SITE INSPECTION Mossville North of Highway 90 Sulphur and Westlake, Calcasieu Parish, Louisiana LAN000607014 Prepared in cooperation with the U.S. Environmental Protection Agency, Region 6 May 03, 2011 SITE INSPECTION Mossville North of Highway 90 Sulphur and Westlake, Calcasieu Parish, Louisiana LAN000607014 SIGNATURE PAGE __________________________________________ David Anderson Dynamac START Project Manager ___________________ Date __________________________________________ Debra Pandak Dynamac START Program Manager ___________________ Date __________________________________________ Brenda Nixon Cook U.S. Environmental Protection Agency Site Assessment Manager ___________________ Date i PROJECT CONTACTS Brenda Nixon Cook Site Assessment Manager U.S. Environmental Protection Agency, Region 6 Superfund Division (6SF-TR) 1445 Ross Avenue; Suite 1200 Dallas, Texas 75202 (214) 665-7436 Debra Pandak Program Manager Dynamac START 1202 Executive Drive West Richardson, TX 75081 (214) 575-3344 ex. 11 David Anderson Project Manager Dynamac START 1202 Executive Drive West Richardson, TX 75081 (214) 757-3344 ex. 16 ii SITE INSPECTION Mossville North of Highway 90 Sulphur and Westlake, Calcasieu Parish, Louisiana LAN000607014 TABLE OF CONTENTS Section Page 1 INTRODUCTION .................................................................................................................... 1 2 SITE BACKGROUND ............................................................................................................ 3 2.1 SITE LOCATION .......................................................................................................... 3 2.2 SITE DESCRIPTION ................................................................................................... 3 2.3 SITE OWNERSHIP HISTORY ................................................................................... 4 2.4 SITE OPERATIONS AND SOURCE CHARACTERISTICS.................................. 4 2.4.1 Areas of Investigation ................................................................................ 5 2.5 PREVIOUS INVESTIGATIONS ................................................................................. 6 2.6 SI PLANNING ............................................................................................................. 11 2.6.1 Community Involvement .......................................................................... 11 2.6.2 Summary of SI Investigation Locations .................................................... 12 3 FIELD ACTIVITIES AND ANALYTICAL PROTOCOL .................................................... 14 3.1 SAMPLING METHODOLOGY ........................................................................ 15 3.1.1 Groundwater Sampling ............................................................................ 15 3.1.2 Distribution System and Residential Water Sampling .............................. 15 3.1.3 Soil Gas Sampling ................................................................................... 15 3.1.4 Surface Water Sampling ................................................................................... 16 3.1.5 Sediment Sampling ...................................................................................16 3.1.6 Fish Sampling .......................................................................................... 16 3.1.7 Soil Sampling ........................................................................................... 17 3.2 ANALYTICAL PROTOCOL ...................................................................................... 17 3.3 GLOBAL POSITIONING SYSTEM.......................................................................... 18 3.4 INVESTIGATION-DERIVED WASTE ..................................................................... 18 4 QUALITY ASSURANCE/QUALITY CONTROL .............................................................. 19 4.1 SATISFACTION OF DATA QUALITY OBJECTIVES ........................................... 20 4.2 QUALITY ASSURANCE/QUALITY CONTROL SAMPLES ................................ 21 4.3 PROJECT-SPECIFIC DATA QUALITY OBJECTIVES ........................................ 21 4.4 LABORATORY QUALITY ASSURANCE/QUALITY CONTROL PARAMETERS ........................................................................................................... 21 5 ANALYTICAL RESULTS EVALUATION .......................................................................... 22 5.1 ANALTICAL RESULTS EVALUATION CRITERIA ............................................... 22 6 BACKGROUND SAMPLES ................................................................................................ 24 6.1 BACKGROUND GROUNDWATER SAMPLES..................................................... 24 iii 6.1.1 Sample Locations .................................................................................... 24 6.1.2 Sample Results ........................................................................................ 24 6.2. BACKGROUND SOIL GAS SAMPLES.................................................... 24 6.2.1 Sample Locations ............................................................................. 24 6.2.2 Sample Results................................................................................. 25 6.3 BACKGROUND SURFACE WATER and SEDIMENT SAMPLES ........... 25 6.4 BACKGROUND SOIL SAMPLE .............................................................. 25 6.4.1 Sample Location ............................................................................... 25 6.4.2 Sample Results................................................................................. 25 7 AREAS OF INVESTIGATION ............................................................................................ 26 7.1 AREA OF INVESTIGATION ± Contaminated Soil ................................................ 26 7.1.1 Sample Locations .................................................................................... 26 7.1.2 Sample Results ........................................................................................ 26 7.2 AREA OF INVESTIGATION ± Contaminated Groundwater ............................... 26 7.2.1 Sample Locations .................................................................................... 26 7.2.2 Sample Results ........................................................................................ 27 7.3 AREA OF INVESTIGATION ± Surface Impoundments ....................................... 27 7.3.1 Sample Locations .................................................................................... 27 7.3.2 Sample Results ........................................................................................ 27 8 MIGRATION/EXPOSURE PATHWAYS AND RECEPTORS ....................................... 28 8.1 GROUNDWATER MIGRATION PATHWAY.......................................................... 28 8.1.1 Geologic Setting ...................................................................................... 28 8.1.2 Aquifer System ........................................................................................ 29 8.1.3 Drinking Water Receptors ........................................................................ 32 8.1.4 Sample Locations and Results ................................................................ 35 8.2 SURFACE WATER MIGRATION PATHWAY ....................................................... 37 8.2.1 Overland Route ........................................................................................ 37 8.2.1.1 Sample Locations and Results ......................................................... 39 8.2.2 Drinking Water Receptors ........................................................................ 40 8.2.3 Human Food Chain Receptors ................................................................ 40 8.2.3.1 Sample Locations and Results ......................................................... 