PROPOSED REMEDIAL ACTION PLAN WEST VAN BUREN AREA WATER QUALITY ASSURANCE REVOLVING FUND SITE PHOENIX, ARIZONA Prepared For: Arizona Department of Environmental Quality Prepared By: West Van Buren PRAP Working Group December 2015 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 TABLE OF CONTENTS 1.0 2.0 3.0 4.0 Page No. INTRODUCTION ................................................................................................................................ 1 2.1 2.2 2.3 BACKGROUND .................................................................................................................................. 2 Site Conceptual Model .............................................................................................................. 2 Chronology of Major Site Activities ........................................................................................... 5 A.R.S. §49-287.04(C) Notice ...................................................................................................... 8 FEASIBILITY STUDY PROPOSED REMEDIES ..................................................................................... 10 3.1 WVBWG Proposed Remedy .................................................................................................... 10 3.1.1 Matrix-CALIBRE Review of the WVBWG Proposed Remedy............................................. 11 3.1.2 Statement from the Water Provider Members of the WVB PRAP Working Group (COP and SRP) Regarding the Utility of the 500 GPM Extraction Well ................................................... 12 3.2 RID Proposed Remedy ............................................................................................................. 13 3.2.1 Comments on the RID Proposed Remedy ........................................................................ 13 3.2.2 Matrix-CALIBRE Review of the RID Proposed Remedy ..................................................... 14 PREFERRED REMEDY ...................................................................................................................... 16 Observations and Assumptions ............................................................................................... 16 Preferred Remedy ................................................................................................................... 17 Estimated Remedial Action Costs............................................................................................ 19 Achievement of Remedial Objectives ..................................................................................... 21 4.4.1 Remedial Objectives for Land Use .................................................................................... 21 4.4.2 Remedial Objectives for Groundwater Use ...................................................................... 23 4.4.3 Remedial Objectives for Canal Water Use ........................................................................ 29 4.4.4 Remedial Objectives for Surface Water Use..................................................................... 31 4.5 Consistency with Water Management Plans .......................................................................... 32 4.6 Consistency with Land Use Planning ....................................................................................... 35 4.7 Achievement of Remedial Action Criteria Pursuant to A.R.S. §49-282.06 .............................. 37 4.1 4.2 4.3 4.4 5.0 REFERENCES ................................................................................................................................... 38 LIST OF TABLES Table 1 Table 2 Preferred Remedy Remedial Action Costs Projected General Plan Land Uses – Central City and Estrella Appendix A LIST OF APPENDICES Matrix-CALIBRE Evaluation of Feasibility Studies Regarding Technical Completeness, West Van Buren Water Quality Assurance Revolving Fund Site, Dated July 28, 2015 i Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 LIST OF ACRONYMS 1,1-DCE µg/L A.A.C. ADEQ ADHS ADWR AFY Air Liquide ALSCo A.R.S. AWQS bgs CAP ChemResearch COCs COP COT Dolphin ERA (ft/ft) FS GAC gpm LAU M52 MAU MNA NFA NPV O&M OU2 PCE PRAP PRP Prudential RCRA RI RID RO ROD 1,1-dichloroethene micrograms per Liter Arizona Administrative Code Arizona Department of Environmental Quality Arizona Department of Health Services Arizona Department of Water Resources acre-feet per year Air Liquide USA, LLC and Air Liquide America Specialty Gases, LLC American Linen Supply Company Arizona Revised Statutes Aquifer Water Quality Standard below ground surface Central Arizona Project ChemResearch Company, Inc. Compounds of Concern City of Phoenix City of Tolleson Dolphin Incorporated Early Response Action feet per foot Feasibility Study granular activated carbon gallon per minute Lower Alluvial Unit Motorola 52nd Street Federal Superfund Site Middle Alluvial Unit monitored natural attenuation No Further Action Net Present Value Operations and Maintenance Operable Unit 2 tetrachloroethylene Proposed Remedial Action Plan Potentially Responsible Party Prudential Overall Supply Resource Conservation and Recovery Act Remedial Investigation Roosevelt Irrigation District remedial objective Record of Decision ii Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 LIST OF ACRONYMS SCM SRP SVE TCE UAU VOC WOC WQARF WVB WVBA WVBWG WWTP Site Conceptual Model Salt River Project soil vapor extraction trichloroethylene Upper Alluvial Unit Volatile organic compound West Osborn Complex Water Quality Assurance Revolving Fund West Van Buren West Van Buren Area West Van Buren Working Group Wastewater Treatment Plant iii Proposed Remedial Action Plan   Phoenix, Arizona  West Van Buren Area WQARF Site December 2015    1.0 INTRODUCTION This Proposed Remedial Action Plan (PRAP) has been prepared for the West Van Buren Area (WVBA)  Water Quality Assurance Revolving Fund (WQARF) registry site by the West Van Buren (WVB) PRAP  Working Group, a sub‐group of the WVB Working Group (WVBWG). The WVB PRAP Working Group  participants are the City of Phoenix (COP), Dolphin Incorporated (Dolphin), Freescale Semiconductor,  Inc., Honeywell International, Inc., Prudential Overall Supply (Prudential), Salt River Project (SRP), and  Univar USA Inc. (Univar).  The purpose of this document is to describe and present the proposed Preferred Remedy for the WVBA  WQARF registry site for the Arizona Department of Environmental Quality’s (ADEQ) consideration. The  proposed Preferred Remedy in this PRAP is capable of meeting the remedial objectives (ROs) established  and provided by ADEQ for the Site (ADEQ, 2012). ADEQ is required under Arizona Revised Statutes  (A.R.S.) §49‐287.04 to issue a PRAP for the proposed Preferred Remedy to the public for review and  comment. This PRAP has been prepared in accordance with Arizona Administrative Code (A.A.C.) R18‐ 16‐408 and relies on the data and findings from the Remedial Investigation (RI) Report prepared for  ADEQ by Terranext (Terranext, 2012a). The PRAP considers the preferred groundwater remedies  proposed in the WVBWG Feasibility Study (FS) Report (Haley & Aldrich, 2014) and the Roosevelt  Irrigation District (RID) FS Report (Synergy, 2014), and the evaluation conducted by Matrix‐CALIBRE  under contract to ADEQ to provide a neutral evaluation of the two FS Reports. The Matrix‐CALIBRE  evaluation is presented in their “Evaluation of Feasibility Studies Regarding Technical Completeness,  West Van Buren Water Quality Assurance Revolving Fund” technical memorandum (Matrix‐CALIBRE,  2015), which is attached as Appendix A.        1  Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 2.0 BACKGROUND The WVBA is located in the western-central portion of the COP and is approximately bounded by West McDowell Road to the north, 7th Avenue to the east, West Buckeye Road to the south, and 75th Avenue to the west. Volatile organic compounds (VOCs), including trichloroethylene (TCE) and tetrachloroethylene (PCE), were first detected in groundwater within the WVBA in 1985, during a groundwater investigation conducted by Chevron USA Inc. at its facility located south of Van Buren Street between 51st Avenue and 55th Avenue (Dames & Moore, 1985). This discovery was the inception of the WVBA WQARF site. ADEQ’s November 1987 Decision Record created the Van Buren Tank Farm WQARF Area, and a December 1987 amended Decision Record changed the name to the WVBA WQARF Site (ADEQ, 2010). Beginning in 1988, several facilities within the WVBA conducted site investigations and remedial actions under the guidance of ADEQ (Terranext, 2012a). The WVBA was placed on the State of Arizona WQARF registry in 1998 (ADEQ, 1998) and a community advisory board was formed in 1999 (ADEQ, 2010). The RI Report, which includes the Land and Water Use Report, was prepared in August 2012 by Terranext on behalf of ADEQ (Terranext, 2012b). The RI Report also includes the RO Report prepared by ADEQ (ADEQ, 2012). 2.1 Site Conceptual Model A detailed Site Conceptual Model (SCM) is provided in the FS Report prepared by the WVBWG (Haley & Aldrich, 2014). The SCM provides an overview of the geology and hydrogeology of the WVBA, a description of surface waters and canals within the project area, a brief description of the facilities within the WVBA identified in the RI Report as having performed site investigations (and, in most cases, facility-specific remedial activities), a summary of the nature and extent of groundwater contamination within and adjacent to the WVBA, including impacts to groundwater from inorganic constituents resulting from historical agricultural land use, and an evaluation of the overall WVBA plume stability and concentration trends in groundwater for constituents of interest. The main concepts of the WVBA SCM as described in the WVBWG FS Report are summarized below. 2 Proposed Remedial Action Plan Phoenix, Arizona • West Van Buren Area WQARF Site December 2015 The Upper Alluvial Unit (UAU) 1 is the uppermost aquifer, consisting primarily of coarse grained sand and gravel with some silt and clay, including occasional thin interbedded silt and clay layers. UAU1 hydraulic conductivities used in the WVBA groundwater flow model ranged from 100 to 1,000 feet per day in the upper, more permeable UAU1 to 75 to 500 feet per day in the lower UAU1 (Brown and Caldwell, 2014). • The underlying UAU2 consists of sand and gravel with a higher percentage of silt and clay and interbedded fine-grained layers compared to the UAU1. UAU2 hydraulic conductivities used in the WVBA groundwater flow model ranged from 1 to 100 feet per day (Brown and Caldwell, 2014). • The UAU (UAU1 and UAU2 combined) saturated thickness is approximately 200 feet. • The UAU aquifer is generally unconfined. The current depth to the water table is approximately 100 to 150 feet below ground surface (bgs). • Groundwater extracted from production wells within the WVBA is likely primarily derived from the UAU1, due to its prolific water-producing nature relative to the other alluvial units. • Groundwater contamination within the WVBA is generally constrained to the UAU1 and the UAU2. • UAU groundwater is also impacted by inorganic constituents, primarily total dissolved solids, resulting from extensive historical agricultural land use within the WVBA. • Overall groundwater flow direction within the WVBA is from east to west at hydraulic gradients ranging from approximately 0.002 feet per foot (ft/ft) to 0.004 ft/ft in the eastern WVBA, generally flattening to 0.0005 ft/ft in the central and western WVBA. • RID pumps approximately 75,000 acre-feet per year (AFY) for irrigation use on a seasonal basis, primarily March through September, from approximately 32 production wells located within and adjacent to the WVBA. The aggregate pumping of these irrigation wells creates a regional hydraulic trough or sink within the WVBA. Should RID irrigation pumping within the WVBA (the current and historical overarching local hydraulic control) cease, the overall groundwater flow direction would 3 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 likely shift to the northwest towards the regional pumping depression known as the Luke Sink, near the Luke Air Force Base • Historical operations at some facilities within the WVBA have impacted groundwater. The primary Compounds of Concern (COCs) in WVBA groundwater are PCE, TCE, and to a lesser extent 1,1dichloroethene (1,1-DCE). A localized plume of dissolved chromium is also present within the southeast portion of the WVBA. • Facility-specific source remediation at select WVBA facilities has reduced the VOC source input at these WVBA facilities to the regional WVBA plume. At several facilities, COC concentrations within facility-specific monitoring wells have declined significantly following source remediation work, in some cases by orders of magnitude. • Some areas of persistent, relatively elevated VOC concentrations near and/or downgradient of other WVBA facilities indicate the potential for ongoing source inputs to the regional WVBA plume in these areas. • According to the WVBA RI Report, "Groundwater contamination enters the WVBA from the east from the Motorola 52nd Street Federal Superfund Site [M52] Operable Unit [OU] 3 area.” TCE and 1,1-DCE, and to a lesser extent, PCE, are the primary COCs in the M52 OU3 plume. • While the M52 OU3 RI/FS is currently being completed, it is assumed that the M52 Site plume has commingled with the regional plume of groundwater contamination originating from historical WVBA facility operations. Although not fully defined, the downgradient extent of the West Osborn Complex WQARF site plume, with TCE as the primary COC, also appears to have merged with the north-central portion of the WVBA plume. • Operation of the M52 OU2 groundwater extraction system since 2001 has effectively cut off the dissolved-phase plume at the OU2/OU3 boundary, resulting in overall COC concentration declines in M52 OU3 monitoring wells and in UAU1 monitoring wells in the eastern and central portion of the WVBA. 4 Proposed Remedial Action Plan Phoenix, Arizona • West Van Buren Area WQARF Site December 2015 As a result of the WVBA facility-specific remedial work, the M52 OU2 groundwater extraction system, and irrigation pumping, the WVBA plume appears to be stable with generally declining concentration trends in the UAU1. Within the more fine-grained UAU2, VOC concentrations in UAU2 monitoring wells located along the axis of the WVBA plume have remained generally consistent over time. 2.2 Chronology of Major Site Activities ADEQ’s website lists major site activities, which are summarized below along with some recent critical milestone additions: 1987: The November 13 Decision Record created the Van Buren Tank Farm WQARF area. The amended decision record dated December 11 changed the name to WVB. 1992: In November, Univar (formerly Vopak, formerly Van Waters and Rogers Inc.) began operations of a soil vapor extraction (SVE) system. 1994: ChemResearch Company, Inc. (ChemResearch) entered into a Resource Conservation and Recovery Act (RCRA) Consent Order with ADEQ. 1996: On September 20, Univar entered into Consent Order W-109-96 with ADEQ. 1997: Maricopa County began SVE system operation. After 6 months of operation, soil contaminant levels were reduced below the regulatory standards. In May, American Linen Supply Company (ALSCo), located at 720 W. Buchanan Street, settled with ADEQ for $2 million dollars. 1998: In April, WVB was placed on the WQARF Registry with an Eligibility and Evaluation score of 50 out of a possible 120. In October, Dolphin, located at 740 S. 59th Avenue, began operation of SVE and air sparge systems at their facility. 2000: In 2000, Reynolds Metals (now ALCOA), located between 35th Avenue and 43rd Avenue and West Van Buren Street and the Southern Pacific Railroad right-of-way, excavated and removed contaminated soil from their site and received a No Further Action (NFA) for soils in specific areas from ADEQ. In January, Dolphin entered into RCRA Consent Order Z-2-00. Consent Judgment CV 2000-001824 was filed. 5 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 2001: In March, ADEQ/ALSCo began an Early Response Action (ERA) utilizing SVE, air sparge and groundwater pump and treat systems. Union Pacific Railroad Company and Maricopa County settled with ADEQ for $450,000. 2002: In June, Reynolds/ALCOA settled with ADEQ for $1.96 million. In August, Univar received a NFA determination for soil from ADEQ and the Univar Consent Order W-109-96 was terminated by ADEQ. By October, the ALSCo SVE system had removed over 900 pounds of VOCs from the soil and the system operation was ceased. In December, Dolphin ceased remedial system operation and conducted rebound testing. 2003: The ALSCo ERA groundwater pump and treat system ceased operation in September after treating approximately 118 million gallons of groundwater. 2004: In April, Dolphin completed rebound testing and received ADEQ authorization for SVE system shut down. 2006: In September, ADEQ installed seven monitoring wells and sampled 125 groundwater monitoring wells as part of the semi-annual sampling process. Dolphin satisfied the Consent Order and Consent Judgment, which were closed on June 6. 2007: A new Land and Water Use Questionnaire was sent to stakeholders to update the Land and Water Use Study completed in October 2001. In June, ADEQ completed installation of six groundwater monitoring wells. Air Liquide USA, LLC and Air Liquide America Specialty Gases, LLC (Air Liquide) signed a Consent Order to continue conducting investigation work on their property. 2008: Three monitoring wells were installed by ADEQ to help delineate the extent of the groundwater plume and to further investigate potential source areas. Air Liquide completed the installation of four groundwater monitoring wells and conducted quarterly groundwater sampling. Prudential signed a Consent Order to continue investigating soil and groundwater at their facility. Prudential also conducted a passive soil gas survey at their facility in May and June and installed three groundwater monitoring wells in July. Water levels were measured monthly and groundwater samples were collected in August and September. 6 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 2009: Air Liquide and Prudential continued to do work under consent orders. ADEQ solicited comments for the ROs of WVB. ADEQ signed a working agreement with RID to review its regional groundwater ERA proposal. 2010: Groundwater monitoring and sampling was conducted in June and September. Groundwater sampling of RID wells and surface sampling of RID canals was also conducted in June. Prudential performed a pilot test to determine if SVE would be suitable for soil remediation. ADEQ conditionally approved RID’s ERA on June 24. 2011: Groundwater monitoring and sampling was conducted in March and September. Groundwater sampling of RID wells and surface sampling of RID canals was also conducted in April and September. Prudential began installation of a SVE system to remediate soils beneath the facility. RID began a pilot test at well RID-95 to observe and study the use of granular activated carbon (GAC) in treating VOCs in groundwater. 2012: Groundwater monitoring and sampling was conducted in March and September. Air Liquide finalized a SVE pilot test work plan in March and conducted testing in June. The RI was completed for WVB in August. RID submitted a modified ERA in October. 2012: ADEQ issued the WVB RI Report and the ROs (Terranext 2012a). 