.8 1 (s) (d) 1 0.8 figure 11 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C150 - 75 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C150-DDN-75FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 0.8 1 EXT-18(s) 0.8 0.8 1 0.8 EXT-3(d) 1 EXT-4(s) 1 0.8 EXT-1(s) EXT-9(d) EXT-10(s) EXT-8(s) EXT-15(s) 1 EXT-16(s) 1 0.8 EXT-5(s) 0.8 1 (s) (d) 1 EXT-21(s) 0.8 1 0.8 figure 12 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C150 - 100 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C150-DDN-100FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 0.8 1 0.8 1 EXT-18(s) EXT-3(d) 0. 8 EXT-4(s) 0.8 EXT-1(s) EXT-9(d) 1 8 0. EXT-10(s) EXT-8(s) EXT-15(s) 1 0.8 EXT-16(s) 0. 8 1 EXT-5(s) 0.8 1 (s) (d) EXT-21(s) 1 0.8 0.8 figure 13 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C150 - 130 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C150-DDN-130FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 0.25 0.25 0.2 5 0.5 0.25 EXT-3(d) EXT-18(s) 0.5 EXT-4(s) EXT-9(d) 0.2 5 0.5 0.5 0.25 EXT-1(s) 0.5 EXT-8(s) EXT-10(s) 0.2 5 0.2 5 EXT-15(s) 0.5 0.5 0.25 0.5 8 0 .2 5 0. 5 0.2 EXT-16(s) EXT-5(s) 5 0. (s) (d) EXT-21(s) 0.5 5 0.2 1 0.8 0. 5 0. 5 0.5 0.5 0.25 0.25 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C150-DDN-160FT.srf) JAN 18/2017 0.25 figure 14 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS 0.25 FOR CONTAINMENT ALTERNATIVE C150 - 160 FT ZONE Occidental Chemical Corporation, Tacoma, Washington TRUE NORTH PLANT NORTH 0 1 400ft 1 1 1 200 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) EXT-9(d) EXT-8(s) EXT-10(s) 1 EXT-15(s) 1 EXT-16(s) EXT-5(s) (s) (d) EXT-21(s) 1 1 1 1 figure 15 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C200 - 15 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C200-DDN-15FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 1 400ft 1 1 1 200 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) 1 EXT-9(d) 1 EXT-10(s) EXT-8(s) EXT-15(s) EXT-16(s) 1 EXT-5(s) 1 (s) (d) EXT-21(s) 1 1 1 figure 16 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C200 - 25 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C200-DDN-25FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 1 1 200 400ft 1 1 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) EXT-10(s) 1 1 EXT-9(d) EXT-8(s) EXT-15(s) EXT-16(s) EXT-5(s) 1 1 (s) (d) EXT-21(s) 1 1 1 figure 17 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C200 - 50 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C200-DDN-50FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 1 1 1 1 EXT-3(d) EXT-18(s) EXT-4(s) 1 EXT-1(s) EXT-9(d) EXT-10(s) EXT-8(s) 1 EXT-15(s) 1 EXT-16(s) 1 EXT-5(s) 1 (s) (d) EXT-21(s) 1 1 1 figure 18 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C200 - 75 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C200-DDN-75FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 1 1 1 1 EXT-3(d) EXT-18(s) EXT-4(s) EXT-1(s) EXT-9(d) EXT-8(s) EXT-10(s) 1 EXT-15(s) EXT-16(s) 1 EXT-5(s) (s) (d) EXT-21(s) 1 1 1 1 figure 19 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C200 - 100 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C200-DDN-100FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 1 1 1 EXT-3(d) EXT-18(s) EXT-4(s) 1 EXT-1(s) 1 EXT-9(d) 1 1 EXT-8(s) 1 EXT-10(s) EXT-15(s) EXT-16(s) 1 EXT-5(s) 1 (s) (d) EXT-21(s) 1 1 1 figure 20 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C200 - 130 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C200-DDN-130FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 0.25 5 0.2 0 .2 5 0.5 0.5 EXT-3(d) EXT-18(s) EXT-4(s) 0.5 EXT-1(s) 0.5 0.25 EXT-9(d) 0.2 5 5 EXT-10(s) 0. 5 0.5 EXT-15(s) 5 0 .2 0.2 EXT-8(s) 0 .5 0.25 EXT-16(s) 0.5 0.5 1 EXT-5(s) (s) (d) 0.25 0.5EXT-21(s) 0.2 5 0. 5 1 1 0.5 0.5 0.5 0.25 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\C200-DDN-160FT.srf) JAN 18/2017 0.25 figure 21 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR CONTAINMENT ALTERNATIVE C200 - 160 FT ZONE 0.25 Occidental Chemical Corporation, Tacoma, Washington TRUE NORTH PLANT NORTH 0 200 400ft EXT-23(s) EXT-22(d) (s) (d) figure 22 EXTRACTION WELL LOCATIONS FOR VOC MASS REDUCTION ALTERNATIVES M100, M150, AND M200 Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\F23-Ext22 and 23 Map.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 1 1 1 1 1 (s) (d) 1 figure 23 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR VOC MASS REDUCTION ALTERNATIVE MSP - 15 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\Opt5-DDN-15FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 400ft 1 1 1 1 1 200 1 1 1 figure 24 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR VOC MASS REDUCTION ALTERNATIVE MSP - 25 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\Opt5-DDN-25FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 1 200 400ft 1 1 1 1 1 1 1 figure 25 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR VOC MASS REDUCTION ALTERNATIVE MSP - 50 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\Opt5-DDN-50FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 1 1 1 1 1 1 1 1 1 figure 26 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR VOC MASS REDUCTION ALTERNATIVE MSP - 75 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\Opt5-DDN-75FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 1 1 1 1 1 1 1 1 figure 27 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR VOC MASS REDUCTION ALTERNATIVE MSP - 100 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\Opt5-DDN-100FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 0 200 400ft 1 1 1 1 1 1 1 1 figure 28 SIMULATED DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR VOC MASS REDUCTION ALTERNATIVE MSP - 130 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\Opt5-DDN-130FT.srf) JAN 18/2017 TRUE NORTH PLANT NORTH 200 400ft 0.25 0. 25 0.25 0 1 0.5 0.5 0.2 0.5 5 0.25 0.5 1 0.25 1 0.25 0.25 0.25 1 0.5 0. 5 0.5 0.2 5 1 0.5 0. 25 5 0 .2 0.5 SIMULATED 0.25 0.25 0.25 007843-C2D2(RPT139) GN-WA-HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Figures\Opt5-DDN-160FT.srf) JAN 18/2017 figure 29 DRAWDOWN AND GROUNDWATER FLOW DIRECTIONS FOR VOC MASS REDUCTION ALTERNATIVE MSP - 160 FT ZONE Occidental Chemical Corporation, Tacoma, Washington 800,000 M100 ‐ Outside Areas of pH > 10 s.u. M150 ‐ Outside Areas of pH > 10 s.u. 700,000 M200 ‐ Outside Areas of pH > 10 s.u. MSP ‐ Outside Areas of pH > 10 s.u. 600,000 Mass Captured (lbs) 500,000 400,000 300,000 200,000 100,000 0 0 10 20 30 40 50 60 70 80 90 100 Time (Years) figure 30 CUMMULATIVE TOTAL TCVOC MASS-WEIGHTED PARTICLE CAPTURE OVER 100 YEARS Occidental Chemical Corporation, Tacoma, Washington 007843-C2D2(139)GN-WA HYD (Z:\HEG\07843\RPT139\Appendix E\Jan2017-Rev\Tables\007843-139-APPE-T4 Outside Elev pH.xlsx) Jan 18/2017 Table 1 Page 1 of 1 Remedial Alternative Summary and Initial Chemistry Occidental Chemical Corporation Tacoma, Washington Well ID Potential (P) or Installed (I) EXT-1(s) EXT-3(d) EXT-4(s) EXT-5(s) EXT-8(s) EXT-9(d) EXT-10(s) EXT-15(s) EXT-16(s) EXT-18(s) EXT-21(s) EXT-22(d) EXT-23(s) MR1 MR2 MR3 NW1 NW2 NW3 NW4 NW5 NW6 NW7 NW8 P P P P P I P P P P P P P P P P P P P P P P P P Well Screen Interval (ft NGVD) Top Bottom 5 -50 -2.5 5.0 -2.5 -97.4 -2.5 -25.0 -25.0 -2.5 5.0 -136.0 -25 -94 -94 -94 -1.5 -24 -61.5 -109 -111.5 -121.5 -11.25 -11.25 -15 -70 -22.5 -15.0 -22.5 -117.4 -22.5 -45.0 -45.0 -22.5 -15.0 -166.0 -45 -120 -120 -120 -18.75 -38.75 -76.25 -141.25 -123.75 -153.75 -36.25 -36.25 Screen Length (ft) 20 20 20 20 20 20 20 20 20 20 20 30 20 26 26 26 17 15 15 32 12 32 25 25 15.0 10.0 20.0 15.0 15.0 20.0 15.0 7.5 20.0 15.0 5.0 - 16.5 15.0 30.0 18.5 22.5 30.0 22.5 11.25 30.0 22.5 7.5 - 157.5 226.25 30,318.8 43,553.2 Total Extraction Flow (gpm): 3 Total Extraction Flow (ft /d): Note: (1) Barrier wall applied in the model remediation alternative with the following properties: Length: 2,180 ft Width: 2.5 ft Depth: 73.25 ft (s) Shallow extraction well screened above the 75-ft zone (at -60 ft NGVD). (d) Deep extraction well screened below the 75-ft zone (at -60 ft NGVD). GHD 007843(139) (1) Containment (1) Alternative C100 Modeled Extraction Rate (gpm) Containment Alternative C150 Factor Modeled Increase Extraction From Rate C100 (gpm) 1.1 1.5 1.5 1.2 1.5 1.5 1.5 1.5 1.5 1.5 1.5 - (1) Containment Alternative C200 Factor Modeled Increase Extraction From Rate C100 (gpm) 15.0 20.0 40.0 17.5 30.0 40.0 30.0 12.0 40.0 29.0 8.0 - 1.0 2.0 2.0 1.2 2.0 2.0 2.0 1.6 2.0 1.9 1.6 - VOC Mass Reduction Alternative M100(1) Modeled Extraction Rate (gpm) VOC Mass Reduction (1) Alternative M150 Factor Modeled Increase Extraction From Rate M100 (gpm) 1.5 1.5 - VOC Mass Reduction (1) Alternative M200 Factor Modeled Increase Extraction From Rate M100 (gpm) 40.0 30.0 - 2.0 2.0 - Mass Reduction (1) Alternative MSP Modeled Extraction Rate (gpm) 20.0 15.0 - 30.0 22.5 - 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 10.0 281.5 35.0 52.5 70.0 210.0 54,188.8 6,737.5 10,106.3 13,475.0 40,425.0 Initial Groundwater Initial Soil TCVOC TCVOC Concetration at Concetration at Well Screen Well Screen Midpoint Midpoint (µg/L) (ug/kg) 121.8 0.2 2.3 0.2 204 274,200 36,033 18.3 0.7 3.6 0.2 158,124 141,351 100,461 157,144 73,696 77,014 75,408 108,108 77,811 26,654 213,482 0.5 0.1 41.8 0.9 1.9 2.7 15.9 171,841 2,748 2.6 3.5 16.1 1.7 36,426 71,524 63,856 72,412 57,947 1,851,321 243,136 420,986 1,828,853 311,899 1,863,691 0.1 1.7 Initial pH at Well Screen Midpoint (s.u.) 8.9 7.8 9.0 8.1 8.4 7.3 8.0 7.7 8.0 7.3 8.6 9.1 8.6 7.4 7.3 7.1 8.7 9.0 8.9 7.9 9.4 9.8 9.1 8.8 Page 1 of 1 Table 2 Summary of Aqueous Phase TCVOC Mass-Weighted Particle Capture Occidental Chemical Corporation Tacoma, Washington I. Aqueous Phase Mass-Weighted Particle Capture Summary - All Depths (lbs) Containment Alternative C100 145,632 11,143 188 27,190 16,385 13,651 Containment Alternative C150 147,073 9,852 35 35,176 22,235 17,153 Containment Alternative C200 148,013 8,917 30 42,511 26,021 18,598 VOC Mass Reduction Alternative MSP 153,356 3,623 22 83,897 26,870 15,552 Total Mass-Weighted Capture After 30 Years 57,226 74,564 87,130 126,318 Captured Between 30 and 40 years Captured Between 40 and 100 years 10,504 36,360 12,138 33,439 12,643 29,416 8,443 11,899 Total Mass-Weighted Capture After 100 Years 104,090 120,140 129,189 146,660 Captured Between 100 and 1000 years 41,541 26,933 18,824 6,655 Total Mass-Weighted Capture After 1000 years Mass In System After 1000 Years Mass Discharged to Surface Water After 1000 years Captured Between 0 and 10 years Captured Between 10 and 20 years Captured Between 20 and 30 years II. Aqueous Phase Mass-Weighted Particle Capture Summary as Percentage of Total Dissolved TCVOC Mass in Groundwater(1) - All Depths (%) Containment Alternative C100 92.8 7.1 0.02 17.3 10.4 8.7 Containment Alternative C150 93.7 6.3 0.004 22.4 14.2 10.9 Containment Alternative C200 94.3 5.7 0.004 27.1 16.6 11.8 VOC Mass Reduction Alternative MSP 97.7 2.3 0.003 53.5 17.1 9.9 Total Mass-Weighted Capture After 30 Years 36.5 47.5 55.5 80.5 Captured Between 30 and 40 years Captured Between 40 and 100 years 6.7 23.2 7.7 21.3 8.1 18.7 5.4 7.6 Total Mass-Weighted Capture After 100 Years 66.3 76.5 82.3 93.4 Captured Between 100 and 1000 years 26.5 17.2 12.0 4.2 Total Mass-Weighted Capture After 1000 years Mass In System After 1000 Years Mass Discharged to Surface Water After 1000 years(2) Captured Between 0 and 10 years Captured Between 10 and 20 years Captured Between 20 and 30 years Notes: (1) Percent of dissolved TCVOC mass in groundwater is determined as the aqueous phase mass-weighted particle capture presented in Section I divided by the total dissolved phase mass in groundwater of approximately 157,000 lbs. (2) Determined as percent of total TCVOC mass in aquifer based on the aqueous phase mass-weighted particle capture presented in Section I divided by the total TCVOC mass in the aquifer of approximately 787,000 lbs (calculated from soil concentrations). GHD 007832 (139) Table 3 Page 1 of 1 Summary of Total TCVOC Mass-Weighted Particle Capture Occidental Chemical Corporation Tacoma, Washington I. Total Mass-Weighted Particle Capture Summary - All Depths (lbs) Containment Alternative C100 736,358 50,559 0 67,218 77,905 54,573 Containment Alternative C150 745,746 41,172 0 120,855 122,877 80,352 Containment Alternative C200 748,201 38,716 0 178,276 154,204 78,424 VOC Mass Reduction Alternative MSP 785,595 1,322 0 656,140 62,717 18,556 Total Mass-Weighted Capture After 30 Years 199,696 324,084 410,905 737,412 Captured Between 30 and 40 years Captured Between 40 and 100 years 45,161 122,649 51,590 136,884 45,696 132,194 8,640 20,782 Total Mass-Weighted Capture After 100 Years 367,506 512,559 588,795 766,835 Captured Between 100 and 1000 years 368,844 233,187 159,406 18,760 Total Mass-Weighted Capture After 1000 years Mass In System After 1000 Years Mass Discharged to Surface Water After 1000 years Captured Between 0 and 10 years Captured Between 10 and 20 years Captured Between 20 and 30 years II. Total Mass-Weighted Particle Capture Summary as Percentage of Total TCVOC Mass in Aquifer (1) - All Depths (%) Containment Alternative C100 93.6 6.4 0.00 8.5 9.9 6.9 Containment Alternative C150 94.8 5.2 0.00 15.4 15.6 10.2 Containment Alternative C200 95.1 4.9 0.00 22.7 19.6 10.0 VOC Mass Reduction Alternative MSP 99.8 0.2 0.00 83.4 8.0 2.4 Total Mass-Weighted Capture After 30 Years 25.4 41.2 52.2 93.7 Captured Between 30 and 40 years Captured Between 40 and 100 years 5.7 15.6 6.6 17.4 5.8 16.8 1.1 2.6 Total Mass-Weighted Capture After 100 Years 46.7 65.1 74.8 97.4 Captured Between 100 and 1000 years 46.9 29.6 20.3 2.4 Total Mass-Weighted Capture After 1000 years Mass In System After 1000 Years Mass Discharged to Surface Water After 1000 years Captured Between 0 and 10 years Captured Between 10 and 20 years Captured Between 20 and 30 years Notes: (1) Percent of total mass is determined as the total mass-weighted particle capture presented in Section I divided by the total TCVOC mass in soil of approximately 787,000 lbs. GHD 007832 (139) Page 1 of 1 Table 4 Summary of Total TCVOC Mass-Weighted Particle Capture Outside pH >10 s.u. Occidental Chemical Corporation Tacoma, Washington I. Total Mass-Weighted Particle Capture Summary - All Depths (lbs) Captured at 2 years Captured at 20 years Captured at 100 years GHD 007832 (139) VOC Mass Reduction Alternative M100 59,644 275,132 304,597 VOC Mass Reduction Alternative M150 83,650 285,394 316,373 VOC Mass Reduction Alternative M200 105,419 291,648 325,595 VOC Mass Reduction Alternative MSP 232,271 323,883 328,540 Appendix F Acid-Neutralizing Capacity (ANC) Evaluation GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) Appendix F Acid-Neutralizing Capacity (ANC) Evaluation Former Occidental Chemical Corporation Facility - Tacoma, Washington This Appendix presents the evaluation of estimated acid-neutralizing capacity (ANC) in soil/groundwater at the "Occidental" Site associated in part with the former Occidental Chemical Corporation (OCC) facility located in Tacoma, Washington (Site). Portions of the Site contain soil and groundwater impacted by releases of caustic soda and have measured pH values greater than or equal to 12.5 s.u. (standard units of pH). The Site areas with elevated pH may be targeted for treatment or enhanced containment. The standard units of pH (i.e., the negative log of hydrogen ion concentration) are not a measure that can be used directly for determining a "quantity" or "mass" of pH in soil and groundwater. The Agencies requested that some metric analogous to mass per volume be used to evaluate remediation of Site areas with elevated pH. A metric provided by the Agencies was to estimate the ANC of the soil/groundwater with elevated pH. The University of Washington study, "Summary of KD and Other Soil/Groundwater Characteristics" (UofW, 2015; Figure 9[B]), provides a Site-specific method to convert the pH of soil/groundwater into ANC in the units of milliequivalents (meq) acid per gram of dry soil. This amount, or "quantity", of ANC then may be calculated for a volume of aquifer at a given pH value. The method permits quantifying areas of elevated pH (i.e., greater than or equal to 12.5 s.u.) that may be targeted for treatment or enhanced containment. The quantity of ANC per aquifer volume at a given pH then can be compared to the "total quantity" of ANC for all Site soil/groundwater equal to or above a pH of 7 s.u. (i.e., neutral pH). The calculation procedure used to determine the quantity of ANC per aquifer volume at pH values ranging from 9.5 to approximately 13 s.u. in increments of 0.5 s.u., as requested by the Agencies, is described below. Table F.1 presents the calculation results for the quantity of ANC per aquifer volume at a given pH for both shallow (above -60 feet [ft] National Geodetic Vertical Datum [NGVD]) and deep (below -60 ft NGVD) zones as well as the total quantity of ANC for all Site soil/groundwater equal to or above a pH of 7 s.u. The values in Table F.1 were calculated as follows:  A three-dimensional interpolation of the Site groundwater pH data was developed using the Mining Visualization System/Environmental Visualization System (MVS/EVS) software package, developed by C Tech Development Corporation (C Tech) (C Tech, 2007). MVS/EVS was used to calculate the volume of aquifer having pH values of 7 and from 9.5 to approximately 13 s.u. at increments of 0.5 s.u. The highest pH for the shallow zone (i.e., -60 ft NGVD and above) was 13.036 s.u., which represents the average pH above 12.5 s.u. in the shallow zone. The highest pH for the deep zone was 12.920 s.u., which represents the average pH above 12.5 s.u. in the deep zone. The Site groundwater pH data were used because they represent pH in the largest portion of the aquifer and measured values of elevated pH in soil are within the same volume (see Appendix B).  The aquifer volume associated with each incremental pH value was calculated by determining the difference between the MVS/EVS calculated volumes for successive pH values. For example, the aquifer volume of a pH value of 12 s.u. was calculated as the MVS/EVS calculated volume for the pH value of 12 s.u. minus the MVS/EVS calculated volume for the pH value of 12.5 s.u.  The mass of aquifer dry soil associated with each incremental pH value was calculated as the corresponding volume multiplied by the Site dry bulk density.  Each incremental pH value was assumed to have uniform pH equal to increment value. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report Appendix F 007843 (139) 1  For each incremental pH value, the regression line that UofW determined between soil/water pH and ANC (y = 0.49x – 3.29; where y = log of ANC, and x = pH) (UofW, 2015; Figure 9[B]) was used to calculate ANC in terms of milliequivalents (meq) acid per gram of aquifer dry soil (meq acid/g).  The quantity of ANC (in meq acid) for each incremental pH value was calculated by multiplying the ANC in terms of meq acid/g by the mass of aquifer dry soil corresponding to the incremental pH value.  The total quantity of ANC for all Site soil/groundwater equal to or above a pH of 7 s.u. was calculated by summing the quantity of ANC determined from successive incremental pH values, beginning at a pH of 7 s.u.  The percentage of the total quantity of ANC associated with each incremental pH value was calculated by dividing the quantity of ANC for each incremental pH value by the total estimated quantity of ANC for a pH equal to or above 7 s.u. Figure F.1 presents a graph of the cumulative aquifer volume versus the calculated quantities of ANC for each incremental pH value ranging from 9.5 to approximately 13 s.u. at increments of 0.5 s.u., as requested by the Agencies. A second vertical axis is provided on the right side of the graph to show the percent of the estimated total quantity of ANC associated with each incremental pH value. In the shallow zone (i.e., -60 ft NGVD and above), a pH greater than or equal to 12.5 s.u. represents approximately 11.2 percent of the total quantity of ANC in the aquifer. In the shallow and deep zones combined, a pH greater than or equal to 12.5 s.u. represents approximately 23.3 percent of the total quantity of ANC. References C Tech, 2007. MVS (Mining Visualization System)/EVS (Environmental Visualization System), Version 8.54, Kaneohe, Hawaii. UofW, 2015. Summary of KD and Other Soil/Groundwater Characteristics, Composite Mid-project Review (Composite_mid-project_summary_07-17-15.pdf), M. Benjamin, University of Washington, received via email on July 17, 2015. GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study Report Appendix F 007843 (139) 2 300 00% 90% 9?3) 80% F030 50% 400 50% 40% 12 30% Estimated Quantity of ANC (Meq acid) ted Percent Of the TOtel Quantity Of AM 12.5 20% Eetlma 12.98 10% Legend . . . . ,000,000 2,000,000 3,000,000 4,000,000 5,000,000 Cumulative Aquifer Volume OCCIDENTAL CHEMICAL CORPORATION JOE NUMBER W34343202 TACOMA, WA DATE June 13. 2010 ESTIMATED QUANTITY OF ACID-NEUTRALIZING CAPACITY (ANC) VS. AQUIFER VOLUME FIGURE mamas-meme Table F.1 Page 1 of 1 Calculation of Estimated Acid-Neutralizing Capacity (ANC) in Aquifer Occidental Chemical Corporation Tacoma, Washington MVS/EVS Model Parameters Values Soil Dry Bulk Density (g/cm3) Porosity 1.61 0.43 Zone pH Values Shallow zone(1) (1) Deep zone (2) Full Depth ~ 13 s.u. >= 12.5 s.u. >= 12 s.u. >= 11.5 s.u. >= 11 s.u. >= 10.5 s.u. >= 10 s.u. >= 9.5 s.u. >= 7 s.u. ~ 13 s.u. >= 12.5 s.u. >= 12 s.u. >= 11.5 s.u. >= 11 s.u. >= 10.5 s.u. >= 10 s.u. >= 9.5 s.u. >= 7 s.u. ~ 13 s.u. >= 12.5 s.u. >= 12 s.u. >= 11.5 s.u. >= 11 s.u. >= 10.5 s.u. >= 10 s.u. >= 9.5 s.u. >= 7 s.u. Cumulative Soil Volume(3) (cy) 35,528 78,006 155,750 299,470 548,490 909,290 1,387,600 1,963,800 17,374,000 31,627 96,374 273,500 618,410 970,410 1,377,210 1,866,000 2,557,900 55,750,000 67,155 174,380 429,250 917,880 1,518,900 2,286,500 3,253,600 4,521,700 73,124,000 Soil Volume Associated with pH Increment (cy) 35,528 42,478 77,744 143,720 249,020 360,800 478,310 576,200 15,410,200 31,627 64,747 177,126 344,910 352,000 406,800 488,790 691,900 53,192,100 67,155 107,225 254,870 488,630 601,020 767,600 967,100 1,268,100 68,602,300 Soil Mass Assumed pH Associated with pH Associated with Increment Increment (g) (s.u.) 43,732,619,748 13.036 (5) 52,287,610,383 12.50 95,697,725,448 12.00 176,909,820,712 11.50 306,527,160,824 11.00 444,120,952,636 10.50 588,767,995,718 10.00 709,264,115,601 9.50 18,968,937,650,522 7.00 38,930,746,588 12.920 (5) 79,699,277,495 12.50 218,030,398,716 12.00 424,561,412,898 11.50 433,288,734,279 11.00 500,743,912,229 10.50 601,668,183,035 10.00 851,683,168,317 9.50 65,475,959,325,662 7.00 82,663,366,337 12.981 (5) 131,986,887,878 12.50 313,728,124,164 12.00 601,471,233,610 11.50 739,815,895,103 11.00 944,864,864,865 10.50 1,190,436,178,753 10.00 1,560,947,283,918 9.50 84,444,896,976,184 7.00 ANC(4) Associated with Increment (meq acid/g of dry soil) 1.25 0.68 0.39 0.22 0.13 0.07 0.04 0.02 0.00 1.10 0.68 0.39 0.22 0.13 0.07 0.04 0.02 0.00 1.18 0.68 0.39 0.22 0.13 0.07 0.04 0.02 0.00 Amount of ANC In pH Increment (meq acid) 54,757,737,311 35,760,105,749 37,230,735,473 39,151,818,829 38,589,483,217 31,805,429,357 23,985,246,966 16,436,448,669 26,184,423,049 42,765,419,095 54,507,264,159 84,823,668,081 93,959,461,679 54,547,819,823 35,860,445,295 24,510,775,155 19,736,860,177 90,381,983,963 97,315,941,958 90,267,369,908 122,054,403,554 133,111,280,508 93,137,303,039 67,665,874,651 48,496,022,121 36,173,308,846 116,566,407,012 Cumulative Amount of ANC (meq) 54,757,737,311 90,517,843,060 127,748,578,533 166,900,397,362 205,489,880,579 237,295,309,936 261,280,556,902 277,717,005,571 303,901,428,620 42,765,419,095 97,272,683,254 182,096,351,336 276,055,813,014 330,603,632,837 366,464,078,132 390,974,853,287 410,711,713,464 501,093,697,427 97,315,941,958 187,583,311,866 309,637,715,420 442,748,995,929 535,886,298,968 603,552,173,620 652,048,195,740 688,221,504,587 804,787,911,599 Cumulative Quantity of ANC (Meq acid) 55 91 128 167 205 237 261 278 304 43 97 182 276 331 366 391 411 501 97 188 310 443 536 604 652 688 805 Notes: (1) (2) (3) (4) The shallow zone is between the water surface and -60 ft NGVD in MVS/EVS model. The deep zone is below -60 ft NGVD in MVS/EVS model The full depth zone is between the water surface and the bottom of MVS/EVS model Volumes calculated by MVS/EVS model Acid-neutralizing capacity (ANC) calculations based on The University of Washington study, "Summary of KD and Other Soil/Groundwater Characteristics" [UofW, 2015; Figure 9(B)], which provides a Site-specific method to convert the pH of soil/groundwater into ANC in the units of milliequivalents (meq) acid per gram of dry soil (5) Average pH above 12.5 s.u. in the shallow zone, deep zone, and for full depth determined from MVS/EVS model meq milliequivalents Meq Megaequivalents = 109 x meq g grams 3 cm cubic centimeters cy cubic yards MVS/EVS model Mining Visualization System/Environmental Visualization System (MVS/EVS) software package, developed by C Tech Development Corporation (C Tech) (C Tech, 2007) model for the Site GHD 007843 (139) Percentage of Full Depth Total ANC (%) 6.8% 11.2% 15.9% 20.7% 25.5% 29.5% 32.5% 34.5% 37.8% 5.3% 12.1% 22.6% 34.3% 41.1% 45.5% 48.6% 51.0% 62.3% 12.1% 23.3% 38.5% 55.0% 66.6% 75.0% 81.0% 85.5% 100.0% Appendix G Alternatives Cost Estimates GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) Appendix G-1 Containment Alternatives Cost Estimates GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) COMPARISON OF TOTAL COST OF CONTAINMENT ALTERNATIVES Site: Location: Phase: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) Base Year: Date: Alternative C1 Alternative C150 Alternative C200 No Groundwater Extraction Shallow and Groundwater Extraction Shallow and Action Deep Zones Deep Zones 0 30 30 Capital Cost Annual O&M Cost $0 $0 $38,700,240 $1,180,644 $38,700,240 $1,247,834 Total Periodic Cost $0 $2,920,670 $2,920,670 Total Present Value of Alternative (7%) Total Present Value of Alternative (1.5%) $0 $0 $54,356,480 $69,352,840 $55,190,240 $70,966,460 DESCRIPTION Total Project Duration (Years) 007843 (139)AppG.1 - Comparison Containment 2016 December 6, 2016 Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 6, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY C150 Containment Alternative C150 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. UNIT COST QTY UNIT TOTAL Mobilization/Demobilization Construction Equipment & Facilities Temporary facilities and Utilities H&S Plans and Submittals Design, Work Plans, Permits Design, Work Plans, Permits Post-construction Submittals SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 $ $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 390,000 Site Work Demolition of North Dock Demolition of South Dock Demolition of Existing Structures Construction Oversight SUBTOTAL 1 1 1 50 LS LS LS DAY $ $ $ $ 446,000 248,000 250,000 1,920 $ $ $ $ $ 446,000 248,000 250,000 96,000 1,040,000 Barrier Wall East Installation Mobilization/Demobilization Sheet Pile Unload Sheet Pile Install Perimeter SP Wall Fill along embankment behind wall Construction Oversight Mitigation of Intertidal Areas SUBTOTAL 1 4300 220 160000 40370 130 1 LS TN LS SF CY DAY LS $ $ $ $ $ $ $ 50,000 1,900 2,350 12 18 1,920 250,000 $ $ $ $ $ $ $ $ 50,000 8,170,000 517,000 1,920,000 726,670 249,600 250,000 11,883,270 Physical Direct Contact Exposure Barrier Mobilization/Demobilization Preparation Aggregate Base Asphalt Cover (assume 4") Construction Oversight SUBTOTAL 1 1502820 27830 1502820 130 LS SF CY SF DAY $ $ $ $ $ 50,000 0.6 35 2 1,920 $ $ $ $ $ $ 50,000 901,700 974,050 3,005,640 249,600 5,180,990 Hydraulic Containment Mobilization/Demobilization Groundwater Extraction System Groundwater Treatment Equipment Groundwater Treatment Facility Building High pH Treatment Additional Equipment Construction Oversight SUBTOTAL 1 1 1 1 1 260 LS LS LS LS LS Day $ $ $ $ $ $ 50,000 927,470 2,544,230 2,145,820 27,000 1,920 $ $ $ $ $ $ $ 50,000 927,470 2,544,230 2,145,820 27,000 499,200 6,193,720 Off-Site Treatment / Disposal Off-Site T&D of Soil Cuttings Off-Site T&D of Spoils Off-Site T&D of Spoils - Hazardous SUBTOTAL 20 1250 750 CY CY CY $ $ $ 394 394 977 $ $ $ $ 7,880 Vendor Quote 491,920 Vendor Quote 732,780 Vendor Quote 1,232,580 SUBTOTAL $ Contingency 25% $ SUBTOTAL Project Management Remedial Design Construction Management Institutional Controls Institutional Controls Plan Groundwater Use Restrictions Site Database Documentation Perimeter fence SUBTOTAL TOTAL CAPITAL COSTS 5% 8% 6% 1 1 1 1 5300 LS LS LS LS FOOT $ $ $ $ $ 13,000 10,000 5,000 20,000 18 NOTES Excavators, Loaders, etc. Fence, roads, signs, trailers, etc. HASP, quality control, etc. Barrier wall Physical Direct Contact Exposure Barrier Report completed work Quotation from vendor - See Cost Worksheet C-1 Quotation from vendor - See Cost Worksheet C-2 Treatment plant, office, misc. - Assumption Assume 2 people 2,180 ft long by 73.5 ft deep. Assuming barge installation Vendor quote (PZ-27 sheet) Vendor quote Vendor quote (Adeka sealant; Anchor piles on 6' centers) Avg. Depth 10 ft; 50 ft wide Assume 2 people Allowance Remove debris and prepare surface. 