40 8.2.4 Environmental Receptors......................................................................... 40 8.2.4.1 Sample Locations and Results ......................................................... 41 8.3 SOIL EXPOSURE PATHWAY ................................................................................. 41 8.3.1 Site Setting and Exposed Sources .......................................................... 41 8.3.2 Receptors ................................................................................................ 42 8.3.2.1 Sample Locations and Results ......................................................... 42 8.4 AIR MIGRATION PATHWAY ................................................................................... 43 8.4.1 Human Receptors .................................................................................... 43 8.4.2 Environmental Receptors......................................................................... 44 8.4.2.1 Sample Locations and Results ......................................................... 44 9 SUMMARY AND CONCLUSIONS .................................................................................... 45 9.1 SOURCES ................................................................................................................... 46 9.2 RECEPTORS.............................................................................................................. 46 iv 9.3 CONCLUSIONS ......................................................................................................... 47 10 REFERENCES ..................................................................................................................... 49 FIGURES Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Site Location Topographic Map Aerial Location Map LDEQ Permitted Facilities in Vicinity of Area of Interest Contaminated Groundwater Plume ± 50 Foot Sand Sample Location Map Public Supply Wells Within Four Mile Radius of Area of Interest 15-Mile Downstream Target Distance Limit Map Air Migration Pathway 4-Mile Radius Map TABLES Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8 Table 9 Table 10 Table 11 Table 12 Table 13 Table 14 Table 15 Table 16 Table 17 Table 18 Table 19 Table 20 Number of Samples Collected Sample Locations and Analyses Water Quality Measurements Analysis by Laboratory and Matrix Analytical and Field Data Collection Parameters Trip Blanks, PE Samples EPA PRG, SSL and MCL Registered Wells Within Area of Interest Public Supply Wells Within 4 Miles of Area of Interest Active Domestic Supply Wells Within 4 Miles of Area of Interest Groundwater Receptor by Distance Analytical Results for Groundwater Samples Analytical Results for Distribution System Samples Analytical Results for Soil Gas Samples Analytical Results for Surface Water Samples Pond Sediment Results Above SSLs Analytical Results for Sediment Samples Analytical Results for Fish Sample Analytical Results Exceeding Benchmarks for Soil Samples Analytical Results for Soil Samples APPENDICES Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Appendix G Photo-documentation Chain of Custody Forms Data Validation Memoranda Global Positioning System Coordinates Access Agreements Drinking Water Receptor Calculations Chronology of Events, Mossville, Calcasieu Parish, Louisiana v ABBREVIATIONS AND ACRONYMS ȝJ .J micrograms per kilogram ȝJ / micrograms per liter AI Areas of Investigation AOI Area of Interest ATSDR Agency for Toxic Substances and Disease Registry bgs below ground surface CAA Clean Air Act CDD chlorinated dibenzodioxin CDF chlorinated dibenzofuran CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CLP Contract Laboratory Program CRQL Contract Required Quantitation Limit DQO Data Quality Objective ELCR Estimated Lifetime Cancer Risk EPA United States Environmental Protection Agency ERT Environmental Response Team FEMA Federal Emergency Management Agency gpm gallons per minute GPS Global positioning system HpCDD Heptachlorodibenzo-p-dioxin HRS Hazard Ranking System Hwy Highway HxCDD Hexachlorodibenzo-p-dioxin HxCDF Hexachlorodibenzofuran IDW Investigation Derived Waste LA Louisiana LDEQ Louisiana Department of Environmental Quality LDHH Louisiana Department of Health and Hospitals LDOT Louisiana Department of Transportation MCL Maximum Contaminant Level vi MEAN Mossville Environmental Action Now mg/kg Milligrams per Kilogram msl mean sea level MS/MSD Matrix Spike/Matrix Spike Duplicate ng/kg nanograms per kilogram NPDES National Pollutant Discharge Elimination System NPL National Priorities List OCDD Octachlorodibenzo-p-dioxin ORP oxidation reduction potential PAH polynuclear aromatic hydrocarbon PARCC Precision, accuracy, representativeness, comparability and completeness PCB polychlorinated biphenyl PCD polychlorinated dioxin PDF polychlorinated furan PE performance evaluation PeCDD Pentachlorodibenzo-p-dioxin PeCDF Pentachlorodibenzofuran PEST Pesticide pg/g Picograms per gram pg/L Picograms per Liter ppb Parts per billion PPE Probable point of entry Ppm Parts per million ppq Parts per quadrillion ppt Parts per trillion PRG Preliminary Remediation Goal QA Quality assurance QA/QC Quality assurance/quality control QC Quality control QASP Quality Assurance Sampling Plan RCRA Resource Conservation and Recovery Act Rd Road RI/FS Remedial Investigation/Feasibility Study vii SAM Site Assessment Manager SARA Superfund Amendments and Reauthorization Act SDG sample delivery group SI Site Inspection SOP Standard Operating Procedure SSL Soil Screening Level START Superfund Technical Assistance and Response Team SVOC Semi-volatile Organic Compound TAL Target Analyte List TCDD Tetrachlorodibenzo-p-dioxin; 2,3,7,8-tetrachlorodibenzo-p-dioxin TCL Target Compound List TDD Technical Direction Document TDL Target distance limit TDS Total dissolved solids TEF Toxicity Equivalency Factor TEQ Toxicity Equivalent Quotients TPH Total Petroleum Hydrocarbons ug/kg Micrograms per kilogram VOC volatile organic compound viii Mossville 1 CERCLIS No. LAN000607014 INTRODUCTION The Dynamac Corporation (Dynamac) Superfund Technical Assessment and Response Team (START) was tasked by the United States Environmental Protection Agency (EPA) Region 6 under Technical Direction Document (TDD) No. TO-0009-09-08-01, to conduct a Site Investigation (SI) at the Mossville site located in Sulphur and Westlake, Calcasieu Parish, Louisiana. This SI was conducted under authority of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA). The purpose of this investigation was to collect information concerning conditions at the Mossville site sufficient to assess the threat posed to human health and the environment and to determine the need for additional investigation under CERCLA or other authority, and, if appropriate, support site evaluation using the Hazard Ranking System (HRS) for proposal to the National Priorities List (NPL). Completion of the SI included reviewing existing site information, determining regional characteristics, collecting receptor information within the range of site influence, executing a sampling plan, and producing this report. The report is organized as follows: ƒ Section 1, Introduction ± authority for performance of this work, goals for the project, and summary of the report contents; ƒ Section 2, Background ± site description, site operations and waste characteristics, and a summary of investigation locations; ƒ Section 3, Field Activities and Analytical Protocol ± Summary of the field effort; ƒ Section 4, Quality Assurance/Quality Control (QA/QC) ± Summary of the laboratory data; ƒ Section 5, Analytical Results Evaluation ± Discussion of results reporting criteria. ƒ Section 6, Background Samples ± Discussion of background sample locations and analytical results; ƒ Section 7, Potential Sources ± Discussion of site sources, sample locations, and analytical results; Site Inspection Report 1 Date Mossville ƒ CERCLIS No. LAN000607014 Section 8, Migration/Exposure Pathways and