2013: Groundwater monitoring and sampling was conducted in March and September. Groundwater sampling of RID wells and surface sampling of RID canals was conducted in April and September. ADEQ conditionally approved RID’s modified ERA on February 1. Prudential began operation of a SVE system in December to remediate soils beneath the facility. ADEQ signed a working agreement with the WVBWG to review their regional FS Work Plan and RID submitted a separate regional FS Work Plan for approval. RID and the WVBWG began conducting two separate FSs. Penn Racquet Sports, Inc., (Penn), located at 306 South 45th Avenue, settled with ADEQ for $30,000 dollars under Consent Decree 1301631. 2014: Groundwater monitoring and sampling was conducted in March. Groundwater sampling of RID wells and surface sampling of RID canals was conducted in March. Three new monitoring wells were 7 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 installed by ADEQ to help delineate the extent of the groundwater contamination and to investigate potential source areas. Air Liquide continued to monitor groundwater conditions beneath its facility. Prudential continued to operate its SVE system and monitor groundwater conditions below its facility. The operations and maintenance (O&M) manual for RID’s modified ERA was put out for public comment in June. The WVBWG (Haley & Aldrich, 2014) and RID (Synergy, 2014) submitted individual regional FS reports for the WVBA to ADEQ in July. 2015: The Arizona Department of Health Services (ADHS) prepared a Health Consultation evaluating the potential human health risk to exposure to RID well water and to RID canal water. 2015: ADEQ issued letters to both the WVBWG and RID regarding the draft feasibility studies in April (ADEQ, 2015a and 2015b). 2015: ADEQ received the “Evaluation of Feasibility Studies Regarding Technical Completeness, West Van Buren Water Quality Assurance Revolving Fund (WQARF) Site” technical memorandum from their consultant, Matrix-CALIBRE, in July (Matrix-CALIBRE, 2015). 2.3 A.R.S. §49-287.04(C) Notice The WVBA RI Report discusses numerous WVBA facilities that may have contributed to the groundwater plume. WVBA facilities identified in the RI Report as having conducted site investigations and, in most cases, remedial activities, include the following: • Air Liquide; • ALSCo; • ChemResearch; • Department of Energy; • Dolphin; • Maricopa County Materials Management; 8 Proposed Remedial Action Plan   Phoenix, Arizona  West Van Buren Area WQARF Site December 2015     Prudential;   Reynolds Metals Co.; and   Van Waters & Rogers (now Univar USA Inc.).  Many more WVBA facilities identified in the RI Report, as well as other potential sources in the WVBA  have not yet conducted site investigations. ADEQ’s Potentially Responsible Party (PRP) search for the  WVBA, including orphan sites, is ongoing. The WVB PRAP Working Group is preparing a preliminary list  of orphans for notice under A.R.S. §49‐287.04(C) as a separate filing.        9  Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 3.0 FEASIBILITY STUDY PROPOSED REMEDIES Separate FS reports were prepared for the WVBA WQARF registry site by the WVBWG (Haley & Aldrich 2014) and by RID (Synergy, 2014) in 2014. On April 13, 2015, ADEQ issued letters to the WVBWG (ADEQ, 2015a) and RID (ADEQ, 2015b) that both stated, “ADEQ has determined that the FS Report meets the requirements of Arizona Revised Statutes 49-287.03 and Arizona Administrative Code R18-16-407 and therefore ADEQ is approving the…FS Report. Please be aware though, that because competing Statewide budget priorities have resulted in the continued underfunding of WQARF, ADEQ will be discontinuing all discretionary work on the WVB WQARF site at this time. Should funding levels change, ADEQ will of course re-evaluate this decision.” On July 28, 2015, ADEQ received from its consultant, Matrix-CALIBRE, a technical memorandum entitled, “Evaluation of Feasibility Studies Regarding Technical Completeness, West Van Buren Water Quality Assurance Revolving Fund (WQARF) Site” (hereafter referred to as the Matrix Report) that “summarizes the technical completeness review of the two Feasibility Studies.” (Matrix-CALIBRE, 2015). Accordingly, this PRAP presents the Preferred Remedy for ADEQ’s consideration based on evaluating the proposed remedies from each FS, and incorporating comments from the Matrix Report. The separate proposed remedies are described in detail in the two FS reports (Haley & Aldrich, 2014 and Synergy, 2014), with the key elements of each summarized below. 3.1 WVBWG Proposed Remedy The WVBWG FS Report identified its “Reference Remedy” as the proposed groundwater remedy for the WVBA. As described in the FS, the WVBWG proposed remedy included the following base elements: 1) continued groundwater monitoring as part of a monitored natural attenuation (MNA) remedy; 2) completing an expanded private well inventory in an area adjacent to the WVBA. Although no private wells impacted by contamination from the WVBA are known to exist, for costing purposes it was assumed that five private wells would be replaced by a connection to the COP municipal supply; 3) focused plume core extraction with a new 500 gallon per minute (gpm) extraction well near 35th Avenue to potentially reduce the risk for implementing future contingent measures in 2026 when RID’s pumping ceases. Although safe for its intended use without treatment, due to RID’s policy regarding third-party discharges to its system, the extracted water would have to be treated prior to discharge to the RID Main canal for beneficial re-use as an irrigation water supply. As described in detail in the WVBWG FS, 10 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 and as discussed further below, in addition to the base remedy elements, the WVBWG proposed remedy also identified a number of contingent measures with triggers, one or more of which may be implemented in the future, if needed, based on Site conditions. 3.1.1 Matrix-CALIBRE Review of the WVBWG Proposed Remedy Matrix-CALIBRE, on behalf of ADEQ, reviewed the WVBWG proposed remedy and deemed it technically complete. The Matrix Report agreed with the overall SCM and technical practicability of the WVBWG proposed remedy, with some comments directed at the reasonableness of the proposed additional 500 gpm extraction well at the start of the remedy. For example, as stated in Table 3 of the Matrix Report, “Current risks are within acceptable thresholds for present use, remedial actions taken would not lower current risks by an appreciable amount.” The Matrix Report also noted that, “Contingency remedial actions are planned that would lower risk if resource is used for potable supply in the future.” (Table 3, page 1 of 8). With the exception of a specific element of the WVBWG proposed remedy discussed below, the overall finding of the Matrix Report was that, “The [WVBWG] recommended remedy is protective of public health and the environment; it provides for practicable control, management or cleanup of the hazardous substances to allow the maximum beneficial use of the waters of the state; and is reasonable, necessary, cost-effective, and technically feasible.” (Table 3, page 2 of 8). In regard to A.R.S. § 49-282.06(C)(1-2), which addresses the factors that the [ADEQ] Director shall consider in evaluating a proposed remedy, such as population, environmental, and welfare concerns at risk, and routes of exposure, the Matrix Report determined that for the WVBWG proposed remedy, “Presently, levels are not above risk thresholds (ADHS, 2015); future changes in groundwater use and corresponding risk are addressed.” In regard to A.R.S. § 49-282.06(C)(3), which addresses the amount, concentration, hazardous properties, environmental fate, persistence, and probability of contaminants reaching the waters of the state, and the form of the substance present, the Matrix Report determined that, “Most of the plume [which is noted as already being in the ‘waters of the state’] is at concentrations near the AWQSs [Aquifer Water Quality Standards] for PCE and TCE,” and that, “Limited areas have higher concentrations (more than 4 times the AWQSs).” As explained in the WVBWG FS, these “limited” areas are accounted for via contingencies in the proposed remedy should they be necessary at the time of planned implementation. 11 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 In addition to explaining that the WVBWG proposed remedy is reasonable and necessary for the WVBA, the Matrix Report also determined the proposed additional extraction well pumping at 500 gpm at the start of the remedy was “not reasonable” because it “does not appreciably improve current mass removal…” (Table 3, page 1 of 8). On a regional scale, the substantial volume of groundwater currently being pumped by the RID irrigation network represents the primary hydraulic influence on groundwater within the WVBA, already removes mass from the subsurface, and results in overall hydraulic containment of the current WVBA plume (Haley & Aldrich, 2014). Whether that extracted groundwater is treated at the surface or not does not change the fact that this dissolved-phase mass is already being removed from the subsurface by pumping for its intended use. Because of Matrix’s determination, the WVB PRAP Working Group re-evaluated the timeline for installation of this well, and now includes it in the Preferred Remedy as a primary contingency for future consideration, if needed. This contingent measure would be necessary, if, for example, future long-term groundwater pumpage from nearby cities overwhelm RID irrigation pumpage, which could result in reduced hydraulic containment of the plume in the WVBA and potential impact to downgradient wells (City of Tolleson [COT] and SRP). Details of this evaluation are presented in Section 4.0. 3.1.2 Statement from the Water Provider Members of the WVB PRAP Working Group (COP and SRP) Regarding the Utility of the 500 GPM Extraction Well The water provider members of the WVB PRAP Working Group (COP and SRP) believe it is important to clarify that although the Matrix Report concluded the 500 gpm well was “not reasonable” from a mass removal standpoint, the overall purpose for this well was to provide a proactive approach through additional control of plume migration in the highest concentration area until 2026, thereby reducing downgradient concentrations and the potential need to implement contingencies in the future at downgradient supply wells. The WVBWG FS modeling results show that the 500 gpm extraction well, pumping simultaneously with RID-95, would improve capture of the COC mass flux at 35th Avenue (Haley & Aldrich, 2014). The water providers also believe the 500 gpm extraction well helps, in part, to address the Matrix Report’s other criticism of the WVBWG FS proposed remedy; namely that some elements of the remedy may not be a robust solution if/when RID ceases pumping, including: 1) allowing the plume to migrate to downgradient COT/SRP wells; and 2) plume projections in 2026 may be ‘optimistic’ based on current attenuation rates. The WVBWG FS Report indicates VOC concentrations in the UAU2 plume 12 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 core are stable or increasing. The water providers continue to see the utility in this additional extraction well sooner rather than later in order to be protective of other downgradient production wells (COT and SRP), especially when the RID contract expires and ceases pumping no later than 2026. 3.2 RID Proposed Remedy The RID FS Report identified its “Less Aggressive Remedy” as RID’s proposed groundwater remedy for the WVBA. As described in the RID FS, which was mirrored in its Draft PRAP, the RID proposed remedy included the following key elements: 1) installing well head treatment at six RID wells (including the four wells where treatment units are already in place) and adjusting some of the pumping rates at these wells; 2) blending of six additional RID wells where VOCs have been observed; 3) replacing one RID well with a well with increased capacity; and 4) increasing the size of the pump and motor at one existing RID well to increase capacity (Synergy, 2014). Discharged water from the RID proposed remedy would be placed in the RID canal, including the canal containing treated wastewater effluent, and used for irrigation supplies for at least the near future as the required financing, legislative changes, legal decisions, permits, contracts, and infrastructure necessary to provide potable water from RID’s wells are serious obstacles to overcome. RID identified one contingent measure of injecting reclaimed wastewater into its identified replacement well on a seasonal basis (Synergy, 2014). No remedial measures or contingent measures were identified for other water providers, including the COP and SRP, in the vicinity of the WVBA. 3.2.1 Comments on the RID Proposed Remedy Extensive comments on the RID FS were prepared by the WVBWG (Gaylord, 2014). Numerous issues and errors in the RID FS were identified in these comments, the most significant of which are: 1) there is no current risk to public health that needs to be addressed by RID’s “remedy;” 2) the water produced from the RID wells is fit for its current use without treatment; and 3) the RID proposed remedy fails to meet, or even consider, the ROs of other water providers in the vicinity of the WVBA, including the conservation of water in the SRP and COP use areas (Gaylord, 2014). To focus more on these first two comments, the absence of current risk to the public health and the fitness of water extracted from RID wells for its current use without treatment were verified by the 13 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 ADHS which, in 2015, completed a Health Risk Consultation on the RID wells and canals. ADHS concluded that exposure to TCE, PCE, and 1,1-DCE concentrations in RID well RID-84 without any treatment would not be expected to harm people’s health under typical conditions of household water use (e.g. drinking, cooking, bathing, washing clothes and dishes, brushing teeth, gardening) (ADHS, 2015). ADHS further concluded that ingestion exposure to TCE and PCE in groundwater and canal water in the RID sampling area (29 RID irrigation wells and the RID canal) is not expected to harm people’s health (ADHS, 2015). The ADHS conclusion is supported by several prior health risk evaluations, which reached similar conclusions. RID confirmed that there is no current risk to the public health and the RID wells are fit for current use without treatment by operating wells RID-89, RID-92, RID-95, and RID-114 in bypass mode (circumventing the treatment units installed at those wellheads) in the latter portion (August and September) of the 2013 RID high pumping season and the 2014 high pumping season (May through September). ADEQ allowed RID to operate these wells in bypass mode without the need for treatment. RID does not own or operate the wellhead treatment systems, but the operator of the systems also removed Receiver Box Breathers (to control VOC emissions) from the wellheads because air samples at these boxes were similar to normal/background ambient air quality. This is shown through a comparison of the RID O&M Plan dated October 2013 (Revision 3, pp. 12-13; Synergy, 2013) and the RID O&M Plan dated May 3, 2012 (Revision 2, page 15; Synergy, 2012). 3.2.2 Matrix-CALIBRE Review of the RID Proposed Remedy Matrix-CALIBRE, on behalf of ADEQ, also reviewed the RID proposed remedy and similarly deemed it technically complete. The Matrix Report determined, however, that the RID proposed remedy was not reasonable, necessary, or cost effective. In the table of WQARF remedy requirements, the Matrix Report left blank the requirement that the proposed remedy is “reasonable, necessary, cost-effective, and technically feasible.” (Table 2, page 2 of 8). In the text of that table, the Matrix Report states as to the nonexistence of risk and unreasonableness of any current remedial action that, “Current risks are within acceptable thresholds for present use, remedial actions taken would not lower risk by an appreciable amount” and, “Remedial actions are not required for current use therefore they are not reasonable at this time…” (Table 2, page 1 of 8). The Matrix Report also determined that the RID proposed remedy is, “Not necessary until such time as future use of the resource is for potable supply; includes elements targeted more for water supply development rather than remediation.” (Table 2, page 1 of 8). The 14 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 Matrix Report also noted with respect to RID’s proposed remedy that, “The remedial action removes the groundwater resource from the current water basin.” (Table 2, page 3 of 8). RID’s proposal is designed to facilitate it’s attorneys’, consultants’, and investors’ development plans to become a potable water supplier despite issues raised by other water providers: “The FS presents remedial actions that are consistent with RID’s development plans. Other water providers and local governments have raised issues regarding RID’s plans in the public comments.” (Table 2, page 5 of 8). The Matrix Report also identified flaws in RID’s risk evaluation, noting that the evaluation was based on “…historical conditions (without historical exposure estimates) rather than current resource use and exposure pathways.” (Table 2, page 6 of 8). Given these fundamental deficiencies of the RID proposed remedy, as well as the numerous other issues with RID’s proposed remedy documented to ADEQ, the RID proposed remedy is not considered to be reasonable, necessary, or cost effective and was, therefore, rejected for consideration in the WVBA. In summary, the findings presented in the Matrix Report are that current risks are acceptable and RID’s proposed remedial actions are not reasonable, necessary, or cost effective. Further, the Matrix Report concludes that RID’s proposed remedy fails to meet certain ROs because elements of RID’s proposed remedy are geared towards RID’s development plans, and those plans export water from the current groundwater basin, inconsistent with the objectives of other water providers and local governments in the WVBA. In accordance with these findings, there are no components of the RID proposed remedy that will be incorporated into the Preferred Remedy identified in this PRAP. 15 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 4.0 PREFERRED REMEDY Based on review of the RID FS and comments provided in the Matrix Report, the Preferred Remedy for ADEQ’s consideration for the WVBA is a modified version of the WVBWG Reference Remedy that moves the proposed extraction well at 500 gpm from a base component to a primary contingency. The Preferred Remedy also includes more frequent hydrogeologic evaluations as a base component to determine if contingencies are needed at that time. 4.1 Observations and Assumptions The Preferred Remedy is based on the following primary observations and assumptions used during the development of the various remedial alternatives: • Regional irrigation pumping has a significant influence on overall water levels, hydraulic gradients, and groundwater flow directions within the WVBA. • Facility-specific remedial work within the WVBA has resulted in declining source inputs to the WVBA regional plume; ADEQ will continue to implement source control measures. • The M52 OU2 groundwater extraction system has contained the VOC mass flux at the OU2 boundary. • VOC concentrations in UAU1 regional groundwater have generally been on the decline. • The overall lateral extent of the WVBA plume has either decreased or remained stable, depending on the area. • The West Osborn Complex implements its WQARF remedy that addresses continuing migration of VOCs into the north-central portion of the WVBA. • RID irrigation pumping will continue at existing rates until 2026. 