34.5 acres. 6 inch base Facility Construction Cost - RSMeans (2016) Assume 2 personal See Cost Worksheet C-3 Assume 300 gpm System - See Cost Worksheet C-4 See Cost Worksheet C-5 Acid metering pump and equalization tank. 25,920,560 6,480,140 10% scope + 15% bid $ 32,400,700 $ $ $ 1,620,040 2,592,060 1,944,040 $ $ $ $ $ $ 13,000 10,000 5,000 20,000 95,400 143,400 $ 38,700,240 Description and implementation Legal fees Data management system other submittals and documents 605 and 709 properties Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 6, 2016 ANNUAL O&M COSTS: DESCRIPTION COST ESTIMATE SUMMARY C150 Containment Alternative C150 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. UNIT COST QTY UNIT 1 1 LS LS $ $ 2,600 5,200 $ $ $ Monitoring Groundwater Monitoring, sampling and reporting 1 LS $ 297,000 $ Physical Direct Contact Exposure Barrier Maintenance Annual maintenance 1 LS $ 10,000 $ 1 6 1 1 59460 year EXCHANGE LS LS $/1000 gals $ $ $ $ $ 124,500 19,124 20,000 6,000 2.60 $ $ $ $ $ $ Extraction Wells and Forcemains Annual maintenance 1 LS $ 20,000 $ 20,000 Two weeks of work Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 45 ton $ 720 $ 32,400 Vendor Quote Inspections Mobilization and Inspection Reporting SUBTOTAL Groundwater Treatment Plant Operation Carbon Consumption pH Adjustment Equipment Allowance Dilution Water SUBTOTAL TOTAL SUBTOTAL Contingency 30% SUBTOTAL 1 5% 10% LS $ 4,000 297,000 Will be in OMMP 10,000 Allowance 124,500 114,744 20,000 6,000 154,600 419,844 GHD Quote GHD Quote GHD Quote Allowance Assume city water for dilution - quote 787,044 $ 236,120 10% scope + 20% bid $ $ $ $ TOTAL ANNUAL O&M COSTS 2,600 Barriers and fencing 5,200 Inspection documentation 7,800 $ $ Project Management Technical Support Site Info Database NOTES 1,023,164 51,160 102,320 4,000 Update and maintain database 1,180,644 PERIODIC COSTS: DESCRIPTION YEAR QTY UNIT UNIT COST TOTAL Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 5 5 5 1 1 1 EA LS EA $ $ $ 75,000 19,100 3,000 $ $ $ $ 75,000 Report after 5 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 97,100 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 10 10 10 1 1 1 EA LS EA $ $ $ 50,000 19,100 3,000 $ $ $ $ 50,000 Report after 10 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 72,100 Five Year Review Report Cap Repair Equipment Replacement Update IC Plan Remedial Action Report SUBTOTAL 15 15 15 15 15 1 1 1 1 1 EA LS LS EA EA $ $ $ $ $ 40,000 300,570 1,503,910 3,000 10,000 $ $ $ $ $ $ Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 20 20 20 1 1 1 EA LS EA $ $ $ 40,000 788,890 3,000 $ $ $ $ 40,000 Report after 20 years 788,890 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 831,890 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 25 25 25 1 1 1 EA LS EA $ $ $ 40,000 19,100 3,000 $ $ $ $ 40,000 Report after 25 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 62,100 40,000 300,570 1,503,910 3,000 10,000 1,857,480 NOTES Report after 15 years 10 percent of asphalt Equipment Replacement- See Cost Worksheet C-6 Update Plan Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 6, 2016 PRESENT VALUE ANALYSIS: TOTAL COST TYPE YEAR COST Capital Cost 0 $ 38,700,240 Annual O&M Cost 1-30 $ 35,419,320 Periodic Cost 5 $ 97,100 Periodic Cost 10 $ 72,100 Periodic Cost 15 $ 1,857,480 Periodic Cost 20 $ 831,890 25 $ 62,100 Periodic Cost $ 77,040,230 TOTAL PRESENT VALUE OF ALTERNATIVE COST ESTIMATE SUMMARY C150 Containment Alternative C150 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. TOTAL COST PER YEAR $ 38,700,240 $ 1,180,644 $ 97,100 $ 72,100 $ 1,857,480 $ 831,890 $ 62,100 DISCOUNT FACTOR (1.5%) 1 12.41 0.713 0.508 0.362 0.258 0.184 $ $ $ $ $ $ $ $ PRESENT VALUE 38,700,240 14,650,670 69,240 36,660 673,240 214,980 11,450 54,356,480 $ 54,356,480 NOTES 30 years 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 6, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY C150 Containment Alternative C150 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. UNIT COST QTY UNIT TOTAL Mobilization/Demobilization Construction Equipment & Facilities Temporary facilities and Utilities H&S Plans and Submittals Design, Work Plans, Permits Design, Work Plans, Permits Post-construction Submittals SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 $ $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 390,000 Site Work Demolition of North Dock Demolition of South Dock Demolition of Existing Structures Construction Oversight SUBTOTAL 1 1 1 50 LS LS LS DAY $ $ $ $ 446,000 248,000 250,000 1,920 $ $ $ $ $ 446,000 248,000 250,000 96,000 1,040,000 Barrier Wall East Installation Mobilization/Demobilization Sheet Pile Unload Sheet Pile Install Perimeter SP Wall Fill along embankment behind wall Construction Oversight Mitigation of Intertidal Areas SUBTOTAL 1 4300 220 160000 40370 130 1 LS TN LS SF CY DAY LS $ $ $ $ $ $ $ 50,000 1,900 2,350 12 18 1,920 250,000 $ $ $ $ $ $ $ $ 50,000 8,170,000 517,000 1,920,000 726,670 249,600 250,000 11,883,270 Physical Direct Contact Exposure Barrier Mobilization/Demobilization Preparation Aggregate Base Asphalt Cover (assume 4") Construction Oversight SUBTOTAL 1 1502820 27830 1502820 130 LS SF CY SF DAY $ $ $ $ $ 50,000 0.6 35 2 1,920 $ $ $ $ $ $ 50,000 901,700 974,050 3,005,640 249,600 5,180,990 Hydraulic Containment Mobilization/Demobilization Groundwater Extraction System Groundwater Treatment Equipment Groundwater Treatment Facility Building High pH Treatment Additional Equipment Construction Oversight SUBTOTAL 1 1 1 1 1 260 LS LS LS LS LS Day $ $ $ $ $ $ 50,000 927,470 2,544,230 2,145,820 27,000 1,920 $ $ $ $ $ $ $ 50,000 927,470 2,544,230 2,145,820 27,000 499,200 6,193,720 Off-Site Treatment / Disposal Off-Site T&D of Soil Cuttings Off-Site T&D of Spoils Off-Site T&D of Spoils - Hazardous SUBTOTAL 20 1250 750 CY CY CY $ $ $ 394 394 977 $ $ $ $ 7,880 Vendor Quote 491,920 Vendor Quote 732,780 Vendor Quote 1,232,580 SUBTOTAL $ Contingency 25% $ SUBTOTAL Project Management Remedial Design Construction Management Institutional Controls Institutional Controls Plan Groundwater Use Restrictions Site Database Documentation Perimeter fence SUBTOTAL TOTAL CAPITAL COSTS 5% 8% 6% 1 1 1 1 5300 LS LS LS LS FOOT $ $ $ $ $ 13,000 10,000 5,000 20,000 18 NOTES Excavators, Loaders, etc. Fence, roads, signs, trailers, etc. HASP, quality control, etc. Barrier wall Physical Direct Contact Exposure Barrier Report completed work Quotation from vendor - See Cost Worksheet C-1 Quotation from vendor - See Cost Worksheet C-2 Treatment plant, office, misc. - Assumption Assume 2 people 2,180 ft long by 73.5 ft deep. Assuming barge installation Vendor quote (PZ-27 sheet) Vendor quote Vendor quote (Adeka sealant; Anchor piles on 6' centers) Avg. Depth 10 ft; 50 ft wide Assume 2 people Allowance Remove debris and prepare surface. 34.5 acres. 6 inch base Facility Construction Cost - RSMeans (2016) Assume 2 personal See Cost Worksheet C-3 Assume 300 gpm System - See Cost Worksheet C-4 See Cost Worksheet C-5 Acid metering pump and equalization tank. 25,920,560 6,480,140 10% scope + 15% bid $ 32,400,700 $ $ $ 1,620,040 2,592,060 1,944,040 $ $ $ $ $ $ 13,000 10,000 5,000 20,000 95,400 143,400 $ 38,700,240 Description and implementation Legal fees Data management system other submittals and documents 605 and 709 properties Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 6, 2016 ANNUAL O&M COSTS: DESCRIPTION COST ESTIMATE SUMMARY C150 Containment Alternative C150 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. UNIT COST QTY UNIT 1 1 LS LS $ $ 2,600 5,200 $ $ $ Monitoring Groundwater Monitoring, sampling and reporting 1 LS $ 297,000 $ Physical Direct Contact Exposure Barrier Maintenance Annual maintenance 1 LS $ 10,000 $ 1 6 1 1 59460 year EXCHANGE LS LS $/1000 gals $ $ $ $ $ 124,500 19,124 20,000 6,000 2.60 $ $ $ $ $ $ Extraction Wells and Forcemains Annual maintenance 1 LS $ 20,000 $ 20,000 Two weeks of work Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 45 ton $ 720 $ 32,400 Vendor Quote Inspections Mobilization and Inspection Reporting SUBTOTAL Groundwater Treatment Plant Operation Carbon Consumption pH Adjustment Equipment Allowance Dilution Water SUBTOTAL TOTAL SUBTOTAL Contingency 30% SUBTOTAL 1 5% 10% LS $ 4,000 297,000 Will be in OMMP 10,000 Allowance 124,500 114,744 20,000 6,000 154,600 419,844 GHD Quote GHD Quote GHD Quote Allowance Assume city water for dilution - quote 787,044 $ 236,120 10% scope + 20% bid $ $ $ $ TOTAL ANNUAL O&M COSTS 2,600 Barriers and fencing 5,200 Inspection documentation 7,800 $ $ Project Management Technical Support Site Info Database NOTES 1,023,164 51,160 102,320 4,000 Update and maintain database 1,180,644 PERIODIC COSTS: DESCRIPTION YEAR QTY UNIT UNIT COST TOTAL Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 5 5 5 1 1 1 EA LS EA $ $ $ 75,000 19,100 3,000 $ $ $ $ 75,000 Report after 5 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 97,100 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 10 10 10 1 1 1 EA LS EA $ $ $ 50,000 19,100 3,000 $ $ $ $ 50,000 Report after 10 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 72,100 Five Year Review Report Cap Repair Equipment Replacement Update IC Plan Remedial Action Report SUBTOTAL 15 15 15 15 15 1 1 1 1 1 EA LS LS EA EA $ $ $ $ $ 40,000 300,570 1,503,910 3,000 10,000 $ $ $ $ $ $ Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 20 20 20 1 1 1 EA LS EA $ $ $ 40,000 788,890 3,000 $ $ $ $ 40,000 Report after 20 years 788,890 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 831,890 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 25 25 25 1 1 1 EA LS EA $ $ $ 40,000 19,100 3,000 $ $ $ $ 40,000 Report after 25 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 62,100 40,000 300,570 1,503,910 3,000 10,000 1,857,480 NOTES Report after 15 years 10 percent of asphalt Equipment Replacement- See Cost Worksheet C-6 Update Plan Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 6, 2016 PRESENT VALUE ANALYSIS: TOTAL COST TYPE YEAR COST Capital Cost 0 $ 38,700,240 Annual O&M Cost 1-30 $ 35,419,320 Periodic Cost 5 $ 97,100 Periodic Cost 10 $ 72,100 Periodic Cost 15 $ 1,857,480 Periodic Cost 20 $ 831,890 25 $ 62,100 Periodic Cost $ 77,040,230 TOTAL PRESENT VALUE OF ALTERNATIVE COST ESTIMATE SUMMARY C150 Containment Alternative C150 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. TOTAL COST PER YEAR $ 38,700,240 $ 1,180,644 $ 97,100 $ 72,100 $ 1,857,480 $ 831,890 $ 62,100 DISCOUNT FACTOR (1.5%) 1 24.02 0.928 0.862 0.800 0.742 0.689 $ $ $ $ $ $ $ $ PRESENT VALUE 38,700,240 28,354,160 90,140 62,130 1,485,710 617,660 42,800 69,352,840 $ 69,352,840 NOTES 30 years 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 6, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY C200 Containment Alternative C200 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. UNIT COST QTY UNIT TOTAL Mobilization/Demobilization Construction Equipment & Facilities Temporary facilities and Utilities H&S Plans and Submittals Design, Work Plans, Permits Design, Work Plans, Permits Post-construction Submittals SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 $ $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 390,000 Site Work Demolition of North Dock Demolition of South Dock Demolition of Existing Structures Construction Oversight SUBTOTAL 1 1 1 50 LS LS LS DAY $ $ $ $ 446,000 248,000 250,000 1,920 $ $ $ $ $ 446,000 248,000 250,000 96,000 1,040,000 Barrier Wall East Installation Mobilization/Demobilization Sheet Pile Unload Sheet Pile Install Perimeter SP Wall Fill along embankment behind wall Construction Oversight Mitigation of Intertidal Areas SUBTOTAL 1 4300 220 160000 40370 130 1 LS TN LS SF CY DAY LS $ $ $ $ $ $ $ 50,000 1,900 2,350 12 18 1,920 250,000 $ $ $ $ $ $ $ $ 50,000 8,170,000 517,000 1,920,000 726,670 249,600 250,000 11,883,270 Physical Direct Contact Exposure Barrier Mobilization/Demobilization Preparation Aggregate Base Asphalt Cover (assume 4") Construction Oversight SUBTOTAL 1 1502820 27830 1502820 130 LS SF CY SF DAY $ $ $ $ $ 50,000 0.6 35 2 1,920 $ $ $ $ $ $ 50,000 901,700 974,050 3,005,640 249,600 5,180,990 Hydraulic Containment Mobilization/Demobilization Groundwater Extraction System Groundwater Treatment Equipment Groundwater Treatment Facility Building High pH Treatment Additional Equipment Construction Oversight SUBTOTAL 1 1 1 1 1 260 LS LS LS LS LS Day $ $ $ $ $ $ 50,000 927,470 2,544,230 2,145,820 27,000 1,920 $ $ $ $ $ $ $ 50,000 927,470 2,544,230 2,145,820 27,000 499,200 6,193,720 Off-Site Treatment / Disposal Off-Site T&D of Soil Cuttings Off-Site T&D of Spoils Off-Site T&D of Spoils - Hazardous SUBTOTAL 20 1250 750 CY CY CY $ $ $ 394 394 977 $ $ $ $ 7,880 Vendor Quote 491,920 Vendor Quote 732,780 Vendor Quote 1,232,580 SUBTOTAL $ Contingency 25% $ SUBTOTAL Project Management Remedial Design Construction Management Institutional Controls Institutional Controls Plan Groundwater Use Restrictions Site Database Documentation Perimeter fence SUBTOTAL TOTAL CAPITAL COSTS 5% 8% 6% 1 1 1 1 5300 LS LS LS LS FOOT $ $ $ $ $ 13,000 10,000 5,000 20,000 18 NOTES Excavators, Loaders, etc. Fence, roads, signs, trailers, etc. HASP, quality control, etc. Barrier wall Physical Direct Contact Exposure Barrier Report completed work Quotation from vendor - See Cost Worksheet C-1 Quotation from vendor - See Cost Worksheet C-2 Treatment plant, office, misc. - Assumption Assume 2 people 2,180 ft long by 73.5 ft deep. Assuming barge installation Vendor quote (PZ-27 sheet) Vendor quote Vendor quote (Adeka sealant; Anchor piles on 6' centers) Avg. Depth 10 ft; 50 ft wide Assume 2 people Allowance Remove debris and prepare surface. 34.5 acres. 6 inch base Facility Construction Cost - RSMeans (2016) Assume 2 personal See Cost Worksheet C-3 Assume 300 gpm System - See Cost Worksheet C-4 See Cost Worksheet C-5 Acid metering pump and equalization tank. 25,920,560 6,480,140 10% scope + 15% bid $ 32,400,700 $ $ $ 1,620,040 2,592,060 1,944,040 $ $ $ $ $ $ 13,000 10,000 5,000 20,000 95,400 143,400 $ 38,700,240 Description and implementation Legal fees Data management system other submittals and documents 605 and 709 properties Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 6, 2016 ANNUAL O&M COSTS: DESCRIPTION COST ESTIMATE SUMMARY C200 Containment Alternative C200 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. UNIT COST QTY UNIT 1 1 LS LS $ $ 2,600 5,200 $ $ $ Monitoring Groundwater Monitoring, sampling and reporting 1 LS $ 297,000 $ Physical Direct Contact Exposure Barrier Maintenance Annual maintenance 1 LS $ 10,000 $ 1 6 1 1 73980 year EXCHANGE LS LS $/1000 gals $ $ $ $ $ 124,500 19,124 20,000 6,000 2.60 $ $ $ $ $ $ Extraction Wells and Forcemains Annual maintenance 1 LS $ 20,000 $ 20,000 Two weeks of work Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 55 ton $ 720 $ 39,600 Vendor Quote Inspections Mobilization and Inspection Reporting SUBTOTAL Groundwater Treatment Plant Operation Carbon Consumption pH Adjustment Equipment Allowance Dilution Water SUBTOTAL TOTAL SUBTOTAL Contingency 30% SUBTOTAL 1 5% 10% LS $ 4,000 297,000 Will be in OMMP 10,000 Allowance 124,500 114,744 20,000 6,000 192,350 457,594 GHD Quote GHD Quote GHD Quote Allowance Assume city water for dilution - quote 831,994 $ 249,600 10% scope + 20% bid $ $ $ $ TOTAL ANNUAL O&M COSTS 2,600 Barriers and fencing 5,200 Inspection documentation 7,800 $ $ Project Management Technical Support Site Info Database NOTES 1,081,594 54,080 108,160 4,000 Update and maintain database 1,247,834 PERIODIC COSTS: DESCRIPTION YEAR QTY UNIT UNIT COST TOTAL Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 5 5 5 1 1 1 EA LS EA $ $ $ 75,000 19,100 3,000 $ $ $ $ 75,000 Report after 5 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 97,100 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 10 10 10 1 1 1 EA LS EA $ $ $ 50,000 19,100 3,000 $ $ $ $ 50,000 Report after 10 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 72,100 Five Year Review Report Cap Repair Equipment Replacement Update IC Plan Remedial Action Report SUBTOTAL 15 15 15 15 15 1 1 1 1 1 EA LS LS EA EA $ $ $ $ $ 40,000 300,570 1,503,910 3,000 10,000 $ $ $ $ $ $ Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 20 20 20 1 1 1 EA LS EA $ $ $ 40,000 788,890 3,000 $ $ $ $ 40,000 Report after 20 years 788,890 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 831,890 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 25 25 25 1 1 1 EA LS EA $ $ $ 40,000 19,100 3,000 $ $ $ $ 40,000 Report after 25 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 62,100 40,000 300,570 1,503,910 3,000 10,000 1,857,480 NOTES Report after 15 years 10 percent of asphalt Equipment Replacement- See Cost Worksheet C-6 Update Plan Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 6, 2016 PRESENT VALUE ANALYSIS: TOTAL COST TYPE YEAR COST Capital Cost 0 $ 38,700,240 Annual O&M Cost 1-30 $ 37,435,020 Periodic Cost 5 $ 97,100 Periodic Cost 10 $ 72,100 Periodic Cost 15 $ 1,857,480 Periodic Cost 20 $ 831,890 25 $ 62,100 Periodic Cost $ 79,055,930 TOTAL PRESENT VALUE OF ALTERNATIVE COST ESTIMATE SUMMARY C200 Containment Alternative C200 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. TOTAL COST PER YEAR $ 38,700,240 $ 1,247,834 $ 97,100 $ 72,100 $ 1,857,480 $ 831,890 $ 62,100 DISCOUNT FACTOR (1.5%) 1 12.41 0.713 0.508 0.362 0.258 0.184 $ $ $ $ $ $ $ $ PRESENT VALUE 38,700,240 15,484,430 69,240 36,660 673,240 214,980 11,450 55,190,240 $ 55,190,240 NOTES 30 years 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 6, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY C200 Containment Alternative C200 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. UNIT COST QTY UNIT TOTAL Mobilization/Demobilization Construction Equipment & Facilities Temporary facilities and Utilities H&S Plans and Submittals Design, Work Plans, Permits Design, Work Plans, Permits Post-construction Submittals SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 $ $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 390,000 Site Work Demolition of North Dock Demolition of South Dock Demolition of Existing Structures Construction Oversight SUBTOTAL 1 1 1 50 LS LS LS DAY $ $ $ $ 446,000 248,000 250,000 1,920 $ $ $ $ $ 446,000 248,000 250,000 96,000 1,040,000 Barrier Wall East Installation Mobilization/Demobilization Sheet Pile Unload Sheet Pile Install Perimeter SP Wall Fill along embankment behind wall Construction Oversight Mitigation of Intertidal Areas SUBTOTAL 1 4300 220 160000 40370 130 1 LS TN LS SF CY DAY LS $ $ $ $ $ $ $ 50,000 1,900 2,350 12 18 1,920 250,000 $ $ $ $ $ $ $ $ 50,000 8,170,000 517,000 1,920,000 726,670 249,600 250,000 11,883,270 Physical Direct Contact Exposure Barrier Mobilization/Demobilization Preparation Aggregate Base Asphalt Cover (assume 4") Construction Oversight SUBTOTAL 1 1502820 27830 1502820 130 LS SF CY SF DAY $ $ $ $ $ 50,000 0.6 35 2 1,920 $ $ $ $ $ $ 50,000 901,700 974,050 3,005,640 249,600 5,180,990 Hydraulic Containment Mobilization/Demobilization Groundwater Extraction System Groundwater Treatment Equipment Groundwater Treatment Facility Building High pH Treatment Additional Equipment Construction Oversight SUBTOTAL 1 1 1 1 1 260 LS LS LS LS LS Day $ $ $ $ $ $ 50,000 927,470 2,544,230 2,145,820 27,000 1,920 $ $ $ $ $ $ $ 50,000 927,470 2,544,230 2,145,820 27,000 499,200 6,193,720 Off-Site Treatment / Disposal Off-Site T&D of Soil Cuttings Off-Site T&D of Spoils Off-Site T&D of Spoils - Hazardous SUBTOTAL 20 1250 750 CY CY CY $ $ $ 394 394 977 $ $ $ $ 7,880 Vendor Quote 491,920 Vendor Quote 732,780 Vendor Quote 1,232,580 SUBTOTAL $ Contingency 25% $ SUBTOTAL Project Management Remedial Design Construction Management Institutional Controls Institutional Controls Plan Groundwater Use Restrictions Site Database Documentation Perimeter fence SUBTOTAL TOTAL CAPITAL COSTS 5% 8% 6% 1 1 1 1 5300 LS LS LS LS FOOT $ $ $ $ $ 13,000 10,000 5,000 20,000 18 NOTES Excavators, Loaders, etc. Fence, roads, signs, trailers, etc. HASP, quality control, etc. Barrier wall Physical Direct Contact Exposure Barrier Report completed work Quotation from vendor - See Cost Worksheet C-1 Quotation from vendor - See Cost Worksheet C-2 Treatment plant, office, misc. - Assumption Assume 2 people 2,180 ft long by 73.5 ft deep. Assuming barge installation Vendor quote (PZ-27 sheet) Vendor quote Vendor quote (Adeka sealant; Anchor piles on 6' centers) Avg. Depth 10 ft; 50 ft wide Assume 2 people Allowance Remove debris and prepare surface. 34.5 acres. 6 inch base Facility Construction Cost - RSMeans (2016) Assume 2 personal See Cost Worksheet C-3 Assume 300 gpm System - See Cost Worksheet C-4 See Cost Worksheet C-5 Acid metering pump and equalization tank. 25,920,560 6,480,140 10% scope + 15% bid $ 32,400,700 $ $ $ 1,620,040 2,592,060 1,944,040 $ $ $ $ $ $ 13,000 10,000 5,000 20,000 95,400 143,400 $ 38,700,240 Description and implementation Legal fees Data management system other submittals and documents 605 and 709 properties Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 6, 2016 ANNUAL O&M COSTS: DESCRIPTION COST ESTIMATE SUMMARY C200 Containment Alternative C200 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. UNIT COST QTY UNIT 1 1 LS LS $ $ 2,600 5,200 $ $ $ Monitoring Groundwater Monitoring, sampling and reporting 1 LS $ 297,000 $ Physical Direct Contact Exposure Barrier Maintenance Annual maintenance 1 LS $ 10,000 $ 1 6 1 1 73980 year EXCHANGE LS LS $/1000 gals $ $ $ $ $ 124,500 19,124 20,000 6,000 2.60 $ $ $ $ $ $ Extraction Wells and Forcemains Annual maintenance 1 LS $ 20,000 $ 20,000 Two weeks of work Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 55 ton $ 720 $ 39,600 Vendor Quote Inspections Mobilization and Inspection Reporting SUBTOTAL Groundwater Treatment Plant Operation Carbon Consumption pH Adjustment Equipment Allowance Dilution Water SUBTOTAL TOTAL SUBTOTAL Contingency 30% SUBTOTAL 1 5% 10% LS $ 4,000 297,000 Will be in OMMP 10,000 Allowance 124,500 114,744 20,000 6,000 192,350 457,594 GHD Quote GHD Quote GHD Quote Allowance Assume city water for dilution - quote 831,994 $ 249,600 10% scope + 20% bid $ $ $ $ TOTAL ANNUAL O&M COSTS 2,600 Barriers and fencing 5,200 Inspection documentation 7,800 $ $ Project Management Technical Support Site Info Database NOTES 1,081,594 54,080 108,160 4,000 Update and maintain database 1,247,834 PERIODIC COSTS: DESCRIPTION YEAR QTY UNIT UNIT COST TOTAL Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 5 5 5 1 1 1 EA LS EA $ $ $ 75,000 19,100 3,000 $ $ $ $ 75,000 Report after 5 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 97,100 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 10 10 10 1 1 1 EA LS EA $ $ $ 50,000 19,100 3,000 $ $ $ $ 50,000 Report after 10 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 72,100 Five Year Review Report Cap Repair Equipment Replacement Update IC Plan Remedial Action Report SUBTOTAL 15 15 15 15 15 1 1 1 1 1 EA LS LS EA EA $ $ $ $ $ 40,000 300,570 1,503,910 3,000 10,000 $ $ $ $ $ $ Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 20 20 20 1 1 1 EA LS EA $ $ $ 40,000 788,890 3,000 $ $ $ $ 40,000 Report after 20 years 788,890 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 831,890 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 25 25 25 1 1 1 EA LS EA $ $ $ 40,000 19,100 3,000 $ $ $ $ 40,000 Report after 25 years 19,100 Equipment Replacement- See Cost Worksheet C-6 3,000 Update Plan 62,100 40,000 300,570 1,503,910 3,000 10,000 1,857,480 NOTES Report after 15 years 10 percent of asphalt Equipment Replacement- See Cost Worksheet C-6 Update Plan Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 6, 2016 PRESENT VALUE ANALYSIS: TOTAL COST TYPE YEAR COST Capital Cost 0 $ 38,700,240 Annual O&M Cost 1-30 $ 37,435,020 Periodic Cost 5 $ 97,100 Periodic Cost 10 $ 72,100 Periodic Cost 15 $ 1,857,480 Periodic Cost 20 $ 831,890 25 $ 62,100 Periodic Cost $ 79,055,930 TOTAL PRESENT VALUE OF ALTERNATIVE COST ESTIMATE SUMMARY C200 Containment Alternative C200 is designed to eliminate potentially complete exposure pathways and includes: institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. TOTAL COST PER YEAR $ 38,700,240 $ 1,247,834 $ 97,100 $ 72,100 $ 1,857,480 $ 831,890 $ 62,100 DISCOUNT FACTOR (1.5%) 1 24.02 0.928 0.862 0.800 0.742 0.689 $ $ $ $ $ $ $ $ PRESENT VALUE 38,700,240 29,967,780 90,140 62,130 1,485,710 617,660 42,800 70,966,460 $ 70,966,460 NOTES 30 years 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternatives C100, C150, C200 Capital Cost Sub-Element NORTH DOCK DEMOLITION AND DISPOSAL Site: Location: Phase: Base Year: COST WORKSHEET C-1 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: The work includes the demolition and legal disposal of a approximately 18,430 square feet creosote timber dock from the water side of the dock structure. Material to be demolished includes, bull rail, water decking, joists, pile caps, and minimal cross bracing. Excludes timber pile removal. Cost analysis: Costs per demolition of 18,430 square feet dock. DESCRIPTION Dock Demolition and Removal Construction Oversight (40 Days) SUBTOTAL QTY 1 UNIT LS 50 DAY LABOR - EQUIP - MTRL - - - 1,920 UNIT TOTAL 350,000 1,920 Prime Contractor Overhead SUBTOTAL 0% Prime Contractor Profit 0% TOTAL UNIT COST December 17, 2013. From Nicolas Arvberger. American Construction Company. Oversight costs Cost Adjustment Checklist: 07843(139)AppG - Cost Worksheet C-1 446,000 $ 446,000 Source of Cost Data: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit TOTAL 350,000 Includes contractor profits Engineer ($1200/day) to 96,000 Supervisor ($720/day) 446,000 NOTES: Quote is for Level D 2016 Quotes is from local vendor Included in unit pricing Included in unit pricing Containment Alternatives C100, C150, C200 Capital Cost Sub-Element SOUTH DOCK DEMOLITION AND DISPOSAL Site: Location: Phase: Base Year: COST WORKSHEET C-2 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: The work includes the demolition and legal disposal of a approximately 18,430 square feet creosote timber dock from the water side of the dock structure. Material to be demolished includes, bull rail, water decking, joists, pile caps, and minimal cross bracing. Excludes timber pile removal. Cost analysis: Costs per demolition of 18,430 square feet dock. DESCRIPTION Dock Demolition and Removal Construction Oversight (40 Days) SUBTOTAL QTY 1 UNIT LS 25 DAY LABOR - EQUIP - MTRL - - - 1,920 UNIT TOTAL 200,000 1,920 Prime Contractor Overhead SUBTOTAL 0% Prime Contractor Profit 0% TOTAL UNIT COST December 17, 2013. From Nicolas Arvberger. American Construction Company. Oversight costs Cost Adjustment Checklist: 07843(139)AppG - Cost Worksheet C-2 248,000 $ 248,000 Source of Cost Data: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit TOTAL 200,000 Includes contractor profits Engineer ($1200/day) to 48,000 Supervisor ($720/day) 248,000 NOTES: Quote is for Level D 2016 Quotes is from local vendor Included in unit pricing Included in unit pricing Containment Alternatives C100, C150, C200 Capital Cost Sub-Element EXTRACTION WELLS AND CONVEYANCES Site: Location: Phase: Base Year: COST WORKSHEET C-3 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: The work includes groundwater extraction wells, pumps, well vaults, forcemains, electrical conduit, etc. to extract and convey groundwater to the treatment system. Cost analysis: Costs for equipment, preparation, and installation. DESCRIPTION Well Installation Mobilization/demobilization Wells Installation (-15 ft NGVD) Wells Installation (-22.5 ft NGVD) Wells Installation (-45 ft NGVD) Well Installation (-70 ft NGVD) Well Installation (EXT-9(d)) Drilling Oversight Surveyor Pumps Wiring Well Development @ 8 hours each Well Vaults (3' x 4' x 4') w/HD 20 Cover Asphalt Removal (Assume 6") Asphalt Disposal Excavation Sand Fill Aggregate Fill Asphalt Replacement SUBTOTAL Piping/Electrical Electrical Power Allowance Piping (HDPE) Electrical Conduit (2.0") Electrical Pull Boxes Hydro-Test Piping SUBTOTAL QTY UNIT LABOR 1 3 4 2 1 0 40 1 11 11 88 11 1960 260 3012 1857 1155 260 LS EA EA EA EA EA DAY LS EA EA HR EA SY TN CY CY CY TN 1,920 20,000 250 10 incl. 9 30 35 105 26,600 27,700 30,900 34,500 1,736 1,800 incl. 3,500 incl. incl. incl. incl. incl. 1 5050 5050 17 1 LS LF LF EA LS 35,000 incl. incl. incl. 2,500 incl. incl. incl. incl. incl. incl. incl. incl. incl. EQUIP MTRL incl. incl. incl. incl. incl. incl. incl. incl. incl. 4 12 315 - UNIT TOTAL TOTAL 44,800 26,600 27,700 30,900 34,500 1,920 20,000 1,736 1,800 250 3,500 10 9 30 35 105 44,800 79,800 110,800 61,800 34,500 76,800 20,000 19,100 19,800 22,000 38,500 18,620 25,602 55,246 40,425 27,300 695,090 35,000 4 12 315 2,500 35,000 20,200 60,600 5,355 2,500 123,660 Prime Contractor Overhead SUBTOTAL 15% 61,538 880,288 Prime Contractor Profit 10% 47,180 TOTAL UNIT COST $ 927,470 Source of Cost Data: Estimate from GHD Construction Division ( April 27, 2016) and Drilling Contractor Previous Invoices for Site Work (2013) Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet C-3 NOTES: Assume Level D 2016 Based on general pricing Not included in unit prices except for well construction and oversight Not included in unit prices except for well construction and oversight Driller Invoice 6 inch well 6 inch well 6 inch well 6 inch well Installed previously Two drill rigs operating Containment Alternatives C100, C150, C200 Capital Cost Sub-Element TREATMENT SYSTEM EQUIPMENT - 300 GPM SYSTEM Site: Location: Phase: Base Year: COST WORKSHEET C-4 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: The work includes system equipment necessary to treat extracted groundwater. Cost analysis: Costs for equipment, preparation, and installation. DESCRIPTION QTY UNIT LABOR Equipment: Inclined Plate Clarifier Filter Press Multimedia Filter Skid Air Stripper Blower Cartridge Filter Skid Carbon Filters (2 vessels) Regenerative Thermal Oxidizer Package Air Compressor Compressed Air Desiccant Dryer Freight and Tax SUBTOTAL 1 1 1 1 1 1 1 1 1 1 LS LS LS LS LS LS LS LS LS LS incl. incl. incl. incl. incl. incl. incl. incl. incl. HVAC Treatment building heaters Control room HVAC Exhaust fans SUBTOTAL 4 1 4 EA LS EA incl. incl. incl. Pumps Clarifier Feed Pump Sand Filter Feed Pump Air Stripper Transfer Pump Sand Filter Backwash Pump Building Sump Pump Clarifier Bottoms Pump Filter Press Sludge Pump Dirty Backwash Recycle Pump SUBTOTAL 1 1 1 1 1 1 1 1 EA EA EA EA EA EA EA EA Metering Pumps Coagulant Metering Pump Polymer Metering / Blending Unit Sequestering Agent Metering Pump SUBTOTAL 1 1 1 Tanks Equalization Tank Clarifier Sludge Tank Filter Feed Tank Dirty Backwash Tank Effluent Tank Add metal tanks higher grade lining Add high seismic zone - extra 10% SUBTOTAL 1 1 1 1 1 1 10 EQUIP MTRL 260,000 208,000 180,000 83,440 13,429 300,000 900,200 14,600 5,483 - incl. incl. incl. incl. incl. incl. incl. incl. incl. 1,423 3,718 806 incl. incl. incl. incl. incl. incl. incl. incl. LS LS LS EA EA EA EA EA LS % UNIT TOTAL 260,000 208,000 180,000 83,440 13,429 300,000 900,200 14,600 5,483 277,000 260,000 208,000 180,000 83,440 13,429 300,000 900,200 14,600 5,483 277,000 2,242,150 incl. incl. incl. 1,423 3,718 806 5,692 3,718 3,222 12,630 18,280 22,356 22,356 24,243 2,563 1,941 2,561 1,941 incl. incl. incl. incl. incl. incl. incl. incl. 18,280 22,356 22,356 24,243 2,563 1,941 2,561 1,941 18,280 22,356 22,356 24,243 2,563 1,941 2,561 1,941 96,241 incl. incl. incl. 2,000 15,000 2,000 incl. incl. incl. 2,000 15,000 2,000 2,000 15,000 2,000 19,000 incl. incl. incl. incl. incl. 39,371 25,096 19,200 47,081 16,469 11,155 158,372 incl. incl. incl. incl. incl. 39,371 25,096 19,200 47,081 16,469 11,155 158,372 39,371 25,096 19,200 47,081 16,469 11,155 15,837 174,209 - $ $ $ - - - Prime Contractor Overhead SUBTOTAL 0% Prime Contractor Profit 0% TOTAL UNIT COST Source of Cost Data: Estimate from Gary Pritchard, GHD Process Engineer, April 29, 2016 TOTAL 2,544,230 $2,544,230 Containment Alternatives C100, C150, C200 Capital Cost Sub-Element TREATMENT SYSTEM EQUIPMENT - 300 GPM SYSTEM Site: Location: Phase: Base Year: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 COST WORKSHEET C-4 Prepared By: AW Date: 6/2/2016 Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet C-4 NOTES: Assume Level D 2016 Based on general pricing Included in unit pricing Included in unit pricing Checked By: RJH Date: 12/6/2016 Containment Alternatives C100, C150, C200 Capital Cost Sub-Element TREATMENT SYSTEM BUILDING - 300 GPM SYSTEM Site: Location: Phase: Base Year: COST WORKSHEET C-5 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: The work includes construction of a building to house groundwater treatment equipment. Cost analysis: Costs for equipment, preparation, and installation. DESCRIPTION Building Building Pre-engineered Steel 115'x55' Building/Indoor Equipment Foundation Piping Instrumentation (plus wiring) Electrical Rigging Tax SUBTOTAL QTY UNIT 1 1 1 2 1 1 1 LS LS LS LS LS LS LS LABOR 219,000 232,000 123,500 122,385 166,641 93,000 - EQUIP 219,000 232,000 123,500 122,385 166,641 - MTRL - UNIT TOTAL 438,000 464,000 247,000 244,770 333,282 93,000 81,000 Prime Contractor Overhead SUBTOTAL 0% Prime Contractor Profit 0% TOTAL UNIT COST TOTAL 438,000 464,000 247,000 489,540 333,282 93,000 81,000 2,145,820 2,145,820 $2,145,820 Source of Cost Data: Estimate from Gary Pritchard, GHD Process Engineer, April 29, 2016 Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet C-5 NOTES: Assume Level D 2016 Based on general pricing Not included in unit prices except for well construction and oversight Not included in unit prices except for well construction and oversight Vendor pricing GHD Estimate GHD Estimate GHD Estimate GHD Estimate GHD Estimate Vendor pricing Containment Alternatives C100, C150, C200 O&M Sub-Element TREATMENT SYSTEM EQUIPMENT - 300 GPM SYSTEM Site: Location: Phase: Base Year: COST WORKSHEET C-6 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: This work sheet includes equipment replacement costs based on typical product lives. Cost analysis: Costs for equipment, preparation, and installation. DESCRIPTION 5 Year Replacement EXT-1s Pump EXT-3d Pump EXT-4s Pump EXT-5s Pump EXT-8s Pump EXT-9d Pump EXT-10s Pump EXT-15s Pump EXT-16s Pump EXT-18s Pump EXT-21s Pump SUBTOTAL QTY UNIT LABOR 1 1 1 1 1 1 1 1 1 1 1 EA EA EA EA EA EA EA EA EA EA EA 15 Year Replacement Inclined Plate Clarifier Air Stripper Blower Regenerative Thermal Oxidizer Package Air Compressor Compressed Air Desiccant Dryer Clarifier Feed Pump Air Stripper Transfer Pump Building Sump Pump Clarifier Bottoms Pump Dirty Backwash Recycle Pump Coagulant Metering Pump Polymer Metering / Blending Unit Sequestering Agent Metering Pump Equalization Tank Clarifier Sludge Tank Dirty Backwash Tank Effluent Tank Add metal tanks higher grade lining Add tanks high seismic zone - extra 10% SUBTOTAL 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10 LS LS LS LS LS EA EA EA EA EA LS LS LS EA EA EA EA LS % incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. 20 Year Replacement Filter Press Multimedia Filter Skid Cartridge Filter Skid Carbon Filters (2 vessels) Sand Filter Feed Pump Sand Filter Backwash Pump Filter Press Sludge Pump Filter Feed Tank SUBTOTAL 1 1 1 1 1 1 1 1 LS LS LS LS EA EA EA EA incl. incl. incl. incl. incl. incl. incl. incl. EQUIP MTRL - 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. - 260,000 83,440 900,200 14,600 5,483 18,280 22,356 2,563 1,941 1,941 2,000 15,000 2,000 39,371 25,096 47,081 16,469 11,155 158,372 208,000 180,000 13,429 300,000 22,356 24,243 2,561 19,200 incl. incl. incl. incl. incl. incl. incl. incl. UNIT TOTAL TOTAL - 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 19,100 - 260,000 83,440 900,200 14,600 5,483 18,280 22,356 2,563 1,941 1,941 2,000 15,000 2,000 39,371 25,096 47,081 16,469 11,155 158,372 260,000 83,440 900,200 14,600 5,483 18,280 22,356 2,563 1,941 1,941 2,000 15,000 2,000 39,371 25,096 47,081 16,469 11,155 15,837 1,484,810 208,000 180,000 13,429 300,000 22,356 24,243 2,561 19,200 208,000 180,000 13,429 300,000 22,356 24,243 2,561 19,200 769,790 Prime Contractor Overhead SUBTOTAL 15% 2,865 2,276,565 Prime Contractor Profit 10% 1,910 TOTAL UNIT COST Source of Cost Data: Estimate from Gary Pritchard, GHD Process Engineer, April 29, 2016 $2,278,480 Containment Alternatives C100, C150, C200 O&M Sub-Element TREATMENT SYSTEM EQUIPMENT - 300 GPM SYSTEM Site: Location: Phase: Base Year: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 COST WORKSHEET C-6 Prepared By: AW Date: 6/2/2016 Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet C-6 NOTES: Assume Level D 2016 Based on general pricing Included in unit pricing except pumps Included in unit pricing except pumps Checked By: RJH Date: 12/6/2016 Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 6, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 7.0% Discount Rate Cost $ 38,700,240 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 97,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 72,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 831,890 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 831,890 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 5,453,300 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 831,890 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 COST ESTIMATE SUMMARY C150 100-Year Cash Flow Projection at 7 percent Discount Rate 1.000 0.935 0.873 0.816 0.763 0.713 0.713 0.666 0.623 0.582 0.544 0.508 0.508 0.475 0.444 0.415 0.388 0.362 0.362 0.339 0.317 0.296 0.277 0.258 0.258 0.242 0.226 0.211 0.197 0.184 0.184 0.172 0.161 0.150 0.141 0.131 0.131 0.123 0.115 0.107 0.100 0.094 0.094 0.088 0.082 0.076 0.071 0.067 0.067 0.062 0.058 0.055 0.051 0.048 0.048 0.044 0.042 0.039 0.036 0.034 0.034 0.034 0.032 0.030 0.028 0.026 0.024 0.024 0.023 0.021 0.020 0.018 0.017 0.017 0.016 0.015 0.014 0.013 0.012 0.012 0.011 0.011 0.010 0.009 0.009 0.009 Present Value $ 38,700,240 $ 1,103,406 $ 1,031,220 $ 963,757 $ 900,708 $ 841,783 $ 69,231 $ 786,713 $ 735,246 $ 687,146 $ 642,192 $ 600,180 $ 36,652 $ 560,915 $ 524,220 $ 489,925 $ 457,874 $ 427,920 $ 673,236 $ 399,925 $ 373,762 $ 349,310 $ 326,458 $ 305,101 $ 214,976 $ 285,141 $ 266,487 $ 249,053 $ 232,760 $ 217,533 $ 11,442 $ 203,302 $ 190,001 $ 177,571 $ 165,955 $ 155,098 $ 244,012 $ 144,951 $ 135,468 $ 126,606 $ 118,323 $ 110,583 $ 5,816 $ 103,348 $ 96,587 $ 90,268 $ 84,363 $ 78,844 $ 55,554 $ 73,686 $ 68,865 $ 64,360 $ 60,150 $ 56,215 $ 88,441 $ 52,537 $ 49,100 $ 45,888 $ 42,886 $ 40,080 $ 2,108 $ 185,127 $ 37,458 $ 35,008 $ 32,717 $ 30,577 $ 28,577 $ 1,503 $ 26,707 $ 24,960 $ 23,327 $ 21,801 $ 20,375 $ 14,356 $ 19,042 $ 17,796 $ 16,632 $ 15,544 $ 14,527 $ 764 $ 13,577 $ 12,688 $ 11,858 $ 11,083 $ 10,357 $ 545 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Repair sheet pile wall (50 percent of full install) 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 6, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs Annual O&M Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Periodic Costs 80 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs Annual O&M Costs 85 Periodic Costs 85 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Annual O&M Costs 90 Periodic Costs Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition 100 Final Completion Report TOTAL PRESENT VALUE OF ALTERNATIVE Description: 7.0% Discount Rate Cost $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 831,890 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,000,000 $ 100,000 $ 176,600,000 COST ESTIMATE SUMMARY C150 100-Year Cash Flow Projection at 7 percent Discount Rate 0.008 0.008 0.007 0.007 0.006 0.006 0.006 0.005 0.005 0.005 0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.001 Present Value $ 9,680 $ 9,047 $ 8,455 $ 7,902 $ 7,385 $ 11,618 $ 6,902 $ 6,450 $ 6,028 $ 5,634 $ 5,265 $ 3,710 $ 4,921 $ 4,599 $ 4,298 $ 4,017 $ 3,754 $ 197 $ 3,508 $ 3,279 $ 3,064 $ 2,864 $ 2,677 $ 4,211 $ 2,501 $ 2,338 $ 2,185 $ 2,042 $ 1,908 $ 100 $ 1,784 $ 1,667 $ 1,558 $ 1,456 $ 1,361 $ 1,152 $ 115 $ 57,170,000 $ 57,170,000 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 6, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 1.5% Discount Rate Cost $ 38,700,240 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 97,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 72,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 831,890 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 831,890 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 5,453,300 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 831,890 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 COST ESTIMATE SUMMARY C150 100-Year Cash Flow Projection at 1.5 percent Discount Rate 1.000 0.985 0.971 0.956 0.942 0.928 0.928 0.915 0.901 0.888 0.875 0.862 0.862 0.849 0.836 0.824 0.812 0.800 0.800 0.788 0.776 0.765 0.754 0.742 0.742 0.731 0.721 0.710 0.700 0.689 0.689 0.679 0.669 0.659 0.649 0.640 0.640 0.630 0.621 0.612 0.603 0.594 0.594 0.585 0.576 0.568 0.560 0.551 0.551 0.543 0.535 0.527 0.519 0.512 0.512 0.504 0.497 0.489 0.482 0.475 0.475 0.475 0.468 0.461 0.454 0.448 0.441 0.441 0.434 0.428 0.422 0.415 0.409 0.409 0.403 0.397 0.391 0.386 0.380 0.380 0.374 0.369 0.363 0.358 0.353 0.353 Present Value $ 38,700,240 $ 1,163,196 $ 1,146,006 $ 1,129,070 $ 1,112,384 $ 1,095,945 $ 90,134 $ 1,079,749 $ 1,063,792 $ 1,048,071 $ 1,032,582 $ 1,017,322 $ 62,126 $ 1,002,288 $ 987,476 $ 972,883 $ 958,505 $ 944,340 $ 1,485,708 $ 930,384 $ 916,635 $ 903,088 $ 889,742 $ 876,593 $ 617,654 $ 863,639 $ 850,876 $ 838,301 $ 825,912 $ 813,707 $ 42,800 $ 801,682 $ 789,834 $ 778,162 $ 766,662 $ 755,332 $ 1,188,346 $ 744,169 $ 733,172 $ 722,337 $ 711,662 $ 701,144 $ 36,879 $ 690,783 $ 680,574 $ 670,516 $ 660,607 $ 650,845 $ 458,590 $ 641,226 $ 631,750 $ 622,414 $ 613,215 $ 604,153 $ 950,500 $ 595,225 $ 586,428 $ 577,762 $ 569,224 $ 560,811 $ 29,498 $ 2,590,343 $ 552,524 $ 544,358 $ 536,313 $ 528,388 $ 520,579 $ 27,382 $ 512,886 $ 505,306 $ 497,839 $ 490,481 $ 483,233 $ 340,489 $ 476,091 $ 469,056 $ 462,124 $ 455,294 $ 448,566 $ 23,594 $ 441,937 $ 435,406 $ 428,971 $ 422,632 $ 416,386 $ 21,901 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Repair sheet pile wall (50 percent of full install) 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 6, 2016 PRESENT VALUE ANALYSIS Base YR 2016 Year Cost Type Annual O&M Costs 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Periodic Costs 75 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Annual O&M Costs 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs Annual O&M Costs 84 Annual O&M Costs 85 Periodic Costs 85 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Annual O&M Costs 90 Periodic Costs Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition 100 Final Completion Report TOTAL PRESENT VALUE OF ALTERNATIVE Description: 1.5% Discount Rate Cost $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 831,890 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,857,480 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 62,100 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,180,644 $ 1,000,000 $ 100,000 $ 176,600,000 COST ESTIMATE SUMMARY C150 100-Year Cash Flow Projection at 1.5 percent Discount Rate 0.347 0.342 0.337 0.332 0.327 0.327 0.323 0.318 0.313 0.308 0.304 0.304 0.299 0.295 0.291 0.286 0.282 0.282 0.278 0.274 0.270 0.266 0.262 0.262 0.258 0.254 0.250 0.247 0.243 0.243 0.239 0.236 0.232 0.229 0.226 0.226 0.226 Present Value $ 410,232 $ 404,170 $ 398,197 $ 392,312 $ 386,515 $ 608,094 $ 380,802 $ 375,175 $ 369,630 $ 364,168 $ 358,786 $ 252,803 $ 353,484 $ 348,260 $ 343,113 $ 338,043 $ 333,047 $ 17,518 $ 328,125 $ 323,276 $ 318,498 $ 313,792 $ 309,154 $ 486,385 $ 304,585 $ 300,084 $ 295,649 $ 291,280 $ 286,976 $ 15,094 $ 282,735 $ 278,556 $ 274,440 $ 270,384 $ 266,388 $ 225,629 $ 22,563 $ 109,240,000 $ 109,240,000 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 6, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 7.0% Discount Rate Cost $ 38,700,240 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 97,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 72,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 831,890 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 831,890 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 5,453,300 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 831,890 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 COST ESTIMATE SUMMARY C200 100-Year Cash Flow Projection at 7 percent Discount Rate 1.000 0.935 0.873 0.816 0.763 0.713 0.713 0.666 0.623 0.582 0.544 0.508 0.508 0.475 0.444 0.415 0.388 0.362 0.362 0.339 0.317 0.296 0.277 0.258 0.258 0.242 0.226 0.211 0.197 0.184 0.184 0.172 0.161 0.150 0.141 0.131 0.131 0.123 0.115 0.107 0.100 0.094 0.094 0.088 0.082 0.076 0.071 0.067 0.067 0.062 0.058 0.055 0.051 0.048 0.048 0.044 0.042 0.039 0.036 0.034 0.034 0.034 0.032 0.030 0.028 0.026 0.024 0.024 0.023 0.021 0.020 0.018 0.017 0.017 0.016 0.015 0.014 0.013 0.012 0.012 0.011 0.011 0.010 0.009 0.009 0.009 Present Value $ 38,700,240 $ 1,166,200 $ 1,089,907 $ 1,018,604 $ 951,967 $ 889,688 $ 69,231 $ 831,484 $ 777,088 $ 726,251 $ 678,739 $ 634,336 $ 36,652 $ 592,837 $ 554,053 $ 517,807 $ 483,932 $ 452,272 $ 673,236 $ 422,685 $ 395,032 $ 369,189 $ 345,036 $ 322,464 $ 214,976 $ 301,368 $ 281,653 $ 263,227 $ 246,006 $ 229,912 $ 11,442 $ 214,871 $ 200,814 $ 187,677 $ 175,399 $ 163,924 $ 244,012 $ 153,200 $ 143,178 $ 133,811 $ 125,057 $ 116,876 $ 5,816 $ 109,230 $ 102,084 $ 95,405 $ 89,164 $ 83,331 $ 55,554 $ 77,879 $ 72,784 $ 68,023 $ 63,573 $ 59,414 $ 88,441 $ 55,527 $ 51,894 $ 48,499 $ 45,326 $ 42,361 $ 2,108 $ 185,127 $ 39,590 $ 37,000 $ 34,579 $ 32,317 $ 30,203 $ 1,503 $ 28,227 $ 26,380 $ 24,655 $ 23,042 $ 21,534 $ 14,356 $ 20,125 $ 18,809 $ 17,578 $ 16,428 $ 15,354 $ 764 $ 14,349 $ 13,410 $ 12,533 $ 11,713 $ 10,947 $ 545 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Repair sheet pile wall (50 percent of full install) 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 6, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs Annual O&M Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Periodic Costs 80 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs Annual O&M Costs 85 Periodic Costs 85 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Annual O&M Costs 90 Periodic Costs Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition 100 Final Completion Report TOTAL PRESENT VALUE OF ALTERNATIVE Description: 7.0% Discount Rate Cost $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 831,890 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,000,000 $ 100,000 $ 183,320,000 COST ESTIMATE SUMMARY C200 100-Year Cash Flow Projection at 7 percent Discount Rate 0.008 0.008 0.007 0.007 0.006 0.006 0.006 0.005 0.005 0.005 0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.001 Present Value $ 10,231 $ 9,561 $ 8,936 $ 8,351 $ 7,805 $ 11,618 $ 7,294 $ 6,817 $ 6,371 $ 5,954 $ 5,565 $ 3,710 $ 5,201 $ 4,861 $ 4,543 $ 4,245 $ 3,968 $ 197 $ 3,708 $ 3,466 $ 3,239 $ 3,027 $ 2,829 $ 4,211 $ 2,644 $ 2,471 $ 2,309 $ 2,158 $ 2,017 $ 100 $ 1,885 $ 1,762 $ 1,646 $ 1,539 $ 1,438 $ 1,152 $ 115 $ 58,130,000 $ 58,130,000 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 6, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 1.5% Discount Rate Cost $ 38,700,240 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 97,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 72,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 831,890 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 831,890 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 5,453,300 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 831,890 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 COST ESTIMATE SUMMARY C200 100-Year Cash Flow Projection at 1.5 percent Discount Rate 1.000 0.985 0.971 0.956 0.942 0.928 0.928 0.915 0.901 0.888 0.875 0.862 0.862 0.849 0.836 0.824 0.812 0.800 0.800 0.788 0.776 0.765 0.754 0.742 0.742 0.731 0.721 0.710 0.700 0.689 0.689 0.679 0.669 0.659 0.649 0.640 0.640 0.630 0.621 0.612 0.603 0.594 0.594 0.585 0.576 0.568 0.560 0.551 0.551 0.543 0.535 0.527 0.519 0.512 0.512 0.504 0.497 0.489 0.482 0.475 0.475 0.475 0.468 0.461 0.454 0.448 0.441 0.441 0.434 0.428 0.422 0.415 0.409 0.409 0.403 0.397 0.391 0.386 0.380 0.380 0.374 0.369 0.363 0.358 0.353 0.353 Present Value $ 38,700,240 $ 1,229,393 $ 1,211,225 $ 1,193,325 $ 1,175,690 $ 1,158,315 $ 90,134 $ 1,141,197 $ 1,124,332 $ 1,107,716 $ 1,091,346 $ 1,075,218 $ 62,126 $ 1,059,328 $ 1,043,673 $ 1,028,249 $ 1,013,053 $ 998,082 $ 1,485,708 $ 983,332 $ 968,800 $ 954,483 $ 940,377 $ 926,480 $ 617,654 $ 912,788 $ 899,299 $ 886,008 $ 872,915 $ 860,014 $ 42,800 $ 847,305 $ 834,783 $ 822,446 $ 810,292 $ 798,317 $ 1,188,346 $ 786,520 $ 774,896 $ 763,444 $ 752,162 $ 741,046 $ 36,879 $ 730,095 $ 719,305 $ 708,675 $ 698,202 $ 687,884 $ 458,590 $ 677,718 $ 667,703 $ 657,835 $ 648,113 $ 638,535 $ 950,500 $ 629,099 $ 619,802 $ 610,642 $ 601,618 $ 592,727 $ 29,498 $ 2,590,343 $ 583,967 $ 575,337 $ 566,835 $ 558,458 $ 550,205 $ 27,382 $ 542,074 $ 534,063 $ 526,170 $ 518,394 $ 510,733 $ 340,489 $ 503,186 $ 495,749 $ 488,423 $ 481,205 $ 474,094 $ 23,594 $ 467,087 $ 460,184 $ 453,384 $ 446,683 $ 440,082 $ 21,901 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Repair sheet pile wall (50 percent of full install) 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Containment Alternative C200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 6, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs Annual O&M Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Periodic Costs 80 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs Annual O&M Costs 85 Periodic Costs 85 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Annual O&M Costs 90 Periodic Costs Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition 100 Final Completion Report TOTAL PRESENT VALUE OF ALTERNATIVE Description: 1.5% Discount Rate Cost $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 831,890 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,857,480 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 62,100 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,247,834 $ 1,000,000 $ 100,000 $ 183,320,000 COST ESTIMATE SUMMARY C200 100-Year Cash Flow Projection at 1.5 percent Discount Rate 0.347 0.342 0.337 0.332 0.327 0.327 0.323 0.318 0.313 0.308 0.304 0.304 0.299 0.295 0.291 0.286 0.282 0.282 0.278 0.274 0.270 0.266 0.262 0.262 0.258 0.254 0.250 0.247 0.243 0.243 0.239 0.236 0.232 0.229 0.226 0.226 0.226 Present Value $ 433,579 $ 427,171 $ 420,858 $ 414,639 $ 408,511 $ 608,094 $ 402,474 $ 396,526 $ 390,666 $ 384,893 $ 379,204 $ 252,803 $ 373,600 $ 368,079 $ 362,640 $ 357,280 $ 352,000 $ 17,518 $ 346,798 $ 341,673 $ 336,624 $ 331,649 $ 326,748 $ 486,385 $ 321,919 $ 317,162 $ 312,475 $ 307,857 $ 303,307 $ 15,094 $ 298,825 $ 294,409 $ 290,058 $ 285,771 $ 281,548 $ 225,629 $ 22,563 $ 112,710,000 $ 112,710,000 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Appendix G-2 VOC Mass Alternatives Cost Estimates GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) COMPARISON OF TOTAL COST OF VOC MASS REMEDIAL ALTERNATIVES Site: Location: Phase: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) Base Year: Date: Alternative M1 2016 January 11, 2017 ERH/SVE Alternative M6 Soil Excavation And On-Site Treatment And ERH/SVE Action Deep Zones Deep Zones Deep Zones Deep Zones Shallow Zone Shallow Zone Shallow Zone Shallow Zone Deep Zones 0 30 30 30 30 30 30 30 30 30 1 30 1.5 30 2 30 19 30 19 30 Capital Cost Annual O&M Cost $38,700,240 $1,180,644 $38,903,190 $1,250,644 $38,903,190 $1,282,584 $38,903,190 $1,314,324 $38,854,780 $1,210,180 $41,366,240 $1,180,644 $50,712,040 $1,180,644 $52,488,140 $1,180,644 $114,264,240 $1,189,644 $354,880,940 $1,195,644 Total Periodic Cost $2,920,670 $2,956,070 $2,956,070 $2,956,070 $2,920,670 $2,920,670 $2,920,670 $2,920,670 $29,796,220 $71,578,970 Total Present Value of Alternative (7%) Total Present Value of Alternative (1.5%) $54,356,480 $69,352,840 $55,442,430 $71,265,400 $55,838,770 $72,032,470 $56,232,640 $72,794,730 $54,877,530 $70,216,710 $57,022,480 $72,018,840 $66,368,280 $81,364,640 $68,144,380 $83,140,740 $142,006,010 $167,471,640 $401,254,360 $442,991,030 No Additional DESCRIPTION Total Project Duration without C150 (Years) Total Project Duration with C150 (Years) Alternative M100 Alternative M150 Alternative M200 Alternative MSP Strategic Groundwater Groundwater Groundwater Groundwater Extraction Extraction Extraction Pumping Shallow and Shallow and Shallow and Shallow and Alternative M3 Soil Excavation And On-Site Treatment Note: Costs for Alternative C150 (Containment) are added to all VOC mass remedial alternatives except Alternative MSP, which includes cost for containment already. 