Receptors ± Discussion of the migration/exposure pathways, sample locations, and analytical results; ƒ Section 9, Summary and Conclusions ± summary of the investigation and recommendation for the site based on the information gathered during the investigation; ƒ Section 10, References ± Alphabetical listing of the references cited throughout the text; ƒ Appendix A, Photographic Documentation ± Photographs taken during the sampling event and site visit; ƒ Appendix B, Chain-of-Custody Forms ± forms documenting sample chain-of-custody for the sampling event; ƒ Appendix C, Data Validation Memoranda ± laboratory results and quality assurance evaluation for all samples; ƒ Appendix D, Global Positioning System (GPS) Coordinates ± latitude and longitude coordinates of sample locations; ƒ Appendix E, Access Agreements; ƒ Appendix F, Drinking Water Receptor Calculations; and ƒ Appendix G, Chronology of Events, Mossville, Calcasieu Parish, Louisiana. Site Inspection Report 2 Date Mossville 2 CERCLIS No. LAN000607014 SITE BACKGROUND This section describes the background of the site including location, description, ownership history, operations and source characteristics, previous investigations, and a summary of the site investigation locations. 2.1 SITE LOCATION Site Name: Mossville CERCLIS ID No.: LAN000607014 Location: Sulphur and Westlake, Calcasieu Parish, Louisiana Latitude: 30.248590oN Longitude: 93.304523oW Legal Description: There are over 1,600 properties within the Mossville Area of Interest (AOI). Congressional District: Louisiana 7th. Site Owner: Multiple owners. Site Contact: See the access agreements (Appendix E) for contact information for the individual property owners. 2.2 SITE DESCRIPTION The AOI in Mossville consists of residential communities located west and northwest of the concentration of chemical plants in Westlake and northern Lake Charles, Louisiana (Figures 1 and 2). The site is predominately residential, with areas of woodlands and a few commercial properties/businesses (Figure 2). The AOI encompasses the properties along Old Spanish Trail/Burton Road (Rd.), Prater Rd., Evergreen Rd., and LA 108N Cities Service Highway (Hwy.). The area is roughly bounded by the KCS Railroad tracks on the south, VCM Plant Rd. on the east, Junius Rd. on the west, and Village Orphanage on the north. Old Spanish Trail/East Bruton Rd. passes thru the Mossville AOI, providing the primary access to the area Site Inspection Report 3 Date Mossville CERCLIS No. LAN000607014 (Figures 1 and 2). The AOI is approximately 1.5 square miles in size, measured from the topographic maps (Ref. 5). The latitude and longitude measurements were made at the Rigmaiden Recreation Center which is located in the central area of the AOI. 2.3 SITE OWNERSHIP HISTORY There are over 1,600 properties within the AOI, the majority of the properties are privately owned. In the Bel Air Subdivision, the easternmost portion of the Mossville AOI, bounded by Rigmaiden Rd., Old Spanish Trail Rd., VCM Plant Rd., and 7th/8th Street, the majority of the lots (295 of 329) are currently owned by Sasol North America (Ref. 6). The lots were purchased by Condea Vista (which became Sasol) between 1998 and 2004 as part of a buyout from a class action lawsuit (Ref 7, p. 23). The majority of the structures were removed by 2004 (Ref. 8). Access to many of the streets in this area are blocked. Brush and trees have overgrown the vacant lots. A limited number of the lots appear to be used for residences or horse barns. Lots west of the Bel Air Subdivision are in use as private residences. Industrial development in the Lake Charles area began after the discovery of petroleum and gas reserves in the DUHD LQ WKH ¶V 5HI , p. 9). Chemical plants/refineries operated by Georgia Gulf, Sasol North America, and ConocoPhillips are located adjacent to the eastern boundary of the Mossville AOI (Ref.10). Other industrial facilities southeast of Mossville include Air Liquide, Arch Chemicals Corp., BioLab, CertainTeed Products, Lyondell Chemical Co., Matheson TriGas Inc., Olin Chemical Co., TDC-LLC, Air Products and Chemicals Inc., Praxair Inc., PPG Industries, Tessenderlo Kerley Inc., and Tetra Chemicals (Figure 3, Ref. 10). The Entergy Roy S. Nelson power plant is located north-northeast of Mossville (Ref. 11, p. ii). 2.4 SITE OPERATIONS AND SOURCE CHARACTERISTICS Mossville is a residential community; there is no direct regulatory involvement by either the EPA or Louisiana Department of Environmental Quality (LDEQ). The surrounding industrial facilities operate under Clean Air Act (CAA) and National Pollution Discharge Elimination System (NPDES) permits, and solid wastes are regulated under the Resource Conservation and Recovery Act (RCRA). Site Inspection Report 4 Date Mossville 2.4.1 CERCLIS No. LAN000607014 Areas of Investigation Mossville is a residential community located adjacent to an industrial area of Lake Charles. The areas of investigation (AI) within the Mossville AOI consist of soil potentially contaminated by deposition from air emissions from nearby chemical plants. Residents of the community have expressed concerns regarding the long term exposure to industrial chemicals that may have migrated from the surrounding plants. These chemicals may include: 1,1-dichloroethane, 1,2dichloroethene, 1,1-dichloropropene, 1,1,2-trichloroethene, 1,1,2,2-tetrachloroethane, 1,2dibromo-2-chloropropane, 1,2-dichloroethane, cis-1,2-dichloroethene, trans-1,2-dichloroethene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3trichloropropane, 2-chlorotoluene, 4-chlorotoluene, benzene, chlorobenzene, chloroethane, chloroform, ethyl benzene, isopropylbenzene, naphthalene, tetrachloroethene, trichloroethene, toluene, o-xylene, m,p-xylene, and vinyl chloride (Refs. 12, 13, 15, and 16). Dioxins and furans are also released from the plants per their Toxic Release Inventories. A limited number of soil samples have been collected during Agency for Toxic Substances and Disease Registry (ASTDR) Exposure Investigations; however, chemical analysis of collected samples was limited to dioxins and furans. Dioxins have been detected in soil samples within the Mossville AOI; however, dioxin concentrations are generally within the range of samples collected within other areas of Calcasieu Parish, and may not be elevated in comparison to the natural background levels (Ref. 21). Groundwater contamination has been documented in various aquifers/zones at the Sasol North America, Georgia Gulf, and ConocR3KLOLSV IDFLOLWLHV LQFOXGLQJ WKH ³ IRRW´ VDQG ³ IRRW´ VDQG ³ IRRW´ VDQG ³ IRRW´ VDQG DQG ³ IRRW´ VDQG XQLWV 5HI 5HI 5HI 5HI 5HI 16) (Figure 4). Natural groundwater flow is typically to the south or southwest, however regional flow is often impacted by the proximity of the bayous and rivers, as well as by tidal actions, especially within the shallowest zones (Ref. 13, pp. 3-5). Based on the typical flow, the Sasol and Georgia Gulf facilities would be the most likely contributors to potential groundwater contamination in the AOI. Since the ConocoPhillips facility is downgradient of the AOI, it is not likely to contribute to groundwater contamination. Plumes from the SASOL facility which underlie the AOI contain 1,2-dichloroethane, 1,1-dichloroethene, 1,1,2-trichloroethane, trichloroethene, 1,1-dichloroethane and vinyl chloride ( Ref. 12, Ref 13). Active groundwater Site Inspection Report 5 Date Mossville CERCLIS No. LAN000607014 contamination remediation programs are currently in operation at both the Sasol and ConocoPhillips facilities. Pumping for these remediation programs has also impacted groundwater flow directions, in some cases reversing the natural flow from the south to the north. Allegations have also been made by residents that wastes were deposited in various areas within the AOI, including ponds and other discrete areas. EPA solicited input from residents during public meetings held on January 21 and April 12, 2010, allowing