16 Proposed Remedial Action Plan Phoenix, Arizona 4.2 West Van Buren Area WQARF Site December 2015 Preferred Remedy The Preferred Remedy incorporates, as all groundwater remedies must, the existing and ongoing hydraulic controls (due to ongoing RID irrigation pumping) within the area to be addressed, along with an evaluation of the actual risk associated with the subsurface impacts. The Preferred Remedy is consistent with the neutral evaluation presented in the Matrix Report by modifying it to make installation of the 500 gpm extraction well a primary contingent measure subject to periodic hydrogeologic evaluations, as described below. As modified, the Preferred Remedy provides the most reasonable, necessary, cost-effective, and technically feasible remedial alternative to address the groundwater plume in the WVBA considering that until 2026, ongoing RID irrigation pumping is maintaining hydraulic control of the plume. The Preferred Remedy relies on an enhanced groundwater monitoring program, MNA, hydrogeological evaluations, and more contingent remedial measures in the event that wells (public or private) located within or outside of the WVBA are threatened to be rendered unfit for their current and reasonably foreseeable end uses as a result of migration of groundwater contamination within or from the WVBA. The Preferred Remedy includes the following components: Base Components (assumes RID is pumping at current volumes): • Groundwater monitoring program. • Although no impacted private wells have been identified, for costing purposes provides for the connection of five private wells within the WVBA to the COP municipal system. • Conduct of a hydrogeological evaluation beginning in 2019, and every 3 years thereafter through 2025, to determine the benefits of focused groundwater extraction with a 500 gpm plume core extraction well, treatment, and subsequent reinjection of the extracted water into the Lower Alluvial Unit (LAU). The hydrogeologic evaluation would evaluate existing groundwater data and calculate projected COC mass removal (if any) based upon a trend analysis of the most recent (at the time) water quality data. It may also include use of a groundwater model to determine if the pumping would have beneficial impacts on protecting current or future downgradient production 17 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 wells. The detailed hydrogeological evaluation could also assess alternative remedial technologies if available. The hydrogeologic evaluation would be reviewed by ADEQ, the COP and SRP, and other involved WVBWG members to determine if contingencies are needed at that time. Potential Contingencies after 2025 (assumes RID ceases groundwater pumping): The potential contingent measures that have been identified include: • Conduct of a hydrogeologic evaluation for the need to install one 500 gpm plume core extraction well if one had not been previously installed, or continue, expand, or terminate operation of the well if one had been previously installed, beyond 2025. The hydrogeologic evaluation would evaluate existing groundwater data and calculate projected COC mass removal (if any) based upon a trend analysis of the most recent (at the time) water quality data. It may also include use of a groundwater model to determine if the pumping would have beneficial impacts on protecting current or future downgradient production wells. The detailed hydrogeological evaluation could also assess alternative remedial technologies if available. The hydrogeologic evaluation would be reviewed by ADEQ, the COP and SRP, and other involved WVBWG members to determine if contingencies are needed at that time. • Conduct of a hydrogeologic evaluation for the need to install an additional 1,000 gpm extraction well in an area most beneficial to addressing any remaining COC mass that has the potential to impact current and future downgradient production wells. The primary goal of this contingent remedial action would be to reduce (if needed) the potential future risk of impairing SRP, COP, and other production wells. The detailed hydrogeological evaluation would assess alternative remedial technologies if available and calculate projected COC mass removal (if any) by the 1,000 gpm extraction well based upon a trend analysis of the most recent (at the time) water quality data from wells within the plume. A groundwater model may be used to evaluate if the extra pumping will have an additional beneficial impact on capture of upgradient COC impacted groundwater and protecting current or future downgradient extraction wells, and to evaluate the potential impact to current and future production wells if no additional contingent remedial actions are conducted. Replacing up to two SRP wells (with or without any additional groundwater pumping) and other 18 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 appropriate alternative contingent actions should any be deemed necessary at the appropriate time would also be evaluated. The hydrogeologic evaluation would be reviewed by ADEQ, the COP and SRP, and other involved WVBWG members to determine if contingencies are needed at that time. • Drill and construct up to nine new sentinel monitoring wells if groundwater flow directions change in response to reduced or eliminated RID irrigation pumping. • An allowance for conducting quarterly monitoring at up to sixteen monitoring wells and eleven SRP wells based on future groundwater flow conditions. • An allowance to connect up to five private wells outside the WVBA to the COP municipal system if groundwater flow directions change in response to reduced or eliminated RID irrigation pumping and such wells exist and are threatened by any remaining impacted groundwater. • An allowance to replace RID-114 with a new UAU production well at a different location to be determined based on need and the regional hydraulics at that time. 4.3 Estimated Remedial Action Costs Consistent with the WVBWG FS and R18-16-407(H)(3)(c), the estimated cost of the Preferred Remedy includes expenses and losses, including capital, operating, maintenance, and life cycle costs. The estimated cost for the Preferred Remedy is presented for both the base components and contingencies, with the understanding that it is unlikely that all contingencies listed may be necessary in the future. A discount rate of 6 percent was used to calculate the Net Present Value (NPV) for O&M and capital costs required beyond the year one of the remedy. NPV analysis is the standard method accepted by established guidance for conducting FSs to evaluate both capital and O&M expenditures that are expected to occur over time. EPA guidance notes that while non-discounted constant dollar values can 19 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 be provided for illustrative purposes, they should not be used in place of NPV costs in selecting remedies (EPA, 2000).1 The Preferred Remedy base components total NPV cost is estimated at $3.28M ($10.35M nondiscounted with 3 percent inflation rate). The estimated NPV costs for the Preferred Remedy individual contingencies described above range from $0.02M to $5.10M ($0.07M to $28.10M non-discounted with 3 percent inflation rate). The total NPV for all Preferred Remedy contingencies, should the unlikely event occur that all contingencies are required for the full remedy period is approximately $15.96M, including $8.40M capital and $7.56M O&M expenses. Consistent with R18-16-407(H)(3)(c), it is reasonable to assume that less than 50 percent of the identified contingent costs would require implementation. Table 1. Preferred Remedy Remedial Action Costs Base Components Contingencies (sum of all) Total Estimated Cost (including all contingencies) NPV at 6 percent Discount Rate* Non-discounted with 3 percent Inflation* $3.28 $10.35 $0.02 to $5.10 ($15.96) $0.07 to $28.10 ($72.53) $19.24 $82.88 *All dollars in millions There is a significant cost savings in investing today’s dollars for future contingent actions. As such, when evaluating total costs for the Preferred Remedy, one does not look at the total cost today (nondiscounted cost) because that overestimates the amount of money needed for an action to be implemented years in the future. That is the reason why remedial action costs are always presented in NPV terms. At a NPV value cost of <$20 million, the Preferred Remedy presented in this PRAP meets the ROs. Under WQARF, ADEQ is responsible for the shares of orphan parties who contributed to the plume. In other words, ADEQ is responsible for protecting the State’s resources from being spent on remedies 1 The Matrix Report presented the total cost for the WVBWG Reference Remedy in current dollars, without converting these costs to NPV. As noted in the text, NPV cost is the appropriate cost to consider in selecting remedies. Consistent with MatrixCALIBRE’S determinations, the Preferred Remedy relies primarily on contingent future actions (if needed), so showing the NPV cost also documents for the public relative cost savings associated with investing remedial dollars over time. 20 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 that are not cost effective, reasonable, or necessary. The Preferred Remedy as modified is cost-effective, reasonable, and necessary and represents a significant cost savings to Arizona taxpayers. 4.4 Achievement of Remedial Objectives In 2012, ADEQ established WVBA ROs for impacted or threatened land and water in terms of current and reasonably foreseeable land use and current and reasonably foreseeable beneficial uses of the waters of the state [(R18-16-406(D) and (I)]. Reasonably foreseeable land uses are those uses of land likely to occur at the Site. Reasonably foreseeable water uses are those likely to occur within 100 years unless a longer time period is shown to be reasonable based on site-specific information. ADEQ’s ROs for the WVBA were based on the 2012 Land and Water Use Report that contains descriptions of current and reasonably foreseeable land use for the COP and COT, and current and reasonably foreseeable use of water for the COP, COT, SRP, RID, and private wells within the WVBA (Terranext, 2012a). The WVBWG consulted with the area water providers to obtain additional information to develop remedial measures. As part of a October 2, 2013 meeting between the WVBWG’s consultant Haley & Aldrich and local water providers, the COP, SRP, and RID provided additional information regarding their current and reasonably foreseeable future use of groundwater within and adjacent to the WVBA (Haley & Aldrich, 2014). Information on the proposed future COT production wells was provided by COT’s Supervisor of Water Utilities (COT, 2014). The ROs for each impacted or threatened land and water use and the methods by which the ROs would be achieved by the Preferred Remedy are listed in the following. 4.4.1 Remedial Objectives for Land Use The ROs for land use in the WVBA are: • “Protect against possible exposure to hazardous substances in surface and subsurface soils that could occur during development of property based upon applicable zoning regulations”; 21 Proposed Remedial Action Plan Phoenix, Arizona • West Van Buren Area WQARF Site December 2015 “Protect against possible leaching of hazardous substances in surface and subsurface soils to the groundwater”; and • “Protect against the loss or impairment of current and all reasonably foreseeable future uses of land as provided in zoning regulations and the Land and Water Use report as a result of hazardous substances in surface and subsurface soils. Appropriate remedial actions will be implemented as an Early Response Action (ERA) or after the record of decision (ROD) is finalized, whichever is warranted and continued until hazardous substances causing the impairment or restriction to the land use are remediated.” The WVBA is located within the COP and abuts the COT’s eastern boundary at 75th Avenue. Current and future land use is provided in the COP’s General Plan, which includes the goals, policies, and recommendations for land use development during the next 10 to 20+ years. In 2000, the highest percentages of land use for the COT were agriculture (46 percent); industrial/warehouse (24 percent); and residential (14 percent). Land use in the eastern portion of the COT, adjacent to the WVBA, is primarily agriculture and industrial (Terranext, 2012b). Land use within a portion of the WVBA and adjacent areas has been transitioning from irrigated agricultural lands to more urbanized municipal uses (residential and industrial) and that trend is expected to continue into the future. Mitigating or eliminating facility-specific source areas is critical to addressing any potential exposure to hazardous substances, protecting against possible leaching of hazardous substances in surface and subsurface soils to the groundwater, and protecting against the loss or impairment of current and all reasonably foreseeable future uses of land. Without addressing ongoing sources, the regional plume will likely persist. Facility-specific remedial work within the WVBA has resulted in declining source inputs to land and water. Some facilities within the WVBA have performed remedial work and as a result, VOC concentrations in soils have been reduced to concentrations below applicable standards and COC concentrations in facility-specific groundwater monitoring wells have been reduced. The effect of this work has reduced VOC source inputs in soils and the WVBA regional plume, resulting, in part, in overall declining VOC concentration trends. 22 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 The Preferred Remedy assumes that additional facility-specific source work, to the extent any is necessary, will be completed under ADEQ guidance separate from the Preferred Remedy, and ADEQ has confirmed its intention to continue to work to identify and address any facility sources in the WVBA. 4.4.2 Remedial Objectives for Groundwater Use ADEQ’s RO report included ROs for municipal, agricultural, and private uses of groundwater. Municipal Groundwater Use: The ROs for current and reasonably foreseeable future municipal groundwater use in and near the WVBA are: • “To protect, restore, replace or otherwise provide a water supply for municipal use by currently and reasonably foreseeable future municipal well owners within the WVBA WQARF site if the current and reasonably foreseeable future uses are impaired or lost due to contamination from the site. Remedial actions will be in place for as long as need for the water exists, the resource remains available and the contamination associated with the WVBA WQARF site prohibits or limits groundwater use. Remedial actions to meet ROs will be implemented upon issuance of the ROD. If there is an imminent risk to human health or the environment, then an ERA may be initiated prior to implementation of the ROD.” • “To protect, restore, replace or otherwise provide a water supply for municipal groundwater use by currently and reasonably foreseeable future municipal well owners outside the current plume boundaries of the WVBA WQARF site if the current and reasonably foreseeable future uses are impaired or lost due to contamination from the site. Remedial actions will be in place for as long as need for the water exists, the resource remains available and the contamination associated with the WVBA WQARF site prohibits or limits groundwater use. Remedial actions to meet ROs will be implemented upon issuance of the ROD. If there is an imminent risk to human health or the environment, then an ERA may be initiated prior to implementation of the ROD.” COP: The COP has no wells within the WVBA that are either supplying water or are part of the COP’s water system, and no existing COP production wells with anticipated production within the next 30 years are located northwest of the WVBA, should regional irrigation pumping cease and the overall 23 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 groundwater flow direction shift to a more northwest flow direction. While the COP does not have specific plans for groundwater wells within the WVBA today, the COP states in its 2011 Groundwater Management Plan, “With regard to remediation of contaminated groundwater within Phoenix’s service area, it has been the City’s stated intent to preserve that water for future service area use.” The COP’s Groundwater Management Plan envisions groundwater within the WVBA will someday be a necessary component of the COP’s drought supply, and that the SRP is likely to serve a role in delivering the groundwater. COT: The COT has no wells within the WVBA that are either supplying water or are part of the COT’s water system. The COT has four production wells located west of the WVBA that are mainly used in the summer months as a backup supply (COT, 2005). The COT also intends to drill and construct five new production wells over the next 3 to 10 years (COT, 2014). Based on the WVBWG FS groundwater modeling results, none of the existing or proposed future COT production wells would likely become impaired under the Preferred Remedy (Haley & Aldrich, 2014). However, to reduce uncertainty, consultation with the COT is suggested regarding the proposed location of future wells. RID: RID operates 32 groundwater production wells within or adjacent to the WVBA. These wells are not impaired today, as they are currently fit for their current irrigation end use without the need for treatment of COCs (ADHS, 2015; Haley & Aldrich, 2014). The ROs establish future drinking water use as reasonably foreseeable. If changes of end use occur before declining contaminant levels render the water fit for drinking water use without the need for treatment of COCs, and RID is able to obtain legal authorization to deliver water to third-party drinking water providers for potable use, strategies or measures will be needed to provide for the new use. Regarding reasonably foreseeable water uses, the November 12, 2007 Land and Water Use Report questionnaire completed by RID (RID, 2007) stated that RID’s current water use is “for non-potable purposes within the District’s boundaries” and RID’s future water use of wells, canals, and laterals for the foreseeable future “will continue to be used much as they are today.” The RID questionnaire also stated the future use (up to 100 years) for any RID well impacted by the WVBA plume would be, “Same as today.” RID submitted a revised questionnaire to ADEQ dated January 12, 2010 (RID, 2010) which stated that “Currently, the wells in the WVB site provide water supply for irrigation but the wells will 24 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 transition to drinking water supply as residential and commercial development continues in the District.” The revised questionnaire did not explain the legal mechanism or timing of this proposed transition. RID clarified in its response to the water provider questionnaire that it does not intend to itself become a potable water provider or provide direct delivery of potable water to its own customers. RID has proposed sale of its water supply to water providers outside the WVBA. RID proposed that the water would serve as a raw water supply for drinking water