07843(139)AppG - Summary Worksheet VOC Mass Alternative M5 Alternative M8 Alternative M9 ERH/SVE And ISCO/ISB ERH/SVE And ISCO/ISB Shallow and VOC Mass Reduction Alternative M100 GROUNDWATER EXTRACTION COST ESTIMATE SUMMARY M100 Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION QTY Mass Reduction Alternative M100 was designed to extract shallow and deep groundwater with high concentrations of VOC outside the areas of high pH. The pumping rate is estimated to be 35 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. UNIT COST UNIT TOTAL NOTES Installation of Extraction Wells and Conveyance $ 136,250 See Cost Worksheet M-1 SUBTOTAL $ 136,250 Contingency 25% $34,100 10% scope + 15% bid SUBTOTAL $170,350 Project Management Remedial Design Construction Management 5% 8% 6% $8,600 $13,700 $10,300 TOTAL CAPITAL COSTS $202,950 ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT Inspection 1 LS $ 500 $ 500 Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ $ $ 19,124 2,333 2.60 $ $ $ $ Groundwater Treatment (Assumes GWETS for Containment Alternative) Carbon Consumption 0.7 EXCHANGE pH Adjustment 1 LS Dilution Water 9198 $/1000 gals SUBTOTAL TOTAL Extraction Wells and Forcemains Annual maintenance 1 LS $ 3,000 $ Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 5 ton $ 720 $ SUBTOTAL Contingency 30% SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES Included in containment alternative 13,387 GHD Quote 2,333 GHD Quote 23,918 Assume city water for dilution - quote 39,600 3,000 1.5 days 3,600 Vendor Quote $ 46,700 $ 14,100 10% scope + 20% bid $ 60,800 $ $ 3,100 6,100 $ 70,000 PERIODIC COSTS: DESCRIPTION UNIT COST YEAR QTY UNIT TOTAL NOTES Pump Replacement 5 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 10 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 15 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 20 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 25 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 YEAR 0 1-30 5 10 15 20 25 TOTAL COST $ 202,950 $ 2,100,000 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 2,338,350 TOTAL COST PER YEAR $ 202,950 $ 70,000 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost TOTAL PRESENT VALUE OF ALTERNATIVE DISCOUNT FACTOR (7%) 1 12.41 0.713 0.508 0.362 0.258 0.184 $ $ $ $ $ $ $ $ PRESENT VALUE 202,950 868,640 5,050 3,600 2,570 1,830 1,310 1,085,950 $ 1,085,950 NOTES 30 years Equipment replacement Equipment replacement Equipment replacement Equipment replacement Equipment replacement VOC Mass Reduction Alternative M100 GROUNDWATER EXTRACTION COST ESTIMATE SUMMARY M100 Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION QTY Mass Reduction Alternative M100 was designed to extract shallow and deep groundwater with high concentrations of VOC outside the areas of high pH. The pumping rate is estimated to be 35 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. UNIT COST UNIT TOTAL NOTES Installation of Extraction Wells and Conveyance $ 136,250 See Cost Worksheet M-1 SUBTOTAL $ 136,250 Contingency 25% $34,100 10% scope + 15% bid SUBTOTAL $170,350 Project Management Remedial Design Construction Management 5% 8% 6% $8,600 $13,700 $10,300 TOTAL CAPITAL COSTS $202,950 ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT Inspection 1 LS $ 500 $ 500 Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ $ $ 19,124 2,333 2.60 $ $ $ $ Groundwater Treatment (Assumes GWETS for Containment Alternative) Carbon Consumption 0.7 EXCHANGE pH Adjustment 1 LS Dilution Water 9198 $/1000 gals SUBTOTAL TOTAL Extraction Wells and Forcemains Annual maintenance 1 LS $ 3,000 $ Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 5 ton $ 720 $ SUBTOTAL Contingency 30% SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES Included in containment alternative 13,387 GHD Quote 2,333 GHD Quote 23,918 Assume city water for dilution - quote 39,600 3,000 1.5 days 3,600 Vendor Quote $ 46,700 $ 14,100 10% scope + 20% bid $ 60,800 $ $ 3,100 6,100 $ 70,000 PERIODIC COSTS: DESCRIPTION UNIT COST YEAR QTY UNIT TOTAL NOTES Pump Replacement 5 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 10 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 15 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 20 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 25 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 YEAR 0 1-30 5 10 15 20 25 TOTAL COST $ 202,950 $ 2,100,000 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 2,338,350 TOTAL COST PER YEAR $ 202,950 $ 70,000 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost TOTAL PRESENT VALUE OF ALTERNATIVE DISCOUNT FACTOR (1.5%) 1 24.02 0.928 0.862 0.800 0.742 0.689 $ $ $ $ $ $ $ $ PRESENT VALUE 202,950 1,681,110 6,580 6,110 5,670 5,260 4,880 1,912,560 $ 1,912,560 NOTES 30 years Equipment replacement Equipment replacement Equipment replacement Equipment replacement Equipment replacement VOC Mass Reduction Alternative M150 GROUNDWATER EXTRACTION COST ESTIMATE SUMMARY M150 Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION QTY Mass Reduction Alternative M150 was designed to extract shallow and deep groundwater with high concentrations of VOC outside the areas of high pH. The pumping rate is estimated to be 52.5 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. UNIT COST UNIT TOTAL NOTES Installation of Extraction Wells and Conveyance $ 136,250 See Cost Worksheet M-1 SUBTOTAL $ 136,250 Contingency 25% $34,100 10% scope + 15% bid SUBTOTAL $170,350 Project Management Remedial Design Construction Management 5% 8% 6% $8,600 $13,700 $10,300 TOTAL CAPITAL COSTS $202,950 ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT Inspection 1 LS $ 500 $ 500 Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ $ $ 19,124 3,500 2.60 $ $ $ $ Groundwater Treatment (Assumes GWETS for Containment Alternative) Carbon Consumption 1.05 EXCHANGE pH Adjustment 1 LS Dilution Water 13797 $/1000 gals SUBTOTAL TOTAL Extraction Wells and Forcemains Annual maintenance 1 LS $ 3,000 $ Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 7 ton $ 720 $ SUBTOTAL Contingency 30% SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES Included in containment alternative 20,080 GHD Quote 3,500 GHD Quote 35,877 Assume city water for dilution - quote 59,500 3,000 1.5 days 5,040 Vendor Quote $ 68,040 $ 20,500 10% scope + 20% bid $ 88,540 $ $ 4,500 8,900 $ 101,940 PERIODIC COSTS: DESCRIPTION UNIT COST YEAR QTY UNIT TOTAL NOTES Pump Replacement 5 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 10 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 15 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 20 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 25 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 YEAR 0 1-30 5 10 15 20 25 TOTAL COST $ 202,950 $ 3,058,200 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 3,296,550 TOTAL COST PER YEAR $ 202,950 $ 101,940 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost TOTAL PRESENT VALUE OF ALTERNATIVE DISCOUNT FACTOR (7%) 1 12.41 0.713 0.508 0.362 0.258 0.184 $ $ $ $ $ $ $ $ PRESENT VALUE 202,950 1,264,980 5,050 3,600 2,570 1,830 1,310 1,482,290 $ 1,482,290 NOTES 30 years Equipment replacement Equipment replacement Equipment replacement Equipment replacement Equipment replacement VOC Mass Reduction Alternative M150 GROUNDWATER EXTRACTION COST ESTIMATE SUMMARY M150 Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION QTY Mass Reduction Alternative M150 was designed to extract shallow and deep groundwater with high concentrations of VOC outside the areas of high pH. The pumping rate is estimated to be 52.5 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. UNIT COST UNIT TOTAL NOTES Installation of Extraction Wells and Conveyance $ 136,250 See Cost Worksheet M-1 SUBTOTAL $ 136,250 Contingency 25% $34,100 10% scope + 15% bid SUBTOTAL $170,350 Project Management Remedial Design Construction Management 5% 8% 6% $8,600 $13,700 $10,300 TOTAL CAPITAL COSTS $202,950 ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT Inspection 1 LS $ 500 $ 500 Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ $ $ 19,124 3,500 2.60 $ $ $ $ Groundwater Treatment (Assumes GWETS for Containment Alternative) Carbon Consumption 1.05 EXCHANGE pH Adjustment 1 LS Dilution Water 13797 $/1000 gals SUBTOTAL TOTAL Extraction Wells and Forcemains Annual maintenance 1 LS $ 3,000 $ Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 7 ton $ 720 $ SUBTOTAL Contingency 30% SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES Included in containment alternative 20,080 GHD Quote 3,500 GHD Quote 35,877 Assume city water for dilution - quote 59,500 3,000 1.5 days 5,040 Vendor Quote $ 68,040 $ 20,500 10% scope + 20% bid $ 88,540 $ $ 4,500 8,900 $ 101,940 PERIODIC COSTS: DESCRIPTION UNIT COST YEAR QTY UNIT TOTAL NOTES Pump Replacement 5 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 10 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 15 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 20 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 25 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 YEAR 0 1-30 5 10 15 20 25 TOTAL COST $ 202,950 $ 3,058,200 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 3,296,550 TOTAL COST PER YEAR $ 202,950 $ 101,940 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost TOTAL PRESENT VALUE OF ALTERNATIVE DISCOUNT FACTOR (1.5%) 1 24.02 0.928 0.862 0.800 0.742 0.689 $ $ $ $ $ $ $ $ PRESENT VALUE 202,950 2,448,180 6,580 6,110 5,670 5,260 4,880 2,679,630 $ 2,679,630 NOTES 30 years Equipment replacement Equipment replacement Equipment replacement Equipment replacement Equipment replacement VOC Mass Reduction Alternative M200 GROUNDWATER EXTRACTION COST ESTIMATE SUMMARY M200 Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 7% Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION QTY Mass Reduction Alternative M200 was designed to extract shallow and deep groundwater with high concentrations of VOC outside the areas of high pH. The pumping rate is estimated to be 70 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. UNIT COST UNIT TOTAL NOTES Installation of Extraction Wells and Conveyance $ 136,250 See Cost Worksheet M-1 SUBTOTAL $ 136,250 Contingency 25% $34,100 10% scope + 15% bid SUBTOTAL $170,350 Project Management Remedial Design Construction Management 5% 8% 6% $8,600 $13,700 $10,300 TOTAL CAPITAL COSTS $202,950 ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT Inspection 1 LS $ 500 $ 500 Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ $ $ 19,124 4,667 2.60 $ $ $ $ Groundwater Treatment (Assumes GWETS for Containment Alternative) Carbon Consumption 1.4 EXCHANGE pH Adjustment 1 LS Dilution Water 18396 $/1000 gals SUBTOTAL TOTAL Extraction Wells and Forcemains Annual maintenance 1 LS $ 3,000 $ Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 9 ton $ 720 $ SUBTOTAL Contingency 30% SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES Included in containment alternative 26,774 GHD Quote 4,667 GHD Quote 47,836 Assume city water for dilution - quote 79,300 3,000 1.5 days 6,480 Vendor Quote $ 89,280 $ 26,800 10% scope + 20% bid $ 116,080 $ $ 5,900 11,700 $ 133,680 PERIODIC COSTS: DESCRIPTION UNIT COST YEAR QTY UNIT TOTAL NOTES Pump Replacement 5 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 10 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 15 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 20 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 25 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 YEAR 0 1-30 5 10 15 20 25 TOTAL COST $ 202,950 $ 4,010,400 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 4,248,750 TOTAL COST PER YEAR $ 202,950 $ 133,680 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost TOTAL PRESENT VALUE OF ALTERNATIVE DISCOUNT FACTOR (7%) 1 12.41 0.713 0.508 0.362 0.258 0.184 $ $ $ $ $ $ $ $ PRESENT VALUE 202,950 1,658,850 5,050 3,600 2,570 1,830 1,310 1,876,160 $ 1,876,160 NOTES 30 years Equipment replacement Equipment replacement Equipment replacement Equipment replacement Equipment replacement VOC Mass Reduction Alternative M200 GROUNDWATER EXTRACTION COST ESTIMATE SUMMARY M200 Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) - 1.5% Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION QTY Mass Reduction Alternative M200 was designed to extract shallow and deep groundwater with high concentrations of VOC outside the areas of high pH. The pumping rate is estimated to be 70 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. UNIT COST UNIT TOTAL NOTES Installation of Extraction Wells and Conveyance $ 136,250 See Cost Worksheet M-1 SUBTOTAL $ 136,250 Contingency 25% $34,100 10% scope + 15% bid SUBTOTAL $170,350 Project Management Remedial Design Construction Management 5% 8% 6% $8,600 $13,700 $10,300 TOTAL CAPITAL COSTS $202,950 ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT Inspection 1 LS $ 500 $ 500 Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ $ $ 19,124 4,667 2.60 $ $ $ $ Groundwater Treatment (Assumes GWETS for Containment Alternative) Carbon Consumption 1.4 EXCHANGE pH Adjustment 1 LS Dilution Water 18396 $/1000 gals SUBTOTAL TOTAL Extraction Wells and Forcemains Annual maintenance 1 LS $ 3,000 $ Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 9 ton $ 720 $ SUBTOTAL Contingency 30% SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES Included in containment alternative 26,774 GHD Quote 4,667 GHD Quote 47,836 Assume city water for dilution - quote 79,300 3,000 1.5 days 6,480 Vendor Quote $ 89,280 $ 26,800 10% scope + 20% bid $ 116,080 $ $ 5,900 11,700 $ 133,680 PERIODIC COSTS: DESCRIPTION UNIT COST YEAR QTY UNIT TOTAL NOTES Pump Replacement 5 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 10 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 15 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 20 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 Pump Replacement 25 1 EA $ 7,080 $ 7,080 See Cost Worksheet M-2 YEAR 0 1-30 5 10 15 20 25 TOTAL COST $ 202,950 $ 4,010,400 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 4,248,750 TOTAL COST PER YEAR $ 202,950 $ 133,680 $ 7,080 $ 7,080 $ 7,080 $ 7,080 $ 7,080 PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost TOTAL PRESENT VALUE OF ALTERNATIVE DISCOUNT FACTOR (1.5%) 1 24.02 0.928 0.862 0.800 0.742 0.689 $ $ $ $ $ $ $ $ PRESENT VALUE 202,950 3,210,440 6,580 6,110 5,670 5,260 4,880 3,441,890 $ 3,441,890 NOTES 30 years Equipment replacement Equipment replacement Equipment replacement Equipment replacement Equipment replacement VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 7% 2016 December 8, 2016 COST ESTIMATE SUMMARY MSP Mass Reduction Alternative MSP is designed to reduce VOC mass and eliminate potentially complete exposure pathways, and includes: extraction of shallow and deep groundwater with high concentrations of VOC outside the areas of high pH; institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. The pumping rate is estimated to be 210 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. CAPITAL COSTS DESCRIPTION UNIT COST QTY UNIT TOTAL Mobilization/Demobilization Construction Equipment & Facilities Temporary facilities and Utilities H&S Plans and Submittals Design, Work Plans, Permits Design, Work Plans, Permits Post-construction Submittals SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 $ $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 390,000 Site Work Demolition of North Dock Demolition of South Dock Demolition of Existing Structures Construction Oversight SUBTOTAL 1 1 1 50 LS LS LS DAY $ $ $ $ 446,000 248,000 250,000 1,920 $ $ $ $ $ 446,000 248,000 250,000 96,000 1,040,000 Barrier Wall East Installation Mobilization/Demobilization Sheet Pile Unload Sheet Pile Install Perimeter SP Wall Fill along embankment behind wall Construction Oversight Mitigation of Intertidal Areas SUBTOTAL 1 4300 220 160000 40370 130 1 LS TN LS SF CY DAY LS $ $ $ $ $ $ $ 50,000 1,900 2,350 12 18 1,920 250,000 $ $ $ $ $ $ $ $ 50,000 8,170,000 517,000 1,920,000 726,670 249,600 250,000 11,883,270 Physical Direct Contact Exposure Barrier Mobilization/Demobilization Preparation Aggregate Base Asphalt Cover (assume 4") Construction Oversight SUBTOTAL 1 1502820 27830 1502820 130 LS SF CY SF DAY $ $ $ $ $ 50,000 0.6 35 2 1,920 $ $ $ $ $ $ 50,000 901,700 974,050 3,005,640 249,600 5,180,990 VOC Mass Extraction and Hydraulic Containment Mobilization/Demobilization Groundwater Extraction System Groundwater Treatment Equipment Groundwater Treatment Facility Building High pH Treatment Additional Equipment Construction Oversight SUBTOTAL 1 1 1 1 1 260 LS LS LS LS LS Day $ $ $ $ $ $ 50,000 1,031,360 2,544,230 2,145,820 27,000 1,920 $ $ $ $ $ $ $ 50,000 1,031,360 2,544,230 2,145,820 27,000 499,200 6,297,610 Off-Site Treatment / Disposal Off-Site T&D of Soil Cuttings Off-Site T&D of Spoils Off-Site T&D of Spoils - Hazardous SUBTOTAL 20 1250 750 CY CY CY $ $ $ 394 394 977 $ $ $ $ 7,880 Vendor Quote 491,920 Vendor Quote 732,780 Vendor Quote 1,232,580 SUBTOTAL $ Contingency 25% $ SUBTOTAL Project Management Remedial Design Construction Management Institutional Controls Institutional Controls Plan Groundwater Use Restrictions Site Database Documentation Perimeter fence SUBTOTAL TOTAL CAPITAL COSTS 5% 8% 6% 1 1 1 1 5300 LS LS LS LS FOOT $ $ $ $ $ 13,000 10,000 5,000 20,000 18 NOTES Excavators, Loaders, etc. Fence, roads, signs, trailers, etc. HASP, quality control, etc. Barrier wall Physical Direct Contact Exposure Barrier Report completed work Quotation from vendor - See Cost Worksheet C-1 Quotation from vendor - See Cost Worksheet C-2 Treatment plant, office, misc. - Assumption Assume 2 people 2,180 ft long by 73.5 ft deep. Assuming barge installation Vendor quote (PZ-27 sheet) Vendor quote Vendor quote (Adeka sealant; Anchor piles on 6' centers) Avg. Depth 10 ft; 50 ft wide Assume 2 people Allowance Remove debris and prepare surface. 34.5 acres. 6 inch base Facility Construction Cost - RSMeans (2016) Assume 2 personal See Cost Worksheet M-13 Assume 300 gpm System - See Cost Worksheet C-4 See Cost Worksheet C-5 Acid metering pump and equalization tank. 26,024,450 6,506,110 10% scope + 15% bid $ 32,530,560 $ $ $ 1,626,530 2,602,450 1,951,840 $ $ $ $ $ $ 13,000 10,000 5,000 20,000 95,400 143,400 $ 38,854,780 Description and implementation Legal fees Data management system other submittals and documents 605 and 709 properties VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 7% 2016 December 8, 2016 COST ESTIMATE SUMMARY MSP Mass Reduction Alternative MSP is designed to reduce VOC mass and eliminate potentially complete exposure pathways, and includes: extraction of shallow and deep groundwater with high concentrations of VOC outside the areas of high pH; institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. The pumping rate is estimated to be 210 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT 1 1 LS LS $ $ 2,600 5,200 $ $ $ Monitoring Groundwater Monitoring, sampling and reporting 1 LS $ 297,000 $ Physical Direct Contact Exposure Barrier Maintenance Annual maintenance 1 LS $ 10,000 $ 1 7.5 1 1 55190 year EXCHANGE LS LS $/1000 gals $ $ $ $ $ 124,500 19,124 25,000 6,000 2.60 $ $ $ $ $ $ Extraction Wells and Forcemains Annual maintenance 1 LS $ 20,000 $ 20,000 Two weeks of work Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 41 ton $ 720 $ 29,520 Vendor Quote Inspections Mobilization and Inspection Reporting SUBTOTAL Groundwater Treatment Plant Operation Carbon Consumption pH Adjustment Equipment Allowance Dilution Water SUBTOTAL TOTAL SUBTOTAL Contingency 30% SUBTOTAL 1 5% 10% LS $ 4,000 TOTAL ANNUAL O&M COSTS 2,600 Barriers and fencing 5,200 Inspection documentation 7,800 297,000 Will be in OMMP 10,000 Allowance 124,500 143,430 25,000 6,000 143,500 442,430 GHD Quote GHD Quote GHD Quote Allowance Assume city water for dilution - quote $ 806,750 $ 242,030 10% scope + 20% bid $ Project Management Technical Support Site Info Database NOTES $ $ $ $ 1,048,780 52,500 104,900 4,000 Update and maintain database 1,210,180 PERIODIC COSTS: DESCRIPTION YEAR QTY UNIT UNIT COST TOTAL Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 5 5 5 1 1 1 EA LS EA $ $ $ 75,000 19,100 3,000 $ $ $ $ 75,000 Report after 5 years 19,100 Equipment Replacement- See Cost Worksheet M-14 3,000 Update Plan 97,100 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 10 5 10 1 1 1 EA LS EA $ $ $ 50,000 19,100 3,000 $ $ $ $ 50,000 Report after 10 years 19,100 Equipment Replacement- See Cost Worksheet M-14 3,000 Update Plan 72,100 Five Year Review Report Cap Repair Equipment Replacement Update IC Plan Remedial Action Report SUBTOTAL 15 15 15 15 15 1 1 1 1 1 EA LS LS EA EA $ $ $ $ $ 40,000 300,570 1,503,910 3,000 10,000 $ $ $ $ $ $ Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 20 20 20 1 1 1 EA LS EA $ $ $ 40,000 788,890 3,000 $ $ $ $ 40,000 Report after 20 years 788,890 Equipment Replacement- See Cost Worksheet M-14 3,000 Update Plan 831,890 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 25 25 25 1 1 1 EA LS EA $ $ $ 40,000 19,100 3,000 $ $ $ $ 40,000 Report after 25 years 19,100 Equipment Replacement- See Cost Worksheet M-14 3,000 Update Plan 62,100 40,000 300,570 1,503,910 3,000 10,000 1,857,480 NOTES Report after 15 years 10 percent of asphalt Equipment Replacement- See Cost Worksheet M-14 Update Plan VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 7% 2016 December 8, 2016 COST ESTIMATE SUMMARY MSP Mass Reduction Alternative MSP is designed to reduce VOC mass and eliminate potentially complete exposure pathways, and includes: extraction of shallow and deep groundwater with high concentrations of VOC outside the areas of high pH; institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. The pumping rate is estimated to be 210 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost YEAR 0 1-30 5 10 15 20 25 TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST $ 38,854,780 $ 36,305,400 $ 97,100 $ 72,100 $ 1,857,480 $ 831,890 $ 62,100 $ 78,080,850 TOTAL COST PER YEAR $ 38,854,780 $ 1,210,180 $ 97,100 $ 72,100 $ 1,857,480 $ 831,890 $ 62,100 DISCOUNT FACTOR (1.5%) 1 12.41 0.713 0.508 0.362 0.258 0.184 $ $ $ $ $ $ $ $ PRESENT VALUE 38,854,780 15,017,180 69,240 36,660 673,240 214,980 11,450 54,877,530 $ 54,877,530 NOTES 30 years 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 1.5% 2016 December 8, 2016 COST ESTIMATE SUMMARY MSP Mass Reduction Alternative MSP is designed to reduce VOC mass and eliminate potentially complete exposure pathways, and includes: extraction of shallow and deep groundwater with high concentrations of VOC outside the areas of high pH; institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. The pumping rate is estimated to be 210 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. CAPITAL COSTS DESCRIPTION UNIT COST QTY UNIT TOTAL Mobilization/Demobilization Construction Equipment & Facilities Temporary facilities and Utilities H&S Plans and Submittals Design, Work Plans, Permits Design, Work Plans, Permits Post-construction Submittals SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 $ $ $ $ $ $ $ 25,000 50,000 15,000 100,000 50,000 150,000 390,000 Site Work Demolition of North Dock Demolition of South Dock Demolition of Existing Structures Construction Oversight SUBTOTAL 1 1 1 50 LS LS LS DAY $ $ $ $ 446,000 248,000 250,000 1,920 $ $ $ $ $ 446,000 248,000 250,000 96,000 1,040,000 Barrier Wall East Installation Mobilization/Demobilization Sheet Pile Unload Sheet Pile Install Perimeter SP Wall Fill along embankment behind wall Construction Oversight Mitigation of Intertidal Areas SUBTOTAL 1 4300 220 160000 40370 130 1 LS TN LS SF CY DAY LS $ $ $ $ $ $ $ 50,000 1,900 2,350 12 18 1,920 250,000 $ $ $ $ $ $ $ $ 50,000 8,170,000 517,000 1,920,000 726,670 249,600 250,000 11,883,270 Physical Direct Contact Exposure Barrier Mobilization/Demobilization Preparation Aggregate Base Asphalt Cover (assume 4") Construction Oversight SUBTOTAL 1 1502820 27830 1502820 130 LS SF CY SF DAY $ $ $ $ $ 50,000 0.6 35 2 1,920 $ $ $ $ $ $ 50,000 901,700 974,050 3,005,640 249,600 5,180,990 VOC Mass Extraction and Hydraulic Containment Mobilization/Demobilization Groundwater Extraction System Groundwater Treatment Equipment Groundwater Treatment Facility Building High pH Treatment Additional Equipment Construction Oversight SUBTOTAL 1 1 1 1 1 260 LS LS LS LS LS Day $ $ $ $ $ $ 50,000 1,031,360 2,544,230 2,145,820 27,000 1,920 $ $ $ $ $ $ $ 50,000 1,031,360 2,544,230 2,145,820 27,000 499,200 6,297,610 Off-Site Treatment / Disposal Off-Site T&D of Soil Cuttings Off-Site T&D of Spoils Off-Site T&D of Spoils - Hazardous SUBTOTAL 20 1250 750 CY CY CY $ $ $ 394 394 977 $ $ $ $ 7,880 Vendor Quote 491,920 Vendor Quote 732,780 Vendor Quote 1,232,580 SUBTOTAL $ Contingency 25% $ SUBTOTAL Project Management Remedial Design Construction Management Institutional Controls Institutional Controls Plan Groundwater Use Restrictions Site Database Documentation Perimeter fence SUBTOTAL TOTAL CAPITAL COSTS 5% 8% 6% 1 1 1 1 5300 LS LS LS LS FOOT $ $ $ $ $ 13,000 10,000 5,000 20,000 18 NOTES Excavators, Loaders, etc. Fence, roads, signs, trailers, etc. HASP, quality control, etc. Barrier wall Physical Direct Contact Exposure Barrier Report completed work Quotation from vendor - See Cost Worksheet C-1 Quotation from vendor - See Cost Worksheet C-2 Treatment plant, office, misc. - Assumption Assume 2 people 2,180 ft long by 73.5 ft deep. Assuming barge installation Vendor quote (PZ-27 sheet) Vendor quote Vendor quote (Adeka sealant; Anchor piles on 6' centers) Avg. Depth 10 ft; 50 ft wide Assume 2 people Allowance Remove debris and prepare surface. 34.5 acres. 