residents to identify the possible disposal locations on maps. 2.5 PREVIOUS INVESTIGATIONS Appendix G is a timeline of investigation activities conducted in Mossville. In 1997, EPA requested that ATSDR conduct a health consultation on samples provided by a resident of Calcasieu Parish (Ref. 17, p. 2). Blood samples from eleven residents living in the 0RVVYLOOH %D\RX G¶,QGH DUHD RQH FRPSRVLWH SRROHG EORRG VDPSOH UHSRUWHGO\ IURP individuals, nine sediment samples from unspecified locations, and one composite biota (clam) sample from the north beach on Lake Charles were collected as part of the study (Ref. 17, p.2). Samples were analyzed for polychlorinated dioxins and furans (PCD and PCF) and for nine polychlorinated biphenyl (PCB) congeners (Ref. 17, p. 2). Three of the eleven individual blood samples had 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD), Toxicity Equivalency Quotients (TEQs), or TEQs+PCBs greater than the reference ranges utilized in the study (Ref. 17, p. 6). The pooled composite blood sample also had TCDD and TEQ concentrations greater than the reference values (Ref. 17, p. 6). Sediment concentrations ranged from 0.0027 to 2.958 parts per billion (ppb) dry weight. The one sediment sample exceeding one ppb was collected on the QRUWK VKRUH RI %D\RX '¶,QGH (Ref. 17, p. 5). The concentration of dioxin TEQ of the clam sample was 0.24 parts per trillion (ppt), wet weight, which did not exceed concentrations in samples collected from reference locations (Ref. 17, pp. 5, 7). ATSDR concluded that the dioxin concentrations in the sediments and clams did not present a public health hazard. ATSDR concluded that the dioxin levels in the three blood samples were higher than the Site Inspection Report 6 Date Mossville CERCLIS No. LAN000607014 reference ranges and recommended additional investigation to determine the source (Ref. 17, p. 10). Based on the analytical results of the 1997 samples, ATSDR conducted an Exposure Investigation in 1998, collecting blood samples from 28 residents, four surface soil (0-3 inches below ground surface [bgs]) samples from three residences, two chicken egg samples and one breast milk sample (Ref. 7, p. 3). Samples were analyzed for dioxins and PCBs (Ref. 7, p. 3). The ATSDR discussion indicates that the samples were collected primarily from the Bel Air Subdivision, immediately adjacent to the SASOL chemical plant along VCM Plant Road (Ref. 7, p. 4). Samples were analyzed for the dioxins, furans and PCBs with TCDD-like activity (Ref. 7, pp. 4-5). TEQ concentrations in the blood samples ranged from 3.8 to 188 ppt on a lipid adjusted basis. Median and mean TCDD-TEQs for the samples exceeded the 95th percentile of a comparison population (Ref. 7, pp. 6). Soil sample concentrations ranged from 0.0006 to 0.028 ppb, however the lowest concentration sample may not be representative of the soil since it was collected from a location where sand had been placed over the native soil (Ref. 7, p. 11). The breast milk sample contained 13.5 ppt of TCDD-TEQ on a lipid-adjusted basis. The eggs contained 1.76 - 2.09 picogram/gram (pg/g) of TCDD-TEQ on a lipid-adjusted basis (Ref. 7, p. 11). ATSDR concluded that the blood levels of the residents participating in the study were elevated and that older residents (greater than 47 years of age) were the most likely to have elevated levels, however the blood levels were unlikely to be associated with known clinical health effects (chloracne or elevated liver enzyme levels). Dioxin TEQ levels in the breast milk sample were not considered to be elevated, and the soil and egg concentrations were not at levels of health concern. In May 1999, the Louisiana Department of Health and Hospitals (LDHH) District 5 office, under a grant from the USEPA, collected samples from the Mossville Public Water System for analysis for dioxins and furans. Samples were collected based on the elevated dioxin levels found in the previous ATSDR blood survey to determine if drinking water was a source. Dioxin and furans were not detected in the samples at concentrations above the quantitation limit of 10 pg/L (parts per qualdrillion [ppq]), which is less than the health based standard of 30 ppq (Ref. 74, p. 1). Site Inspection Report 7 Date Mossville CERCLIS No. LAN000607014 Beginning in 1999, EPA conducted a Remedial Investigation/Feasibility Study (RI/FS) of the &DOFDVLHX (VWXDU\ WR ³DGGUHVV WKUHDWV WR KXPDQ KHDOWK DQG WKH HQYLURQPHQW UHODWHG WR XQFRQWUROOHG UHOHDVHV RI RUJDQLF DQG LQRUJDQLF FKHPLFDOV WR WKH HVWXDU\´ Ref. 18, p. 1). The study area extended from the saltwater barrier north of Lake Charles to Moss Lake, and included both Bayou Verdine and Maple Fork Bayou, which receive surface drainage from the AOI (Ref. 18, p. 1). Objectives of the RI/FS included identification of contaminants of potential concern within the estuary, conduct a statistically-based sediment and surface water program to support reporting and risk assessments, determine and evaluate contaminant gradients in the sediments, collect biota samples to characterize potential impacts of selected fauna, and assess the risk to human health and ecological receptors (Ref. 18, p. 2). While Bayou Verdine is a source of contamination to the Upper Calcasieu Estuary, the upper reaches of the bayou which pass through the AOI were determined to be relatively un-impacted by industry (Ref. 18, p. 24). Contaminants detected in water and sediment samples from Bayou Verdine included polynuclear aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), dioxins and metals. Maple Fork originates in the western portion of the AOI and flows south to its FRQIOXHQFH ZLWK %D\RX G¶ ,QGH Ref. 18, p. 60). Sampling during the RI/FS did not extend into the AOI, although elevated levels of contaminants (dioxins, PAHs, PCBs and metals) were detected downstream (Ref. 18. pp. 19-20). There are no major contaminant sources in Maple Fork Bayou (Figure 4). The lower reaches of Bayou Verdine are being addressed by ConocoPhillips and Sasol under Superfund authority with EPA oversight. The West Ditch area was addressed under a time-critical removal action in 2002 that removed high concentrations of VOCs in Bayou Verdine. On October 12, 2010, a consent decree that will require ConocoPhillips and Sasol to address PAH contamination in the lower reaches of Bayou Verdine was lodged in federal district court. The consent decree requires the companies to perform clean-up work of hazardous substances along Bayou Verdine (estimated to cost $10 million) and to reimburse government response costs of approximately $4.5 million (Ref. 75). ATSDR conducted Health Consultations using the contaminants of concern from the surface water and sediment samples collected during the RI/FS (Ref. 19; Ref. 20). For the water, Site Inspection Report 8 Date Mossville CERCLIS No. LAN000607014 $76'5 FRQFOXGHG WKDW ³Where is no public health hazard involved with skin contact or ingestion RI ZDWHU LQ WKH &DOFDVLHX (VWXDU\ GXULQJ UHFUHDWLRQDO H[SRVXUH´ Ref. 19, p. 4). ATSDR also FRQFOXGHG WKDW ³5HVLGHQWLDO H[SRVXUH WR WKHVH ZDWHUV LV XQOLNHO\ EHFDXVH WKH HVWXDU\ GRHV not VHUYH DV WKH 3DULVK¶V PDLQ ZDWHU VRXUFH´ Ref. 19, p. 5). For the sediments, ATSDR concluded: ³WKDW WKHUH LV QR DSSDUHQW SXEOLF KHDOWK KD]DUG IURP UHFUHDWLRQ H[SRVXUHV WR VHGLPHQWV IURP WKH &DOFDVLHX (VWXDU\´ 5HI S 5). In 2001, ATSDR conducted a Follow-Up Exposure Investigation in the Mossville area (Ref. 21). Included in this investigation were blood serum samples from five of the eleven persons who provided blood samples in 1997, and 17 of the 28 persons who provided blood samples in the 1998 exposure investigation. In addition, 20 soil (19 locations), 18 indoor dust, 14 attic dust and three water wells samples were collected, as well as nine vegetable/fruit/nut samples produced in the area and eight fish caught by area residents (Ref. 21, p. 2-3). Only two of the soil, indoor dust and attic dust sample locations were within the