end uses by the purchasers’ customers (RID, 2010). The Arizona Department of Water Resources (ADWR) has expressed concern about RID’s authority to move groundwater from within the boundaries of a water provider that has obtained a Designation of Assured Water Supply (in this case, the COP) and the potential to negatively affect that Designation (ADWR, 2010). Others have raised additional concerns regarding RID’s authority to move groundwater from within the WVBA in the future (SRP, 2011; Gaylord, 2011). These legal issues have not yet been resolved. SRP: SRP has several groundwater production wells near the WVBA, although none of them are located within the WVBA boundaries. To date, SRP’s use of these wells has not been impacted by the WVBA groundwater plume. As a result of changing land use in the area, SRP anticipates that some SRP wells will eventually transition to a drinking water use in the reasonably foreseeable future, either by directly connecting the wells to municipal distribution systems within the Salt River Reservoir District (SRRD), or piping to municipal water treatment plants located on the SRP canal system as a drought supply (SRP, 2011). With ADEQ-directed source control measures and continued RID groundwater extraction, contaminant concentrations in groundwater will continue to decrease over time and could fall below the AWQS before future potable water uses become viable (Haley & Aldrich, 2014). Extensive groundwater monitoring within the WVBA will provide the basis for determining which, if any, proposed contingent remedial measures will be implemented. The proposed monitoring program will include the sampling of the existing monitoring network of 68 UAU1, 27 UAU2, and 6 Middle Alluvial Unit (MAU) monitoring wells for COC analysis, and total chromium and filtered total chromium analyses at select wells. A subset of monitoring wells within the interior of the plume would also be sampled and 25 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 analyzed for MNA parameters annually. Water level elevation measurements would be taken from approximately 120 monitoring wells semiannually. If the existing monitoring program was determined to be inadequate should RID stop pumping in 2026 and groundwater flow direction in the WVBA system changes, seven existing UAU1 monitoring wells located along the northern and western perimeter of the WVBA, along with five new sentinel wells located to the west-northwest of the WVBA, would be sampled and analyzed for COCs quarterly for the first year and then at an appropriate frequency thereafter. If operating, the eleven SRP wells located west and northwest of the WVBA, will also be sampled and analyzed for COCs during the sentinel monitoring events. In addition to the planned evaluations included in the Preferred Remedy base components, if routine groundwater monitoring indicates a significant change to hydraulic and/or water quality conditions (i.e., COC concentrations increase significantly, groundwater flow directions change significantly, and/or plume migration is more rapid than predicted), further hydrogeologic evaluations would be conducted to assess the need for changes to the existing monitoring well network. These would include additional model simulations to determine if the changes in hydraulic and/or water quality conditions would have negative impacts on planned remedial actions and downgradient users, and if additional, unplanned remedial activities are warranted. Remedial activities that may be considered in this analysis include more frequent monitoring and installing a more enhanced monitoring network. The monitoring program will provide data on: (1) the nature and extent of the WVBA plume; (2) the overall stability of the plume’s lateral and vertical extent; (3) COC concentration trends over time; and (4) intrinsic MNA processes within the UAU aquifer. Water level elevation data would also be used to evaluate seasonal hydraulic gradients, long-term water level elevation trends, and aquifer response to changes in regional pumping conditions. The overall stability of the UAU2 plume extent over time would also be further evaluated using data from UAU2 monitoring wells. The hydrogeologic evaluation conducted at the end of 2025 in accordance with Section 4.2 of this PRAP would be used to determine, based upon the 2025 water level elevation and water quality conditions within the WVBA plume, if proposed contingencies or other technically feasible contingencies should be implemented to protect current or future downgradient production wells. Any contingent extraction 26 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 wells will be evaluated to ensure that the remedial benefit of extraction is balanced with the value of the resource (i.e., groundwater will be removed from storage only as necessary to achieve the ROs and the value of leaving groundwater in storage within the aquifer for potential future use will be considered). Depending on the results of the hydrogeologic evaluation that would be reviewed by ADEQ, the COP and SRP, and other involved WVBWG members, the Preferred Remedy could result in implementation of one or more of the following additional contingent remedial measures: • Installation, operation and treatment of a new 500 gpm extraction well, or if one had been previously installed, continued operation or expanded operation, with reinjection of the treated water; • Installation, operation and treatment of a new 1,000 gpm extraction well, with reinjection of the treated water; • In the event that SRP wells become impaired for their intended use as a result of WVBA contamination, then a contingent measure such as well replacement, or special well design and construction features may be appropriate. Up to two SRP wells could be replaced with collocated production wells of equivalent capacity completed solely in the LAU; • Replacing well RID-114 at another location along the Salt Canal, outside of the plume boundary, combined with a well operational approach as currently employed by RID; and/or • Other technically feasible measures. Agricultural Groundwater Use: The ROs for current and reasonably foreseeable future agricultural groundwater use in and near the WVBA are: • “To protect, restore, replace or otherwise provide for the current and reasonably foreseeable future supply of groundwater for agricultural/irrigation use and for the associated recharge capacity that is threatened by or lost due to contamination associated with the WVBA WQARF site. Remedial actions will be in place for as long as need for the water exists, the resource remains available and 27 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 the contamination associated with the WVBA WQARF site prohibits or limits groundwater use. Remedial actions to meet ROs will be implemented upon issuance of the ROD. If there is an imminent risk to human health or the environment, then an ERA may be initiated prior to implementation of the ROD.” RID operates 32 groundwater production wells within or adjacent to the WVBA. The results of the Human Health Risk Assessment (Haley & Aldrich, 2014) indicate that water from RID production wells is currently safe for its current agricultural/irrigation use without remedial measures. Concentrations of COCs in WVBA groundwater have generally declined or are stable. With ADEQ-directed source control measures, continued operation of the M52 remedy, and continued RID irrigation pumping until 2026, COC concentrations are expected to continue to decrease over time. The potential that COC concentrations will increase in RID wells used for irrigation is low. However, if concentrations of COCs in WVBA groundwater increase to levels that threaten or impair agricultural/irrigation use by RID or others, contingencies as identified in the Municipal Groundwater Use subsection could be implemented based on the actual conditions at that time. Private Groundwater Use: The ROs for current and reasonably foreseeable future private groundwater use in and near the WVBA are: • “To protect, restore, replace or otherwise provide a water supply for potable or non-potable use by currently impacted commercial, industrial, and domestic well owners within the WVBA WQARF site if the current and reasonably foreseeable future uses are impaired or lost due to contamination from the site. Remedial actions will be in place for as long as need for the water exists, the resource remains available and the contamination associated with the WVBA WQARF site prohibits or limits groundwater use. Remedial actions to meet ROs will be implemented upon issuance of the ROD. If there is an imminent risk to human health or the environment, then an ERA may be initiated prior to implementation of the ROD.” • “To protect, restore, replace or otherwise provide a water supply for potable or non-potable use by commercial, industrial, and domestic well owners outside the current plume boundaries of the WVBA WQARF site if the current and reasonably foreseeable future uses are impaired or lost due to 28 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 contamination from the site. Remedial actions will be in place for as long as need for the water exists, the resource remains available and the contamination associated with the WVBA WQARF site prohibits or limits groundwater use. Remedial actions to meet ROs will be implemented upon issuance of the ROD. If there is an imminent risk to human health or the environment, then an ERA may be initiated prior to implementation of the ROD.” The Land and Water Use study (Terranext, 2012b) identified a number of private wells within the WVBA plume area. Most of these private wells are used for irrigation or livestock. The private wells sampled have water quality suitable for their current uses according to ADEQ (Haley &Aldrich, 2014). There are no currently impaired private wells outside the WVBA. The water supply to any impaired private wells that become unfit for their end use as a result of WVBA contamination would be replaced. Such well properties will be connected to the COP municipal water distribution system at the appropriate time. 4.4.3 Remedial Objectives for Canal Water Use The ROs for RID’s current and reasonably foreseeable future canal water use in and near the WVBA are: • “To protect, restore, replace or otherwise provide a water supply for potable or non-potable use by currently impacted RID wells within the WVBA WQARF site if the current and reasonably foreseeable future uses are impaired or lost due to contamination from the site. Remedial actions will be in place for as long as need for the water exists, the resource remains available and the contamination associated with the WVBA WQARF site prohibits or limits groundwater use. Remedial actions to meet ROs will be implemented upon issuance of the ROD. If there is an imminent risk to human health or the environment, then an ERA may be initiated prior to implementation of the ROD.” • “To protect, restore, replace or otherwise provide a water supply for potable or non-potable use by RID wells outside the current plume boundaries of the WVBA WQARF site if the current and reasonably foreseeable future uses are impaired or lost due to contamination from the site. Remedial actions will be in place for as long as need for the water exists, the resource remains available and the contamination associated with the WVBA WQARF site prohibits or limits groundwater use. Remedial actions to meet ROs will be implemented upon issuance of the ROD. If 29 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 there is an imminent risk to human health or the environment, then an ERA may be initiated prior to implementation of the ROD.” If RID is authorized in the reasonably foreseeable future to deliver water to third-party drinking water providers for potable use, measures may be needed to provide for that use. To the extent reclaimed wastewater from the COP’s 23rd Avenue Wastewater Treatment Plant (WWTP) is conveyed via the Main Canal, the Main Canal cannot be used for delivering drinking water. Any use of the Main Canal for deliveries of water to drinking water providers could only begin after effluent discharges cease. Assuming there is no effluent being conveyed in the Main Canal, to determine whether measures may be needed, a mass balance approach could be used to estimate TCE and PCE concentrations at the end of the Salt Canal, the end of the Main Canal, and the confluence of the two canals. A blending approach could be employed, consisting of blending extracted groundwater from RID wells at current rates within and adjacent to the WVBA. Mass balance calculations indicate that, under current RID pumping conditions, and using the most recent available water quality data from RID wells, blended water at the confluence of the Salt Canal and Main Canal would be below the AWQS for PCE and slightly above the AWQS for TCE (Haley & Aldrich, 2014). Blending additional water from other RID wells located within the SRRD and RID wells west of the Aqua Fria River would serve to reduce concentrations to below regulatory thresholds in the blended water prior to delivery to the west valley. Continued COC concentration declines over time within the WVBA would also result in lower concentrations in the future. Water in the Salt Canal may meet AWQSs and be suitable for delivery to third-party drinking water providers should RID obtain authorization to make such deliveries and after RID completes construction of the infrastructure and obtains the contracts required to make such deliveries. If it does not, well RID114 could be replaced as a contingent well measure should RID obtain authorization to employ only wells on the Salt Canal for drinking water supply end use. The highest VOC concentrations in RID wells along the Salt Canal are observed in well RID-114 based on historical data. If this well were addressed with a remedial measure such as well replacement, and the VOC concentrations were assumed to be non-detect in the replacement well, the blended TCE and PCE concentrations at the end of the Salt 30 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 Canal, based on 2014 concentrations, would calculate to 3.9 micrograms per Liter (µg/L) and 4.9 µg/L, respectively. Both of these concentrations are less than their respective AWQS. 4.4.4 Remedial Objectives for Surface Water Use The ROs for SRP’s current and reasonably foreseeable future surface water use in and near the WVBA are: • “To protect, restore, replace or otherwise provide a water supply for potable or non-potable use by SRP wells outside the current plume boundaries of the WVBA WQARF site if the current and foreseeable future uses are impaired or lost due to contamination from the site. Remedial actions will be in place for as long as need for the water exists, the resource remains available and the contamination associated with the WVBA WQARF site prohibits or limits groundwater use. Remedial actions to meet ROs will be implemented upon issuance of the ROD. If there is an imminent risk to human health or the environment, then an ERA may be initiated prior to implementation of the ROD.” No SRP wells are currently located within the WVBA, but SRP has several groundwater production wells located in the vicinity of the WVBA that feed the SRP lateral system. Because SRP wells are used to supplement surface water supply on an as-needed basis, their annual groundwater use fluctuates depending upon the availability of surface water (SRP, 1996). To date, SRP’s use of these wells has not been impacted by the WVBA groundwater plume. As a result of changing land use in the area, SRP anticipates that some SRP wells will eventually transition to a drinking water use in the reasonably foreseeable future, either by directly connecting the wells to municipal distribution systems within the SRRD, or piping to municipal water treatment plants located on the SRP canal system as a drought supply (SRP, 2011). Several SRP wells are located northwest of the WVBA. Should regional pumping within and adjacent to the WVBA be significantly reduced or cease altogether, a rise in the water table and associated shift in groundwater flow direction from westerly to a more northwesterly direction is anticipated based on historical groundwater flow directions and the WVBWG’s FS modeling results (Haley & Aldrich, 2014). 31 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 As described in the Municipal Groundwater Use subsection, extensive groundwater monitoring within the WVBA will provide the basis for determining which, if any, proposed contingent measures will be implemented. If the existing monitoring program was determined to be inadequate in the event that RID stops irrigation pumping in 2026 and groundwater flow direction in the WVBA system changes, additional new and existing UAU1 monitoring wells (twelve total) located along the northern and western perimeter of the WVBA, would be monitored for COCs starting in 2026. In addition, if operating, the eleven SRP wells located west and northwest of the WVBA, would also be sampled and analyzed for COCs during the sentinel monitoring events The hydrogeologic evaluation conducted at the end of 2025 would be used to determine, based upon the 2025 water level elevation and water quality conditions within the WVBA plume, if proposed contingencies or other technically feasible contingencies should be implemented to protect current or future downgradient production wells. In the event that the SRP wells become impaired for their intended use as a result of WVBA contamination, then a contingent measure such as well replacement, or special well design and construction features may be appropriate. Up to two SRP wells could be replaced with collocated production wells of equivalent capacity completed solely in the LAU. 4.5 Consistency with Water Management Plans City of Phoenix: Currently there are no COP production wells within the WVBA. The 2011 update to the COP’s Water Resources Plan provided information on water acquisition, water management, and infrastructure needed to ensure a sustainable water supply for current customers and anticipated growth over the next 50 years. In a normal supply year, the COP water demand of approximately 302,000 AFY is currently met with the following sources: • SRP (50 percent); • Central Arizona Project ([CAP]; 44 percent); • Reclaimed Water (3 percent); and 32 Proposed Remedial Action Plan Phoenix, Arizona • West Van Buren Area WQARF Site December 2015 Groundwater (3 percent). In years with surface water shortfalls, a portion of the COP supply may consist of groundwater pumped from SRP wells. The COP also maintains a number of groundwater production wells for operational flexibility and use when CAP and/or SRP supplies are reduced (COP, 2011). As noted above, currently there are no COP or SRP production wells within the WVBA. Historically, the COP developed or acquired more than 200 production wells, although the COP has removed a majority of these wells from service due to age, decreased efficiency, and/or degraded groundwater quality.2 From 1981 to 2000, the total loss of COP well production due to degraded groundwater quality exceeded 90,000 AFY. While some COP production wells have been impacted by VOCs, many COP wells have been closed due to groundwater degradation from inorganic constituents such as chromium, arsenic, and nitrate (COP, 2011). The COP currently has access to 25 groundwater production wells that can generate 28 million gallons of water per day, or approximately 31,350 AFY. These wells are located 1 mile or more from the WVBA, mostly in the north-central portion of the COP, and are used for operational flexibility and during times of reduced CAP and/or SRP surface water supplies. The actual number of available production wells varies at any given time due to maintenance issues. Based on the current COP production well capacity and a 65 percent duty cycle, the COP can produce approximately 20,000 AFY from these wells (COP, 2011). The current projected groundwater use for normal supply years and General Plan-based growth is 15,000 AFY, although withdrawals in recent years have been lower, averaging approximately 9,000 AFY. The COP is evaluating the expansion of its groundwater production well network to increase operational flexibility, manage water quality, and reduce the impacts of potential future surface water shortages. 