6 inch base Facility Construction Cost - RSMeans (2016) Assume 2 personal See Cost Worksheet M-13 Assume 300 gpm System - See Cost Worksheet C-4 See Cost Worksheet C-5 Acid metering pump and equalization tank. 26,024,450 6,506,110 10% scope + 15% bid $ 32,530,560 $ $ $ 1,626,530 2,602,450 1,951,840 $ $ $ $ $ $ 13,000 10,000 5,000 20,000 95,400 143,400 $ 38,854,780 Description and implementation Legal fees Data management system other submittals and documents 605 and 709 properties VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 1.5% 2016 December 8, 2016 COST ESTIMATE SUMMARY MSP Mass Reduction Alternative MSP is designed to reduce VOC mass and eliminate potentially complete exposure pathways, and includes: extraction of shallow and deep groundwater with high concentrations of VOC outside the areas of high pH; institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. The pumping rate is estimated to be 210 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT 1 1 LS LS $ $ 2,600 5,200 $ $ $ Monitoring Groundwater Monitoring, sampling and reporting 1 LS $ 297,000 $ Physical Direct Contact Exposure Barrier Maintenance Annual maintenance 1 LS $ 10,000 $ 1 7.5 1 1 55190 year EXCHANGE LS LS $/1000 gals $ $ $ $ $ 124,500 19,124 25,000 6,000 2.60 $ $ $ $ $ $ Extraction Wells and Forcemains Annual maintenance 1 LS $ 20,000 $ 20,000 Two weeks of work Off-Site Treatment / Disposal Off-Site Transport/disposal of Solids 41 ton $ 720 $ 29,520 Vendor Quote Inspections Mobilization and Inspection Reporting SUBTOTAL Groundwater Treatment Plant Operation Carbon Consumption pH Adjustment Equipment Allowance Dilution Water SUBTOTAL TOTAL SUBTOTAL Contingency 30% SUBTOTAL 1 5% 10% LS $ 4,000 297,000 Will be in OMMP 10,000 Allowance 124,500 143,430 25,000 6,000 143,500 442,430 GHD Quote GHD Quote GHD Quote Allowance Assume city water for dilution - quote 806,750 $ 242,030 10% scope + 20% bid $ $ $ $ TOTAL ANNUAL O&M COSTS 2,600 Barriers and fencing 5,200 Inspection documentation 7,800 $ $ Project Management Technical Support Site Info Database NOTES 1,048,780 52,500 104,900 4,000 Update and maintain database 1,210,180 PERIODIC COSTS: DESCRIPTION YEAR QTY UNIT UNIT COST TOTAL Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 5 5 5 1 1 1 EA LS EA $ $ $ 75,000 19,100 3,000 $ $ $ $ 75,000 Report after 5 years 19,100 Equipment Replacement- See Cost Worksheet M-14 3,000 Update Plan 97,100 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 10 5 10 1 1 1 EA LS EA $ $ $ 50,000 19,100 3,000 $ $ $ $ 50,000 Report after 10 years 19,100 Equipment Replacement- See Cost Worksheet M-14 3,000 Update Plan 72,100 Five Year Review Report Cap Repair Equipment Replacement Update IC Plan Remedial Action Report SUBTOTAL 15 15 15 15 15 1 1 1 1 1 EA LS LS EA EA $ $ $ $ $ 40,000 300,570 1,503,910 3,000 10,000 $ $ $ $ $ $ Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 20 20 20 1 1 1 EA LS EA $ $ $ 40,000 788,890 3,000 $ $ $ $ 40,000 Report after 20 years 788,890 Equipment Replacement- See Cost Worksheet M-14 3,000 Update Plan 831,890 Five Year Review Report Equipment Replacement Update IC Plan SUBTOTAL 25 25 25 1 1 1 EA LS EA $ $ $ 40,000 19,100 3,000 $ $ $ $ 40,000 Report after 25 years 19,100 Equipment Replacement- See Cost Worksheet M-14 3,000 Update Plan 62,100 40,000 300,570 1,503,910 3,000 10,000 1,857,480 NOTES Report after 15 years 10 percent of asphalt Equipment Replacement- See Cost Worksheet M-14 Update Plan VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 1.5% 2016 December 8, 2016 COST ESTIMATE SUMMARY MSP Mass Reduction Alternative MSP is designed to reduce VOC mass and eliminate potentially complete exposure pathways, and includes: extraction of shallow and deep groundwater with high concentrations of VOC outside the areas of high pH; institutional controls; groundwater monitoring; a Physical Direct Contact Exposure (PDCE) Barrier for 605 & 709 Alexander Avenue Properties, Navy Todd Dump, N Landfill, and 709 Embankment Fill Area; a sheet pile barrier wall adjacent to Hylebos; and hydraulic containment using a newly constructed GWETS. The pumping rate is estimated to be 210 gpm. Assume soil cuttings and trench spoils are placed under PDCE Barrier. Capital Costs occur in Year 0. Annual O&M costs occur in Years 1-30. Periodic costs occur in years 5,10, 15, 20, and 25. PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost YEAR 0 1-30 5 10 15 20 25 TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST $ 38,854,780 $ 36,305,400 $ 97,100 $ 72,100 $ 1,857,480 $ 831,890 $ 62,100 $ 78,080,850 TOTAL COST PER YEAR $ 38,854,780 $ 1,210,180 $ 97,100 $ 72,100 $ 1,857,480 $ 831,890 $ 62,100 DISCOUNT FACTOR (1.5%) 1 24.02 0.928 0.862 0.800 0.742 0.689 $ $ $ $ $ $ $ $ PRESENT VALUE 38,854,780 29,063,490 90,140 62,130 1,485,710 617,660 42,800 70,216,710 $ 70,216,710 NOTES 30 years 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs VOC Mass Removal Alternative M3 SHALLOW SOIL EXCAVATION WITH ON-SITE TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION Description: COST ESTIMATE SUMMARY M3 Mass Removal Alternative M3 was designed to remove near surface soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M3 alternative includes the following elements: Excavation of shallow soil above -4 ft NGVD containing TCVOC concentrations greater than 100 mg/kg; Removal of VOC from the excavated soil by on-Site treatment; Backfill on Site of treated excavated soil. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT 1 1 1 1 LS LS LS LS $ $ $ $ 25,000 25,000 15,000 10,000 $ $ $ $ $ Soil Excavation Above -4ft NGVD Excavate Dry Soil over Impacted Zone Excavate Dry Impacted Soil Excavate Wet Soil over Impacted Zone Excavate Wet Impacted Soil Backfill With Soil Not Being Treated Backfill With Imported Fill Grade Treated Soil Asphalt cover (assume 4" thickness) SUBTOTAL 18,800 2,820 12,870 7,910 31,670 10,730 10,730 25710 CY CY CY CY CY CY CY SF $ $ $ $ $ $ $ $ 8 8 8 8 6 23 6 2 $ $ $ $ $ $ $ $ $ 150,400 22,560 102,960 63,280 190,020 246,790 64,380 51,420 891,800 Ex Situ Soil Vapor Extraction (SVE) Preparation and Setup Electrical Portable Air Treatment Equipment Establish Unsaturated Treatment Pile Establish Saturated Treatment Pile VE Piping for Piles VE Header Piping System Testing and Startup Operation Consumables SUBTOTAL 1 1 1 2,820 7,910 2050 400 1 9 9 LS LS LS CY CY LF LF LS Months Months $ $ $ $ $ $ $ $ $ $ 20,000 20,000 400,000 10.75 10.25 4.25 15 18,000 15,000 10,000 $ $ $ $ $ $ $ $ $ $ $ 20,000 20,000 400,000 30,315 81,078 8,713 6,000 18,000 135,000 90,000 809,100 1 LS $ 16,200 $ $ Mobilization/Demobilization Construction Equipment & Facilities Temporary facilities and Utilities H&S Plans and Submittals Demobilization SUBTOTAL Sampling and Analysis Field Sampling and Analysis SUBTOTAL TOTAL SUBTOTAL $ Contingency 25% NOTES 25,000 Excavators, Loaders, etc. 25,000 Fence, roads, signs, trailers, etc. 15,000 HASP, quality control, etc. 10,000 75,000 Stockpiled Staged for Ex Situ SVE Stockpiled and drained Staged for Ex Situ SVE Treated soils backfilled on 605 property Off 605 Property; RSMeans (2016) GDH Construction Division Estimate GDH Construction Division Estimate Vendor quote GDH Construction Division Estimate GDH Construction Division Estimate 4 inch - Vendor quote GDH Construction Division Estimate GDH Construction Division Estimate GDH Construction Division Estimate GDH Construction Division Estimate 16,200 Estimate 16,200 1,792,100 $448,000 10% scope + 15% bid SUBTOTAL $2,240,100 Project Management Remedial Design Construction Management 5% 8% 6% $112,100 $179,300 $134,500 TOTAL CAPITAL COSTS $2,666,000 ANNUAL O&M COSTS: No annual O&M costs PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (7%) PRESENT VALUE $2,666,000 $0 $0 $2,666,000 $2,666,000 $0 $0 1.000 - $2,666,000 $0 $0 $2,666,000 $2,666,000 NOTES No annual O&M No periodic costs VOC Mass Removal Alternative M5 SHALLOW SOIL TREATMENT BY ERH/SVE Site: Location: Phase: Base Year: Date: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 December 8, 2016 Description: COST ESTIMATE SUMMARY M5 Mass Reduction Alternative M5 was designed to further reduce, by in situ treatment, TCVOC concentrations in a greater quantity of shallow soil, compared to M3 alternative, potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M5 alternative includes the following elements: Treatment using in situ electrical resistance heating (ERH) of shallow saturated soil below 2.5 ft NGVD and above -21 ft NGVD containing TCVOC concentrations greater than 500 mg/kg; Treatment using in situ SVE of shallow unsaturated (vadose zone) soil above 2.5 ft NGVD containing TCVOC concentrations greater than 500 mg/kg. Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. CAPITAL COSTS: DESCRIPTION Mobilization/Demobilization Design, Work Plans, Permits Materials Mobilization Electrical Permit and Connection Demobilization and Final Report SUBTOTAL ERH and SVE Subsurface Installation - Drill Subsurface Installation - Install Surface Installation and Start-up Month 8 Month 9 Month 10 Month 11 Remediation System Operation Month 11 Month 12 Month 13 Month 14 Month 15 Electrical Energy Usage Month 11 Month 12 Month 13 Month 14 Month 15 Carbon Regeneration Misc. Operational Cost SUBTOTAL Monitoring Shallow Stainless Steel Wells Sampling SUBTOTAL QTY UNIT UNIT COST 1 1 1 1 LS LS LS LS $ $ $ $ 233,000 1,681,000 120,000 128,000 $ $ $ $ $ 233,000 1,681,000 120,000 128,000 2,162,000 1 1 LS LS $ $ 1,181,818 118,182 $ $ 1,181,818 Vendor Quote 118,182 Vendor Quote 1 1 1 1 LS LS LS LS $ $ $ $ 407,182 452,424 452,424 180,970 $ $ $ $ 407,182 452,424 452,424 180,970 Vendor Quote Vendor Quote Vendor Quote Vendor Quote 1 1 1 1 1 LS LS LS LS LS $ $ $ $ $ 283,600 472,667 472,667 472,667 425,400 $ $ $ $ $ 283,600 472,667 472,667 472,667 425,400 Vendor Quote Vendor Quote Vendor Quote Vendor Quote Vendor Quote 1 1 1 1 1 1 1 LS LS LS LS LS LS LS $ $ $ $ $ $ $ 106,267 177,111 177,111 177,111 159,400 4,000 92,000 $ $ $ $ $ $ $ $ 106,267 177,111 177,111 177,111 159,400 4,000 92,000 5,813,000 Vendor Quote Vendor Quote Vendor Quote Vendor Quote Vendor Quote Vendor Quote Vendor Quote 10 6 EA EA $ $ 5,800 7,000 $ $ $ SUBTOTAL Contingency NOTES Vendor Quote Vendor Quote Vendor Quote Vendor Quote 58,000 Previous Drilling Invoice 42,000 Estimated 100,000 $ 8,075,000 25% $ 2,018,800 10% scope + 15% bid $ 10,093,800 5% 8% 6% $ $ $ 504,700 807,600 605,700 $ 12,011,800 SUBTOTAL Project Management Remedial Design Construction Management TOTAL TOTAL CAPITAL COSTS ANNUAL O&M COSTS: No annual O&M costs PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (7%) PRESENT VALUE $12,011,800 $0 $0 $12,011,800 $12,011,800 $0 $0 1.000 - $12,011,800 $0 $0 $12,011,800 $12,011,800 NOTES No annual O&M No periodic costs VOC Mass Removal Alternative M6 SHALLOW SOIL EXCAVATION WITH ON-SITE TREATMENT AND SHALLOW SOIL TREATMENT BY ERH/SVE Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS: DESCRIPTION Description: QTY COST ESTIMATE SUMMARY M6 The M6 alternative is a combination of the excavation and ERH treatment elements from the M3 and M5 alternatives. The total area/volume for ERH is approximately 7 percent less. Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT UNIT COST TOTAL NOTES VOC Mass Removal Alternative M3 $ 1,792,100 See Cost Estimate Summary M3 VOC Mass Removal Alternative M5 $ 7,476,852 See Cost Estimate Summary M5; Adjusted for smaller volume SUBTOTAL $ 9,269,000 25% $ 2,317,300 10% scope + 15% bid $ 11,586,300 5% 8% 6% $ $ $ 579,400 927,000 695,200 $ 13,787,900 Contingency SUBTOTAL Project Management Remedial Design Construction Management TOTAL CAPITAL COSTS ANNUAL O&M COSTS: No annual O&M costs PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (7%) PRESENT VALUE $13,787,900 $0 $0 $13,787,900 $13,787,900 $0 $0 1.000 - $13,787,900 $0 $0 $13,787,900 $13,787,900 NOTES No annual O&M No periodic costs VOC Mass Removal Alternative M8 SHALLOW SOIL TREATMENT BY ERH/SVE AND SHALLOW GROUNDWATER/SOIL TREATMENT BY ISCO/ISB Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 7% 2016 December 8, 2016 COST ESTIMATE SUMMARY M8 Mass Reduction Alternative M8 was designed to further reduce, by in situ treatment, TCVOC concentrations in shallow groundwater and in shallow soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M8 alternative includes the M5 alternative (ERH and SVE) plus elements for treatment of shallow groundwater as follows: Treatment using in situ chemical oxidation (ISCO) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u.; Treatment using enhanced in situ bioremediation (ISB) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is less than 10 s.u. Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. CAPITAL COSTS: DESCRIPTION QTY UNIT UNIT COST VOC Mass Removal Alternative M5 TOTAL $ NOTES 8,075,000 See Cost Estimate Summary M5 In Situ Chemical Oxidation (ISCO) Installation of Shallow Injection Wells Injection Event 1 Injection Event 2 Injection Event 3 Injection Event 4 Well Abandonment SUBTOTAL 340 1 1 1 1 1 EA LS LS LS LS LS $ $ $ $ $ $ 8,075 1,936,370 1,936,370 1,936,370 1,936,370 170,000 $ $ $ $ $ $ $ 2,745,500 1,936,370 1,936,370 1,936,370 1,936,370 170,000 10,661,000 See Cost Worksheet M-3; 10-foot radius See Cost Worksheet M-5 See Cost Worksheet M-5 See Cost Worksheet M-5 See Cost Worksheet M-5 Estimate Enhanced In Situ Bioremediation (ISB) Installation of Shallow Injection Wells Injection Event 1 Injection Event 2 Injection Event 3 SUBTOTAL 280 1 1 1 EA LS LS LS $ $ $ $ 8,075 9,934,060 9,934,060 9,934,060 $ $ $ $ $ 2,261,000 9,934,060 9,934,060 9,934,060 32,063,200 See Cost Worksheet M-3; 10-foot radius, 150-foot spacing See Cost Worksheet M-6 See Cost Worksheet M-6 See Cost Worksheet M-6 Monitoring, Sampling, Testing, Analysis $ SUBTOTAL $ 50,799,200 $ 12,699,800 10% scope + 15% bid $ 63,499,000 $ $ $ 3,175,000 5,080,000 3,810,000 $ 75,564,000 Contingency 25% SUBTOTAL Project Management Remedial Design Construction Management 5% 8% 6% TOTAL CAPITAL COSTS - Included in containment alternative ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT TOTAL Inspection 1 LS $ 6,000 $ Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ 6,000 $ 1,800 10% scope + 20% bid $ 7,800 $ $ 400 800 $ 9,000 SUBTOTAL Contingency 30% SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES 6,000 3 days Included in containment alternative PERIODIC COSTS: DESCRIPTION YEAR Enhanced In Situ Bioremediation (ISB) Injection Event 4 8 Injection Event 5 10 Injection Event 6 12 Injection Event 7 14 Injection Event 8 16 Injection Event 9 18 Well Abandonment 19 QTY UNIT 1 1 1 1 1 1 1 EA EA EA EA EA EA EA UNIT COST $ $ $ $ $ $ $ 5,551,560 5,551,560 5,551,560 3,360,290 3,360,290 3,360,290 140,000 TOTAL $ $ $ $ $ $ $ 5,551,560 5,551,560 5,551,560 3,360,290 3,360,290 3,360,290 140,000 NOTES See Cost Worksheet M-7 See Cost Worksheet M-7 See Cost Worksheet M-7 See Cost Worksheet M-8 See Cost Worksheet M-8 See Cost Worksheet M-8 Estimate VOC Mass Removal Alternative M8 SHALLOW SOIL TREATMENT BY ERH/SVE AND SHALLOW GROUNDWATER/SOIL TREATMENT BY ISCO/ISB Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 7% 2016 December 8, 2016 COST ESTIMATE SUMMARY M8 Mass Reduction Alternative M8 was designed to further reduce, by in situ treatment, TCVOC concentrations in shallow groundwater and in shallow soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M8 alternative includes the M5 alternative (ERH and SVE) plus elements for treatment of shallow groundwater as follows: Treatment using in situ chemical oxidation (ISCO) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u.; Treatment using enhanced in situ bioremediation (ISB) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is less than 10 s.u. Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost YEAR 0 1-19 8 10 12 14 16 18 19 TOTAL COST $ 75,564,000 $ 171,000 $ 5,551,560 $ 5,551,560 $ 5,551,560 $ 3,360,290 $ 3,360,290 $ 3,360,290 $ 140,000 $102,610,550 TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST PER YEAR $ 75,564,000 $ 9,000 $ 5,551,560 $ 5,551,560 $ 5,551,560 $ 3,360,290 $ 3,360,290 $ 3,360,290 $ 140,000 DISCOUNT FACTOR (7%) 1 10.34 0.582 0.508 0.444 0.388 0.339 0.296 0.277 $ $ $ $ $ $ $ $ $ PRESENT VALUE 75,564,000 93,030 3,231,060 2,822,140 2,464,960 1,303,180 1,138,250 994,190 38,720 $ 87,649,530 $ 87,649,530 NOTES 19 Years Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB VOC Mass Removal Alternative M8 SHALLOW SOIL TREATMENT BY ERH/SVE AND SHALLOW GROUNDWATER/SOIL TREATMENT BY ISCO/ISB Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 1.5% 2016 December 8, 2016 COST ESTIMATE SUMMARY M8 Mass Reduction Alternative M8 was designed to further reduce, by in situ treatment, TCVOC concentrations in shallow groundwater and in shallow soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M8 alternative includes the M5 alternative (ERH and SVE) plus elements for treatment of shallow groundwater as follows: Treatment using in situ chemical oxidation (ISCO) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u.; Treatment using enhanced in situ bioremediation (ISB) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is less than 10 s.u. Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. CAPITAL COSTS: DESCRIPTION QTY UNIT UNIT COST VOC Mass Removal Alternative M5 TOTAL $ NOTES 8,075,000 See Cost Estimate Summary M5 In Situ Chemical Oxidation (ISCO) Installation of Shallow Injection Wells Injection Event 1 Injection Event 2 Injection Event 3 Injection Event 4 Well Abandonment SUBTOTAL 340 1 1 1 1 1 EA LS LS LS LS LS $ $ $ $ $ $ 8,075 1,936,370 1,936,370 1,936,370 1,936,370 170,000 $ $ $ $ $ $ $ 2,745,500 1,936,370 1,936,370 1,936,370 1,936,370 170,000 10,661,000 See Cost Worksheet M-3; 10-foot radius See Cost Worksheet M-5 See Cost Worksheet M-5 See Cost Worksheet M-5 See Cost Worksheet M-5 Estimate Enhanced In Situ Bioremediation (ISB) Installation of Shallow Injection Wells Injection Event 1 Injection Event 2 Injection Event 3 SUBTOTAL 280 1 1 1 EA LS LS LS $ $ $ $ 8,075 9,934,060 9,934,060 9,934,060 $ $ $ $ $ 2,261,000 9,934,060 9,934,060 9,934,060 32,063,200 See Cost Worksheet M-3; 10-foot radius, 150-foot spacing See Cost Worksheet M-6 See Cost Worksheet M-6 See Cost Worksheet M-6 Monitoring, Sampling, Testing, Analysis $ SUBTOTAL $ 50,799,200 $ 12,699,800 10% scope + 15% bid $ 63,499,000 $ $ $ 3,175,000 5,080,000 3,810,000 $ 75,564,000 Contingency 25% SUBTOTAL Project Management Remedial Design Construction Management 5% 8% 6% TOTAL CAPITAL COSTS - Included in containment alternative ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT TOTAL Inspection 1 LS $ 6,000 $ Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ 6,000 $ 1,800 10% scope + 20% bid $ 7,800 $ $ 400 800 $ 9,000 SUBTOTAL Contingency 30% SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES 6,000 3 days Included in containment alternative PERIODIC COSTS: DESCRIPTION YEAR Enhanced In Situ Bioremediation (ISB) Injection Event 4 8 Injection Event 5 10 Injection Event 6 12 Injection Event 7 14 Injection Event 8 16 Injection Event 9 18 Well Abandonment 19 QTY UNIT 1 1 1 1 1 1 1 EA EA EA EA EA EA EA UNIT COST $ $ $ $ $ $ $ 5,551,560 5,551,560 5,551,560 3,360,290 3,360,290 3,360,290 140,000 TOTAL $ $ $ $ $ $ $ 5,551,560 5,551,560 5,551,560 3,360,290 3,360,290 3,360,290 140,000 NOTES See Cost Worksheet M-7 See Cost Worksheet M-7 See Cost Worksheet M-7 See Cost Worksheet M-8 See Cost Worksheet M-8 See Cost Worksheet M-8 Estimate VOC Mass Removal Alternative M8 SHALLOW SOIL TREATMENT BY ERH/SVE AND SHALLOW GROUNDWATER/SOIL TREATMENT BY ISCO/ISB Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 1.5% 2016 December 8, 2016 COST ESTIMATE SUMMARY M8 Mass Reduction Alternative M8 was designed to further reduce, by in situ treatment, TCVOC concentrations in shallow groundwater and in shallow soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M8 alternative includes the M5 alternative (ERH and SVE) plus elements for treatment of shallow groundwater as follows: Treatment using in situ chemical oxidation (ISCO) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u.; Treatment using enhanced in situ bioremediation (ISB) of shallow groundwater above -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is less than 10 s.u. Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost YEAR 0 1-19 8 10 12 14 16 18 19 TOTAL COST $ 75,564,000 $ 171,000 $ 5,551,560 $ 5,551,560 $ 5,551,560 $ 3,360,290 $ 3,360,290 $ 3,360,290 $ 140,000 $102,610,550 TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST PER YEAR $ 75,564,000 $ 9,000 $ 5,551,560 $ 5,551,560 $ 5,551,560 $ 3,360,290 $ 3,360,290 $ 3,360,290 $ 140,000 DISCOUNT FACTOR (1.5%) 1 16.43 0.888 0.862 0.836 0.812 0.788 0.765 0.754 $ $ $ $ $ $ $ $ $ PRESENT VALUE 75,564,000 147,840 4,928,190 4,783,600 4,643,260 2,728,050 2,648,020 2,570,330 105,510 $ 98,118,800 $ 98,118,800 NOTES 19 Years Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB VOC Mass Removal Alternative M9 SHALLOW SOIL TREATMENT BY ERH/SVE AND SHALLOW/DEEP GROUNDWATER/SOIL TREATMENT BY ISCO/ISB Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 7% 2016 December 8, 2016 COST ESTIMATE SUMMARY M9 Mass Reduction Alternative M9 was designed to further reduce, by in situ treatment, TCVOC concentrations in deep groundwater and in deep soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M9 alternative includes the M8 alternative plus ISCO and ISB to treat deep groundwater and soil below -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u. (ISCO) and within the zone where pH is less than 10 s.u. (ISB). Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. CAPITAL COSTS: DESCRIPTION QTY UNIT UNIT COST VOC Mass Removal Alternative M8 TOTAL NOTES $ 75,564,000 See Cost Estimate Summary M8 In Situ Chemical Oxidation (ISCO) Installation of Shallow Injection Wells Injection Event 1 Injection Event 2 Injection Event 3 Injection Event 4 Well Abandonment SUBTOTAL 1360 1 1 1 1 1 EA LS LS LS LS LS $ $ $ $ $ $ 13,810 9,472,270 9,472,270 9,472,270 9,472,270 680,000 $ $ $ $ $ $ $ 18,781,600 9,472,270 9,472,270 9,472,270 9,472,270 680,000 57,350,680 See Cost Worksheet M-4 See Cost Worksheet M-9 See Cost Worksheet M-9 See Cost Worksheet M-9 See Cost Worksheet M-9 Estimate Enhanced In Situ Bioremediation (ISB) Installation of Shallow Injection Wells Injection Event 1 Injection Event 2 Injection Event 3 SUBTOTAL 450 1 1 1 EA LS LS LS $ $ $ $ 13,810 24,476,415 24,476,415 24,476,415 $ $ $ $ $ 6,214,500 24,476,415 24,476,415 24,476,415 79,643,750 See Cost Worksheet M-4 See Cost Worksheet M-10 See Cost Worksheet M-10 See Cost Worksheet M-10 Monitoring, Sampling, Testing, Analysis $ SUBTOTAL $ 212,558,430 Contingency 25% $ SUBTOTAL - Included in containment alternative 53,139,610 10% scope + 15% bid $ 265,698,000 Project Management Remedial Design Construction Management 5% 8% 6% $ $ $ TOTAL CAPITAL COSTS 13,284,900 21,255,900 15,941,900 $ 316,180,700 ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT TOTAL Inspection 1 LS $ 10,000 $ Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ 10,000 SUBTOTAL Contingency 30% $ SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES 10,000 5 days Included in containment alternative 3,000 10% scope + 20% bid $ 13,000 $ $ 700 1,300 $ 15,000 PERIODIC COSTS: DESCRIPTION YEAR Enhanced In Situ Bioremediation (ISB) Injection Event 4 8 Injection Event 5 10 Injection Event 6 12 Injection Event 7 14 Injection Event 8 16 Injection Event 9 18 Well Abandonment 19 QTY UNIT 1 1 1 1 1 1 1 EA EA EA EA EA EA EA UNIT COST $ $ $ $ $ $ $ 14,019,723 14,019,723 14,019,723 8,791,377 8,791,377 8,791,377 225,000 TOTAL $ $ $ $ $ $ $ 14,019,723 14,019,723 14,019,723 8,791,377 8,791,377 8,791,377 225,000 NOTES See Cost Worksheet M-11 See Cost Worksheet M-11 See Cost Worksheet M-11 See Cost Worksheet M-12 See Cost Worksheet M-12 See Cost Worksheet M-12 Estimate VOC Mass Removal Alternative M9 SHALLOW SOIL TREATMENT BY ERH/SVE AND SHALLOW/DEEP GROUNDWATER/SOIL TREATMENT BY ISCO/ISB Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 7% 2016 December 8, 2016 COST ESTIMATE SUMMARY M9 Mass Reduction Alternative M9 was designed to further reduce, by in situ treatment, TCVOC concentrations in deep groundwater and in deep soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M9 alternative includes the M8 alternative plus ISCO and ISB to treat deep groundwater and soil below -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u. (ISCO) and within the zone where pH is less than 10 s.u. (ISB). Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost YEAR 0 1-19 8 10 12 14 16 18 19 $ $ $ $ $ $ $ $ $ TOTAL COST 316,180,700 285,000 14,019,723 14,019,723 14,019,723 8,791,377 8,791,377 8,791,377 225,000 $385,124,000 TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST PER YEAR $ 316,180,700 $ 15,000 $ 14,019,723 $ 14,019,723 $ 14,019,723 $ 8,791,377 $ 8,791,377 $ 8,791,377 $ 225,000 DISCOUNT FACTOR (7%) 1 10.34 0.582 0.508 0.444 0.388 0.339 0.296 0.277 $ $ $ $ $ $ $ $ $ PRESENT VALUE 316,180,700 155,040 8,159,610 7,126,920 6,224,930 3,409,450 2,977,950 2,601,060 62,220 $ 346,897,880 $ 346,897,880 NOTES 19 Years Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB VOC Mass Removal Alternative M9 SHALLOW SOIL TREATMENT BY ERH/SVE AND SHALLOW/DEEP GROUNDWATER/SOIL TREATMENT BY ISCO/ISB Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 1.5% 2016 December 8, 2016 COST ESTIMATE SUMMARY M9 Mass Reduction Alternative M9 was designed to further reduce, by in situ treatment, TCVOC concentrations in deep groundwater and in deep soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M9 alternative includes the M8 alternative plus ISCO and ISB to treat deep groundwater and soil below -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u. (ISCO) and within the zone where pH is less than 10 s.u. (ISB). Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. CAPITAL COSTS: DESCRIPTION QTY UNIT UNIT COST VOC Mass Removal Alternative M8 TOTAL NOTES $ 75,564,000 See Cost Estimate Summary M8 In Situ Chemical Oxidation (ISCO) Installation of Shallow Injection Wells Injection Event 1 Injection Event 2 Injection Event 3 Injection Event 4 Well Abandonment SUBTOTAL 1360 1 1 1 1 1 EA LS LS LS LS LS $ $ $ $ $ $ 13,810 9,472,270 9,472,270 9,472,270 9,472,270 680,000 $ $ $ $ $ $ $ 18,781,600 9,472,270 9,472,270 9,472,270 9,472,270 680,000 57,350,680 See Cost Worksheet M-4 See Cost Worksheet M-9 See Cost Worksheet M-9 See Cost Worksheet M-9 See Cost Worksheet M-9 Estimate Enhanced In Situ Bioremediation (ISB) Installation of Shallow Injection Wells Injection Event 1 Injection Event 2 Injection Event 3 SUBTOTAL 450 1 1 1 EA LS LS LS $ $ $ $ 13,810 24,476,415 24,476,415 24,476,415 $ $ $ $ $ 6,214,500 24,476,415 24,476,415 24,476,415 79,643,750 See Cost Worksheet M-4 See Cost Worksheet M-10 See Cost Worksheet M-10 See Cost Worksheet M-10 Monitoring, Sampling, Testing, Analysis $ SUBTOTAL $ 212,558,430 Contingency 25% $ SUBTOTAL - Included in containment alternative 53,139,610 10% scope + 15% bid $ 265,698,000 Project Management Remedial Design Construction Management 5% 8% 6% $ $ $ TOTAL CAPITAL COSTS 13,284,900 21,255,900 15,941,900 $ 316,180,700 ANNUAL O&M COSTS: DESCRIPTION UNIT COST QTY UNIT TOTAL Inspection 1 LS $ 10,000 $ Monitoring Groundwater Monitoring, Sampling, and Reporting 0 LS $ - $ - $ 10,000 SUBTOTAL Contingency 30% $ SUBTOTAL Project Management Technical Support 5% 10% TOTAL ANNUAL O&M COSTS NOTES 10,000 5 days Included in containment alternative 3,000 10% scope + 20% bid $ 13,000 $ $ 700 1,300 $ 15,000 PERIODIC COSTS: DESCRIPTION YEAR Enhanced In Situ Bioremediation (ISB) Injection Event 4 8 Injection Event 5 10 Injection Event 6 12 Injection Event 7 14 Injection Event 8 16 Injection Event 9 18 Well Abandonment 19 QTY UNIT 1 1 1 1 1 1 1 EA EA EA EA EA EA EA UNIT COST $ $ $ $ $ $ $ 14,019,723 14,019,723 14,019,723 8,791,377 8,791,377 8,791,377 225,000 TOTAL $ $ $ $ $ $ $ 14,019,723 14,019,723 14,019,723 8,791,377 8,791,377 8,791,377 225,000 NOTES See Cost Worksheet M-11 See Cost Worksheet M-11 See Cost Worksheet M-11 See Cost Worksheet M-12 See Cost Worksheet M-12 See Cost Worksheet M-12 Estimate VOC Mass Removal Alternative M9 SHALLOW SOIL TREATMENT BY ERH/SVE AND SHALLOW/DEEP GROUNDWATER/SOIL TREATMENT BY ISCO/ISB Site: Location: Phase: Base Year: Date: "Occidental" Site Description: Tacoma, Washington Feasibility Study (-30% to +50%) - 1.5% 2016 December 8, 2016 COST ESTIMATE SUMMARY M9 Mass Reduction Alternative M9 was designed to further reduce, by in situ treatment, TCVOC concentrations in deep groundwater and in deep soil potentially containing DNAPL (PTW) that could be a future source of contamination in soil and groundwater. The M9 alternative includes the M8 alternative plus ISCO and ISB to treat deep groundwater and soil below -60 ft NGVD containing TCVOC concentrations greater than 10 mg/L within the zone where pH is between 10 s.u. and 12.5 s.u. (ISCO) and within the zone where pH is less than 10 s.u. (ISB). Assume soil cuttings are placed under PDCE Barrier. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. PRESENT VALUE ANALYSIS: COST TYPE Capital Cost Annual O&M Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost Periodic Cost YEAR 0 1-19 8 10 12 14 16 18 19 $ $ $ $ $ $ $ $ $ TOTAL COST 316,180,700 285,000 14,019,723 14,019,723 14,019,723 8,791,377 8,791,377 8,791,377 225,000 $385,124,000 TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST PER YEAR $ 316,180,700 $ 15,000 $ 14,019,723 $ 14,019,723 $ 14,019,723 $ 8,791,377 $ 8,791,377 $ 8,791,377 $ 225,000 DISCOUNT FACTOR (1.5%) 1 16.43 0.888 0.862 0.836 0.812 0.788 0.765 0.754 $ $ $ $ $ $ $ $ $ PRESENT VALUE 316,180,700 246,400 12,445,470 12,080,340 11,725,920 7,137,280 6,927,880 6,724,630 169,570 $ 373,638,190 $ 373,638,190 NOTES 19 Years Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB Injection Event for ISB VOC Mass Removal/Reduction Alternatives M100, M150, and M200 Capital Cost Sub-Element GROUNDWATER EXTRACTION WELLS AND CONVEYANCE Site: Location: Phase: Base Year: COST WORKSHEET M-1 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Install two six-inch diameter groundwater extraction wells, well vaults, and forcemain. Installation includes drilling subcontractor, well materials including twenty-foot screens, pumps, piping, conduit, electrical hookup, asphalt removal/disposal and restoration. Assumes system will be constructed with a containment system GWETS. Cost analysis: Costs for major equipment, preparation, and Installation. DESCRIPTION Well Installation Mobilization/Demobilization Wells Installation (-45 ft NGVD) Well Installation (-70 ft NGVD) Drilling Oversight Surveyor Pumps Wiring Well Development @ 8 hours each Well Vaults (3' x 4' x 4') w/HD 20 Cover Asphalt Removal (Assume 6") Asphalt Disposal Excavation Sand Fill Aggregate Fill Asphalt Replacement SUBTOTAL Piping/Electrical Electrical Power Allowance Piping (HDPE) Electrical Conduit (2.0") Electrical Pull Boxes Hydro-Test Piping SUBTOTAL QTY UNIT LABOR 1 1 1 7 0 2 2 16 2 167 22 156 56 100 22 LS EA EA DAY LS EA EA HR EA SY TN CY CY CY TN incl. incl. 1,920 20,000 250 10 incl. 9 30 35 105 0 300 300 1 0 LS LF LF EA LOT 35,000 - EQUIP 30,900 34,500 2,800 1,800 3,500 incl. - 4 12 315 2,500 MTRL - UNIT TOTAL TOTAL - 5,125 30,900 34,500 1,920 20,000 2,800 1,800 250 3,500 10 260 9 30 35 105 5,125 30,900 34,500 13,440 5,600 3,600 4,000 7,000 1,583 5,720 1,322 1,653 3,500 2,333 120,280 Driller invoice 6 inch well; Driller Invoice 6 inch well; Driller Invoice One drill rig operating Included with containment Vendor pricing GHD Estimate GHD Estimate Vendor pricing GHD Estimate Vendor pricing GHD Estimate GHD Estimate GHD Estimate GHD Estimate - 35,000 4 12 315 2,500 1,106 3,600 315 5,020 Included with containment Vendor pricing Vendor pricing Vendor pricing Included with containment incl. incl. Prime Contractor Overhead SUBTOTAL 15% 6,200 131,500 Prime Contractor Profit 10% 4,750 TOTAL UNIT COST $ 136,250 Source of Cost Data: Estimate from GHD Construction Division ( April 27, 2016) and Drilling Contractor Previous Invoices for Site Work (2013) Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-1 NOTES: Assume Level D 2016 Based on local pricing Not included in unit prices except for well construction and oversight Not included in unit prices except for well construction and oversight VOC Mass Removal/Reduction Alternatives M100, M150, and M200 Maintenance Cost Sub-Element EQUIPMENT REPLACEMENT COST - EXTRACTION PUMPS Site: Location: Phase: Base Year: COST WORKSHEET M-2 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/12/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Replace pumps in extraction wells. Cost analysis: Costs for major equipment. DESCRIPTION 5 Year Replacement: EXT-22d Pump EXT-23s Pump SUBTOTAL QTY UNIT 1 1 EA EA LABOR - EQUIP 2,800 2,800 MTRL - UNIT TOTAL TOTAL 2800 2800 2800 2800 5600 Prime Contractor Overhead SUBTOTAL 15% 840 6,440 Prime Contractor Profit 10% 640 TOTAL UNIT COST $ Source of Cost Data: Estimate from Gary Pritchard, GHD Process Engineer, April 18, 2016 Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-2 NOTES: Assume Level D 2016 Based on local pricing Added Added 7,080 VOC Mass Removal/Reduction Alternatives M8 and M9 Capital Cost Sub-Element INJECTION WELL - SHALLOW Site: Location: Phase: Base Year: COST WORKSHEET M-3 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Install an injection well in the shallow impacted zone to a depth of approximately -60 ft NGVD (approximately 75 ft bgs). The well would be 4-inch diameter PVC, Schedule 40. In the injection zone a No. 10 slot 5-foot long screen would be alternated with a 5-foot long length of casing. Bentonite chips would be placed in between each screened interval. Cost analysis: Costs per injection well. DESCRIPTION Mobilization/Demobilization Setup/Decontamination/Clearance PPE Drill Well Install -4" PVC Flush Mount Casing Development IDW Handling SUBTOTAL QTY 1 1.5 1.5 75 75 1 8 1.5 UNIT LS HR DAY FEET FEET EA HR HR LABOR 255 45 incl. incl. 250 300 EQUIP incl. incl. incl. incl. - MTRL 35 15 550 - UNIT TOTAL 140 255 35 45 15 550 250 300 TOTAL 140 % mob/demob for wells 383 53 3375 1125 550 2000 450 8075 Prime Contractor Overhead SUBTOTAL 0% 0 8075 Prime Contractor Profit 0% 0 TOTAL UNIT COST $ Source of Cost Data: Estimate from Drilling Contractor Previous Invoices for Site Work (2013) Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-3 NOTES: Assume Level D 2016 Based on local pricing Included in unit pricing Included in unit pricing 8,075 VOC Mass Removal/Reduction Alternatives M8 and M9 Capital Cost Sub-Element INJECTION WELL - DEEP Site: Location: Phase: Base Year: COST WORKSHEET M-4 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Install an injection well in the deep impacted zone to a depth of approximately -150 ft NGVD (approximately 165 ft bgs). The well would be 4-inch diameter PVC, Schedule 40. In the injection zone a No. 10 slot 5-foot long screen would be alternated with a 5-foot long length of casing. Bentonite chips would be placed in between each screened interval. Cost analysis: Costs per injection well. DESCRIPTION Mobilization/Demobilization Setup/Decontamination/Clearance PPE Drill Well Install -4" PVC Flush Mount Casing Development IDW Handling SUBTOTAL QTY 1 1.5 2.5 170 170 1 8 1.5 UNIT LS HR DAY FEET FEET EA HR HR LABOR 255 45 incl. incl. 250 300 EQUIP incl. incl. incl. incl. - MTRL 35 15 550 - UNIT TOTAL 140 255 35 45 15 550 250 300 TOTAL 140 % mob/demob for wells 383 88 7650 2550 550 2000 450 13810 Prime Contractor Overhead SUBTOTAL 0% 0 13810 Prime Contractor Profit 0% 0 TOTAL UNIT COST $ Source of Cost Data: Estimate from Drilling Contractor Previous Invoices for Site Work (2013) Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-4 NOTES: Assume Level D 2016 Based on local pricing Included in unit pricing Included in unit pricing 13,810 VOC Mass Removal/Reduction Alternatives M8 and M9 Capital Cost Sub-Element IN SITU CHEMICAL OXIDATION (ISCO) INJECTION - SHALLOW Site: Location: Phase: Base Year: COST WORKSHEET M-5 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Injection of alkaline persulfate. This cost sheet includes the shallow target zone. Cost analysis: Costs per ISCO treatment event. DESCRIPTION Mobilization/Demobilization Equipment (tubing, pumps, ) Reagent (alkaline persulfate) Injection Labor Waste Management SUBTOTAL QTY 1 1 62038 170 1% UNIT LS LS CY DAYS % LABOR 3000 - EQUIP - MTRL 15 - UNIT TOTAL 50000 25000 15 3000 1515570 TOTAL 50000 25000 930570 510000 15160 1530730 Prime Contractor Overhead SUBTOTAL 15% 229610 1760340 Prime Contractor Profit 10% 176030 TOTAL UNIT COST $1,936,370 ` Source of Cost Data: Estimate Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-5 NOTES: Assume Level D 2016 Based on general pricing Added Added Assumption 15 lbs/cy 1/2 day/well; 340 Wells 1% of injection costs VOC Mass Removal/Reduction Alternatives M8 and M9 Capital Cost Sub-Element ENHANCED IN SITU BIOREMEDIATION (ISB) INJECTION - SHALLOW Site: Location: Phase: Base Year: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 COST WORKSHEET M-6 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Injection of substrate, DHC, and enhancements at a rate of 100 percent of the original dosage in years 2, 4, 6. This cost sheet includes the shallow target zone. Cost analysis: Costs per ISB treatment event. DESCRIPTION Mobilization/Demobilization Equipment (tubing, pumps, etc.) Substrate (emulsified veg. oil) DHC and Enhancements Injection - field techs Waste Management SUBTOTAL QTY 1 1 428766 428766 280 1% UNIT LS LS CY CY DAYS % LABOR 3000 - EQUIP - MTRL 6 10 - UNIT TOTAL 50000 25000 6 10 3000 7775256 TOTAL 50000 25000 2572596 4287660 840000 77753 7853010 Prime Contractor Overhead SUBTOTAL 15% 1177950 9030960 Prime Contractor Profit 10% 903100 TOTAL UNIT COST $9,934,060 Source of Cost Data: Estimate Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-6 NOTES: Assume Level D 2016 Based on general pricing Added Added Assumption 3 lbs per CY 1 dose per CY 1 day/well; 280 Wells 1% of injection costs VOC Mass Removal/Reduction Alternatives M8 and M9 Capital Cost Sub-Element ENHANCED IN SITU BIOREMEDIATION (ISB) INJECTION - SHALLOW Site: Location: Phase: Base Year: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 COST WORKSHEET M-7 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Injection of substrate, DHC, and enhancements at a rate of 50 percent of the original dosage in years 8, 10, 12 because of anticipated mass reduction. This cost sheet includes the shallow target zone. Cost analysis: Costs per ISB treatment event. DESCRIPTION Mobilization/Demobilization Equipment (tubing, pumps, etc.) Substrate (emulsified veg. oil) DHC and Enhancements Injection - field techs Waste Management SUBTOTAL QTY 1 1 428766 428766 280 1% UNIT LS LS CY CY DAYS % LABOR 3000 - EQUIP - MTRL 3 5 - UNIT TOTAL 50000 25000 3 5 3000 4345128 TOTAL 50000 25000 1286298 2143830 840000 43451 4388580 Prime Contractor Overhead SUBTOTAL 15% 658290 5046870 Prime Contractor Profit 10% 504690 TOTAL UNIT COST $5,551,560 Source of Cost Data: Estimate Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-7 NOTES: Assume Level D 2016 Based on general pricing Added Added Assumption 1.5 lbs per CY 1/2 dose per CY 1 day/well; 280 Wells 1% of injection costs VOC Mass Removal/Reduction Alternatives M8 and M9 Capital Cost Sub-Element ENHANCED IN SITU BIOREMEDIATION (ISB) INJECTION - SHALLOW Site: Location: Phase: Base Year: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 COST WORKSHEET M-8 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Injection of substrate, DHC, and enhancements at a rate of 25 percent of the original dosage in years 14, 16, 18 because of anticipated mass reduction. This cost sheet includes the shallow target zone. Cost analysis: Costs per ISB treatment event. DESCRIPTION Mobilization/Demobilization Equipment (tubing, pumps, etc.) Substrate (emulsified veg. oil) DHC and Enhancements Injection - field techs Waste Management SUBTOTAL QTY 1 1 428766 428766 280 1% UNIT LS LS CY CY DAYS % LABOR 3000 - EQUIP - MTRL 1.5 3 - UNIT TOTAL 50000 25000 1.5 3 3000 2630064 TOTAL 50000 25000 643149 1071915 840000 26301 2656360 Prime Contractor Overhead SUBTOTAL 15% 398450 3054810 Prime Contractor Profit 10% 305480 TOTAL UNIT COST $3,360,290 Source of Cost Data: Estimate Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-8 NOTES: Assume Level D 2016 Based on general pricing Added Added Assumption 0.75 lbs per CY 1/4 dose per CY 1 day/well; 280 Wells 1% of injection costs VOC Mass Removal/Reduction Alternative M9 Capital Cost Sub-Element IN SITU CHEMICAL OXIDATION (ISCO) INJECTION - DEEP Site: Location: Phase: Base Year: COST WORKSHEET M-9 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Injection of alkaline persulfate. This cost sheet includes the deep target zone. Cost analysis: Costs per ISCO treatment event. DESCRIPTION Mobilization/Demobilization Equipment (tubing, pumps, ) Reagent (alkaline persulfate) Injection Labor Waste Management SUBTOTAL QTY 1 1 350820 680 1.5% UNIT LS LS CY DAYS % LABOR 3000 - EQUIP - MTRL 15 - UNIT TOTAL 50000 25000 15 3000 7377300 TOTAL 50000 25000 5262300 2040000 110660 7487960 Prime Contractor Overhead SUBTOTAL 15% 1123190 8611150 Prime Contractor Profit 10% 861120 TOTAL UNIT COST $9,472,270 ` Source of Cost Data: Estimate Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-9 NOTES: Assume Level D 2016 Based on general pricing Added Added Assumption 15 lbs/cy 1/2 day/well; 1360 Wells 1.5% of injection costs VOC Mass Removal/Reduction Alternative M9 Capital Cost Sub-Element ENHANCED IN SITU BIOREMEDIATION (ISB) INJECTION - DEEP Site: Location: Phase: Base Year: COST WORKSHEET M-10 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Injection of substrate, DHC, and enhancements at a rate of 100 percent of the original dosage in years 2, 4, 6. This cost sheet includes the deep target zone. Cost analysis: Costs per ISB treatment event. DESCRIPTION Mobilization/Demobilization Equipment (tubing, pumps, etc.) Substrate (emulsified veg. oil) DHC and Enhancements Injection - field techs Waste Management SUBTOTAL QTY 1 1 1018000 1018000 900 1.5% UNIT LS LS CY CY DAYS % LABOR 3000 - EQUIP - MTRL 6 10 - UNIT TOTAL 50000 25000 6 10 3000 19063000 TOTAL 50000 25000 6108000 10180000 2700000 285945 19348945 Prime Contractor Overhead SUBTOTAL 15% 2902342 22251287 Prime Contractor Profit 10% 2225129 TOTAL UNIT COST $24,476,415 Source of Cost Data: Estimate Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-10 NOTES: Assume Level D 2016 Based on general pricing Added Added Assumption 3 lbs per CY 1 dose per CY 2 days/well; 450 Wells 1.5% of injection costs VOC Mass Removal/Reduction Alternative M9 Capital Cost Sub-Element ENHANCED IN SITU BIOREMEDIATION (ISB) INJECTION - DEEP Site: Location: Phase: Base Year: COST WORKSHEET M-11 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Injection of substrate, DHC, and enhancements at a rate of 50 percent of the original dosage in years 8, 10, 12 because of anticipated mass reduction. This cost sheet includes the deep target zone. Cost analysis: Costs per ISB treatment event. DESCRIPTION Mobilization/Demobilization Equipment (tubing, pumps, etc.) Substrate (emulsified veg. oil) DHC and Enhancements Injection - field techs Waste Management SUBTOTAL QTY 1 1 1018000 1018000 900 1.5% UNIT LS LS CY CY DAYS % LABOR 3000 - EQUIP - MTRL 3 5 - UNIT TOTAL 50000 25000 3 5 3000 10919000 TOTAL 50000 25000 3054000 5090000 2700000 163785 11082785 Prime Contractor Overhead SUBTOTAL 15% 1662418 12745203 Prime Contractor Profit 10% 1274520 TOTAL UNIT COST $14,019,723 Source of Cost Data: Estimate Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-11 NOTES: Assume Level D 2016 Based on general pricing Added Added Assumption 1.5 lbs per CY 1/2 dose per CY 2 days/well; 450 Wells 1.5% of injection costs VOC Mass Removal/Reduction Alternative M9 Capital Cost Sub-Element ENHANCED IN SITU BIOREMEDIATION (ISB) INJECTION - DEEP Site: Location: Phase: Base Year: COST WORKSHEET M-12 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 6/2/2016 Checked By: RJH Date: 12/6/2016 Work Statement: Injection of substrate, DHC, and enhancements at a rate of 25 percent of the original dosage in years 14, 16, 18 because of anticipated mass reduction. This cost sheet includes the deep target zone. Cost analysis: Costs per ISB treatment event. DESCRIPTION Mobilization/Demobilization Equipment (tubing, pumps, etc.) Substrate (emulsified veg. oil) DHC and Enhancements Injection - field techs Waste Management SUBTOTAL QTY 1 1 1018000 1018000 900 1.5% UNIT LS LS CY CY DAYS % LABOR 3000 - EQUIP - MTRL 1.5 3 - UNIT TOTAL 50000 25000 1.5 3 3000 6847000 TOTAL 50000 25000 1527000 2545000 2700000 102705 6949705 Prime Contractor Overhead SUBTOTAL 15% 1042456 7992161 Prime Contractor Profit 10% 799216 TOTAL UNIT COST $8,791,377 Source of Cost Data: Estimate Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-12 NOTES: Assume Level D 2016 Based on general pricing Added Added Assumption 0.75 lbs per CY 1/4 dose per CY 2 days/well; 450 Wells 1.5% of injection costs VOC Mass Reduction Alternative MSP Capital Cost Sub-Element EXTRACTION WELLS AND CONVEYANCES Site: Location: Phase: Base Year: COST WORKSHEET M-13 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 11/21/2016 Checked By: RJH Date: 12/8/2016 Work Statement: The work includes groundwater extraction wells, pumps, well vaults, forcemains, electrical conduit, etc. to extract and convey groundwater to the treatment system. Cost analysis: Costs for equipment, preparation, and installation. DESCRIPTION Well Installation Mobilization/Demobilization Wells Installation (-18.75 ft NGVD) Wells Installation (-36.25 ft NGVD) Wells Installation (-38.75 ft NGVD) Wells Installation (-76.25 ft NGVD) Wells Installation (-120 ft NGVD) Wells Installation (-123.75 ft NGVD) Well Installation (-141.25 ft NGVD) Well Installation (-153.75 ft NGVD) Drilling Oversight Surveyor Pumps Wiring Well Development @ 8 hours each Well Vaults (3' x 4' x 4') w/HD 20 Cover Asphalt Removal (Assume 6") Asphalt Disposal Excavation Sand Fill Aggregate Fill Asphalt Replacement SUBTOTAL Piping/Electrical Electrical Power Allowance Piping (HDPE) Electrical Conduit (2.0") Electrical Pull Boxes Hydro-Test Piping SUBTOTAL QTY UNIT LABOR EQUIP 1 1 2 1 1 3 1 1 1 44 1 11 11 88 11 2000 260 2250 1850 400 550 LS EA EA EA EA EA EA EA EA DAY LS EA EA HR EA SY TN CY CY CY TN incl. incl. incl. incl. incl. incl. incl. incl. 1,920 20,000 250 10 incl. 9 30 35 105 27,200 29,700 30,100 35,400 41,700 42,300 44,800 46,600 1,736 1,800 incl. 3,500 incl. incl. incl. incl. incl. 1 3600 3500 12 1 LS LF LF EA LS 35,000 incl. incl. incl. 2,500 incl. incl. incl. incl. incl. MTRL - UNIT TOTAL TOTAL incl. incl. incl. 44,800 27,200 29,700 30,100 35,400 41,700 42,300 44,800 46,600 1,920 20,000 1,736 1,800 250 3,500 10 9 30 35 105 44,800 27,200 59,400 30,100 35,400 125,100 42,300 44,800 46,600 84,480 20,000 19,100 19,800 22,000 38,500 19,000 19,125 55,038 14,000 57,750 824,490 incl. 5.75 12 315 - 35,000 6 12 315 2,500 35,000 20,700 42,000 3,780 2,500 103,980 incl. incl. incl. incl. incl. incl. incl. incl. incl. - Prime Contractor Overhead SUBTOTAL 15% 58,244 986,714 Prime Contractor Profit 10% 44,650 TOTAL UNIT COST $1,031,360 Source of Cost Data: Estimate from GHD Construction Division ( April 27, 2016) and Drilling Contractor Previous Invoices for Site Work (2013) Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-13 NOTES: Assume Level D 2016 Based on general pricing Not included in unit prices except for well construction and oversight Not included in unit prices except for well construction and oversight Driller Invoice 6 inch well - Driller Invoice 6 inch well - Driller Invoice 6 inch well - Driller Invoice 6 inch well - Driller Invoice 6 inch well - Driller Invoice 6 inch well - Driller Invoice 6 inch well - Driller Invoice 6 inch well - Driller Invoice Two drill rigs operating VOC Mass Reduction Alternative MSP O&M Sub-Element TREATMENT SYSTEM EQUIPMENT - 300 GPM SYSTEM Site: Location: Phase: Base Year: COST WORKSHEET M-14 "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 11/21/2016 Checked By: RJH Date: 12/8/2016 Work Statement: This work sheet includes equipment replacement costs based on typical product lives. Cost analysis: Costs for equipment, preparation, and installation. DESCRIPTION 5 Year Replacement MR1 - Pump MR2 - Pump MR3 - Pump NW1 - Pump NW2 - Pump NW3 - Pump NW4 - Pump NW5 - Pump NW6 - Pump NW7 - Pump NW8 - Pump SUBTOTAL QTY UNIT LABOR 1 1 1 1 1 1 1 1 1 1 1 EA EA EA EA EA EA EA EA EA EA EA 15 Year Replacement Inclined Plate Clarifier Air Stripper Blower Regenerative Thermal Oxidizer Package Air Compressor Compressed Air Desiccant Dryer Clarifier Feed Pump Air Stripper Transfer Pump Building Sump Pump Clarifier Bottoms Pump Dirty Backwash Recycle Pump Coagulant Metering Pump Polymer Metering / Blending Unit Sequestering Agent Metering Pump Equalization Tank Clarifier Sludge Tank Dirty Backwash Tank Effluent Tank Add metal tanks higher grade lining Add tanks high seismic zone - extra 10% SUBTOTAL 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10 LS LS LS LS LS EA EA EA EA EA LS LS LS EA EA EA EA LS % incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. 20 Year Replacement Filter Press Multimedia Filter Skid Cartridge Filter Skid Carbon Filters (2 vessels) Sand Filter Feed Pump Sand Filter Backwash Pump Filter Press Sludge Pump Filter Feed Tank SUBTOTAL 1 1 1 1 1 1 1 1 LS LS LS LS EA EA EA EA incl. incl. incl. incl. incl. incl. incl. incl. EQUIP MTRL - 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. incl. - 260,000 83,440 900,200 14,600 5,483 18,280 22,356 2,563 1,941 1,941 2,000 15,000 2,000 39,371 25,096 47,081 16,469 11,155 158,372 208,000 180,000 13,429 300,000 22,356 24,243 2,561 19,200 incl. incl. incl. incl. incl. incl. incl. incl. UNIT TOTAL TOTAL - 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 1,736 19,100 - 260,000 83,440 900,200 14,600 5,483 18,280 22,356 2,563 1,941 1,941 2,000 15,000 2,000 39,371 25,096 47,081 16,469 11,155 158,372 260,000 83,440 900,200 14,600 5,483 18,280 22,356 2,563 1,941 1,941 2,000 15,000 2,000 39,371 25,096 47,081 16,469 11,155 15,837 1,484,810 208,000 180,000 13,429 300,000 22,356 24,243 2,561 19,200 208,000 180,000 13,429 300,000 22,356 24,243 2,561 19,200 769,790 Prime Contractor Overhead SUBTOTAL 15% 2,865 2,276,565 Prime Contractor Profit 10% 1,910 TOTAL UNIT COST Source of Cost Data: Estimate from Gary Pritchard, GHD Process Engineer, April 29, 2016 $2,278,480 VOC Mass Reduction Alternative MSP O&M Sub-Element TREATMENT SYSTEM EQUIPMENT - 300 GPM SYSTEM Site: Location: Phase: Base Year: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 COST WORKSHEET M-14 Prepared By: AW Date: 11/21/2016 Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet M-14 NOTES: Assume Level D 2016 Based on general pricing Included in unit pricing except pumps Included in unit pricing except pumps Checked By: RJH Date: 12/8/2016 VOC Mass Alternative M100 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 7.0% Discount Rate Cost $ 202,950 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 COST ESTIMATE SUMMARY M100 100-Year Cash Flow Projection at 7 percent Discount Rate 1.000 0.935 0.873 0.816 0.763 0.713 0.713 0.666 0.623 0.582 0.544 0.508 0.508 0.475 0.444 0.415 0.388 0.362 0.362 0.339 0.317 0.296 0.277 0.258 0.258 0.242 0.226 0.211 0.197 0.184 0.184 0.172 0.161 0.150 0.141 0.131 0.131 0.123 0.115 0.107 0.100 0.094 0.094 0.088 0.082 0.076 0.071 0.067 0.067 0.062 0.058 0.055 0.051 0.048 0.048 0.044 0.042 0.039 0.036 0.034 0.034 0.032 0.030 0.028 0.026 0.024 0.024 0.023 0.021 0.020 0.018 0.017 0.017 0.016 0.015 0.014 0.013 0.012 0.012 0.011 0.011 0.010 0.009 0.009 0.009 Present Value $ 202,950 $ 65,421 $ 61,141 $ 57,141 $ 53,403 $ 49,909 $ 5,048 $ 46,644 $ 43,592 $ 40,741 $ 38,075 $ 35,584 $ 3,599 $ 33,256 $ 31,081 $ 29,048 $ 27,147 $ 25,371 $ 2,566 $ 23,711 $ 22,160 $ 20,710 $ 19,356 $ 18,089 $ 1,830 $ 16,906 $ 15,800 $ 14,766 $ 13,800 $ 12,897 $ 1,304 $ 12,054 $ 11,265 $ 10,528 $ 9,839 $ 9,196 $ 930 $ 8,594 $ 8,032 $ 7,506 $ 7,015 $ 6,556 $ 663 $ 6,127 $ 5,727 $ 5,352 $ 5,002 $ 4,675 $ 473 $ 4,369 $ 4,083 $ 3,816 $ 3,566 $ 3,333 $ 337 $ 3,115 $ 2,911 $ 2,721 $ 2,543 $ 2,376 $ 240 $ 2,221 $ 2,076 $ 1,940 $ 1,813 $ 1,694 $ 171 $ 1,583 $ 1,480 $ 1,383 $ 1,293 $ 1,208 $ 122 $ 1,129 $ 1,055 $ 986 $ 922 $ 861 $ 87 $ 805 $ 752 $ 703 $ 657 $ 614 $ 62 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M100 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Annual O&M Costs 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs 85 Annual O&M Costs 85 Periodic Costs Annual O&M Costs 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Periodic Costs 90 Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 Demolition Final Completion Report 100 TOTAL PRESENT VALUE OF ALTERNATIVE Description: 7.0% Discount Rate Cost $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 50,000 $ 5,000 $ 7,390,000 COST ESTIMATE SUMMARY M100 100-Year Cash Flow Projection at 7 percent Discount Rate 0.008 0.008 0.007 0.007 0.006 0.006 0.006 0.005 0.005 0.005 0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.001 Present Value $ 574 $ 536 $ 501 $ 468 $ 438 $ 44 $ 409 $ 382 $ 357 $ 334 $ 312 $ 32 $ 292 $ 273 $ 255 $ 238 $ 223 $ 23 $ 208 $ 194 $ 182 $ 170 $ 159 $ 16 $ 148 $ 139 $ 130 $ 121 $ 113 $ 11 $ 106 $ 99 $ 92 $ 86 $ 81 $ 58 $ 6 $ 1,220,000 $ 1,220,000 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M100 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 1.5% Discount Rate Cost $ 202,950 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 COST ESTIMATE SUMMARY M100 100-Year Cash Flow Projection at 1.5 percent Discount Rate 1.000 0.985 0.971 0.956 0.942 0.928 0.928 0.915 0.901 0.888 0.875 0.862 0.862 0.849 0.836 0.824 0.812 0.800 0.800 0.788 0.776 0.765 0.754 0.742 0.742 0.731 0.721 0.710 0.700 0.689 0.689 0.679 0.669 0.659 0.649 0.640 0.640 0.630 0.621 0.612 0.603 0.594 0.594 0.585 0.576 0.568 0.560 0.551 0.551 0.543 0.535 0.527 0.519 0.512 0.512 0.504 0.497 0.489 0.482 0.475 0.475 0.468 0.461 0.454 0.448 0.441 0.441 0.434 0.428 0.422 0.415 0.409 0.409 0.403 0.397 0.391 0.386 0.380 0.380 0.374 0.369 0.363 0.358 0.353 0.353 Present Value $ 202,950 $ 68,966 $ 67,946 $ 66,942 $ 65,953 $ 64,978 $ 6,572 $ 64,018 $ 63,072 $ 62,140 $ 61,221 $ 60,317 $ 6,101 $ 59,425 $ 58,547 $ 57,682 $ 56,829 $ 55,990 $ 5,663 $ 55,162 $ 54,347 $ 53,544 $ 52,753 $ 51,973 $ 5,257 $ 51,205 $ 50,448 $ 49,703 $ 48,968 $ 48,244 $ 4,880 $ 47,531 $ 46,829 $ 46,137 $ 45,455 $ 44,783 $ 4,530 $ 44,122 $ 43,470 $ 42,827 $ 42,194 $ 41,571 $ 4,205 $ 40,956 $ 40,351 $ 39,755 $ 39,167 $ 38,588 $ 3,903 $ 38,018 $ 37,456 $ 36,903 $ 36,357 $ 35,820 $ 3,623 $ 35,291 $ 34,769 $ 34,255 $ 33,749 $ 33,250 $ 3,363 $ 32,759 $ 32,275 $ 31,798 $ 31,328 $ 30,865 $ 3,122 $ 30,409 $ 29,959 $ 29,517 $ 29,080 $ 28,651 $ 2,898 $ 28,227 $ 27,810 $ 27,399 $ 26,994 $ 26,595 $ 2,690 $ 26,202 $ 25,815 $ 25,434 $ 25,058 $ 24,687 $ 2,497 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M100 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Annual O&M Costs 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs 85 Annual O&M Costs 85 Periodic Costs Annual O&M Costs 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Periodic Costs 90 Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition Final Completion Report 100 TOTAL PRESENT VALUE OF ALTERNATIVE Description: 1.5% Discount Rate Cost $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 7,080 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 70,000 $ 50,000 $ 5,000 $ 7,390,000 COST ESTIMATE SUMMARY M100 100-Year Cash Flow Projection at 1.5 percent Discount Rate 0.347 0.342 0.337 0.332 0.327 0.327 0.323 0.318 0.313 0.308 0.304 0.304 0.299 0.295 0.291 0.286 0.282 0.282 0.278 0.274 0.270 0.266 0.262 0.262 0.258 0.254 0.250 0.247 0.243 0.243 0.239 0.236 0.232 0.229 0.226 0.226 0.226 Present Value $ 24,323 $ 23,963 $ 23,609 $ 23,260 $ 22,916 $ 2,318 $ 22,578 $ 22,244 $ 21,915 $ 21,591 $ 21,272 $ 2,152 $ 20,958 $ 20,648 $ 20,343 $ 20,042 $ 19,746 $ 1,997 $ 19,454 $ 19,167 $ 18,884 $ 18,605 $ 18,330 $ 1,854 $ 18,059 $ 17,792 $ 17,529 $ 17,270 $ 17,015 $ 1,721 $ 16,763 $ 16,516 $ 16,271 $ 16,031 $ 15,794 $ 11,281 $ 1,128 $ 3,900,000 $ 3,900,000 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 7.0% Discount Rate Cost $ 202,950 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 COST ESTIMATE SUMMARY M150 100-Year Cash Flow Projection at 7 percent Discount Rate 1.000 0.935 0.873 0.816 0.763 0.713 0.713 0.666 0.623 0.582 0.544 0.508 0.508 0.475 0.444 0.415 0.388 0.362 0.362 0.339 0.317 0.296 0.277 0.258 0.258 0.242 0.226 0.211 0.197 0.184 0.184 0.172 0.161 0.150 0.141 0.131 0.131 0.123 0.115 0.107 0.100 0.094 0.094 0.088 0.082 0.076 0.071 0.067 0.067 0.062 0.058 0.055 0.051 0.048 0.048 0.044 0.042 0.039 0.036 0.034 0.034 0.032 0.030 0.028 0.026 0.024 0.024 0.023 0.021 0.020 0.018 0.017 0.017 0.016 0.015 0.014 0.013 0.012 0.012 0.011 0.011 0.010 0.009 0.009 0.009 Present Value $ 202,950 $ 95,271 $ 89,038 $ 83,213 $ 77,770 $ 72,682 $ 5,048 $ 67,927 $ 63,483 $ 59,330 $ 55,449 $ 51,821 $ 3,599 $ 48,431 $ 45,263 $ 42,301 $ 39,534 $ 36,948 $ 2,566 $ 34,531 $ 32,272 $ 30,160 $ 28,187 $ 26,343 $ 1,830 $ 24,620 $ 23,009 $ 21,504 $ 20,097 $ 18,782 $ 1,304 $ 17,554 $ 16,405 $ 15,332 $ 14,329 $ 13,392 $ 