Mossville AOI; the remaining locations were located throughout the general Lake Charles area (Ref. 21). Three of the soil sample locations were located in communities outside of the Lake Charles area, and served as background locations (Ref. 21). There were no water well samples collected within the Mossville AOI as part of this study (Ref. 21). Samples were analyzed for dioxins and PCBs (Ref. 21, p. 3). Lipidadjusted serum total dioxin TEQs for the blood samples ranged from 4.1 to 245.2 ppt (Ref. 21, p. 11). Total dioxin TEQs for the soil samples ranged in concentration from 0.09 to 19.26 ppt (Ref. 21, p. 13). Concentrations in the two soil samples collected within the AOI were 1.22 ppt and 6.47 ppt (Ref. 12). Total dioxin TEQs for the indoor dust samples ranged from 0.26 to 83.13 ppt (Ref. 21, p. 13), with concentrations in the two samples collected within the AOI at 8.44 ppt and 8.85 ppt (Ref. 21, p. 21). Total dioxin TEQs for the attic dust samples ranged from 0.32 to 922.77 ppt (Ref. 21, p. 13), with concentrations in the two samples collected within the AOI at 16.63 ppt and 143.35 ppt (Ref. 21). Dioxins were not detected in the well water samples (Ref. 21, p. 13). ATSDR concluded that blood dioxin concentrations were elevated in many of the participants, although the concentrations had decreased between their initial and follow-up samplings. Older residents were more likely to have elevated blood dioxin levels, attributable to historical exposures. Blood dioxin concentrations are unlikely to produce the known clinical Site Inspection Report 9 Date Mossville CERCLIS No. LAN000607014 health effects of chloracne and elevated liver enzymes (Ref. 21, p. 38). Dioxin concentrations in surface soil, indoor dust, well water and the homegrown produce were not at levels of concern (Ref. 21, p. 38). In 2001 and 2002, ATSDR conducted a study of the serum dioxin levels of residents in Calcasieu Parish (Ref. 9), targeting the industrial corridor around the Calcasieu Estuary, a buffer zone surrounding the industrial corridor, and an outer ring of towns approximately six miles from the corridor (Ref. 9, pp. 13-14). Results were compared to the results from Lafayette Parish, located east of Calcasieu Parish (Ref. 9, p. 14). ATSDR concluded that the mean serum dioxin TEQ levels of residents of Calcasieu and Lafayette Parishes were similar (Calcasieu Parish 16.7 ppt male, 23.0 ppt female; Lafayette Parish 20.5 ppt male, 20.1 ppt female), and that dioxin levels increased with age and length of residence (age 15 to 29 - 8.4 ppt, age 30 to 44 - 14.3 ppt, age 45 to 59 - 18.7 ppt, age >60 - 36.9 ppt) (Ref. 9, pp. 21-22, 30). Residents of both parishes had similar mean serum dioxin TEQ levels versus a combined data set developed for comparison. Residents in the industrial corridor also had similar serum dioxin concentrations as the residents in the two zones further from the plant sites (industrial corridor -19.7 ppt male, 19.3 ppt female; industrial buffer - 15.7 ppt male, 25.8 ppt female; outer ring - 19.1 ppt male, 15.1 ppt female) (Ref. 9, p. 30). ATSDR concluded that levels among the youngest age group were not elevated, suggesting that no unusual dioxin exposure is currently occurring. ATSDR also concluded that the dioxin congener profile is similar in both parishes (Ref. 9, p. 21). In September 2006, Mossville Environmental Action Now (MEAN), The Subra Company, and Advocates for (QYLURQPHQWDO +XPDQ 5LJKWV UHOHDVHG ³,QGXVWULDO 6RXUFHV RI 'LR[LQ 3RLVRQLQJ LQ Mossville ± A Report on tKH )DFWV WKDW *RYHUQPHQWDO $JHQFLHV +DYH +LGGHQ´ ZKLFK ZDV revised in July, 2007 (Ref. 11). This document provides an alternate interpretation of the results from the ATSDR studies. On August 21, 2009, groundwater samples were collected from five locations within the Mossville distribution system and analyzed for volatile and semi-volatile organics and total Site Inspection Report 10 Date Mossville CERCLIS No. LAN000607014 metals (Ref. 72). Metals were detected in the drinking water samples; however, concentrations did not exceed the National Primary Drinking Water Maximum Contaminant Levels (MCL) (Ref. 73, Ref. 76). Low concentrations of trihalomethanes were detected in the samples (Ref. 72). Trihalomethanes are found in treated water supplies (Ref. 73, p. 3). 2.6 SI PLANNING 2.6.1 Community Involvement Community involvement in the SI has been extensive, beginning with a meeting held with the community on January 21, 2010 to discuss the planned assessment of the community. A basic explanation of the Superfund process was presented to the community and the community was asked to provide input. ATSDR conducted a series of health related workshops for the Mossville community in March and April of 2010. The draft Preliminary Assessment and draft sampling plan were posted on EPA web site for the community to review and on April 13, 2010, a meeting was held by EPA in the community to discuss the draft of the Preliminary Assessment, to provide the community with an overview of the proposed sampling plan, an opportunity to comment on the sampling plan and to provide locations of areas of interest within the community to be sampled. Solicitation of access agreements to properties for sampling were initiated during this meeting. Mossville Environmental Action Now (MEAN) assisted in obtaining access agreements for residential. The EPA SAM hosted an informal question and answer session with the residents on April 26, 2010, prior to the field sampling that began that week. On June 30, 2010, EPA held a conference call with community representatives to discuss the problems with the dioxin data and outlined their plans for re-sampling. On August 2, 2010, letters detailing the results of the April sampling were sent by EPA to the owners of the properties samples, as well as a fact sheet indicating the need for the re-sampling for dioxin analysis. On August 16, 2010, EPA held a meeting in the community to discuss the results of the April sampling in regards to the Superfund Site Assessment process and preliminary results of the evaluation of the Mossville Water System, indicating that chemically, the water produced by the system was safe to drink. Site Inspection Report 11 Date Mossville 2.6.2 CERCLIS No. LAN000607014 SUMMARY OF SI INVESTIGATION LOCATIONS In order to obtain representative soil samples from the entire AOI, EPA solicited access agreements from property owners during public meetings held on January 21 and April 12, 2010; through mailings; and with the assistance of MEAN. The AOI was divided into sixteen blocks. Approximately three locations, with access agreements, within each block were selected for soil sampling. Areas that the public alleged to have received wastes were also targeted for sampling. Due to UHVLGHQWV¶ Foncern regarding the quality of the water provided by the water district, sampling was conducted at the wells providing water to the system, as well as at several residences and monitoring taps within the system. Fish sampling from the ponds was added after the public indicated that residents catch and consume fish from the ponds. Comments received on the EPA Quality Assurance Sampling Plan (QASP) for the EPA schedule sampling event in Mossville resulted in soil gas sampling being added. Soil gas sampling was added at residences in the vicinity of the known groundwater plume to assess possible impact of the contaminated groundwater. EPA Region 6 START conducted sampling at residences/properties and from the water system within the Mossville AOI from April 26 to May 1, 2010. START was accompanied during the sampling by Brenda Nixon Cook, EPA Site Assessment Manager (SAM), Beverly Negri, EPA Community Involvement and Bill Little, EPA Community Involvement. Sampling teams were accompanied by representatives of MEAN and by industry representatives. Groundwater samples were collected from the two public supply wells and from two residential wells. Water samples were collected