2 COP Well #179, the only COP production well located within the WVBA, has been abandoned. 33 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 Salt River Project: There are no SRP wells currently located within the WVBA. The SRP manages surface water and groundwater rights within the SRRD geographic region. The WVBA is within SRP “Member” lands and groundwater within the WVBA underlies the SRRD. SRP has several groundwater production wells located in the vicinity of the WVBA that feed the SRP lateral system. Because SRP wells are used to supplement surface water supply on an as-needed basis, their annual groundwater use fluctuates depending upon the availability of surface water (SRP, 1996). From 2003 through 2013, total SRP pumping within 5 miles of the WVBA ranged from 13,500 AFY in 2008 to 72,300 AFY in 2003. The total depth of these wells range from about 500 to 1,500 feet deep, in most cases constructed with 16- to 20-inch casing, and are generally completed within the UAU and MAU, although some are completed in the MAU and LAU. During 2012, approximately 64 percent of water delivered by SRP was for municipal/industrial use within the totality of the SRP service area, with 36 percent for agricultural use, turf irrigation, and recreational use. These percentages have been relatively consistent since 2007 (SRP, 2013). To date, no SRP wells have been impaired by the WVBA plume (SRP, 2011). Roosevelt Irrigation District: RID pumps the largest amount of groundwater within the WVBA under contracts with the SRP, and all of it is used to provide irrigation water to members in RID’s service area west of the Agua Fria River, outside of the WVBA. In the late 1910s, waterlogged land resulting from regional hydrogeologic conditions and irrigation return flows threatened local farming operations within the WVBA. In 1920, SRP entered into an agreement with the Carrick and Mangham Agua Fria Lands and Irrigation Company (RID’s predecessors) to withdraw a certain amount of groundwater to help alleviate the waterlogged conditions. According to SRP, the 1920 agreement and subsequent supplemental agreements for water production with CarrickMangham and RID will expire no later than 2026 (SRP, 2009). RID operates approximately 50 wells within the SRRD during the peak irrigation season, generally from March to September (Terranext, 2012b) and 32 of these wells are located within or adjacent to the WVBA. Total annual RID pumping within the SRRD is approximately 135,000 AFY (SRP, 2009), which is 34 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 conveyed to the RID irrigation service area west of the Agua Fria River via a system of canals and pipelines. About 75,000 AFY is pumped from 32 RID wells within and adjacent to the WVBA and 60,000 AFY are pumped from the remaining 18 RID wells. During 2008 and 2009, the average pumping rate of RID wells within the WVBA ranged from approximately 1,500 to 4,800 gpm (Montgomery & Associates, 2009a). Total depths of RID wells located within and adjacent to the WVBA range from 284 to 1,800 feet deep. Most of the RID wells are screened across the UAU1, UAU2, and into the upper MAU, with some of the deeper wells screened across the UAU1, UAU2, MAU, and into the LAU. The COP 23rd Avenue WWTP discharges approximately 30,000 AFY to the RID Main Canal on a yearround basis as part of a “3-way exchange” between the COP, RID, and SRP in which: (1) the COP delivers up to 30,000 AFY of reclaimed water to RID for irrigation use within RID’s service area; (2) RID leases SRP wells to provide a like amount of water to the SRP canal system; and (3) SRP then delivers up to 20,000 AFY of surface water to the COP water treatment plants and up to 10,000 AFY of surface water to the Salt River Pima-Maricopa Indian Community (COP, 2006). City of Tolleson: The COP supplies the COT with municipal water through an Inter-Governmental Agreement. The COT also has four production wells located west of the WVBA that are mainly used in the summer months as a backup supply (COT, 2005). During 2009, the total production from COT wells was approximately 750 AFY. 4.6 Consistency with Land Use Planning The WVBA is located within the COP and abuts the COT’s eastern boundary at 75th Avenue. Current and future land use is provided in the COP’s General Plan, which includes the goals, policies, and recommendations for land use development during the next 10 to 20+ years. The COP is made up of 15 “urban villages”; the Central City and Estrella urban villages are located within the WVBA. While overall land use, employment, and population within Central City are not expected to change significantly over time, the COP has identified Estrella as a targeted growth area because of the amount of agricultural land available for residential and/or commercial development. Estrella is 35 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 therefore expected to have significant increases in both employment and residential growth. The projected residential growth within Estrella is primarily outside of the WVBA, south of Lower Buckeye Road and west of 75th Avenue. Based on the COP General Plan, land use within the WVBA is projected to continue to be predominantly industrial. The following table provides the actual 2002 and projected General Plan land uses in Central City and Estrella. Table 2. Projected General Plan Land Uses – Central City and Estrella Central City Estrella Land Use Category 2002 Land Use (% of total) General Plan (% of total) 2002 Land Use (% of total) General Plan (% of total) 10% 4% Large Lot Residential 11% 16% 27% Small Lot Residential 4% 1% 4% Medium Density Residential 3% 5% 0.2% 2% 1% 1% High Density Residential 3% 14% 1% Commercial 9% 23% 18% 35% Industrial 16% 0.3% 4% 6% 0.10% Commerce Park 8% 8% 8% 7% Public/Quasi Public Transportation/Airport 28% 21% 1% 1% Parks -Open Space 6% 13% 6% 8% Agriculture 0.01% --49% --Vacant 9% --7% --Source: COP General Plan By 2030, Central City and Estrella are projected to grow to the following numbers (the increase shown is from actual 2000 to projected 2030 numbers): • Central City: Employment (116,000; 1.07X increase); population (164,000; 1.2X increase); and households (66,000; 1.11X increase). • Estrella: Employment (148,000; 3.13X increase); population (146,000; 3.36X increase); and households (40,000; 4.2X increase). In 2000, the highest percentages of land use for the COT were agriculture (46 percent); industrial/warehouse (24 percent); and residential (14 percent). Land use in the eastern portion of the COT, adjacent to the WVBA, is primarily agriculture and industrial (Terranext, 2012b). 36 Proposed Remedial Action Plan Phoenix, Arizona 4.7 West Van Buren Area WQARF Site December 2015 Achievement of Remedial Action Criteria Pursuant to A.R.S. §49-282.06 The Preferred Remedy satisfies the Remedial Action Criteria of A.R.S. §49-282.06. The Preferred Remedy assures the protection of public health, welfare, and the environment. Using remedial strategies, remedial measures, and contingencies reduces the concentration, volume, mass, and toxicity of COCs over time. Risk from potable use of an impaired well in the reasonably foreseeable future is mitigated or eliminated using a combination of remedial measures and contingencies. To the extent practicable, the Preferred Remedy provides for the control, management, or cleanup of hazardous substances to allow for the maximum beneficial use of the waters of the state. Potable water use in the reasonably foreseeable future would be managed using remedial measures and contingencies. The Preferred Remedy remedial strategies, measures, and contingencies allows for beneficial use of groundwater within the WVBA. The Preferred Remedy is reasonable, necessary, cost-effective, and technically feasible. The Preferred Remedy is a balanced, cost-effective approach to meeting the ROs and is reasonable and technically feasible because the remedy components can be implemented using industry-standard methods. The remedial measures and contingent measures also address wells that may become impaired in the future. Using remedial strategies, remedial measures, and contingencies, the Preferred Remedy addresses, at a minimum, any well that at the time of selection of the remedial action either supplies water for municipal, domestic, industrial, irrigation, or agricultural uses or is part of a public water supply system if the well would now or in the reasonably foreseeable future produce water that would not be fit for its current or reasonably foreseeable end uses without treatment due to the release of hazardous substances. The specific measures to address any such well would not reduce the supply of water available to the owner of the well. 37 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 5.0 REFERENCES Arizona Administrative Code R18-16-406, R18-16-407, and R18-16-408. March 31, 2002. Arizona Department of Environmental Quality (ADEQ), 2012. Remedial Objectives Report, West Van Buren WQARF Registry Site, Phoenix, Arizona. August 8. Arizona Department of Environmental Quality (ADEQ), 2015a. Letter from Ms. Laura Malone, ADEQ, to Mr. Joseph Drazek, Ms. Gail Clement, and Mr. Bruce Travers regarding the Draft Feasibility Study – West Van Buren Working Group. April 13. Arizona Department of Environmental Quality (ADEQ), 2015b. Letter from Ms. Laura Malone, ADEQ, to Mr. Donavan Reese, RID regarding the Draft Feasibility Study – Roosevelt Irrigation District. April 13. Arizona Department of Health Services, 2015. Health Consultation – Evaluation of Water Sampling Results in Roosevelt Irrigation District (RID), Phoenix, Maricopa County, Arizona. January 8. Arizona Department of Water Resources, 2010. Letter from Herb Guenther, Director of ADWR, to Mr. Stan Ashby, RID. May 7. Arizona Revised Statutes, Title 49 – The Environment. Section 49-287.04(A) – Proposed remedial action plan. Brown and Caldwell, 2014. West Van Buren Study Area: Univar Groundwater Flow Model Update. June. City of Phoenix, 2006. Water Resources Plan Update 2005, Water Services Department, Water Resources and Developing Planning Section. Adopted by Phoenix City Council, March 8. City of Tolleson, 2005. Tolleson General Plan 2005. A Long Range Planning Tool, the General Plan Affirms Goals and Policies for Tolleson’s Future. Adopted December 13. City of Tolleson, 2014. Email Communication from Supervisor of Water Utilities for City of Tolleson. April 2. 38 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 Gaylord, 2011. Letter from Ms. Karen Gaylord on behalf of the West Van Buren Working Group to Mr. Kevin Snyder, ADEQ regarding the Proposed Remedial Objectives Report for the West Van Buren WQARF Registry Site. June 30. Gaylord, 2015. Letter from Ms. Karen Gaylord on behalf of the West Van Buren Working Group to Ms. Tina LePage, ADEQ, regarding the RID July 2014 Draft Feasibility Study – West Van Buren WQARF Site. November 6. Haley & Aldrich, 2014. Feasibility Study Report, West Van Buren WQARF Site, Phoenix, Arizona. July 14 (Revised December 1). Matrix Design Group, CALIBRE, 2015. Memorandum to Laura Malone, ADEQ. Evaluation of Feasibility Studies Regarding Technical Completeness, West Van Buren Water Quality Assurance Revolving Fund (WQARF) Site. July 28. Montgomery & Associates, 2009. Roosevelt Irrigation District Groundwater Response Action, West Van Buren Water Quality Assurance Revolving Fund Site. September 25. Roosevelt Irrigation District, 2007. Land and Water Use Study Questionnaire for Municipalities/Utilities within the West Van Buren WQARF Registry Site. November 12. Roosevelt Irrigation District, 2010. Revised Land and Water Use Study Questionnaire for Municipalities/Utilities within the West Van Buren WQARF Registry Site. January 12. Salt River Project, 1996. Assured Water Supply Study for Salt River Project Member Lands. Prepared by SRP Water Group. November. Salt River Project, 2009. Letter from Mr. W.R. Powell, SRP to Ms. Julie Riemenschneider, ADEQ, regarding the West Van Buren WQARF Site, Roosevelt Irrigation District’s Proposed Early Response Plan. December 4. Salt River Project, 2011. Letter from Mr. Kevin Wanttaja, SRP, to Mr. Kevin Snyder, ADEQ, regarding the Arizona Department of Environmental Quality Notice of the Availability of the Proposed Remedial Objectives Report for the West Van Buren WQARF Registry Site in Phoenix, Arizona. 39 Proposed Remedial Action Plan Phoenix, Arizona West Van Buren Area WQARF Site December 2015 June 30. Salt River Project, 2013. Water Provider Meeting Questionnaire. October 18. Synergy Environmental, LLC, 2012. Operation and Maintenance Plan, RID Wellhead Treatment Systems, West Van Buren Area WQARF Site, Phoenix, Arizona. May 3. Synergy Environmental, LLC, 2013. Operation and Maintenance Plan, RID Wellhead Treatment Systems, Revision 3, West Van Buren Area WQARF Site, Phoenix, Arizona. October 2. Synergy Environmental, LLC, 2014. Draft Feasibility Study Report, West Van Buren WQARF Site, Phoenix, Arizona. July 11 (Revised November 26). Terranext, 2012a. Remedial Investigation Report, West Van Buren WQARF Registry Site, Phoenix, Arizona. August. Terranext, 2012b. Land and Water Use Report, West Van Buren Area (WVBA) Water Quality Assurance Revolving Fund (WQARF) Registry Site, Phoenix, Arizona. March. United States Environmental Protection Agency, 2000. A Guide to Developing and Documenting Costs During the Feasibility Study, EPA 540-R-00-000, OSWER 9355.0-75, July. 40 APPENDIX A MATRIX-CALIBRE EVALUATION OF FEASIBILITY STUDIES REGARDING TECHNICAL COMPLETENESS, WEST VAN BUREN WATER QUALITY ASSURANCE REVOLVING FUND SITE DATED JULY 28, 2015   Memorandum  To:  Laura Malone, ADEQ   From:  Tom McKeon & Julie Carver, Matrix‐CALIBRE  Date:   July 28, 2015  Subject:  Evaluation of Feasibility Studies Regarding Technical Completeness,  West Van Buren Water Quality Assurance Revolving Fund (WQARF) Site      The  Matrix‐CALIBRE  Team  is  under  contract  with  the  Arizona  Department  of  Environmental  Quality  (ADEQ)  to  complete  a  Task  Order  (TO)  for  the  West  Van  Buren  (WVB)  Water  Quality  Assurance Revolving Fund (WQARF) Site located in Phoenix, Arizona (hereafter referred to as the  Site). An objective of the TO was to evaluate two Feasibility Studies that were prepared for the Site  and submitted to ADEQ by external parties under Arizona Administrative Code (A.A.C.) R18‐16‐413  and A.A.C. R18‐16‐407. One element of the Feasibility Study evaluation was to conduct a review of  the Feasibility Study technical completeness pursuant to the requirements set forth in the Arizona  Revised  Statues  (A.R.S.)  §  49‐282.06  and  the  A.A.C.  R18‐16‐407.  This  Technical  Memorandum  summarizes the technical completeness review of the two Feasibility Studies.     Background   Two  separate  Feasibility  Studies  for  the  Site  were  submitted  to  ADEQ  in  2014;  one  prepared  by  Synergy Environmental, LLC and Montgomery and Associates on behalf of the Roosevelt Irrigation  District  (RID)  and  the  other  prepared  by  Haley  and  Aldrich,  Inc.  on  behalf  the  West  Van  Buren  Working Group (WVBWG).      Feasibility Study Evaluation   The two Feasibility Studies were evaluated and the results are summarized in the attached tables.  Table  1  presents  a  very  brief  summary  of  the  remedial  alternatives  considered  in  the  two  Feasibility  Studies.  The  Table  1  summary  is  intentionally  brief,  for  further  details  consult  the  original Feasibility Studies. The technical completeness evaluation of the two Feasibility Studies is  summarized in Tables 2 and 3 for the selected remedies from each Feasibility Study. The technical  completeness  evaluation  summarizes  the  relevant  requirements  from  A.R.S.  §  49‐282.06  and  A.A.C.  R18‐16‐407  and  describes  how  each  of  the  recommended  remedies  considers  and  addresses those requirements.    Based on the technical completeness evaluation, the two Feasibility Studies were deemed by the  Matrix‐CALIBRE Team as technically complete.  The resumes of the Matrix‐CALIBRE Team staff that  completed the technical evaluation are attached.                          Table 1   WVB Site Feasibility Studies;   Summary Table    Remedial Strategy  Approach  RID   Reference Remedy  RID   Less Aggressive  RID   More Aggressive  RID   Most Aggressive  PR & PC  P&T 9 current  supply wells  PR & PC P&T 6 current  supply wells  PR & PC P&T 6 current  supply wells  PR & PC  P&T 13 current  supply wells  WVBWG   Reference Remedy CM RID operates + P&T  1 new well  Measures/  RID Extraction, Elements to meet goals  RID Extraction &  RID Extraction &  RID Extraction &  RID Extraction &  MNA, minor  Treatment  Treatment  Treatment  Treatment  treatment &  contingencies  Source Control   by ADEQ  by ADEQ by ADEQ by ADEQ  by ADEQ Actions to meet  Blending & 1 well  Treatment at  Treatment at  Treatment at  potable use  Treatment at all  replacement;  selected wells (9) &  selected wells (6) &  selected wells (6) &  wells (13)  Replace any  blending (6 more)  blending (9 more)  blending (9 more)  domestic use well  Well replacement/  Replace 2: RID‐92 &  Replace 1: RID‐106; Replace 1: RID‐106;  Replace 2: RID‐92 &  If converted to  improvement  RID‐106; improve  improve RID‐84,  improve RID‐84,  RID‐106; improve  potable use: move  RID‐84, RID‐114  RID‐114  RID‐114  RID‐84, RID‐114  & replace RID‐114  ** various +  Contingencies for  Other  various**  various**  COT, SRP, and COP  various**  Recharge of WWTP  supply wells  effluent++  Groundwater  Yes + contingency  yes  yes  yes  yes  Monitoring  expansion of MWs Cost over 30 years as  $88.6M  $104M  $71M  $80.6M  $145M  (w’ sum of all  sum of $s spent  contingencies)  (not net present value)  Bold – Proposed Remedy based on FS Evaluation  ** Various system improvements; Enclose lateral from RID‐92 to Main canal, Salt canal improvements, seal all manholes  ++ WWTP effluent recharge via RID‐84, RID‐85, RID‐90, RID‐91, and RID‐93    WVBWG   Less Aggressive  WVBWG   More Aggressive  CM by ADEQ Blending & 1 well  replacement;  Replace any  domestic use well  If converted to  potable use: move  & replace  RID‐114  Contingencies for  COT, SRP, and COP  supply wells  Yes +contingency  expansion of MWs $24.2M  CM & PC RID operates + P&T  2 new wells  RID Extraction, MNA, limited  treatment &  contingencies  by ADEQ Blending & 1 well  replacement;  Replace any  domestic use well  If converted to  potable use: move  & replace RID‐114   Contingencies for  COT, SRP, and COP  supply wells  Yes + contingency  expansion of MWs  $102.5M  (w’ sum of all  contingencies)  (w’ sum of all  contingencies)  RID operates  RID Extraction,  MNA &  contingencies  CM – Controlled migration; PC – Plume containment; PR – Plume remediation; P&T – Groundwater extraction and treatment  ADEQ – Arizona Department of Environmental Quality  COP – City of Phoenix  COT – City of Tolleson  GAC – granular activated carbon  MNA – monitored natural attenuation  RID – Roosevelt Irrigation District  SRP – Salt River Project  WVBWG – West Van Buren Working Group  WWTP – Waste Water Treatment Plant       Matrix‐CALIBRE Team  Table 2  Technical Evaluation: Roosevelt Irrigation District  Proposed Remedy – “Less Aggressive”    TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements)  R18‐16‐407(A)  The feasibility study (FS) is a process to identify a reference remedy and alternative  Administratively complete (1). remedies  that  appear  to  be  capable  of  achieving  remedial  objectives  (ROs)  and  to  evaluate  them  based  on  the  comparison  criteria  to  select  a  remedy  that  complies  with A.R.S. § 49‐282.06.  