930 $ 12,515 $ 11,697 $ 10,932 $ 10,216 $ 9,548 $ 663 $ 8,923 $ 8,340 $ 7,794 $ 7,284 $ 6,808 $ 473 $ 6,362 $ 5,946 $ 5,557 $ 5,193 $ 4,854 $ 337 $ 4,536 $ 4,239 $ 3,962 $ 3,703 $ 3,461 $ 240 $ 3,234 $ 3,023 $ 2,825 $ 2,640 $ 2,467 $ 171 $ 2,306 $ 2,155 $ 2,014 $ 1,882 $ 1,759 $ 122 $ 1,644 $ 1,537 $ 1,436 $ 1,342 $ 1,254 $ 87 $ 1,172 $ 1,096 $ 1,024 $ 957 $ 894 $ 62 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Annual O&M Costs 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs 85 Annual O&M Costs 85 Periodic Costs Annual O&M Costs 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Periodic Costs 90 Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition Final Completion Report 100 TOTAL PRESENT VALUE OF ALTERNATIVE Description: 7.0% Discount Rate Cost $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 50,000 $ 5,000 $ 10,590,000 COST ESTIMATE SUMMARY M150 100-Year Cash Flow Projection at 7 percent Discount Rate 0.008 0.008 0.007 0.007 0.006 0.006 0.006 0.005 0.005 0.005 0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.001 Present Value $ 836 $ 781 $ 730 $ 682 $ 638 $ 44 $ 596 $ 557 $ 520 $ 486 $ 455 $ 32 $ 425 $ 397 $ 371 $ 347 $ 324 $ 23 $ 303 $ 283 $ 265 $ 247 $ 231 $ 16 $ 216 $ 202 $ 189 $ 176 $ 165 $ 11 $ 154 $ 144 $ 135 $ 126 $ 117 $ 58 $ 6 $ 1,680,000 $ 1,680,000 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 1.5% Discount Rate Cost $ 202,950 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 COST ESTIMATE SUMMARY M150 100-Year Cash Flow Projection at 1.5 percent Discount Rate 1.000 0.985 0.971 0.956 0.942 0.928 0.928 0.915 0.901 0.888 0.875 0.862 0.862 0.849 0.836 0.824 0.812 0.800 0.800 0.788 0.776 0.765 0.754 0.742 0.742 0.731 0.721 0.710 0.700 0.689 0.689 0.679 0.669 0.659 0.649 0.640 0.640 0.630 0.621 0.612 0.603 0.594 0.594 0.585 0.576 0.568 0.560 0.551 0.551 0.543 0.535 0.527 0.519 0.512 0.512 0.504 0.497 0.489 0.482 0.475 0.475 0.468 0.461 0.454 0.448 0.441 0.441 0.434 0.428 0.422 0.415 0.409 0.409 0.403 0.397 0.391 0.386 0.380 0.380 0.374 0.369 0.363 0.358 0.353 0.353 Present Value $ 202,950 $ 100,433 $ 98,949 $ 97,487 $ 96,046 $ 94,627 $ 6,572 $ 93,228 $ 91,851 $ 90,493 $ 89,156 $ 87,838 $ 6,101 $ 86,540 $ 85,261 $ 84,001 $ 82,760 $ 81,537 $ 5,663 $ 80,332 $ 79,145 $ 77,975 $ 76,823 $ 75,687 $ 5,257 $ 74,569 $ 73,467 $ 72,381 $ 71,312 $ 70,258 $ 4,880 $ 69,219 $ 68,196 $ 67,189 $ 66,196 $ 65,217 $ 4,530 $ 64,254 $ 63,304 $ 62,368 $ 61,447 $ 60,539 $ 4,205 $ 59,644 $ 58,763 $ 57,894 $ 57,039 $ 56,196 $ 3,903 $ 55,365 $ 54,547 $ 53,741 $ 52,947 $ 52,164 $ 3,623 $ 51,393 $ 50,634 $ 49,886 $ 49,148 $ 48,422 $ 3,363 $ 47,706 $ 47,001 $ 46,307 $ 45,622 $ 44,948 $ 3,122 $ 44,284 $ 43,629 $ 42,985 $ 42,349 $ 41,724 $ 2,898 $ 41,107 $ 40,500 $ 39,901 $ 39,311 $ 38,730 $ 2,690 $ 38,158 $ 37,594 $ 37,039 $ 36,491 $ 35,952 $ 2,497 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M150 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Annual O&M Costs 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs 85 Annual O&M Costs 85 Periodic Costs Annual O&M Costs 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Periodic Costs 90 Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition Final Completion Report 100 TOTAL PRESENT VALUE OF ALTERNATIVE Description: 1.5% Discount Rate Cost $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 7,080 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 101,940 $ 50,000 $ 5,000 $ 10,590,000 COST ESTIMATE SUMMARY M150 100-Year Cash Flow Projection at 1.5 percent Discount Rate 0.347 0.342 0.337 0.332 0.327 0.327 0.323 0.318 0.313 0.308 0.304 0.304 0.299 0.295 0.291 0.286 0.282 0.282 0.278 0.274 0.270 0.266 0.262 0.262 0.258 0.254 0.250 0.247 0.243 0.243 0.239 0.236 0.232 0.229 0.226 0.226 0.226 Present Value $ 35,421 $ 34,897 $ 34,381 $ 33,873 $ 33,373 $ 2,318 $ 32,880 $ 32,394 $ 31,915 $ 31,443 $ 30,979 $ 2,152 $ 30,521 $ 30,070 $ 29,625 $ 29,188 $ 28,756 $ 1,997 $ 28,331 $ 27,913 $ 27,500 $ 27,094 $ 26,693 $ 1,854 $ 26,299 $ 25,910 $ 25,527 $ 25,150 $ 24,778 $ 1,721 $ 24,412 $ 24,051 $ 23,696 $ 23,346 $ 23,001 $ 11,281 $ 1,128 $ 5,550,000 $ 5,550,000 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 7.0% Discount Rate Cost $ 202,950 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 COST ESTIMATE SUMMARY M200 100-Year Cash Flow Projection at 7 percent Discount Rate 1.000 0.935 0.873 0.816 0.763 0.713 0.713 0.666 0.623 0.582 0.544 0.508 0.508 0.475 0.444 0.415 0.388 0.362 0.362 0.339 0.317 0.296 0.277 0.258 0.258 0.242 0.226 0.211 0.197 0.184 0.184 0.172 0.161 0.150 0.141 0.131 0.131 0.123 0.115 0.107 0.100 0.094 0.094 0.088 0.082 0.076 0.071 0.067 0.067 0.062 0.058 0.055 0.051 0.048 0.048 0.044 0.042 0.039 0.036 0.034 0.034 0.032 0.030 0.028 0.026 0.024 0.024 0.023 0.021 0.020 0.018 0.017 0.017 0.016 0.015 0.014 0.013 0.012 0.012 0.011 0.011 0.010 0.009 0.009 0.009 Present Value $ 202,950 $ 124,935 $ 116,761 $ 109,123 $ 101,984 $ 95,312 $ 5,048 $ 89,077 $ 83,249 $ 77,803 $ 72,713 $ 67,956 $ 3,599 $ 63,510 $ 59,356 $ 55,472 $ 51,843 $ 48,452 $ 2,566 $ 45,282 $ 42,320 $ 39,551 $ 36,964 $ 34,545 $ 1,830 $ 32,285 $ 30,173 $ 28,199 $ 26,355 $ 24,630 $ 1,304 $ 23,019 $ 21,513 $ 20,106 $ 18,790 $ 17,561 $ 930 $ 16,412 $ 15,339 $ 14,335 $ 13,397 $ 12,521 $ 663 $ 11,702 $ 10,936 $ 10,221 $ 9,552 $ 8,927 $ 473 $ 8,343 $ 7,797 $ 7,287 $ 6,811 $ 6,365 $ 337 $ 5,949 $ 5,559 $ 5,196 $ 4,856 $ 4,538 $ 240 $ 4,241 $ 3,964 $ 3,704 $ 3,462 $ 3,236 $ 171 $ 3,024 $ 2,826 $ 2,641 $ 2,468 $ 2,307 $ 122 $ 2,156 $ 2,015 $ 1,883 $ 1,760 $ 1,645 $ 87 $ 1,537 $ 1,437 $ 1,343 $ 1,255 $ 1,173 $ 62 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Annual O&M Costs 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs 85 Annual O&M Costs 85 Periodic Costs Annual O&M Costs 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Periodic Costs 90 Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition Final Completion Report 100 TOTAL PRESENT VALUE OF ALTERNATIVE Description: 7.0% Discount Rate Cost $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 50,000 $ 5,000 $ 13,760,000 COST ESTIMATE SUMMARY M200 100-Year Cash Flow Projection at 7 percent Discount Rate 0.008 0.008 0.007 0.007 0.006 0.006 0.006 0.005 0.005 0.005 0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.001 Present Value $ 1,096 $ 1,024 $ 957 $ 895 $ 836 $ 44 $ 781 $ 730 $ 683 $ 638 $ 596 $ 32 $ 557 $ 521 $ 487 $ 455 $ 425 $ 23 $ 397 $ 371 $ 347 $ 324 $ 303 $ 16 $ 283 $ 265 $ 247 $ 231 $ 216 $ 11 $ 202 $ 189 $ 176 $ 165 $ 154 $ 58 $ 6 $ 2,130,000 $ 2,130,000 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 1.5% Discount Rate Cost $ 202,950 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 COST ESTIMATE SUMMARY M200 100-Year Cash Flow Projection at 1.5 percent Discount Rate 1.000 0.985 0.971 0.956 0.942 0.928 0.928 0.915 0.901 0.888 0.875 0.862 0.862 0.849 0.836 0.824 0.812 0.800 0.800 0.788 0.776 0.765 0.754 0.742 0.742 0.731 0.721 0.710 0.700 0.689 0.689 0.679 0.669 0.659 0.649 0.640 0.640 0.630 0.621 0.612 0.603 0.594 0.594 0.585 0.576 0.568 0.560 0.551 0.551 0.543 0.535 0.527 0.519 0.512 0.512 0.504 0.497 0.489 0.482 0.475 0.475 0.468 0.461 0.454 0.448 0.441 0.441 0.434 0.428 0.422 0.415 0.409 0.409 0.403 0.397 0.391 0.386 0.380 0.380 0.374 0.369 0.363 0.358 0.353 0.353 Present Value $ 202,950 $ 131,704 $ 129,758 $ 127,840 $ 125,951 $ 124,090 $ 6,572 $ 122,256 $ 120,449 $ 118,669 $ 116,915 $ 115,188 $ 6,101 $ 113,485 $ 111,808 $ 110,156 $ 108,528 $ 106,924 $ 5,663 $ 105,344 $ 103,787 $ 102,253 $ 100,742 $ 99,253 $ 5,257 $ 97,787 $ 96,342 $ 94,918 $ 93,515 $ 92,133 $ 4,880 $ 90,771 $ 89,430 $ 88,108 $ 86,806 $ 85,523 $ 4,530 $ 84,260 $ 83,014 $ 81,788 $ 80,579 $ 79,388 $ 4,205 $ 78,215 $ 77,059 $ 75,920 $ 74,798 $ 73,693 $ 3,903 $ 72,604 $ 71,531 $ 70,474 $ 69,432 $ 68,406 $ 3,623 $ 67,395 $ 66,399 $ 65,418 $ 64,451 $ 63,499 $ 3,363 $ 62,560 $ 61,636 $ 60,725 $ 59,827 $ 58,943 $ 3,122 $ 58,072 $ 57,214 $ 56,368 $ 55,535 $ 54,715 $ 2,898 $ 53,906 $ 53,109 $ 52,325 $ 51,551 $ 50,789 $ 2,690 $ 50,039 $ 49,299 $ 48,571 $ 47,853 $ 47,146 $ 2,497 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Alternative M200 GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs 75 Periodic Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 Annual O&M Costs 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs 85 Annual O&M Costs 85 Periodic Costs Annual O&M Costs 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 Periodic Costs 90 Annual O&M Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 Annual O&M Costs 100 100 GWTP Demolition Final Completion Report 100 TOTAL PRESENT VALUE OF ALTERNATIVE Description: 1.5% Discount Rate Cost $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 7,080 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 133,680 $ 50,000 $ 5,000 $ 13,760,000 COST ESTIMATE SUMMARY M200 100-Year Cash Flow Projection at 1.5 percent Discount Rate 0.347 0.342 0.337 0.332 0.327 0.327 0.323 0.318 0.313 0.308 0.304 0.304 0.299 0.295 0.291 0.286 0.282 0.282 0.278 0.274 0.270 0.266 0.262 0.262 0.258 0.254 0.250 0.247 0.243 0.243 0.239 0.236 0.232 0.229 0.226 0.226 0.226 Present Value $ 46,449 $ 45,763 $ 45,086 $ 44,420 $ 43,764 $ 2,318 $ 43,117 $ 42,480 $ 41,852 $ 41,233 $ 40,624 $ 2,152 $ 40,024 $ 39,432 $ 38,849 $ 38,275 $ 37,710 $ 1,997 $ 37,152 $ 36,603 $ 36,062 $ 35,529 $ 35,004 $ 1,854 $ 34,487 $ 33,977 $ 33,475 $ 32,981 $ 32,493 $ 1,721 $ 32,013 $ 31,540 $ 31,074 $ 30,615 $ 30,162 $ 11,281 $ 1,128 $ 7,190,000 $ 7,190,000 Notes Pump replacement Pump replacement Pump replacement Pump replacement Pump replacement VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 7.0% Discount Rate Cost $ 38,854,780 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 97,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 72,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 831,890 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 831,890 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 5,453,300 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 831,890 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 COST ESTIMATE SUMMARY MSP 100-Year Cash Flow Projection at 7 percent Discount Rate 1.000 0.935 0.873 0.816 0.763 0.713 0.713 0.666 0.623 0.582 0.544 0.508 0.508 0.475 0.444 0.415 0.388 0.362 0.362 0.339 0.317 0.296 0.277 0.258 0.258 0.242 0.226 0.211 0.197 0.184 0.184 0.172 0.161 0.150 0.141 0.131 0.131 0.123 0.115 0.107 0.100 0.094 0.094 0.088 0.082 0.076 0.071 0.067 0.067 0.062 0.058 0.055 0.051 0.048 0.048 0.044 0.042 0.039 0.036 0.034 0.034 0.034 0.032 0.030 0.028 0.026 0.024 0.024 0.023 0.021 0.020 0.018 0.017 0.017 0.016 0.015 0.014 0.013 0.012 0.012 0.011 0.011 0.010 0.009 0.009 0.009 Present Value $ 38,854,780 $ 1,131,009 $ 1,057,018 $ 987,867 $ 923,241 $ 862,842 $ 69,231 $ 806,394 $ 753,639 $ 704,336 $ 658,258 $ 615,194 $ 36,652 $ 574,948 $ 537,334 $ 502,182 $ 469,329 $ 438,625 $ 673,236 $ 409,930 $ 383,112 $ 358,049 $ 334,625 $ 312,734 $ 214,976 $ 292,274 $ 273,154 $ 255,284 $ 238,583 $ 222,975 $ 11,442 $ 208,388 $ 194,755 $ 182,014 $ 170,106 $ 158,978 $ 244,012 $ 148,577 $ 138,857 $ 129,773 $ 121,283 $ 113,349 $ 5,816 $ 105,934 $ 99,003 $ 92,527 $ 86,473 $ 80,816 $ 55,554 $ 75,529 $ 70,588 $ 65,970 $ 61,654 $ 57,621 $ 88,441 $ 53,851 $ 50,328 $ 47,036 $ 43,959 $ 41,083 $ 2,108 $ 185,127 $ 38,395 $ 35,883 $ 33,536 $ 31,342 $ 29,292 $ 1,503 $ 27,375 $ 25,584 $ 23,911 $ 22,346 $ 20,884 $ 14,356 $ 19,518 $ 18,241 $ 17,048 $ 15,933 $ 14,890 $ 764 $ 13,916 $ 13,006 $ 12,155 $ 11,360 $ 10,617 $ 545 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Repair sheet pile wall (50 percent of full install) 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs Periodic Costs 75 Annual O&M Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs 85 Annual O&M Costs Periodic Costs 85 Annual O&M Costs 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 90 Periodic Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Annual O&M Costs Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 100 Annual O&M Costs 100 GWTP Demolition 100 Final Completion Report TOTAL PRESENT VALUE OF ALTERNATIVE Description: 7.0% Discount Rate Cost $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 831,890 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,000,000 $ 100,000 $ 179,710,000 COST ESTIMATE SUMMARY MSP 100-Year Cash Flow Projection at 7 percent Discount Rate 0.008 0.008 0.007 0.007 0.006 0.006 0.006 0.005 0.005 0.005 0.004 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.001 Present Value $ 9,922 $ 9,273 $ 8,666 $ 8,099 $ 7,569 $ 11,618 $ 7,074 $ 6,611 $ 6,179 $ 5,775 $ 5,397 $ 3,710 $ 5,044 $ 4,714 $ 4,406 $ 4,117 $ 3,848 $ 197 $ 3,596 $ 3,361 $ 3,141 $ 2,936 $ 2,744 $ 4,211 $ 2,564 $ 2,396 $ 2,240 $ 2,093 $ 1,956 $ 100 $ 1,828 $ 1,709 $ 1,597 $ 1,492 $ 1,395 $ 1,152 $ 115 $ 57,750,000 $ 57,750,000 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 0 Capital Costs 1 Annual O&M Costs 2 Annual O&M Costs 3 Annual O&M Costs 4 Annual O&M Costs 5 Annual O&M Costs 5 Periodic Costs 6 Annual O&M Costs 7 Annual O&M Costs 8 Annual O&M Costs 9 Annual O&M Costs 10 Annual O&M Costs 10 Periodic Costs 11 Annual O&M Costs 12 Annual O&M Costs 13 Annual O&M Costs 14 Annual O&M Costs 15 Annual O&M Costs 15 Periodic Costs 16 Annual O&M Costs 17 Annual O&M Costs 18 Annual O&M Costs 19 Annual O&M Costs 20 Annual O&M Costs 20 Periodic Costs 21 Annual O&M Costs 22 Annual O&M Costs 23 Annual O&M Costs 24 Annual O&M Costs 25 Annual O&M Costs 25 Periodic Costs 26 Annual O&M Costs 27 Annual O&M Costs 28 Annual O&M Costs 29 Annual O&M Costs 30 Annual O&M Costs 30 Periodic Costs 31 Annual O&M Costs 32 Annual O&M Costs 33 Annual O&M Costs 34 Annual O&M Costs 35 Annual O&M Costs 35 Periodic Costs 36 Annual O&M Costs 37 Annual O&M Costs 38 Annual O&M Costs 39 Annual O&M Costs 40 Annual O&M Costs 40 Periodic Costs 41 Annual O&M Costs 42 Annual O&M Costs 43 Annual O&M Costs 44 Annual O&M Costs 45 Annual O&M Costs 45 Periodic Costs 46 Annual O&M Costs 47 Annual O&M Costs 48 Annual O&M Costs 49 Annual O&M Costs 50 Annual O&M Costs 50 Periodic Costs 50 Periodic Costs 51 Annual O&M Costs 52 Annual O&M Costs 53 Annual O&M Costs 54 Annual O&M Costs 55 Annual O&M Costs 55 Periodic Costs 56 Annual O&M Costs 57 Annual O&M Costs 58 Annual O&M Costs 59 Annual O&M Costs 60 Annual O&M Costs 60 Periodic Costs 61 Annual O&M Costs 62 Annual O&M Costs 63 Annual O&M Costs 64 Annual O&M Costs 65 Annual O&M Costs 65 Periodic Costs 66 Annual O&M Costs 67 Annual O&M Costs 68 Annual O&M Costs 69 Annual O&M Costs 70 Annual O&M Costs 70 Periodic Costs Description: 1.5% Discount Rate Cost $ 38,854,780 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 97,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 72,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 831,890 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 831,890 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 5,453,300 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 831,890 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 COST ESTIMATE SUMMARY MSP 100-Year Cash Flow Projection at 1.5 percent Discount Rate 1.000 0.985 0.971 0.956 0.942 0.928 0.928 0.915 0.901 0.888 0.875 0.862 0.862 0.849 0.836 0.824 0.812 0.800 0.800 0.788 0.776 0.765 0.754 0.742 0.742 0.731 0.721 0.710 0.700 0.689 0.689 0.679 0.669 0.659 0.649 0.640 0.640 0.630 0.621 0.612 0.603 0.594 0.594 0.585 0.576 0.568 0.560 0.551 0.551 0.543 0.535 0.527 0.519 0.512 0.512 0.504 0.497 0.489 0.482 0.475 0.475 0.475 0.468 0.461 0.454 0.448 0.441 0.441 0.434 0.428 0.422 0.415 0.409 0.409 0.403 0.397 0.391 0.386 0.380 0.380 0.374 0.369 0.363 0.358 0.353 0.353 Present Value $ 38,854,780 $ 1,192,296 $ 1,174,675 $ 1,157,316 $ 1,140,213 $ 1,123,362 $ 90,134 $ 1,106,761 $ 1,090,405 $ 1,074,290 $ 1,058,414 $ 1,042,772 $ 62,126 $ 1,027,362 $ 1,012,179 $ 997,221 $ 982,484 $ 967,964 $ 1,485,708 $ 953,659 $ 939,566 $ 925,681 $ 912,001 $ 898,523 $ 617,654 $ 885,244 $ 872,162 $ 859,273 $ 846,574 $ 834,063 $ 42,800 $ 821,737 $ 809,593 $ 797,629 $ 785,841 $ 774,228 $ 1,188,346 $ 762,786 $ 751,513 $ 740,407 $ 729,465 $ 718,685 $ 36,879 $ 708,064 $ 697,600 $ 687,291 $ 677,134 $ 667,127 $ 458,590 $ 657,268 $ 647,554 $ 637,985 $ 628,556 $ 619,267 $ 950,500 $ 610,115 $ 601,099 $ 592,216 $ 583,464 $ 574,841 $ 29,498 $ 2,590,343 $ 566,346 $ 557,976 $ 549,730 $ 541,606 $ 533,602 $ 27,382 $ 525,716 $ 517,947 $ 510,293 $ 502,752 $ 495,322 $ 340,489 $ 488,002 $ 480,790 $ 473,685 $ 466,684 $ 459,788 $ 23,594 $ 452,993 $ 446,298 $ 439,703 $ 433,205 $ 426,803 $ 21,901 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Repair sheet pile wall (50 percent of full install) 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs VOC Mass Reduction Alternative MSP GROUNDWATER EXTRACTION AND TREATMENT Site: "Occidental" Site Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 Base YR 2016 PRESENT VALUE ANALYSIS Year Cost Type 71 Annual O&M Costs 72 Annual O&M Costs 73 Annual O&M Costs 74 Annual O&M Costs 75 Annual O&M Costs Periodic Costs 75 Annual O&M Costs 76 Annual O&M Costs 77 Annual O&M Costs 78 Annual O&M Costs 79 Annual O&M Costs 80 80 Periodic Costs 81 Annual O&M Costs 82 Annual O&M Costs 83 Annual O&M Costs 84 Annual O&M Costs 85 Annual O&M Costs Periodic Costs 85 Annual O&M Costs 86 Annual O&M Costs 87 Annual O&M Costs 88 Annual O&M Costs 89 Annual O&M Costs 90 90 Periodic Costs 91 Annual O&M Costs 92 Annual O&M Costs 93 Annual O&M Costs 94 Annual O&M Costs 95 Annual O&M Costs Periodic Costs 95 Annual O&M Costs 96 Annual O&M Costs 97 Annual O&M Costs 98 Annual O&M Costs 99 100 Annual O&M Costs 100 GWTP Demolition 100 Final Completion Report TOTAL PRESENT VALUE OF ALTERNATIVE Description: 1.5% Discount Rate Cost $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 831,890 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,857,480 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 62,100 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,210,180 $ 1,000,000 $ 100,000 $ 179,710,000 COST ESTIMATE SUMMARY MSP 100-Year Cash Flow Projection at 1.5 percent Discount Rate 0.347 0.342 0.337 0.332 0.327 0.327 0.323 0.318 0.313 0.308 0.304 0.304 0.299 0.295 0.291 0.286 0.282 0.282 0.278 0.274 0.270 0.266 0.262 0.262 0.258 0.254 0.250 0.247 0.243 0.243 0.239 0.236 0.232 0.229 0.226 0.226 0.226 Present Value $ 420,495 $ 414,281 $ 408,159 $ 402,127 $ 396,184 $ 608,094 $ 390,329 $ 384,561 $ 378,877 $ 373,278 $ 367,762 $ 252,803 $ 362,327 $ 356,972 $ 351,697 $ 346,499 $ 341,379 $ 17,518 $ 336,334 $ 331,363 $ 326,466 $ 321,642 $ 316,888 $ 486,385 $ 312,205 $ 307,591 $ 303,046 $ 298,567 $ 294,155 $ 15,094 $ 289,808 $ 285,525 $ 281,305 $ 277,148 $ 273,052 $ 225,629 $ 22,563 $ 110,920,000 $ 110,920,000 Notes 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs 5 year review, update plan, and Repair Costs Appendix G-3 pH Alternatives Cost Estimates GHD Report for Glenn Springs Holdings, Inc. - Feasibility Study 007843 (139) COMPARISON OF TOTAL COST OF pH REMEDIAL ALTERNATIVES Site: Location: Phase: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) Base Year: Date: 2016 January 11, 2017 Alternative pH1 Alternative pH2 Alternative pH3 Alternative pH4 Alternative pH5 No Additional pH Reduction Mixing Enhanced Containment Mixing Enhanced Containment Slurry Wall Action Shallow Zone Shallow Zone 0 30 2 30 Capital Cost Annual O&M Cost $38,700,240 $1,180,644 Total Periodic Cost Total Present Value of Alternative (7%) Total Present Value of Alternative (1.5%) DESCRIPTION Total Project Duration without C150 (Years) Total Project Duration with C150 (Years) 07843(139)AppG - Summary Worksheet pH pH Reduction Mixing Shallow and Alternative pH6 Enhanced Containment Mixing Shallow and Alternative pH7 Enhanced Containment Slurry Wall Shallow and Shallow Zone Deep Zones Deep Zones Deep Zones 2 30 0.5 30 4 30 4 30 1.5 30 $91,895,240 $1,180,644 $55,682,540 $1,180,644 $41,086,040 $1,180,644 $174,488,040 $1,180,644 $101,386,040 $1,180,644 $50,548,440 $1,180,644 $2,920,670 $2,920,670 $2,920,670 $2,920,670 $2,920,670 $2,920,670 $2,920,670 $54,356,480 $69,352,840 $107,551,480 $122,547,840 $71,338,780 $86,335,140 $56,742,280 $71,738,640 $190,144,280 $205,140,640 $117,042,280 $132,038,640 $66,204,680 $81,201,040 pH Reduction Alternative pH2 pH REDUCTION BY SODIUM PERSULFATE MIXING Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY pH2 Reduce, by in situ treatment, pH >12.5 s.u. in shallow soil and groundwater that could be a future source of contamination in soil and groundwater. The pH2 alternative includes the following elements: Treatment using in situ mixing of sodium persulfate with shallow soil and groundwater above -60 ft NGVD containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT Bench Scale Testing 1 LS $50,000 Mobilization / Demobilization Equipment and Facilities H&S Plans and Submittals HASP Implementation Grading Erosion Controls Demobilization SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $250,000 $15,000 $984,620 $246,160 $738,470 $92,000 $250,000 $15,000 $984,620 $246,160 $738,470 $92,000 $2,326,300 Vendor quote Estimated (1) Estimated from vendor bids Estimated from vendor bids Estimated from vendor bids Estimated from vendor bids 14,400 226 28,430 37,410 29,930 29,930 29,930 29,930 29,930 12,570 17,870 SY CY CY CY CY CY CY CY CY CY CY $10 $32 $32 $32 $32 $32 $32 $32 $37 $32 $32 $136,800 $7,232 $909,760 $1,197,120 $957,760 $957,760 $957,760 $957,760 $1,107,410 $402,240 $571,840 $8,163,400 GHD Construction Division Estimate (1) Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote 8,140 511,810 3,591,640 2,873,320 2,873,320 2,873,320 2,873,320 2,873,320 63,260 1,715,470 LB LB LB LB LB LB LB LB LB LB $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $12,210 $767,720 $5,387,460 $4,309,980 $4,309,980 $4,309,980 $4,309,980 $4,309,980 $94,890 $2,573,210 $30,385,400 1 LS $25,000 Mixing Asphalt/debris Removal (6" thickness) Target Area pH2a (12 to 5ft NGVD) Target Area pH2b (12 to 2.5ft NGVD) Target Area pH2b (2.5 to -10ft NGVD) Target Area pH2b (-10 to -20ft NGVD) Target Area pH2b (-20 to -30ft NGVD) Target Area pH2b (-30 to -40ft NGVD) Target Area pH2b (-40 to -50ft NGVD) Target Area pH2b (-50 to -60ft NGVD) Target Area pH2c (12 to 2.5ft NGVD) Target Area pH2c (2.5 to -11ft NGVD) SUBTOTAL TOTAL NOTES $50,000 GHD Quote (2) Reagent (sodium persulfate) Target Area pH2a (12 to 5ft NGVD) (3) Target Area pH2b (12 to 2.5ft NGVD) Target Area pH2b (2.5 to -10ft NGVD) Target Area pH2b (-10 to -20ft NGVD) Target Area pH2b (-20 to -30ft NGVD) Target Area pH2b (-30 to -40ft NGVD) Target Area pH2b (-40 to -50ft NGVD) Target Area pH2b (-50 to -60ft NGVD) Target Area pH2c (12 to 2.5ft NGVD) Target Area pH2c (2.5 to -11ft NGVD) SUBTOTAL Field Sampling and Analysis SUBTOTAL Approximately 1.3% by weight and current market cost Approximately 1.3% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 1.3% by weight and current market cost Approximately 3.5% by weight and current market cost $25,000 Estimated (50 x 50 grid; approximately 50 boreholes) $40,950,100 Contingency 25% $10,237,500 10% scope + 15% bid SUBTOTAL $51,187,600 Project Management Remedial Design Construction Management 5% 8% 6% $528,300 Excludes reagent costs $845,200 Excludes reagent costs $633,900 Excludes reagent costs $53,195,000 TOTAL CAPITAL COSTS ANNUAL O&M COSTS: No annual O&M costs PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS COST TYPE Capital Cost Annual O&M Cost Periodic Cost YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (1.5%) PRESENT VALUE $53,195,000 $0 $0 $53,195,000 $53,195,000 $0 $0 1.000 - $53,195,000 $0 $0 $53,195,000 NOTES No annual O&M No periodic costs $53,195,000 Notes: (1) Vendor would not breakdown quote for mixing. Vendor quote is $40 to $70 per cubic yard. A typical breakdown of a mixing cost is provided in an associated Cost Worksheet pH-1 and is based on a bid for a different project. Vendor indicated that the price is expected to rise for depths greater than 65 feet. (2) Dosage (96 lbs/cy) based on pH pilot study to reduce average shallow groundwater pH = 13.036 s.u. by 0.536 s.u. Dosage (36 lbs/cy) based on pH pilot study to reduce average shallow soil pH = 12.742 s.u. by 0.242 s.u. ANC calculations suggest dosage rate could be approximately 1.9 times higher (96 lbs/cy compared to 184 lbs/cy). (3) Assume 50 percent of soil above water table has pH > 12.5 s.u. pH Enhanced Containment Alternative pH3 ENHANCED CONTAINMENT BY CEMENT MIXING Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY pH3 Contain, by in situ treatment, pH >12.5 s.u. in shallow soil and groundwater that could be a future source of contamination in soil and groundwater. The pH3 alternative includes the following elements: Treatment using in situ mixing of cement with shallow soil and groundwater above -60 ft NGVD containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT Bench Scale Testing 1 LS $50,000 Mobilization / Demobilization Equipment and Facilities H&S Plans and Submittals HASP Implementation Grading Erosion Controls Demobilization SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $250,000 $15,000 $984,620 $246,160 $738,470 $92,000 $250,000 $15,000 $984,620 $246,160 $738,470 $92,000 $2,326,300 Vendor quote Estimated (1) Estimated from vendor bids Estimated from vendor bids Estimated from vendor bids Estimated from vendor bids 14,400 226 28,430 37,410 29,930 29,930 29,930 29,930 29,930 12,570 17,870 SY CY CY CY CY CY CY CY CY CY CY $10 $32 $32 $32 $32 $32 $32 $32 $37 $32 $32 $136,800 $7,232 $909,760 $1,197,120 $957,760 $957,760 $957,760 $957,760 $1,107,410 $402,240 $571,840 $8,163,400 GHD Construction Division Estimate (1) Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote 36,160 2,274,710 5,986,070 4,788,860 4,788,860 4,788,860 4,788,860 4,788,860 281,150 2,859,120 LB LB LB LB LB LB LB LB LB LB $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $1,450 $90,990 $239,440 $191,550 $191,550 $191,550 $191,550 $191,550 $11,250 $114,360 $1,415,200 Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost 1 LS $25,000 Mixing Asphalt/debris Removal (6" thickness) Target Area pH2a (12 to 5ft NGVD) Target Area pH2b (12 to 2.5ft NGVD) Target Area pH2b (2.5 to -10ft NGVD) Target Area pH2b (-10 to -20ft NGVD) Target Area pH2b (-20 to -30ft NGVD) Target Area pH2b (-30 to -40ft NGVD) Target Area pH2b (-40 to -50ft NGVD) Target Area pH2b (-50 to -60ft NGVD) Target Area pH2c (12 to 2.5ft NGVD) Target Area pH2c (2.5 to -11ft NGVD) SUBTOTAL TOTAL NOTES $50,000 GHD Quote (2) Reagent (cement) Target Area pH2a (12 to 5ft NGVD) (3) Target Area pH2b (12 to 2.5ft NGVD) Target Area pH2b (2.5 to -10ft NGVD) Target Area pH2b (-10 to -20ft NGVD) Target Area pH2b (-20 to -30ft NGVD) Target Area pH2b (-30 to -40ft NGVD) Target Area pH2b (-40 to -50ft NGVD) Target Area pH2b (-50 to -60ft NGVD) Target Area pH2c (12 to 2.5ft NGVD) Target Area pH2c (2.5 to -11ft NGVD) SUBTOTAL Field Sampling and Analysis SUBTOTAL $25,000 Estimated (50 x 50 grid; approximately 50 boreholes) $11,979,900 Contingency 25% $2,995,000 10% scope + 15% bid SUBTOTAL $14,974,900 Project Management Remedial Design Construction Management 5% 8% 6% $528,300 Excludes reagent costs $845,200 Excludes reagent costs $633,900 Excludes reagent costs $16,982,300 TOTAL CAPITAL COSTS ANNUAL O&M COSTS: No annual O&M costs PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS COST TYPE Capital Cost Annual O&M Cost Periodic Cost YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (1.5%) PRESENT VALUE $16,982,300 $0 $0 $16,982,300 $16,982,300 $0 $0 1.000 - $16,982,300 $0 $0 $16,982,300 NOTES No annual O&M No periodic costs $16,982,300 Notes: (1) Vendor would not breakdown quote for mixing. Vendor quote is $40 to $70 per cubic yard. A typical breakdown of a mixing cost is provided in an associated Cost Worksheet pH-1 and is based on a bid for a different project. Vendor indicated that the price is expected to rise for depths greater than 65 feet. (2) Dosage based on vendor estimate of typical cement addition rate between 5 and 7 percent by soil weight. (3) Assume 50 percent of soil above water table has pH > 12.5 s.u. pH Enhanced Containment Alternative pH4 ENHANCED CONTAINMENT BY VERTICAL SLURRY WALL Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION Mobilization / Demobilization Equipment and Facilities H&S plans and submittals SUBTOTAL Vertical Slurry Wall Asphalt/debris Removal (6" thickness) North wall (410 ft) West wall (860 ft) South wall (330 ft) SUBTOTAL COST ESTIMATE SUMMARY pH4 Contain, by in situ vertical barrier, pH >12.5 s.u. in shallow soil and groundwater that could be a future source of contamination in soil and groundwater. The pH4 alternative includes the following elements: Construction of a vertical slurry wall around shallow soil and groundwater above -60 ft NGVD containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT 1 1 LS LS $75,000 $25,000 400 30,750 64,500 24,750 SY SF SF SF $10 $12.5 $12.5 $12.5 SUBTOTAL TOTAL NOTES $75,000 Vendor quote $25,000 Estimated $100,000 $3,800 $384,380 $806,250 $309,380 $1,503,800 GHD Construction Division Estimate (1) mid range from vendor quote (1) mid range from vendor quote (1) mid range from vendor quote $1,603,800 Contingency 25% $401,000 10% scope + 15% bid SUBTOTAL $2,004,800 Project Management Remedial Design Construction Management 5% 8% 6% $100,300 Excludes reagent costs $160,400 Excludes reagent costs $120,300 Excludes reagent costs $2,385,800 TOTAL CAPITAL COSTS ANNUAL O&M COSTS: No annual O&M costs PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS COST TYPE Capital Cost Annual O&M Cost Periodic Cost YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (1.5%) PRESENT VALUE $2,385,800 $0 $0 $2,385,800 $2,385,800 $0 $0 1.000 - $2,385,800 $0 $0 $2,385,800 NOTES No annual O&M No periodic costs $2,385,800 Notes: (1) Vendor quote is $10 to $15 per square yard (horizontal x vertical) for 2-feet thick wall. No dewatering. Includes air monitoring for personnel and Level D PPE. GHD 007843 (I:\IKRGROUP\6-chars\00----\0078--\007843\7843-Report 139-Feasibility_Study\FS_Draft_December2016\AppendixG\007843-139-AppG-December2016\AppG.3-pH\APPG.1-CostEst-pH-Alternatives+SubElement) pH Reduction Alternative pH5 pH REDUCTION BY SODIUM PERSULFATE MIXING Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY pH5 Reduce, by in situ treatment, pH >12.5 s.u. in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH5 alternative includes the following elements: Treatment using in situ mixing of sodium persulfate with shallow and deep soil and groundwater containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT Bench Scale Testing 1 LS $50,000 Mobilization / Demobilization Equipment and Facilities H&S Plans and Submittals HASP Implementation Grading Erosion Controls Demobilization SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $250,000 $15,000 $3,710,600 $927,650 $2,782,950 $92,000 $250,000 $15,000 $3,710,600 $927,650 $2,782,950 $92,000 $7,778,200 31,400 28,430 37,410 29,930 29,930 29,930 29,930 29,930 29,930 29,930 29,930 29,930 31,410 41,320 33,060 33,060 33,060 33,060 33,060 33,060 33,060 33,060 15,700 20,660 16,530 16,530 16,530 16,530 16,530 16,530 16,530 16,530 16,530 12,570 17,870 2,380 3,140 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 1,510 SY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY $10 $32 $32 $32 $32 $32 $32 $37 $37 $37 $42 $42 $40 $32 $32 $32 $32 $32 $37 $37 $37 $42 $32 $32 $32 $32 $32 $32 $37 $37 $37 $42 $42 $32 $32 $32 $32 $32 $32 $32 $32 $37 $37 $37 $42 $42 $47 $47 $52 $57 $62 $298,300 $909,760 $1,197,120 $957,760 $957,760 $957,760 $957,760 $1,107,410 $1,107,410 $1,107,410 $1,257,060 $1,257,060 $1,005,120 $1,322,240 $1,057,920 $1,057,920 $1,057,920 $1,057,920 $1,223,220 $1,223,220 $1,223,220 $1,388,520 $502,400 $661,120 $528,960 $528,960 $528,960 $528,960 $611,610 $611,610 $611,610 $694,260 $694,260 $402,240 $571,840 $76,160 $100,480 $80,320 $80,320 $80,320 $80,320 $92,870 $92,870 $92,870 $105,420 $105,420 $117,970 $117,970 $130,520 $143,070 $93,620 $32,757,100 Mixing Asphalt/debris Removal (6" thickness) Target Area pH2b (12 to 2.5ft NGVD) Target Area pH2b (2.5 to -10ft NGVD) Target Area pH2b (-10 to -20ft NGVD) Target Area pH2b (-20 to -30ft NGVD) Target Area pH2b (-30 to -40ft NGVD) Target Area pH2b (-40 to -50ft NGVD) Target Area pH2b (-50 to -60ft NGVD) Target Area pH5b1 (-60 to -70ft NGVD) Target Area pH5b1 (-70 to -80ft NGVD) Target Area pH5b1 (-80 to -90ft NGVD) Target Area pH5b1 (-90 to -100ft NGVD) Target Area pH5b2 (12 to 2.5ft NGVD) Target Area pH5b2 (2.5 to -10ft NGVD) Target Area pH5b2 (-10 to -20ft NGVD) Target Area pH5b2 (-20 to -30ft NGVD) Target Area pH5b2 (-30 to -40ft NGVD) Target Area pH5b2 (-40 to -50ft NGVD) Target Area pH5b2 (-50 to -60ft NGVD) Target Area pH5b2 (-60 to -70ft NGVD) Target Area pH5b2 (-70 to -80ft NGVD) Target Area pH5b2 (-80 to -90ft NGVD) Target Area pH5b3 (12 to 2.5ft NGVD) Target Area pH5b3 (2.5 to -10ft NGVD) Target Area pH5b3 (-10 to -20ft NGVD) Target Area pH5b3 (-20 to -30ft NGVD) Target Area pH5b3 (-30 to -40ft NGVD) Target Area pH5b3 (-40 to -50ft NGVD) Target Area pH5b3 (-50 to -60ft NGVD) Target Area pH5b3 (-60 to -70ft NGVD) Target Area pH5b3 (-70 to -80ft NGVD) Target Area pH5b3 (-80 to -90ft NGVD) Target Area pH5b3 (-90 to -100ft NGVD) Target Area pH2c (12 to 2.5ft NGVD) Target Area pH2c (2.5 to -11ft NGVD) Target Area pH5a (12 to 2.5ft NGVD) Target Area pH5a (2.5 to -10ft NGVD) Target Area pH5a (-10 to -20ft NGVD) Target Area pH5a (-20 to -30ft NGVD) Target Area pH5a (-30 to -40ft NGVD) Target Area pH5a (-40 to -50ft NGVD) Target Area pH5a (-50 to -60ft NGVD) Target Area pH5a (-60 to -70ft NGVD) Target Area pH5a (-70 to -80ft NGVD) Target Area pH5a (-80 to -90ft NGVD) Target Area pH5a (-90 to -100ft NGVD) Target Area pH5a (-100 to -110ft NGVD) Target Area pH5a (-110 to -120ft NGVD) Target Area pH5a (-120 to -130ft NGVD) Target Area pH5a (-130 to -140ft NGVD) Target Area pH5a (-140 to -146ft NGVD) SUBTOTAL TOTAL NOTES $50,000 GHD Quote Vendor quote Estimated (1) Estimated from vendor bids Estimated from vendor bids Estimated from vendor bids Estimated from vendor bids GHD Construction Division Estimate (1) Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $10 above low end of range from vendor quote $10 above low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $10 above low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $10 above low end of range from vendor quote $10 above low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $10 above low end of range from vendor quote $10 above low end of range from vendor quote $15 above low end of range from vendor quote $15 above low end of range from vendor quote $20 above low end of range from vendor quote $25 above low end of range from vendor quote high end of range from vendor quote GHD 007843 (I:\IKRGROUP\6-chars\00----\0078--\007843\7843-Report 139-Feasibility_Study\FS_Draft_December2016\AppendixG\007843-139-AppG-December2016\AppG.3-pH\APPG.1-CostEst-pH-Alternatives+SubElement) pH Reduction Alternative pH5 pH REDUCTION BY SODIUM PERSULFATE MIXING Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY pH5 Reduce, by in situ treatment, pH >12.5 s.u. in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH5 alternative includes the following elements: Treatment using in situ mixing of sodium persulfate with shallow and deep soil and groundwater containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT TOTAL 8,140 511,810 3,591,640 2,873,320 2,873,320 2,873,320 2,873,320 2,873,320 2,095,130 2,095,130 2,095,130 2,095,130 0 0 0 0 0 0 0 1,047,560 2,095,130 2,095,130 0 0 0 0 0 0 0 0 1,047,560 2,095,130 2,095,130 63,260 1,715,470 0 0 0 0 0 0 0 0 0 0 0 0 0 0 838,050 1,257,080 LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 $1.5 1 LS $55,000 NOTES (2) Reagent (sodium persulfate) Target Area pH2a (12 to 5ft NGVD) (3) Target Area pH2b (12 to 2.5ft NGVD) Target Area pH2b (2.5 to -10ft NGVD) Target Area pH2b (-10 to -20ft NGVD) Target Area pH2b (-20 to -30ft NGVD) Target Area pH2b (-30 to -40ft NGVD) Target Area pH2b (-40 to -50ft NGVD) Target Area pH2b (-50 to -60ft NGVD) Target Area pH5b1 (-60 to -70ft NGVD) Target Area pH5b1 (-70 to -80ft NGVD) Target Area pH5b1 (-80 to -90ft NGVD) Target Area pH5b1 (-90 to -100ft NGVD) Target Area pH5b2 (12 to 2.5ft NGVD) Target Area pH5b2 (2.5 to -10ft NGVD) Target Area pH5b2 (-10 to -20ft NGVD) Target Area pH5b2 (-20 to -30ft NGVD) Target Area pH5b2 (-30 to -40ft NGVD) Target Area pH5b2 (-40 to -50ft NGVD) Target Area pH5b2 (-50 to -60ft NGVD) Target Area pH5b2 (-60 to -70ft NGVD) Target Area pH5b2 (-70 to -80ft NGVD) Target Area pH5b2 (-80 to -90ft NGVD) Target Area pH5b3 (12 to 2.5ft NGVD) Target Area pH5b3 (2.5 to -10ft NGVD) Target Area pH5b3 (-10 to -20ft NGVD) Target Area pH5b3 (-20 to -30ft NGVD) Target Area pH5b3 (-30 to -40ft NGVD) Target Area pH5b3 (-40 to -50ft NGVD) Target Area pH5b3 (-50 to -60ft NGVD) Target Area pH5b3 (-60 to -70ft NGVD) Target Area pH5b3 (-70 to -80ft NGVD) Target Area pH5b3 (-80 to -90ft NGVD) Target Area pH5b3 (-90 to -100ft NGVD) Target Area pH2c (12 to 2.5ft NGVD) Target Area pH2c (2.5 to -11ft NGVD) Target Area pH5a (12 to 2.5ft NGVD) Target Area pH5a (2.5 to -10ft NGVD) Target Area pH5a (-10 to -20ft NGVD) Target Area pH5a (-20 to -30ft NGVD) Target Area pH5a (-30 to -40ft NGVD) Target Area pH5a (-40 to -50ft NGVD) Target Area pH5a (-50 to -60ft NGVD) Target Area pH5a (-60 to -70ft NGVD) Target Area pH5a (-70 to -80ft NGVD) Target Area pH5a (-80 to -90ft NGVD) Target Area pH5a (-90 to -100ft NGVD) Target Area pH5a (-100 to -110ft NGVD) Target Area pH5a (-110 to -120ft NGVD) Target Area pH5a (-120 to -130ft NGVD) Target Area pH5a (-130 to -140ft NGVD) Target Area pH5a (-140 to -146ft NGVD) SUBTOTAL Field Sampling and Analysis SUBTOTAL Contingency TOTAL CAPITAL COSTS Approximately 1.3% by weight and current market cost Approximately 1.3% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 1.3% by weight and current market cost Approximately 3.5% by weight and current market cost Approximately 2.6% by weight and current market cost Approximately 2.6% by weight and current market cost $55,000 Estimated (50 x 50 grid; approximately 110 boreholes) $102,452,700 25% SUBTOTAL Project Management Remedial Design Construction Management $12,210 $767,720 $5,387,460 $4,309,980 $4,309,980 $4,309,980 $4,309,980 $4,309,980 $3,142,700 $3,142,700 $3,142,700 $3,142,700 $0 $0 $0 $0 $0 $0 $0 $1,571,340 $3,142,700 $3,142,700 $0 $0 $0 $0 $0 $0 $0 $0 $1,571,340 $3,142,700 $3,142,700 $94,890 $2,573,210 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $1,257,080 $1,885,620 $61,812,400 $25,613,200 10% scope + 15% bid $128,065,900 5% 8% 6% $2,032,100 Excludes reagent costs $3,251,300 Excludes reagent costs $2,438,500 Excludes reagent costs $135,787,800 GHD 007843 (I:\IKRGROUP\6-chars\00----\0078--\007843\7843-Report 139-Feasibility_Study\FS_Draft_December2016\AppendixG\007843-139-AppG-December2016\AppG.3-pH\APPG.1-CostEst-pH-Alternatives+SubElement) pH Reduction Alternative pH5 pH REDUCTION BY SODIUM PERSULFATE MIXING Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 ANNUAL O&M COSTS: No annual O&M costs COST ESTIMATE SUMMARY pH5 Reduce, by in situ treatment, pH >12.5 s.u. in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH5 alternative includes the following elements: Treatment using in situ mixing of sodium persulfate with shallow and deep soil and groundwater containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS COST TYPE Capital Cost Annual O&M Cost Periodic Cost TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (1.5%) PRESENT VALUE $135,787,800 $0 $0 $135,787,800 $135,787,800 $0 $0 1.000 - $135,787,800 $0 $0 $135,787,800 YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE NOTES No annual O&M No periodic costs $135,787,800 Notes: (1) Vendor would not breakdown quote for mixing. Vendor quote is $40 to $70 per cubic yard. A typical breakdown of a mixing cost is provided in an associated Cost Worksheet pH-1 and is based on a bid for a different project. Vendor indicated that the price is expected to rise for depths greater than 65 feet. (2) Dosage (96 lbs/cy) based on pH pilot study to reduce average shallow groundwater pH = 13.036 s.u. by 0.536 s.u. Dosage (36 lbs/cy) based on pH pilot study to reduce average shallow soil pH = 12.742 s.u. by 0.242 s.u. Dosage (70 lbs/cy) based on pH pilot study to reduce average deep groundwater pH = 12.920 s.u. by 0.420 s.u. ANC calculations suggest dosage rate could be approximately 1.9 times higher (96 lbs/cy compared to 184 lbs/cy and 70 lbs/cy compared to 134 lbs/cy). (3) Assume 50 percent of soil above water table has pH > 12.5 s.u. GHD 007843 (I:\IKRGROUP\6-chars\00----\0078--\007843\7843-Report 139-Feasibility_Study\FS_Draft_December2016\AppendixG\007843-139-AppG-December2016\AppG.3-pH\APPG.1-CostEst-pH-Alternatives+SubElement) pH Reduction Alternative pH6 ENHANCED CONTAINMENT BY CEMENT MIXING Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY pH6 Contain, by in situ treatment, pH >12.5 s.u. in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH6 alternative includes the following elements: Treatment using in situ mixing of cement with shallow and deep soil and groundwater containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT Bench Scale Testing 1 LS $50,000 Mobilization / Demobilization Equipment and Facilities H&S Plans and Submittals HASP Implementation Grading Erosion Controls Demobilization SUBTOTAL 1 1 1 1 1 1 LS LS LS LS LS LS $250,000 $15,000 $3,710,600 $927,650 $2,782,950 $92,000 $250,000 $15,000 $3,710,600 $927,650 $2,782,950 $92,000 $7,778,200 31,400 28,430 37,410 29,930 29,930 29,930 29,930 29,930 29,930 29,930 29,930 29,930 31,410 41,320 33,060 33,060 33,060 33,060 33,060 33,060 33,060 33,060 15,700 20,660 16,530 16,530 16,530 16,530 16,530 16,530 16,530 16,530 16,530 12,570 17,870 2,380 3,140 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 2,510 1,510 SY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY CY $10 $32 $32 $32 $32 $32 $32 $37 $37 $37 $42 $42 $40 $32 $32 $32 $32 $32 $37 $37 $37 $42 $32 $32 $32 $32 $32 $32 $37 $37 $37 $42 $42 $32 $32 $32 $32 $32 $32 $32 $32 $37 $37 $37 $42 $42 $47 $47 $52 $57 $62 $298,300 $909,760 $1,197,120 $957,760 $957,760 $957,760 $957,760 $1,107,410 $1,107,410 $1,107,410 $1,257,060 $1,257,060 $1,005,120 $1,322,240 $1,057,920 $1,057,920 $1,057,920 $1,057,920 $1,223,220 $1,223,220 $1,223,220 $1,388,520 $502,400 $661,120 $528,960 $528,960 $528,960 $528,960 $611,610 $611,610 $611,610 $694,260 $694,260 $402,240 $571,840 $76,160 $100,480 $80,320 $80,320 $80,320 $80,320 $92,870 $92,870 $92,870 $105,420 $105,420 $117,970 $117,970 $130,520 $143,070 $93,620 $32,757,100 Mixing Asphalt/debris Removal (6" thickness) Target Area pH2b (12 to 2.5ft NGVD) Target Area pH2b (2.5 to -10ft NGVD) Target Area pH2b (-10 to -20ft NGVD) Target Area pH2b (-20 to -30ft NGVD) Target Area pH2b (-30 to -40ft NGVD) Target Area pH2b (-40 to -50ft NGVD) Target Area pH2b (-50 to -60ft NGVD) Target Area pH5b1 (-60 to -70ft NGVD) Target Area pH5b1 (-70 to -80ft NGVD) Target Area pH5b1 (-80 to -90ft NGVD) Target Area pH5b1 (-90 to -100ft NGVD) Target Area pH5b2 (12 to 2.5ft NGVD) Target Area pH5b2 (2.5 to -10ft NGVD) Target Area pH5b2 (-10 to -20ft NGVD) Target Area pH5b2 (-20 to -30ft NGVD) Target Area pH5b2 (-30 to -40ft NGVD) Target Area pH5b2 (-40 to -50ft NGVD) Target Area pH5b2 (-50 to -60ft NGVD) Target Area pH5b2 (-60 to -70ft NGVD) Target Area pH5b2 (-70 to -80ft NGVD) Target Area pH5b2 (-80 to -90ft NGVD) Target Area pH5b3 (12 to 2.5ft NGVD) Target Area pH5b3 (2.5 to -10ft NGVD) Target Area pH5b3 (-10 to -20ft NGVD) Target Area pH5b3 (-20 to -30ft NGVD) Target Area pH5b3 (-30 to -40ft NGVD) Target Area pH5b3 (-40 to -50ft NGVD) Target Area pH5b3 (-50 to -60ft NGVD) Target Area pH5b3 (-60 to -70ft NGVD) Target Area pH5b3 (-70 to -80ft NGVD) Target Area pH5b3 (-80 to -90ft NGVD) Target Area pH5b3 (-90 to -100ft NGVD) Target Area pH2c (12 to 2.5ft NGVD) Target Area pH2c (2.5 to -11ft NGVD) Target Area pH5a (12 to 2.5ft NGVD) Target Area pH5a (2.5 to -10ft NGVD) Target Area pH5a (-10 to -20ft NGVD) Target Area pH5a (-20 to -30ft NGVD) Target Area pH5a (-30 to -40ft NGVD) Target Area pH5a (-40 to -50ft NGVD) Target Area pH5a (-50 to -60ft NGVD) Target Area pH5a (-60 to -70ft NGVD) Target Area pH5a (-70 to -80ft NGVD) Target Area pH5a (-80 to -90ft NGVD) Target Area pH5a (-90 to -100ft NGVD) Target Area pH5a (-100 to -110ft NGVD) Target Area pH5a (-110 to -120ft NGVD) Target Area pH5a (-120 to -130ft NGVD) Target Area pH5a (-130 to -140ft NGVD) Target Area pH5a (-140 to -146ft NGVD) SUBTOTAL TOTAL NOTES $50,000 GHD Quote Vendor quote Estimated (1) Estimated from vendor bids Estimated from vendor bids Estimated from vendor bids Estimated from vendor bids GHD Construction Division Estimate (1) Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $10 above low end of range from vendor quote $10 above low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $10 above low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $10 above low end of range from vendor quote $10 above low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote Low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $5 above low end of range from vendor quote $10 above low end of range from vendor quote $10 above low end of range from vendor quote $15 above low end of range from vendor quote $15 above low end of range from vendor quote $20 above low end of range from vendor quote $25 above low end of range from vendor quote high end of range from vendor quote GHD 007843 (I:\IKRGROUP\6-chars\00----\0078--\007843\7843-Report 139-Feasibility_Study\FS_Draft_December2016\AppendixG\007843-139-AppG-December2016\AppG.3-pH\APPG.1-CostEst-pH-Alternatives+SubElement) pH Reduction Alternative pH6 ENHANCED CONTAINMENT BY CEMENT MIXING Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION COST ESTIMATE SUMMARY pH6 Contain, by in situ treatment, pH >12.5 s.u. in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH6 alternative includes the following elements: Treatment using in situ mixing of cement with shallow and deep soil and groundwater containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT 36,160 2,274,710 5,986,070 4,788,860 4,788,860 4,788,860 4,788,860 4,788,860 4,788,860 4,788,860 4,788,860 4,788,860 0 0 0 0 0 0 0 2,394,430 4,788,860 4,788,860 0 0 0 0 0 0 0 0 2,394,430 4,788,860 4,788,860 281,150 2,859,120 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1,915,540 2,873,320 LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB LB $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 $0.04 1 LS $55,000 TOTAL NOTES (2) Reagent (sodium persulfate) Target Area pH2a (12 to 5ft NGVD) (3) Target Area pH2b (12 to 2.5ft NGVD) Target Area pH2b (2.5 to -10ft NGVD) Target Area pH2b (-10 to -20ft NGVD) Target Area pH2b (-20 to -30ft NGVD) Target Area pH2b (-30 to -40ft NGVD) Target Area pH2b (-40 to -50ft NGVD) Target Area pH2b (-50 to -60ft NGVD) Target Area pH5b1 (-60 to -70ft NGVD) Target Area pH5b1 (-70 to -80ft NGVD) Target Area pH5b1 (-80 to -90ft NGVD) Target Area pH5b1 (-90 to -100ft NGVD) Target Area pH5b2 (12 to 2.5ft NGVD) Target Area pH5b2 (2.5 to -10ft NGVD) Target Area pH5b2 (-10 to -20ft NGVD) Target Area pH5b2 (-20 to -30ft NGVD) Target Area pH5b2 (-30 to -40ft NGVD) Target Area pH5b2 (-40 to -50ft NGVD) Target Area pH5b2 (-50 to -60ft NGVD) Target Area pH5b2 (-60 to -70ft NGVD) Target Area pH5b2 (-70 to -80ft NGVD) Target Area pH5b2 (-80 to -90ft NGVD) Target Area pH5b3 (12 to 2.5ft NGVD) Target Area pH5b3 (2.5 to -10ft NGVD) Target Area pH5b3 (-10 to -20ft NGVD) Target Area pH5b3 (-20 to -30ft NGVD) Target Area pH5b3 (-30 to -40ft NGVD) Target Area pH5b3 (-40 to -50ft NGVD) Target Area pH5b3 (-50 to -60ft NGVD) Target Area pH5b3 (-60 to -70ft NGVD) Target Area pH5b3 (-70 to -80ft NGVD) Target Area pH5b3 (-80 to -90ft NGVD) Target Area pH5b3 (-90 to -100ft NGVD) Target Area pH2c (12 to 2.5ft NGVD) Target Area pH2c (2.5 to -11ft NGVD) Target Area pH5a (12 to 2.5ft NGVD) Target Area pH5a (2.5 to -10ft NGVD) Target Area pH5a (-10 to -20ft NGVD) Target Area pH5a (-20 to -30ft NGVD) Target Area pH5a (-30 to -40ft NGVD) Target Area pH5a (-40 to -50ft NGVD) Target Area pH5a (-50 to -60ft NGVD) Target Area pH5a (-60 to -70ft NGVD) Target Area pH5a (-70 to -80ft NGVD) Target Area pH5a (-80 to -90ft NGVD) Target Area pH5a (-90 to -100ft NGVD) Target Area pH5a (-100 to -110ft NGVD) Target Area pH5a (-110 to -120ft NGVD) Target Area pH5a (-120 to -130ft NGVD) Target Area pH5a (-130 to -140ft NGVD) Target Area pH5a (-140 to -146ft NGVD) SUBTOTAL Field Sampling and Analysis SUBTOTAL Contingency TOTAL CAPITAL COSTS Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost Approximately 6.0% by weight and current market cost $55,000 Estimated (50 x 50 grid; approximately 110 boreholes) $43,971,100 25% SUBTOTAL Project Management Remedial Design Construction Management $1,450 $90,990 $239,440 $191,550 $191,550 $191,550 $191,550 $191,550 $191,550 $191,550 $191,550 $191,550 $0 $0 $0 $0 $0 $0 $0 $95,780 $191,550 $191,550 $0 $0 $0 $0 $0 $0 $0 $0 $95,780 $191,550 $191,550 $11,250 $114,360 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $76,620 $114,930 $3,330,800 $10,992,800 10% scope + 15% bid $54,963,900 5% 8% 6% $2,032,100 Excludes reagent costs $3,251,300 Excludes reagent costs $2,438,500 Excludes reagent costs $62,685,800 GHD 007843 (I:\IKRGROUP\6-chars\00----\0078--\007843\7843-Report 139-Feasibility_Study\FS_Draft_December2016\AppendixG\007843-139-AppG-December2016\AppG.3-pH\APPG.1-CostEst-pH-Alternatives+SubElement) pH Reduction Alternative pH6 ENHANCED CONTAINMENT BY CEMENT MIXING Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 ANNUAL O&M COSTS: No annual O&M costs COST ESTIMATE SUMMARY pH6 Contain, by in situ treatment, pH >12.5 s.u. in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH6 alternative includes the following elements: Treatment using in situ mixing of cement with shallow and deep soil and groundwater containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS COST TYPE Capital Cost Annual O&M Cost Periodic Cost YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (1.5%) PRESENT VALUE $62,685,800 $0 $0 $62,685,800 $62,685,800 $0 $0 1.000 - $62,685,800 $0 $0 $62,685,800 NOTES No annual O&M No periodic costs $62,685,800 Notes: (1) Vendor would not breakdown quote for mixing. Vendor quote is $40 to $70 per cubic yard. A typical breakdown of a mixing cost is provided in an associated Cost Worksheet pH-1 and is based on a bid for a different project. Vendor indicated that the price is expected to rise for depths greater than 65 feet. (2) Dosage based on vendor estimate of typical cement addition rate between 5 and 7 percent by soil weight. (3) Assume 50 percent of soil above water table has pH > 12.5 s.u. GHD 007843 (I:\IKRGROUP\6-chars\00----\0078--\007843\7843-Report 139-Feasibility_Study\FS_Draft_December2016\AppendixG\007843-139-AppG-December2016\AppG.3-pH\APPG.1-CostEst-pH-Alternatives+SubElement) pH Enhanced Containment Alternative pH7 ENHANCED CONTAINMENT BY VERTICAL SLURRY WALL Site: "Occidental" Site Description: Location: Tacoma, Washington Phase: Feasibility Study (-30% to +50%) Base Year: 2016 Date: December 8, 2016 CAPITAL COSTS DESCRIPTION Mobilization / Demobilization Equipment and Facilities H&S plans and submittals SUBTOTAL Vertical Slurry Wall Asphalt/debris Removal (6" thickness) North wall deep (320 ft) West wall shallow (640 ft) West wall deep (803 ft) South wall shallow (330 ft) South wall deep (475 ft) East wall deep (648 ft) POT Area deep (624 ft) SUBTOTAL COST ESTIMATE SUMMARY pH7 Contain, by in situ vertical barrier, pH >12.5 s.u. in shallow and deep soil and groundwater that could be a future source of contamination in soil and groundwater. The pH7 alternative includes the following elements: Construction of a vertical slurry wall around shallow and deep soil and groundwater containing pH greater than 12.5 s.u. Capital costs occur in Year 0. No annual O&M costs. No Periodic costs. UNIT COST QTY UNIT 1 1 LS LS $75,000 $25,000 1,000 51,840 48,000 130,090 22,500 76,950 104,980 101,090 SY SF SF SF SF SF SF SF $10 $15 $12.5 $15 $12.5 $15 $15 $15 SUBTOTAL TOTAL NOTES $75,000 Vendor quote $25,000 Estimated $100,000 $9,500 $777,600 $600,000 $1,951,350 $281,250 $1,154,250 $1,574,700 $1,516,350 $7,865,000 GHD Construction Division Estimate (1) high end of range from vendor quote (1) mid range from vendor quote (1) high end of range from vendor quote (1) mid range from vendor quote (1) high end of range from vendor quote (1) high end of range from vendor quote (1) high end of range from vendor quote $7,965,000 Contingency 25% $1,991,300 10% scope + 15% bid SUBTOTAL $9,956,300 Project Management Remedial Design Construction Management 5% 8% 6% $497,900 Excludes reagent costs $796,600 Excludes reagent costs $597,400 Excludes reagent costs $11,848,200 TOTAL CAPITAL COSTS ANNUAL O&M COSTS: No annual O&M costs PERIODIC COSTS: No periodic costs PRESENT VALUE ANALYSIS COST TYPE Capital Cost Annual O&M Cost Periodic Cost YEAR 0 - TOTAL PRESENT VALUE OF ALTERNATIVE TOTAL COST TOTAL COST PER YEAR DISCOUNT FACTOR (1.5%) PRESENT VALUE $11,848,200 $0 $0 $11,848,200 $11,848,200 $0 $0 1.000 - $11,848,200 $0 $0 $11,848,200 NOTES No annual O&M No periodic costs $11,848,200 Notes: (1) Vendor quote is $10 to $15 per square yard (horizontal x vertical) for 2-feet thick wall. No dewatering. Includes air monitoring for personnel and Level D PPE. GHD 007843 (I:\IKRGROUP\6-chars\00----\0078--\007843\7843-Report 139-Feasibility_Study\FS_Draft_December2016\AppendixG\007843-139-AppG-December2016\AppG.3-pH\APPG.1-CostEst-pH-Alternatives+SubElement) pH Reduction/Enhanced Containment Alternatives pH2, pH3, pH5, pH6 Capital Cost Sub-Element COST WORKSHEET pH-1 IN SITU MIXING Site: Location: Phase: Base Year: "Occidental" Site Tacoma, Washington Feasibility Study (-30% to +50%) 2016 Prepared By: AW Date: 5/29/2016 Checked By: RJH Date: 12/8/2016 Work Statement: The pH Enhanced containment includes using an auger to mix specified reagent directly into the soil at specific depth intervals. Cost analysis: Costs include equipment and labor for mixing. The costs do include the supply of the reagent. DESCRIPTION In Situ Mixing Soil Blending and Support Grading Erosion Controls HASP Implementation SUBTOTAL QTY UNIT LABOR EQUIP MTRL 80 3 7 10 % % % % - - - TOTAL UNIT COST UNIT TOTAL TOTAL 40 40 40 40 32 1 3 4 40 $ NOTES Estimated Estimated Estimated Estimated 40 Source of Cost Data: Vendor would not breakdown quote for mixing costs. Vendor quote is $40.00 to $70.00 per cubic yard. GHD utilized a 2013 schedule of prices for in situ mixing at a different superfund site to present a detailed percentage breakdown of the total mixing unit cost. Cost Adjustment Checklist: FACTOR: H&S Productivity Escalation to Base Year Area Cost Factor Subcontractor Overhead and Profit Prime Contractor Overhead and Profit 07843(139)AppG - Cost Worksheet pH-1 NOTES: Assume Level D 2016 Based on local pricing Included in unit pricing Included in unit pricing ?25