from five monitoring taps on the distribution system, and from 34 residences served by the water system. Surface water and sediment samples were collected from three ponds in the AOI. Soil samples were collected from 45 properties within the AOI. Soil gas samples were collected at 5 properties between May 12 and May 19, 2010. Three water samples were collected from residential properties on May 12 and 13, 2010. A single fish sample was collected by START on May 20, 2010. Aqueous and solid Performance Evaluation (PE) samples were provided to the dioxin and furan analytical laboratory. Dioxin and furan Site Inspection Report 12 Date Mossville CERCLIS No. LAN000607014 results from the sampling effort were rejected during Quality Assurance (QA) review due to improper laboratory documentation procedures. EPA Region 6 START conducted re-sampling for dioxin and furan analysis on August 16 through August 20, 2010. START was accompanied during the sampling by EPA representatives Brenda Nixon Cook, Beverly Negri, and Bill Little. Sampling teams were accompanied by representatives of MEAN and by industry representatives. Groundwater samples were collected from the two public supply wells. Water samples were collected from five monitoring taps on the distribution system and from eight residences on the water system. Surface water and sediment samples were collected from the three ponds. Soil samples were collected from 49 properties, including 6 properties not previously sampled. Additional samples were collected at two properties previously sampled to further characterize the properties. Owners of three properties sampled in April declined to participate in the re-sampling effort. Split samples were provided to MEAN from five of the properties. PE samples were provided to the analytical laboratory. The following table lists the samples collected by analysis and matrix. Table 1 - Number of Samples Collected Matrix/ Analysis Metals VOC SVOC Pest PCB Dioxins Coliforms Groundwater Residential Water 36 36 36 36 36 16 Surface Water 4 4 4 4 4 4 Sediment Soil Fish 6 6 6 6 6 8 Municipal Water 5 5 5 5 5 11 QC 1 0 0 1 1 1 Soil Gas 0 10 0 0 0 0 4 4 4 4 4 8 50 50 50 50 50 111 5 5 39 4 0 0 0 0 0 Table 2 lists all of the samples that were collected during the two sampling events. Site Inspection Report 13 Date 0 2 0 0 0 5 Mossville 3 CERCLIS No. LAN000607014 FIELD ACTIVITIES AND ANALYTICAL PROTOCOL The QASP for Mossville, Sulphur-Westlake, Calcasieu Parish, Louisiana for the Mossville AOI was developed by the Dynamac START prior to initiating field sampling (Ref. 22). An amendment to the QASP was submitted prior to the August re-sampling effort (Ref. 23). The QASP describes the sampling strategy, sampling methodology, and analytical program used to investigate potential hazardous substance sources and potential receptors. With few exceptions the field activities were conducted in accordance with the approved QASP. Deviations from the QASP are described, when applicable, in this section and in the sampling location discussions in Section 7 (Source Areas) and Section 8 (Receptors). The initial field sampling event was conducted from April 26 through May 1, 2010. A total of 107 samples, including two background samples and 13 QA (field replicates and trip blanks) samples were collected during the sampling event. Sample types and methods of collection are described below. During the period May 12 to May 20, 2010, a total of 12 samples, including one background and two QA (field replicate and trip blank) samples were collected. The final field sampling event was conducted from August 16 through 20, 2010. A total of 86 samples, including two background and 10 QA (field replicates) samples were collected during this sampling event. Three properties sampled during the April sampling event did not elect to participate in the August sampling event. Five of the soil samples were split with MEAN. A list of all samples collected for laboratory analysis during this sampling event is contained in Table 2. Photographic documentation of the field activities is included as Appendix A. Alphanumeric identification numbers applied to each sample location (e.g., MWW01) are used in the report as the sample location identifiers. Sample locations are shown in Figure 5. This section describes sampling methodology, analytical protocol, global positions system, and investigation-derived waste. Site Inspection Report 14 Date Mossville 3.1 CERCLIS No. LAN000607014 SAMPLING METHODOLOGY Grass, leaves and other vegetative material, rocks, and other debris unsuitable for analysis were removed from samples before being placed into sample containers. Samples were stored on ice in coolers continuously maintained under the custody of field personnel. Sampling methods used for each sample type are described below. 3.1.1 Groundwater Sampling Groundwater samples from the two public supply wells and from two private wells were collected at the tap nearest the well before any treatment (Figure 5, Table 2). After establishing flow from the tap, the samples were collected directly into the pre-preserved sample containers. An aliquot of sample was collected for measurement of pH, temperature, conductivity, turbidity, total dissolved solids (TDS) and oxidation reduction potential (ORP) (Table 3, Ref. 25). After collection, the sample containers were placed in a cooler with ice for transport to the field command post for processing. 3.1.2 Distribution System and Residential Water Sampling Water samples from five distribution system monitoring locations were sampled during both the April and August sampling events. Water samples were collected from 34 residential properties in April and from eight residential properties in August (Figure 5, Table 2). Samples were collected directly from taps at the sample locations. Some taps used for residential sample collection were located inside the homes, while others were located on the exterior of the building. After establishing flow from the tap, the samples were collected directly into the prepreserved sample containers. An aliquot of sample was collected for measurement of pH, temperature, conductivity, turbidity, TDS and ORP (Table 3, Ref. 25). After collection, the sample containers were placed in a cooler with ice for transport to the field command post for processing. 3.1.3 Soil Gas Sampling START installed 10 passive soil gas samplers obtained from Beacon Environmental Services, Inc. (Beacon) in 4 properties within the eastern portion of the Mossville AOI on May 12, 2010 (Figure 5, Table 2). Samplers were installed at a depth of approximately two (2) feet bgs. Site Inspection Report 15 Date Mossville CERCLIS No. LAN000607014 Samplers were retrieved on May 19, 2010. The passive soil gas samplers were installed and retrieved according to Beacon¶V recommended installation/retrieval instructions (Ref. 26). A list of the target analytes and reporting limits is included in the Beacon instructions. After packaging, the samples were shipped to the Beacon laboratory for VOCs chemical analyses. 3.1.4 Surface Water Sampling Surface water samples were collected from three ponds located within the Mossville AOI (Figure 5, Table 2). During the April 2010 sampling, samples were collected using a peristaltic pump directly into the sample containers (except metals/mercury) using EPA Environmental Response Team (ERT) Standard Operation Procedure (SOP) #2013 Surface Water Sampling as guidance. Samples for metals/mercury analysis were filtered using QED Quickfilter 0.5 micron filters discharging directly into the sample container. During the August 2010 sampling, samples were collected using a beaker on an extension pole with the sample being transferred directly into the sample container. An aliquot of sample was collected for measurement of pH, temperature, conductivity, turbidity, TDS and ORP (Table 3, Ref. 25). After collection, the sample containers were placed in a cooler with ice for transport to the field command post for processing. 