A.R.S. § 49‐282.06(A)(1‐3)  Remedial actions shall:    1.   Assure the protection of public health and welfare and the environment. 2. To the extent practicable, provide for the control, management or cleanup of the  Pump and treat will contain the plume and have mass removal but may not  hazardous substances to allow the maximum beneficial use of the waters of the  achieve  aquifer  restoration  in  a  timely  manner.  Acknowledges  that  source  state.  control by ADEQ is necessary.  3. Be reasonable,   Remedial  actions  are not  required  for  current  use  therefore  they  are  not  reasonable at this time; however they are reasonable for future potable use  of the resource.  necessary,  Not  necessary  until  such  time  as  future  use  of  the  resource  is  for  potable  supply;  includes  elements  targeted  more  for  water  supply  development  rather  than  remediation.  Examples  include  converting  the  lateral  canal  to  piping at RID‐92 and sealing all manholes/vaults.  cost‐effective, and  At  the  time  when  potable  use  of  the  water  is  needed,  this  would  be  cost  effective.  technically feasible.  Feasible (liquid phase carbon treatment is a reliable treatment technology). Page 1 of 8  Current  risks  are  within  acceptable  thresholds  for  present  use,  remedial  actions  taken  would  not  lower  current  risks  by  an  appreciable  amount.  Remedial  actions  taken  would  lower  future  risks  when  resource  is  used  for  potable supply.  Table 2  Technical Evaluation: Roosevelt Irrigation District  Proposed Remedy – “Less Aggressive”    TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements)  A.R.S. § 49‐282.06(B)(4)(b)  […]. Rules adopted pursuant to this subsection shall include rules for: […]  4. The  selection  of  remedial  actions  including  the  establishment  of  the  level  and  extent of cleanup at a site or a portion of a site. The rules shall provide for the  selection  of  a  remedial  action  by  comparison  of  alternative  remedial  actions,  which  may  include: no action,  monitoring,  source  control,  controlled  migration,  physical containment, plume remediation, and the consideration of the criteria in  subsection  (C)  of  this  section.  The  rules  also  shall  provide  that  the  selected  remedial  action  meet  the  requirements  of  subsection  A  of  this  section  and  the  following:  a. […soil only...]    b. For remediation of waters of the state, the selected remedial action shall  address,  at  a  minimum,  any  well  that  at  the  time  of  selection  of  the  remedial  action  either  supplies  water  for  municipal,  domestic,  industrial,  irrigation or agricultural uses or is part of a public water system if the well  would  now  or  in  the  reasonably  foreseeable  future  produce  water  that  would not be fit for its current or reasonably foreseeable end uses without  treatment  due  to  the  release  of  hazardous  substances.  The  specific  measures  to  address  any  such  well  shall  not  reduce  the  supply  of  water  available to the owner of the well.  5. Incentives  for  initiating  early  remedial  actions  and  implementing  innovative  remedial technologies    The  basic  remedial  strategies  are  discussed  in  the  FS.  Acknowledges  that  source control by ADEQ is necessary.              Not Applicable.    Current  irrigation  use  is  not  impaired;  foreseeable  future  includes  potable  use. Relies on a combination using treatment of selected wells with blending  to meet potable use criteria in the Salt canal.              An administrative action (2).  1. Population, environmental and welfare concerns at risk. Presently,  levels  are  not  above  risk  thresholds  (ADHS,  2015);  if  and  when  changes in groundwater use occur corresponding risks are addressed.  2. Routes of exposure.  Presently,  levels  are  not  above  risk  thresholds  (ADHS,  2015);  if  and  when  changes in groundwater use occur corresponding risks are addressed.  3. Amount,  concentration,  hazardous  properties,  environmental  fate,  such  as  the  Most  of  the  plume  is  at  concentrations  near  the  Aquifer  Water  Quality  ability  to  bioaccumulate,  persistence  and  probability  of  reaching  the  waters  of  Standards  (AWQSs)  for  PCE  and  TCE  (range:  5‐15  micrograms  per  liter).  the state, and the form of the substance present.  Limited  areas  have  higher  concentrations  (more  than  4  times  the  AWQSs).  Plume is already in ‘waters of the state’.  4. Physical  factors  affecting  human  and  environmental  exposure  such  as  Presently,  levels  are  not  above  risk  thresholds  (ADHS,  2015);  if  and  when  hydrogeology, climate and the extent of previous and expected migration.  changes in groundwater use occur corresponding risks are addressed.  ‐ 28 20 A.R.S. § 49‐282.06(C)(1‐3)  In  adopting  the  rules  required  by  this  section  and  in  selecting  remedial  actions,  the  director shall consider the following factors:     Page 2 of 8  Table 2  Technical Evaluation: Roosevelt Irrigation District  Proposed Remedy – “Less Aggressive”    TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements)  The  technical  practicality  and  cost‐effectiveness  of  alternative  remedial  actions  It  is  feasible/practicable when  potable  supply  is  needed; the  proposed  applicable to a site.  remedy (less aggressive) is more cost‐effective as compared to the reference  remedy.   7. The  availability  of  other  appropriate  federal  or  state  remedial  action  and  Not directly applicable (2). enforcement  mechanisms,  including,  to  the  extent  consistent  with  this  article,  funding sources established under CERCLA, to respond to the release.  A.R.S. § 49‐282.06(D)  6. Notwithstanding  this  article,  the  director  may  approve  a  remedial  action  that  may  An administrative action, to be completed as necessary (3). result in water quality exceeding water quality standards after the completion of the  remedy if the director finds that the remedial action meets the requirements of this  section.  R18‐16‐407(B) & (B)(3)  The  extent  to  which  the  amount  of  water  available  for  beneficial  use  will  be  Future  water  rights  are  to  be  determined  (outside  of  ADEQ).  The  remedial  preserved by a particular type of remedial action.  action removes the groundwater resource from the current water basin.  […]  The  FS  process  shall  include  community  involvement  procedures  in  compliance  with R18‐16‐404. […]    […]Notification to interested persons of the availability of FS workplan in accordance  with R18‐16‐404[(C)(1)(d)].[…]  Completed in conjunction with ADEQ.     Completed in conjunction with ADEQ.  R18‐16‐407(C) & (D)  5. Not Applicable.  Not Applicable.    Page 3 of 8  Table 2  Technical Evaluation: Roosevelt Irrigation District  Proposed Remedy – “Less Aggressive”    TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements)  R18‐16‐407(E)(3)  R18‐16‐407(E)(1‐2)  […],  the  FS  shall  provide  for  the  development  of  a  reference  remedy  and  at  least  2  Reference  remedy  and  3  alternates  (less  aggressive,  more  aggressive,  most  alternative remedies as follows:  aggressive) are presented in the FS.    1. The reference remedy and alternative remedies shall be capable of achieving all  of the ROs. The reference remedy and each alternative remedy shall consist of a  remedial  strategy  under  subsection  (F)  and  all  remedial  measures  to  be  employed. The combination of the remedial strategy and the remedial measures  for each alternative remedy shall achieve the ROs. […] The reference remedy and  other alternative remedies shall be developed and described in the FS report in  sufficient detail to allow evaluation using the comparison criteria, […]. The  FS  describes  how  the  ROs  are  met,  the  4  remedies  considered  are  summarized  and  evaluated  in  comparison  to  the  applicable  criteria  [A.R.S.  §  49‐282.06, and A.A.C. R18‐16‐407(H)].    2. The  reference  remedy  shall  be  developed  based  upon  best  engineering,  geological, or hydrogeological standards of practice, considering the following:  a. The information in the remedial investigation;  b. The  best  available  scientific  information  concerning  available  remedial  technologies, and  c. Preliminary  analysis  of  the  comparison  criteria  and  the  ability  of  the  reference remedy to comply with A.R.S. § 49‐282.06. […] The  remedies  presented  are  developed  based  on  the  RI  data  and  the  best  professional judgments of the authors (licensed engineers and/or geologists).                    3. At a minimum, at least 2 alternative remedies shall be developed for comparison  The  remedies  presented  include  a  reference  remedy  and  three  alternates;  with the reference remedy. At least one of the alternative remedies must employ  two  more  aggressive,  one  less  aggressive  (in  comparison  to  the  reference  a remedial strategy or combination of strategies that is more aggressive than the  remedy).  reference  remedy,  and  at  least  one  of  the  alternative  strategies  that  is  less  aggressive than the reference remedy  R18‐16‐407(F)(1‐6)  The remedial strategies to be developed under subsection (E) are listed below. Source  control shall be considered as an element of the reference remedy and all alternative  remedies, if applicable, except for the monitoring and no action alternatives. […] The  remedial strategies are:  1. Plume remediation […] achieve water quality standards for COCs in waters of the  state throughout the site.  2. Physical containment […] contain contaminants within definite boundaries.  3. Controlled  migration  […]  control  the  direction  or  rate  of  migration  but  not    Page 4 of 8  The  basic  remedial  strategies  are  discussed  in  the  FS.  Acknowledges  that  source control by ADEQ is necessary. Physical containment through extraction  by RID and monitoring is the current condition; increased plume remediation  via preferential pumping of higher concentration wells is added.    Table 2  Technical Evaluation: Roosevelt Irrigation District  Proposed Remedy – “Less Aggressive”    TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  4. 5. 6. (see footnotes regarding administrative status for non technical requirements)  necessarily to contain migration of contaminants. Source control […] eliminate or mitigate a continuing source of contamination.  Monitoring […] observe and evaluate the contamination at the site through the  collection of data.   No action […] consists of no action at a site.  R18‐16‐407(G)  Remedial  measures  necessary  for  each  alternative  remedy  developed  under  subsection  (E)  to  achieve  ROs  or  to  satisfy  the  requirements  of  A.R.S.  §  49‐ 282.06(B)(4)(b) shall be identified in consultation with water providers or known well  owners whose water supplies are affected by the release or threatened release of a  hazardous  substance.  In  identifying  the  remedial  measures,  the  needs  of  the  well  owners  and  the  water  providers  and  their  customers,  including  the  quantity  and  quality of water, water rights and other legal constraints on water supplies, reliability  of water supplies and any operational implications shall be considered.   Such remedial measures may include, but are not limited to:  well  replacement,  well  modification,  water  treatment,  provision  of  replacement  water supplies, and engineering controls.  Where  remedial  measures  are  relied  upon  to  achieve  ROs,  such  remedial  measures  shall  remain  in  effect  as  long  as  required  to  ensure  the  continued  achievement  of  those objectives.[…]  The FS describes consultation and consideration of RID water supply and use;  SRP supply and use; City of Phoenix (COP) supply and use.    Consideration  of  domestic  supply  wells  (if  impaired)  in  the  impacted  area  is  not discussed.   The FS provides a discussion of options for replacement water supplies noting  that the large volume of replacement water that may be required would be  challenging to procure.  In addition, the FS notes that the existing pumping by  RID contains the plume and a replacement supply would therefore allow the  plume to migrate. Based on these considerations, the FS rejects replacement  supply from further consideration.    R18‐16‐407(H)(1‐3a)  The Department shall conduct a comparative evaluation of the reference remedy and  the  alternative  remedies  developed  under  subsection  (E).  For  each  alternative,  the  evaluation shall be reported in a FS report and shall include:  1. A demonstration that the remedial alternative will achieve the ROs. 2. An  evaluation  of  consistency  with  the  water  management  plans  of  affected  The FS presents remedial actions that are consistent with RID’s development  water providers and the general land use plans of local governments with land  plans.  Other  water  providers  and  local  governments  have  raised  issues  use jurisdiction.  regarding RID’s plans in their public comments.  3. An evaluation of the comparison criteria, including: a.   Demonstration  is  presented  to  meet  “protect,  restore,  replace  or  otherwise  provide  a  water  supply  for  municipal  use  by  currently  and  reasonably  foreseeable future municipal well owners within the WVB Area”. The remedial  actions are planned as well‐head treatment to protect the water supply from  existing  irrigation  wells  that  are  planned  to  serve  as  municipal  supply in  the  reasonably foreseeable future.  An evaluation of the practicability of the alternative, It  is  practicable;  however  current  risks  are  within  acceptable  thresholds  for  present use.  Page 5 of 8  Table 2  Technical Evaluation: Roosevelt Irrigation District  Proposed Remedy – “Less Aggressive”    TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements)  including its feasibility,   Yes, it is feasible.  short and long‐term effectiveness, and reliability, Remedial actions are effective for plume containment and potable supply. R18‐16‐407(H)(3b‐3d)  considering  site‐specific  conditions,  characteristics  of  the  contamination  Institutional considerations for resolution include water rights and exporting  resulting  from  the  release,  performance  capabilities  of  available  from  the  current  water  basin.  These  are  outside  of  ADEQ’s  purview.  GAC  technologies, and institutional considerations.  treatment can meet the ROs and project goals.              b. An evaluation of risk, including the overall protectiveness of public health  and  aquatic  and  terrestrial  biota  under  reasonably  foreseeable  use  scenarios and end uses of water. This evaluation shall address:   i. Fate and transport of contaminants and concentrations and toxicity  over the life of the remediation;   ii. Current and future land and resource use; and    iii. Exposure  pathways,  duration  of  exposure,  and  changes  in  risk  over  the life of the remediation;  iv. Protection  of  public  health  and  aquatic  and  terrestrial  biota  while  implementing the remedial action and after the remedial action; and  v. Residual risk in the aquifer at the end of remediation  Remedy  is  protective  for  future  resource  use.  Remedy  is  focused  on  plume  containment and water supply treatment. Source control remedial actions are  to  be  implemented  by  ADEQ.    The  evaluation  of  risk  notes  that  the  current  concentrations  measured  (in vapor  and  in water)  do  not represent  an  acute  risk  (Synergy,  2011).  The  FS  compares  concentrations  with  applicable  screening criteria (i.e., specific numerical criteria established for protection of  human  health)  with  a  prospective  comparison  of  historical  conditions  (without historical exposure estimates) rather than current resource use and  exposure  pathways.  This  presentation  of  risk  evaluation  [under  R18‐16‐ 407(H)(3b)] focuses more on  the prospective impacts as opposed to current  conditions over the life of the remediation.  The consideration of current and  future uses may place more emphasis on the timing as to when the proposed  remedial actions are necessary. Residual risks will remain in the aquifer.  c. An  evaluation  of  the  cost  of  the  remedial  alternative, including  the  expenses  and  losses  including  capital,  operating,  maintenance,  and  life  cycle  costs.  Transactional  costs  necessary  to  implement  the  remedial  alternative,  including  the  transactional  costs  of  establishing  long‐term  financial  mechanisms,  such  as  trust  funds,  for  funding  of  an  alternative  remedy, shall be included in the cost estimate.  The FS presents costs for the reference remedy and each alternate. The costs  for  the  proposed  remedy  (less  aggressive)  are:  $9.5M  capital  plus  $2.05M  operations and maintenance (O&M) for 100 years.                          At 30 years: $71.M spent.  The costs presented above represent the sum of costs and are not converted  to a net present value basis.  Page 6 of 8  Table 2  Technical Evaluation: Roosevelt Irrigation District  Proposed Remedy – “Less Aggressive”    TECHNICAL ANALYSIS    R18‐16‐407(J)  R18‐16‐407(I)  R18‐16‐407(H)(3e) FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements)  d. An  evaluation  of  the  benefit,  or  value,  of  the  remediation. This  analysis  includes factors such as:  i. Lowered risk to human and aquatic and terrestrial biota;  ii. Reduced concentration and reduced volume of contaminated water; iii. Decreased liability; acceptance by the public;  iv. Aesthetics; preservation of existing uses;  v. Enhancement of future uses; and   vi. Improvements to local economies. Potable water will be available; the remedial action will slowly reduce plume  concentration and volume.              e. A  discussion  of  the  comparison  criteria,  as  evaluated  in  relation  to  each  Discussion regarding each remedy in relation to each other is present. other. Based  upon  the  evaluation  and  comparison  of  the  reference  remedy  and  the  other  alternative  remedies  developed  under  subsection  (E),  a  proposed  remedy  shall  be  developed  and  described  in  the  FS  report.  The  proposed  remedy  may  be  the  reference  remedy,  any  of  the  other  alternative  remedies  evaluated  in  the  FS,  or  a  different  combination  of  remedial  strategies  and  remedial  measures  that  were  included in the alternative remedies evaluated in the FS. The FS report shall describe  the reasons for selection of the proposed remedy, including all of the following:  1. How the proposed remedy will achieve the ROs;  2. How the comparison criteria were considered; and  3. How the proposed remedy meets the requirements of A.R.S. § 49‐282.06.  The proposed remedy is the Less Aggressive Alternative Remedy.             The FS describes how the ROs are met.  The FS describes the consideration of comparison criteria.  The  FS  describes  how  the  recommended  remedy  meets  the  A.R.S.  requirements.  Any  person,  other  than  a  person  proposing  to  perform  work  under  an  agreement  under A.R.S. § 49‐287.03(C), may submit a request in compliance with R18‐16‐413 for  the  Department  to  approve  a  work  plan  or  a  report  for  all  or  any  portion  of  a  feasibility  study.  The  Department  shall  approve  a  feasibility  study  report  if  the  feasibility  study  complies  with  this  Section  and  community  involvement  activities  have been conducted under this Article.  Administratively complete for work plan requirement (3).     Technical  evaluation/analysis  presented  in  the  FS  and  the  community  involvement activities that have been completed comply with the referenced   section and article.    (1) Administrative requirement; the FS  submitted (and this specific remedial alternative) meets this threshold    Page 7 of 8  Table 2  Technical Evaluation: Roosevelt Irrigation District  Proposed Remedy – “Less Aggressive”    (2) Not applicable to site status, WQARF process and ADEQ remedy selection.  (3) Process step that is applicable under WQARF and it has been completed  (or in process of completion)    References:  ADHS, 2015. Health Consultation: Evaluation of Water Sampling Results in the Roosevelt Irrigation District (RID) Phoenix, Maricopa County, Arizona. Arizona Department of Health  Services.  January 8, 2015.  Synergy, 2011. Public Health Exposure Assessment and Mitigation Summary Report. Synergy Environmental, LLC. September 16, 2011.    Page 8 of 8  Table 3  Technical Evaluation: West Van Buren Working Group (WVBWG)  Proposed Remedy – “Reference Remedy”      TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements) R18‐16‐407(A)  The  feasibility study (FS)  is  a  process  to  identify  a  reference  remedy  and  alternative  Administratively complete (1). remedies  that  appear  to  be  capable  of  achieving  remedial  objectives  (ROs)  and  to  evaluate them based on the comparison criteria to select a remedy that complies with  A.R.S. § 49‐282.06.  A.R.S. § 49‐282.06(A)(1‐3)  Remedial actions shall:    1.   Assure the protection of public health and welfare and the environment. 2. To the extent practicable, provide for the control, management or cleanup of the  Pump and treat will contain the plume and have mass removal but may not  hazardous substances to allow the maximum beneficial use of the waters of the  achieve aquifer restoration in a timely manner; plume migration is currently  state.  controlled by pumping for irrigation use. Acknowledges that source control  by ADEQ is necessary.  3. Be reasonable,   Most  remedial  actions  are  delayed  until  the  resource  is  used  for  future  potable use; adding one (1) well at 500 gallons per minute (gpm) does not  appreciably improve current mass removal – this element is not reasonable. necessary,  Most  remedial  actions  are  postponed  until  they  are  necessary such  as  future use of resource as potable water supply.  cost‐effective, and  Cost effective when potable use of water supply is needed, relies heavily on  blending to meet potable use criteria.  technically feasible.  Feasible,  although  if/when  Roosevelt  Irrigation  District  (RID)  ceases  pumping, the following elements may not be a robust solution:  Moving RID‐114 to a down‐gradient position.  Projection  of  plume  conditions  in  2026  is  optimistic  based  on  the  estimated rate of attenuation/concentration reductions.  Allowing  the  plume  to  migrate  to  City  of  Tolleson  (COT)  and/or  Salt  River Project (SRP) wells.  Page 1 of 8  Current  risks  are  within  acceptable  thresholds  for  present  use,  remedial  actions  taken  would  not  lower  current  risks  by  an  appreciable  amount.  Contingency remedial actions are planned that would lower risk if resource  is used for potable supply in future.  Table 3  Technical Evaluation: West Van Buren Working Group (WVBWG)  Proposed Remedy – “Reference Remedy”      TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements) A.R.S. § 49‐282.06(B)(4)(b)  […]. Rules adopted pursuant to this subsection shall include rules for: […]  4. The  selection  of  remedial  actions  including  the  establishment  of  the  level  and  extent of cleanup at a site or a portion of a site. The rules shall provide for the  selection  of  a  remedial  action  by  comparison  of  alternative  remedial  actions,  which  may  include:  no  action,  monitoring,  source  control,  controlled  migration,  physical containment, plume remediation, and the consideration of the criteria in  subsection  (C)  of  this  section.  The  rules  also  shall  provide  that  the  selected  remedial  action  meet  the  requirements  of  subsection  A  of  this  section  and  the  following:  a. […soil only...]    b. For remediation of waters of the state, the selected remedial action shall  address,  at  a  minimum,  any  well  that  at  the  time  of  selection  of  the  remedial  action  either  supplies  water  for  municipal,  domestic,  industrial,  irrigation or agricultural uses or is part of a public water system if the well  would  now  or  in  the  reasonably  foreseeable  future  produce  water  that  would not be fit for its current or reasonably foreseeable end uses without  treatment  due  to  the  release  of  hazardous  substances.  The  specific  measures  to  address  any  such  well  shall  not  reduce  the  supply  of  water  available to the owner of the well.  5. Incentives  for  initiating  early  remedial  actions  and  implementing  innovative  remedial technologies    The  basic  remedial  strategies  are  discussed  in  the  FS.  Acknowledges  that  source control by ADEQ is necessary.   The  recommended  remedy  is  protective  of  public  health  and  the  environment; it provides for practicable control, management or cleanup of  the  hazardous  substances  to  allow  the  maximum  beneficial  use  of  the  waters  of  the  state;  and  is  reasonable,  necessary,  cost‐effective,  and  technically feasible.    Not Applicable.     Current  irrigation  use  is  not  impaired;  foreseeable  future  includes  potable  use. This remedy includes remedial actions to meet the potable criteria on  the Salt and RID canals (not on a well‐by‐well basis) and relies on blending  with replacement of one well (RID‐114).            An administrative action (2).  A.R.S. § 49‐282.06(C)(1‐3)  In adopting the rules required by this section and in selecting remedial actions, the  director shall consider the following factors:     1. Population, environmental and welfare concerns at risk. Presently, levels are not above risk thresholds (ADHS, 2015); future changes  in groundwater use and corresponding risk are addressed.  2. Routes of exposure.  Presently, levels are not above risk thresholds (ADHS, 2015); future changes  in groundwater use and corresponding risk are addressed.  3. Amount,  concentration,  hazardous  properties,  environmental  fate,  such  as  the  Most  of  the  plume  is  at  concentrations  near  the  Aquifer  Water  Quality  ability  to  bioaccumulate,  persistence  and  probability  of  reaching  the  waters  of  Standards  (AWQSs)  for  PCE  and  TCE  (range:  5‐15  micrograms  per  liter).  the state, and the form of the substance present.  Limited areas have higher concentrations (more than 4 times the AWQSs).  Plume is already in ‘waters of the state’.  Page 2 of 8  Table 3  Technical Evaluation: West Van Buren Working Group (WVBWG)  Proposed Remedy – “Reference Remedy”      TECHNICAL ANALYSIS    (see footnotes regarding administrative status for non technical requirements) Physical  factors  affecting  human  and  environmental  exposure  such  as  Presently, levels are not above risk thresholds (ADHS, 2015); future changes  hydrogeology, climate and the extent of previous and expected migration.  in groundwater use and corresponding risk are addressed.  5. The  extent  to  which  the  amount  of  water  available  for  beneficial  use  will  be  Future water rights are to be determined (outside of ADEQ). If RID ceases  preserved by a particular type of remedial action.  pumping, the groundwater resource could stay within the boundaries of the  current water basin.  6. The  technical  practicality  and  cost‐effectiveness  of  alternative  remedial  actions  It  is  feasible/practicable  but  some  elements of  the  proposed  remedial  applicable to a site.  measures  may    require  significant  modifications.  An  overall  cost‐effective  approach  is  proposed  but  some  elements  of  the  proposed  remedial  measures are not; 1) adding one 500 gpm extraction well to the existing RID  extraction rates; 2) moving RID‐114 downgradient (shutting down RID‐114  would  likely  impact  RID  ‐113  instead)  and  a  well‐head  treatment  system  already exists on RID‐114.  7. The  availability  of  other  appropriate  federal  or  state  remedial  action  and  Not directly applicable (2). enforcement  mechanisms,  including,  to  the  extent  consistent  with  this  article,    funding sources established under CERCLA, to respond to the release.  A.R.S. § 49‐282.06(D)  4. Notwithstanding  this  article,  the  director  may  approve  a  remedial  action  that  may  An administrative action, to be completed as necessary (3). result in water quality exceeding water quality standards after the completion of the  remedy  if  the director  finds that  the  re0edial  action  meets  the  requirements  of  this  section.  R18‐16‐407(B) & (B)(3)  A.R.S. § 49‐282.06(C)(4‐7)  FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  […]  The  FS  process  shall  include  community  involvement  procedures  in  compliance  with R18‐16‐404. […]    […]Notification to interested persons of the availability of FS workplan in accordance  with R18‐16‐404[(C)(1)(d)].[…]    Page 3 of 8  Completed in conjunction with ADEQ.     Completed in conjunction with ADEQ.  Table 3  Technical Evaluation: West Van Buren Working Group (WVBWG)  Proposed Remedy – “Reference Remedy”      TECHNICAL ANALYSIS    R18‐16‐407(E)(1‐2)  R18‐16‐407(C) & (D)  FEASIBILITY STUDY STATUTE & RULE APPLICABILITY    (see footnotes regarding administrative status for non technical requirements) Not Applicable.  Not Applicable.  […], the FS shall provide for the development of a reference remedy and at least 2  alternative remedies as follows:  Reference  remedy  and  2 alternates  (less  aggressive,  more  aggressive)  are  presented in the FS.  1. The reference remedy and alternative remedies shall be capable of achieving all  of the ROs. The reference remedy and each alternative remedy shall consist of a  remedial  strategy  under  subsection  (F)  and  all  remedial  measures  to  be  employed. The combination of the remedial strategy and the remedial measures  for each alternative remedy shall achieve the ROs. […] The reference remedy and  other alternative remedies shall be developed and described in the FS report in  sufficient detail to allow evaluation using the comparison criteria, […]. A reference remedy and 2 alternates (less aggressive, more aggressive) are  presented in the FS. The FS describes how the ROs are met, the 3 remedies  considered  are  summarized  and  evaluated  in  the  comparison  to  the  applicable criteria [A.R.S. § 282.06, and A.A.C. R18‐16‐407(H)].    2. The remedies presented are developed based on the RI data and the best  professional  judgments  of  the  authors  (licensed  engineers  and/or  geologists).                    The  reference  remedy  shall  be  developed  based  upon  best  engineering,  geological, or hydrogeological standards of practice, considering the following:  a. The information in the remedial investigation;  b. The  best  available  scientific  information  concerning  available  remedial  technologies, and  c. Preliminary  analysis  of  the  comparison  criteria  and  the  ability  of  the  reference remedy to comply with A.R.S. § 49‐282.06. […] Page 4 of 8  Table 3  Technical Evaluation: West Van Buren Working Group (WVBWG)  Proposed Remedy – “Reference Remedy”      TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements) R18‐16‐407(F)(1‐6)  At a minimum, at least 2 alternative remedies shall be developed for comparison  The  remedies  presented  include  a  reference  remedy  and  two  alternates;  with the reference remedy. At least one of the alternative remedies must employ  one  less  aggressive,  one  more  aggressive  (in  comparison  to  the  reference  a remedial strategy or combination of strategies that is more aggressive than the  remedy).  reference  remedy,  and  at  least  one  of  the  alternative  strategies  that  is  less  aggressive than the reference remedy  The remedial strategies to be developed under subsection (E) are listed below. Source  control shall be considered as an element of the reference remedy and all alternative  remedies, if applicable, except for the monitoring and no action alternatives. […] The  remedial strategies are:  1. Plume remediation […] achieve water quality standards for COCs in waters of the  state throughout the site.  2. Physical containment […] contain contaminants within definite boundaries.  3. Controlled  migration  […]  control  the  direction  or  rate  of  migration  but  not  necessarily to contain migration of contaminants.  4. Source control […] eliminate or mitigate a continuing source of contamination.  5. Monitoring […] observe and evaluate the contamination at the site through the  collection of data.  6. No action […] consists of no action at a site.  The  basic  remedial  strategies are  discussed  in  the  FS.  Acknowledges  that  source  control  by  ADEQ  is  necessary.  Physical  containment  through  extraction by RID and monitoring is the current condition; small addition of  plume remediation via mass removal/treatment is added. Blending to meet  beneficial  use  by  RID  is  proposed  with  1  well  replacement  (as  early  as  2019). Future remedial actions are focused on MNA with contingencies to  replace/move  or  otherwise  address  down‐gradient  water  supply  wells,  if  they become impaired in the future.  R18‐16‐407(G)  R18‐16‐407(E)(3)  3. Remedial  measures  necessary  for  each  alternative  remedy  developed  under  subsection  (E)  to  achieve  ROs  or  to  satisfy  the  requirements  of  A.R.S.  §  49‐ 282.06(B)(4)(b) shall be identified in consultation with water providers or known well  owners whose water supplies are affected by the release or threatened release of a  hazardous  substance.  In  identifying  the  remedial  measures,  the  needs  of  the  well  owners  and  the  water  providers  and  their  customers,  including  the  quantity  and  quality of water, water rights and other legal constraints on water supplies, reliability  of water supplies and any operational implications shall be considered.   Such remedial measures may include, but are not limited to:  well replacement, well modification, water treatment, provision of replacement water  supplies, and engineering controls.  Where  remedial  measures  are  relied  upon  to  achieve  ROs,  such  remedial  measures  shall  remain  in  effect  as  long  as  required  to  ensure  the  continued  achievement  of  those objectives.[…]  The  FS  describes  consultation  and  consideration  of  RID  water  supply  and use, SRP supply and use, and City of Phoenix (COP) supply and use. RID has  noted  in  their  response  to  comments  that  they  differ  with  the  consultation/consideration presented.   Consideration of domestic supply wells (if impaired) in the impacted area is  discussed  and  remedial  measures  are  proposed  to  connect  to  the  COP  supply. This remedial action is planned for any domestic wells in the current  plume  footprint;  the  same  contingent  remedial  action  is  included  (as  a  contingency) for future areas if plume migration into down gradient areas  impact any additional domestic supply wells.      Page 5 of 8  Table 3  Technical Evaluation: West Van Buren Working Group (WVBWG)  Proposed Remedy – “Reference Remedy”      TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements) R18‐16‐407(H)(1‐3a)  The Department shall conduct a comparative evaluation of the reference remedy and  the  alternative  remedies  developed  under  subsection  (E).  For  each  alternative,  the  evaluation shall be reported in a FS report and shall include:  1. A demonstration that the remedial alternative will achieve the ROs. 2. An  evaluation  of  consistency  with  the  water  management  plans  of  affected  FS presents contingency remedial actions to meet RID’s future development  water providers and the general land use plans of local governments with land  plans.  RID  has  noted  in  written  comments  that  they  do  not  support  the  use jurisdiction.  plan.  Plan  appears  to  be  supported  by  other  water  providers  and  local  governments (COP, SRP).  3. An evaluation of the comparison criteria, including: a. Demonstration is presented to meet “protect, restore, replace or otherwise  provide  a  water  supply  for  municipal  use  by  currently  and  reasonably  foreseeable future municipal well owners within the WVB Area”. The focus  of the remedial actions are on contingent actions to protect or replace the  water supply for reasonably foreseeable future municipal wells.  An evaluation of the practicability of the alternative, It is practicable however some elements may not be robust:  Moving RID‐114 to a down gradient position.   Projection  of  plume  conditions  in  2026  is  optimistic  based  on  the  estimated rate of attenuation/concentration reductions.   Allowing the plume to migrate to COT and/or SRP wells.  including its feasibility,   Yes, it is feasible. short and long‐term effectiveness, and reliability, Contingency remedial actions are implemented when the resource is used  for potable water supply and the plume would no longer be contained by  irrigation pumping.   considering  site‐specific  conditions,  characteristics  of  the  contamination  Institutional  considerations  for  resolution  include  water  rights,  exporting  resulting  from  the  release,  performance  capabilities  of  available  from basin, pumping costs from replacement of wells into the lower aquifer  technologies, and institutional considerations.  unit,  and  the  water  quality  and  yield  of  the  lower  aquifer  unit.  These  are  outside  of  ADEQ’s  purview.  GAC  treatment  can  meet  the  ROs  and  project  goals  however  the  projection  of  the  effectiveness  of  monitored  natural  attenuation (MNA) is optimistic.    