3.1.5 Sediment Sampling START collected sediment/soil samples from three ponds located within the Mossville AOI (Figure 5, Table 2). Using EPA ERT SOP #2016 Sediment Sampling as guidance, samples were collected using a bottom dredge to obtain material from the bottom of the ponds. The material was placed in stainless steel bowls and homogenized using pre-cleaned stainless steel trowels and placed directly into the sample containers. Aliquots for VOC analysis were collected using (QYLURQPHQWDO 6DPSOLQJ 6XSSO\ &RUH 1¶ 2QH VDPSOHUV After collection, the sample containers were placed in a cooler with ice for transport to the field command post for processing. 3.1.6 Fish Sampling The fish specimen was captured utilizing a baited hook from Pond C (Figure 5, Table 2). After capture, the specimen was placed on ice in a cooler for storage. The specimen was frozen solid before packaging and shipment to the analytical laboratory. Site Inspection Report 16 Date Mossville 3.1.7 CERCLIS No. LAN000607014 Soil Sampling START collected soil samples from 45 locations on the site during the April sampling event and from 58 locations during the August sampling event (Figure 5, Table 2). Using EPA ERT SOP #2012 Soil Sampling as guidance, soil within the 0 to 12 inch bgs horizon was homogenized in place, except the VOC fraction, using pre-cleaned stainless steel trowels and placed directly into the sample containers. Aliquots for VOC analysis were collected using Environmental 6DPSOLQJ 6XSSO\ &RUH 1¶ 2QH VDPSOHUV After collection, the sample containers were placed in a cooler with ice for transport to the field command post for processing. 3.2 ANALYTICAL PROTOCOL Analytical protocols applied to the SI samples included off-site fixed laboratory analysis of: - Target Analyte List (TAL) Total Metals + Mercury: Contract Laboratory Program (CLP) ILM01.2 - TAL Dissolved Metals + Mercury: CLP ILM01.2 - Target Compound List (TCL) Semi-volatile Organic Compounds (SVOC): CLP OLM04.2- water, SOM01.2 ± soil/sediment - TCL VOCs: CLP OLM04.2- water, SOM01.2 ± soil/sediment - TCL Pesticides (PEST): CLP OLM04.2- water, SOM01.2 ± soil/sediment. - TCL PCB as Aroclors: CLP OLM04.2- water, SOM01.2 ± soil/sediment. - Dioxins and Furans: CLP DLM02.2 - Fecal and total coliforms and E. coli: SM21 9222B and 9222D - Total Metals + Mercury, PEST, PCB, Dioxins and Furans in Tissue: SW846 methods 6010B, 7471A, 8081A, 8082 and 8290. - VOC in Air: SW846 8260 modified. Analyses applied to each of the samples collected during the SI are presented in Table 2. Table 4 indicates number of samples by matrix and analyses submitted to CLP, Houston EPA and subcontract laboratories Site Inspection Report 17 Date Mossville 3.3 CERCLIS No. LAN000607014 GLOBAL POSITIONING SYSTEM Trimble GeoExplorer 3 Global Positioning System (GPS) units were utilized to obtain coordinates for each of the soil, sediment and surface water sample locations. Data was processed and corrected utilizing Trimble Pathfinder Office Version 4.10 software. The GPS units utilized the WGS1984 coordinate system. After correction using the Pathfinder Office software, the accuracy of the individual sample points ranged from 0.9 to 2.2 meters. Coordinates of the sampling points are included in Appendix D. 3.4 INVESTIGATION-DERIVED WASTE Investigation-derived wastes (IDW) included solid waste consisting of personal protective equipment and empty boxes/containers. The IDW was contained in accordance with EPA ERT SOP #2049 IDW Management. Solid wastes were double bagged and returned to the START office for proper disposal. Site Inspection Report 18 Date Mossville 4 CERCLIS No. LAN000607014 QUALITY ASSURANCE/QUALITY CONTROL QA/QC data are necessary to determine precision and accuracy and to demonstrate the absence of interferences and/or contamination of sampling equipment, glassware, and reagents. Specific QC requirements for laboratory analyses are incorporated in the USEPA Contract Laboratory Program Statement of Work for Inorganic Analyses, Multi-Media, Multi-Concentration; USEPA Contact Laboratory Program Statement of Work for Organic Analyses, Multi-media, Multi-Concentration; and USEPA Analytical Services Branch Statement of Work for Analysis of Chlorinated Dibenzo-p-Dioxins (CDDs) and Chlorinated Dibenzofurans (CDFs), Multi-Media, Multi-Concentration.. These QC requirements, or equivalent requirements, were followed for analytical work on the Mossville SI. This section describes the QA/QC measures taken for the SI and provides an evaluation of the usability of data presented in this report. All samples were collected following the guidance of the QASP for Mossville, Sulphur-Westlake, Calcasieu Parish, Louisiana for the field activities. Groundwater, municipal supply system water, surface water and soil/sediment samples were analyzed for metals and mercury, VOCs, semivolatile organics, PCBs, pesticides, dioxins and furans and coliforms. The fish tissue sample was analyzed for metals and mercury, PCBs, pesticides, and dioxins and furans. Passive air samples were analyzed for VOCs. Analyses were performed by Houston EPA Laboratory located in Houston, TX; Datachem Laboratories located in Salt Lake City, UT, Accutest Laboratory located in Houston, TX; Beacon Environmental Services located Bel Air, MD; Test America West Sacramento located in West Sacramento, CA; and Cape Fear Analytical located in Wilmington, NC. Analyses were also performed by SGS North America located in Wilmington, NC. All data from analyses performed at the Houston EPA, Datachem Laboratories, SGS North America and Cape Fear Analytical were reviewed and validated by the Houston EPA Laboratory. Data from analyses performed at the Accutest, Beacon and Test America West Sacramento laboratories were reviewed and validated by START personnel. The results from SGS were rejected and deemed unacceptable during QA review due to improper Site Inspection Report 19 Date Mossville CERCLIS No. LAN000607014 laboratory documentation procedures. These samples were recollected for analysis in August 2010. Data qualifiers were applied as necessary according to the following EPA guidance: USEPA Contract Laboratory Program National Functional Guidelines for Inorganic Data Review. USEPA Contract Laboratory Program National Functional Guidelines for Organic Data Review. USEPA Analytical Services Branch National Functional Guidelines for Chlorinated Dibenzo-p-Dioxins (CDDs) and Chlorinated Dibenzofurans (CDFs) Data Review When necessary, laboratory- and method-specific QC criteria were applied to the data. Copies of the data QA memoranda are included in Appendix C. 4.1 SATISFACTION OF DATA QUALITY OBJECTIVES The following EPA guidance document was used to establish data quality objectives (DQOs) for this SI: Data Quality Objectives Process for Superfund, Interim Final Guidance, EPA 540-R-93-071. The EPA SAM determined that definitive data without error and bias determination would be used for the sampling and analyses conducted during the field activities. The data quality achieved during fieldwork produced sufficient data that meet the DQOs stated in the QASP for Mossville, Sulphur-Westlake, Calcasieu Parish, Louisiana. A detailed discussion of the SI objectives that were accomplished are presented in the following sections. Site Inspection Report 20 Date Mossville 4.2 CERCLIS No. LAN000607014 QUALITY ASSURANCE/QUALITY CONTROL SAMPLES QA samples (3 trip blanks) were collected for this project. Trip blanks were analyzed for VOCs. QC samples included blind field duplicate and matrix spike/matrix spike duplicate (MS/MSD) samples. Blind field duplicate samples were collected at a frequency of one in ten samples per matrix and MS/MSD samples were collected at a frequency of one in every twenty samples per matrix. These QC samples were analyzed for metals and mercury, VOCs, semivolatile organics, PCBs, PEST, and dioxins and furans. Two soil and one aqueous PE samples were collected for dioxin analysis. 