Page 6 of 8  Table 3  Technical Evaluation: West Van Buren Working Group (WVBWG)  Proposed Remedy – “Reference Remedy”      TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  (see footnotes regarding administrative status for non technical requirements) An evaluation of risk, including the overall protectiveness of public health  and  aquatic  and  terrestrial  biota  under  reasonably  foreseeable  use  scenarios and end uses of water. This evaluation shall address:   i. Fate and transport of contaminants and concentrations and toxicity  over the life of the remediation;   ii. Current and future land and resource use; and    iii. Exposure  pathways,  duration  of  exposure,  and  changes  in  risk  over  the life of the remediation;  iv. Protection  of  public  health  and  aquatic  and  terrestrial  biota  while  implementing the remedial action and after the remedial action; and  v. Residual risk in the aquifer at the end of remediation.  Remedy  is  protective  under  current  resource  use.  Remedy  is  initially  focused  on  containment  (until  2026)  then  moves  to  managed  migration.  Source  control  remedial  actions  are  to  be  implemented  by  ADEQ.  The  FS   presents  a  risk  evaluation  including  fate and  transport, current  and future  resource use, exposure pathways, duration of exposure, and changes in risk  over the life of the remediation, and evaluation of protectiveness of public  health. Residual risks will remain in the aquifer.  c. An  evaluation  of  the  cost  of  the  remedial  alternative,  including  the  expenses  and  losses  including  capital,  operating,  maintenance,  and  life  cycle  costs.  Transactional  costs  necessary  to  implement  the  remedial  alternative,  including  the  transactional  costs  of  establishing  long‐term  financial  mechanisms,  such  as  trust  funds,  for  funding  of  an  alternative  remedy, shall be included in the cost estimate.  The FS presents costs for the reference remedy and each alternate. The  costs for the proposed remedy (reference remedy) are:  $2.6M capital plus  $17M operations and maintenance (O&M) for 10 years of treatment and 30  years of monitoring  (includes all contingency remedial actions).  New MWs & sampling (20 yrs sampling)                   $2.46M  Replace 2 SRP wells                                                       $5.4M  Replace down gradient domestic private wells       $0.07M  Replace RID 114 (potable use of Salt Canal)            $1.23M  Continue 18 yrs treatment, 1 well at 500 gpm         $18.0M  R18‐16‐407(H)(3b‐3d)  b. (Re‐inject treated water (18 yrs 500 gpm)                          $5.26M)  1 new core extraction well at 1,000 gpm (operates for 18  years)                                                                               $28.1M  (Re‐inject treated water (18 yrs 1,000 gpm)                       $8.51M)                                                             30 years Total $88.6M  The costs presented above represent the sum of costs and are  not converted to a net present value basis. d.   An  evaluation  of  the  benefit,  or  value,  of  the  remediation. This  analysis  Potable  water  will  be  available  when  required;  the  remedial  action will includes factors such as:  slowly  reduce  plume  concentration  and  volume;  groundwater  resource  i. Lowered risk to human and aquatic and terrestrial biota;  within current water basin is preserved for future use. ii. Reduced concentration and reduced volume of contaminated water;  iii. Decreased liability; acceptance by the public;  iv. Aesthetics; preservation of existing uses;  v. Enhancement of future uses; and   vi. Improvements to local economies. Page 7 of 8  Table 3  Technical Evaluation: West Van Buren Working Group (WVBWG)  Proposed Remedy – “Reference Remedy”      TECHNICAL ANALYSIS    FEASIBILITY STUDY STATUTE & RULE APPLICABILITY  R18‐16‐407(J)  R18‐16‐407(I)  R18‐16‐407(H)(3e) e. (see footnotes regarding administrative status for non technical requirements) A  discussion  of  the  comparison  criteria,  as  evaluated  in  relation  to  each  Discussion regarding each remedy in relation to each other is present. other. Based  upon  the  evaluation  and  comparison  of  the  reference  remedy  and  the  other  alternative  remedies  developed  under  subsection  (E),  a  proposed  remedy  shall  be  developed  and  described  in  the  FS  report.  The  proposed  remedy  may  be  the  reference  remedy,  any  of  the  other  alternative  remedies  evaluated  in  the  FS,  or  a  different  combination  of  remedial  strategies  and  remedial  measures  that  were  included in the alternative remedies evaluated in the FS. The FS report shall describe  the reasons for selection of the proposed remedy, including all of the following:  1. How the proposed remedy will achieve the ROs;  2. How the comparison criteria were considered; and  3. How the proposed remedy meets the requirements of A.R.S. § 49‐282.06.  The proposed remedy is the Reference Remedy.             The FS describes how the ROs are met.  The FS describes the consideration of comparison criteria.  The  FS  describes  how  the  recommended  remedy  meets  the  A.R.S.  requirements.  Any  person,  other  than  a  person  proposing  to  perform  work  under  an  agreement  under A.R.S. § 49‐287.03(C), may submit a request in compliance with R18‐16‐413 for  the  Department  to  approve  a  work  plan  or  a  report  for  all  or  any  portion  of  a  feasibility  study.  The  Department  shall  approve  a  feasibility  study  report  if  the  feasibility study complies with this Section and community involvement activities have  been conducted under this Article.  Administratively complete for work plan requirement (3).     Technical  evaluation/analysis  presented  in  the  FS  and  the  community  involvement  activities  that  have  been  completed  comply  with  the  referenced  section and article.    (1) Administrative requirement; the FS  submitted (and this specific remedial alternative) meets this threshold  (2) Not applicable to site status, WQARF process and ADEQ remedy selection.  (3) Process step that is applicable under WQARF and it has been completed  (or in process of completion)      References:  ADHS, 2015. Health Consultation: Evaluation of Water Sampling Results in the Roosevelt Irrigation District (RID) Phoenix, Maricopa County, Arizona. Arizona Department of Health  Services.  January 8, 2015.    Page 8 of 8  JULIE CARVER, PE PROGRAM MANAGER AREAS OF EXPERTISE Project and Program Management Redevelopent of Contaminated Property Environmental Investigation Environmental Remediation Regulatory Agency Negotiations Stakeholder Consensus Building EDUCATION Master of Science in Environmental Science and Engineering, Colorado School of Mines, 1996 Bachelor of Science in Geological Engineering, South Dakota School of Mines & Technology, 1986 PROFESSIONAL REGISTRATIONS Registered Professional Engineer, Arizona (#58115): 2014 to Present Registered Professional Engineer, Alabama (# 27191): 2005 to Present Registered Professional Engineer, Colorado(#33746): 1993 to Present Registered Professional Engineer, Georgia (#34270): 2009 to Present Registered Professional Engineer, Kansas (#20804): 2009 to Present Registered Professional Engineer, New Jersey (#24GE05063100): 2013 to Present Registered Professional Engineer, Virginia (#042950): 2006 to Present NCEES Record #27168 Continuing Education/TRAINING OSHA (29 CFR 1910.120) 40-Hour HAZWOPER and 8-Hour Supervisor AHERA (40 CFR 763.206) Asbestos Building Inspector & Management Planner NPDES (40 CFR 122) Stormwater Management & Erosion Control ‘‘Qualified Person’’ PROFESSIONAL SUMMARY Ms. Carver is a registered professional engineer with over 27 years of public and private-sector experience in the assessment and remediation of sites burdened with environmental contamination. Julie offers a broad range of experience managing multi-disciplinary, cross-functional teams whose purpose is to solve logistically complex, diverse contaminated property issues on programs and projects for both public and private-sector clients. She provides expertise in the assessment and remediation of hazardous substances and wastes, special wastes, and munitions and explosives of concern (MEC), stakeholder consensus building, and regulatory agency compliance and negotiations. Ms. Carver has worked on sites across the United States and the Asia Pacific, including brownfield, municipal, quasi-governmental and private-sector redevelopment sites, active military installations, Base Realignment and Closure (BRAC) Sites, and Formerly Used Defense Sites (FUDS). She is a nationallyrecognized speaker on accelerated environmental closure of contaminated properties in conjunction with redevelopment and beneficial use. As a Vice President with Matrix, she has access to all professional resources within the company and authority to assign work for completion. RELEVANT EXPERIENCE McClellan Development Site, Anniston, Alabama - Project Manager to the McClellan Development Authority’s Program Management Team responsible for developing remedial designs and providing remediation oversight for the closure and longterm monitoring of seven historical legacy landfills contaminated primarily with CERCLA hazardous substances and limited MEC. Also responsible for developing an active operations plan and updated closure plan for a RCRA -permitted landfill, the remediation of multiple sites with solvent contaminated soil and groundwater and technical peer-review of remedial designs for the cleanup of soil contaminated with metals and munitions constituents at this mixed-use redevelopment/BRAC property. Fort Monroe Redevelopment, Hampton Roads, Virginia - Program Manager responsible for providing technical oversight services to the quasi-governmental redevelopemnt authority for the investigation of CERCLA hazardous substances and MEC at this 2005 BRAC site, which is a National Historic Landmark. On behalf of our client and the Commonwealth of Virginia Attorney General’s Office, provided technical expertise for the development and implementation of remedial investigations, feasibility studies and records of decision/remedial action plans for firing ranges, groundwater contaminated with solvents in a marina, a historical legacy landfill, underground storage tanks, and contaminated sediment in a moat Fitzsimons Life Sciences District, Denver, CO - Technical Program Manager to the City of Aurora and Fitzsimons Redevelopment Authority responsible for the $14.5M investigation and cleanup of 3 historical landfills under a RCRA Consent Agreement integrated with the $8.5M design and construction of a 2-mile long, 4-lane bypass and a utility upgrade necessary to accommodate significant redevelopment on this 500acre bioscience and medical facilities redevelopment. McPherson Redevelopment, Atlanta, GA - Program Manager to the McPherson Implementation Local Redevelopment Agency responsible for the due diligence assessment of environmental contamination at this ~500 acre former military installation. This site is located in the immediate vicinity of downtown Atlanta and the Atlanta International Airport and will be redeveloped as a bioscience park and mixed use transit oriented development. JULIE CARVER, PE PROGRAM MANAGER Hamilton Field, Novato, CA - Deputy Project Manager for the accelerated assessment and cleanup of soil contaminated with metals, fuel and polyaromatic hydrocarbons from former aircraft maintenance facilities and fuel storage at this BRAC property located north of San Francisco. Implemented Early Response Actions using bioremediation and low-temperature thermal desorption so that redevelopment at this former industrial/military property allowing residential redevelopment to proceed. Liberty Station, San Diego, CA - Project Manager to the San Diego Redevelopment Authority responsible for the development of a detailed human health and ecological risk assessment based on historical investigation work performed by others, and the development of a financial cost model for a potentially-responsible party cost allocation analysis related to the environmental cleanup of contaminated sediments in San Diego Bay. Uptown Oakland Redevelopment, CA - Environmental Program Manager to Forest City in partnership with the City of Oakland responsible for the initial environmental assessment and characterization of an underutilized, four city-block Brownfield site which was subsequently redeveloped into apartment homes, neighborhood retail and a public park. Hunter’s Point, San Francisco, CA - Program Manager responsible for the implementation of a $14 M RI/FS for a landfill located on San Francisco Bay, the $5.0M assessment and cleanup of a tank farm with a network of over 50 USTs and ancillary pipelines, and the completion of three time critical removal actions involving cleanup of soil and groundwater contaminated with heavy metals, solvents, pesticides and/or PCBs. Underground Storage Tank/Aboveground Storage Tank (UST/AST) Closures, Western United States and the Asia Pacific - Regional Program Manager to the Federal Emergency Management Agency responsible for the investigation/ characterization of fuel releases from storage tanks at Emergency Broadcast Stations, and the subsequent preparation of detailed plans, specifications and cost estimates and construction oversight for the removal and/or closure in place of over 100 USTs and ASTs. RCRA Subtitle C and D Landfill Closure Systems, United States and Asia Pacific Project Manager under a contract with the U.S. Air Force responsible for completing landfill characterization work, landfill closure designs and third-party construction management for RCRA Subtitle C and D landfills in Alabama, Arkansas, Colorado, Guam, Louisiana, Maine and Washington. Aboveground and Underground Mine Closures, CO, NM, AZ, WA - Project Manager for private-sector mining clients responsible for providing regulatory analysis/ compliance services, the implementation of environmental investigations and regulatory agency negotiation assistance related to the development of closure plans. Aliamanu Remedial Investigation, HI - Project Manager responsible for completion of a multi-million dollar remedial investigation, including a CERCLA human health and ecological risk assessment in a military housing area on property that was formerly used as a pineapple plantation.. Tom McKeon, P.E. Senior Project Manager (CALIBRE Systems) EDUCATION M.S., Civil Engineering, University of Washington B.S., Environmental Engineering, Humboldt State University EXPERIENCE Mr. McKeon is a Principal Environmental Engineer with CALIBRE who has specialized in the investigation/analysis of environmental problems and design of remediation systems. He has over 30 years professional experience with a primary focus on sites with soil and groundwater contamination. He has completed numerous site characterization studies, development of hydrogeologic site models, and designed/installed/optimized soil and groundwater treatment systems. Mr. McKeon is a Professional Engineer (P.E.) with experience addressing environmental and regulatory issues at disposal sites, industrial facilities, and landfills throughout the United States and internationally. He has developed expertise in a wide range of compliance issues including regulations under RCRA, CERCLA and the Clean Water Act. Project experience has included technical and regulatory compliance work for the Nuclear Regulatory Commission, Department of Energy, Department of Defense, Environmental Protection Agency, and private industries. SOIL AND GROUNDWATER REMEDIATION EXPERIENCE Remedial Action using Soil Vapor Extraction (SVE), Air Sparging and In-well Stripping. Mr. McKeon has been the lead engineer for dozens of in-situ remediation projects using SVE, air sparging and in-well stripping. Projects have included multiple sites in California, Nevada, Arizona, Washington and international projects in France, Denmark and Taiwan. Responsibilities in these projects have included design, construction oversight, startup, and optimization. He has written remediation design guidance published by the American Soceity of Civil Engineers (ASCE) and taught courses on remedial systems design/optimization for the National Ground Water Association (NGWA) and US consulting companies. Remedial Actions using In-situ Groundwater Treatment at Dry Cleaning Sites. Mr. McKeon has been the lead engineer for remedial actions at multiple sites with perchloroethene (PCE) contamination. Project responsibilities have included system design, construction oversight, startup/optimization and operation/maintenance. Projects have included multiple sites in California, Nevada, Washington, and Oregon. Most recent projects (in the last 10 years) have focused on SVE with biological treatment (enhanced reductive dechlorination) for groundwater. The projects have demonstrated excellent performance with PCE concentration reductions of 99.99+% achieved (meeting water quality criteria). Completing Remedial Investigation/Feasibility Studies (RI/FS) for Protection of City Water Supplies. Mr. McKeon has been the project manager of several RI/FS projects to address solvent impacts to City water supply wells (Santa Barbara and Modesto, California, and Vancouver Washington). Customers have included US EPA and local industries. Remedial actions implemented include well-head treatment (at supply wells) and source-area/plume wide treatment. Performance-Based Contracting. Mr. McKeon provides consulting support for federal agency procurement of environmental restoration services. Recent projects for the DOD include work for the Army, Air Force, and Navy related to project scoping, planning, and performance-based contracting. Licensed Civil Engineer, current in Washington and Arizona. Registered with National Council of Examiners for Engineering and Surveying (NCEES, Record # 16876). Preferred Remedy Cost Summary West Van Buren Area WQARF Site Phoenix, Arizona Non Disc., with 3% Inflation Year (Period) Capital Total O&M Total $10.11 $10.11 NPV @ 6% Disc. Rate Capital Total  O&M Total $3.04 $3.04 Base Groundwater monitoring program Connect five impaired private wells within the  WVBA to the COP municipal system Trust Creation Expense Conduct a hydrogeological evaluation beginning  in 2019, and every 3 years thereafter through  2025 (3 total at $30K each) Base Total 2016‐2044 2016 $0.05 $0.05 $0.05 $0.05 2016 $0.10 $0.10 $0.10 $0.10 2019‐2025 $0.09 $0.09 $0.09 $0.09 $0.24 $10.11 $10.35 $0.24 $3.04 $3.28 2026‐2044 $3.50 $18.03 $21.53 $1.37 $2.82 $4.19 2026‐2044 $3.76 $1.50 $5.26 $1.31 $0.24 $1.55 2026 $0.65 $0.65 $0.23 Contingencies Install one (1) plume core extraction well at 500  gpm and operate well through 2044 Re‐inject 500 gpm treated water Drill and construct nine (9) new sentinel  monitoring wells Quarterly monitoring of sixteen (16) sentinel  wells and eleven (11) SRP wells Replace two (2) SRP wells with new, collocated  LAU wells Connect five (5) private wells outside the WVBA  to the COP municipal system Replace RID‐114 with a new UAU production well  at a different location Add one (1) plume core extraction well at 1,000  gpm and operate well through 2044 Re‐inject 1,000 gpm treated water Contingency Total Total Cost Base All Contingencies Total Notes Costs in Millions WVBA = West Van Buren Area WQARF = Water Quality Assurance Revolving Fund Disc. = Discounted O&M = Operations and Maintenance COP = City of Phoenix gpm = gallons per minute SRP = Salt River Project LAU = Lower Alluvial Unit UAU = Upper Alluvial Unit 2026‐2044 $1.81 $1.81 $0.23 $0.28 $0.28 2030 $5.37 $5.37 $1.32 $1.32 2026 $0.07 $0.07 $0.02 $0.02 2019 $1.23 $1.23 $0.79 $0.79 2026‐2044 $3.67 $24.43 $28.10 $1.28 $3.82 $5.10 2026‐2044 $5.98 $24.23 $2.53 $48.30 $8.51 $72.53 $2.08 $8.40 $0.40 $7.56 $2.48 $15.96 Non Disc., with  NPV @ 6%  3% Inflation Disc. Rate $10.35 $3.28 $72.53 $15.96 $82.88 $19.24