4.3 PROJECT-SPECIFIC DATA QUALITY OBJECTIVES The laboratory and field collection data were reviewed to ensure that DQOs for the project were met. Precision, accuracy, representativeness, completeness and comparability (PARCC) parameters were evaluated and are summarized in Table 5. The data quality was acceptable and 100% of the data was usable. The laboratory and the field team were able to meet DQOs for the project. Data validation reports are included in Appendix C. 4.4 LABORATORY QUALITY ASSURANCE/QUALITY CONTROL PARAMETERS The laboratory data also were reviewed for holding times, laboratory blanks, serial dilution samples, PE samples, and rinsate and trip blanks. These laboratory QA/QC parameters are also summarized in Table 5. In general, the laboratory QA/QC parameters were considered acceptable. The laboratory validation reports are included in Appendix C. Results for the PE samples and trip blanks are in Table 6. Site Inspection Report 21 Date Mossville 5 CERCLIS No. LAN000607014 ANALYTICAL RESULTS EVALUATION This section describes the reporting and methods applied to analytical results presented in Sections 7 (sources) and 8 (receptors) of this report. Table 2 lists all samples collected for laboratory analysis. 5.1 ANALTICAL RESULTS EVALUATION CRITERIA Analytical results presented in the analytical summary tables show all analytes/compounds detected above laboratory quantitation limits and indicating significant/elevated concentrations of contaminants in source samples (Section 7) and receptor samples (Section 8) with respect to background concentrations are shown in bold type. For the purposes of this investigation, significant/elevated concentrations are those concentrations that are: Present at concentrations exceeding risk-based screening levels established by EPA (Table 7, Ref. 73). Concentrations of substances present in residential areas at concentrations significantly above background AND associated with nearby chemical manufacturing (minimum of 3X Bkgd). The analytical summary tables present all analytes/compounds, but only those detected analytes/compounds at potential sources and receptors meeting the significant/elevated concentration criteria are discussed in the report text. All detected concentrations are discussed for the background samples. When samples were diluted for re-analysis at a laboratory, the dilution results were considered for evaluation and are provided in the tables and in the sample results discussion. Dioxins and furans are typically found in complex mixtures and setting of health based risk levels for each of the individual components (congeners) is impractical. Dioxins are evaluated using a TEQ, where the relative toxicity of the individual congeners relative to the most toxic dioxin (2,3,7,8-tetrachloro-p-dibenzodioxin ± 2,3,7,8-TCDD) is established using toxicity equivalency factors (TEF). The concentrations of the individual dioxins and furans are Site Inspection Report 22 Date Mossville CERCLIS No. LAN000607014 multiplied by their TEFs and the results are summed to provide the TEQ value for the sample. This TEQ is compared to the health based risk concentration. A risk based standard has not been finalized for dioxins in soil, therefore the sample TEQs are compared to Preliminary Remediation Goals (PRG) established by the EPA. Site Inspection Report 23 Date Mossville 6 CERCLIS No. LAN000607014 BACKGROUND SAMPLES Background samples were collected for each of the naturally occurring media from which soil gas, public supply and soil samples were collected. These media are soil gas, water and soil. Results for the appropriate background samples are shown in the first column of the analytical results summary tables for comparison against source or target results. 6.1 BACKGROUND GROUNDWATER SAMPLES 6.1.1 Sample Locations No samples were collected directly from public supply or residential wells to serve as background sample locations. Residential well samples were not included in the original sample design but were added during field operations to respond to resident concerns. The water sample collected from Parcel 38 (Figure 5), Westlake Community Center, is a sample of treated groundwater from wells outside of the area of interest and is considered as a background location for the groundwater, including the residential tap samples. 6.1.2 Sample Results Trihalomethane compounds commonly found in treated drinking water were detected in the water sample collected from Parcel 38 (Ref. 73, p. 3) (Table 12, Table 13). Metals (calcium, copper, magnesium and sodium) were also detected at concentrations greater than Contract Required Quantitation Limits (CRQLs) in the background water sample collected from Parcel 38 (Table 12, Table 13). 6.2. BACKGROUND SOIL GAS SAMPLES 6.2.1 Sample Locations The soil gas sample collected from Parcel 33 (Figure 5) is up/cross gradient from the groundwater flow direction in the shallow aquifers identified at the site and is considered the background sample for this matrix. The soil gas samples are associated with the groundwater pathway. Site Inspection Report 24 Date Mossville CERCLIS No. LAN000607014 6.2.2 Sample Results No target analytes were detected in the background soil gas sample from Parcel 33 (Table 14, Ref. 50, p. 3). 6.3 BACKGROUND SURFACE WATER and SEDIMENT SAMPLES No background surface water or sediment samples were collected. Health-based concentrations were used to compare receptor samples from the ponds. 6.4 BACKGROUND SOIL SAMPLE 6.4.1 Sample Location The soil sample collected from Parcel 38 (Figure 5) is utilized as the background sample for the soil matrix. 6.4.2 Sample Results Low concentrations (below CRQLs) of several volatile and semivolatile organics (primarily PAHs) were detected in the background sample. Several metals were detected above CRQLs in the background soil sample. OCDD and 1,2,3,4,6,7,8-HpCDD were detected above CRQLs in the sample. Table 20 contains the full analytical results of the soil background samples. Dioxins and furans are by-products of many chemical processes. There is also a natural background for these materials in soils, as well as for PAHs, as they are also produced as byproducts from the combustion of many materials, including wood. The concentrations in the above background sample reflects the natural occurance of these materials in the environment. Site Inspection Report 25 Date Mossville 7 CERCLIS No. LAN000607014 AREAS OF INVESTIGATION This section describes Areas of Investigation (AI), sample locations, and analytical results of Mossville samples obtained from potential sources. All of the potential sources identified are also evaluated as receptors. 7.1 AREA of INVESTIGATION ± Contaminated Soil All of the soil within the AOI is an AI for the soil exposure pathway and for the surface water pathway (Figure 1). 7.1.1 Sample Locations Samples were collected from 45 properties within the AOI (Figure 5). The samples will be discussed in detail in the Soil Exposure Pathway discussion, section 8.3.2.1. 7.1.2 Sample Results Sample results for the soil samples are discussed in detail in the Soil Exposure Pathway, section 8.3.2.1. 7.2 AREA of INVESTIGATION ± Contaminated Groundwater Contaminated groundwater is documented in several water bearing zones (10, 20, 50, 80 and 200 foot sands) in the eastern portion of the area of interest, originating from the chemical plants to the east. The greatest extent of contamination is within the 50 foot sand (Figure 4), although the extent of contamination is similar for all of the zones. Treatment of contaminated groundwater is being conducted by SASOL and Conoco-Phillips. 7.2.1 Sample Locations No sampling was conducted of the contaminated groundwater source since there are no public supply or residential wells drawing from within the known extent of the contamination. Site Inspection Report 26 Date Mossville 7.2.2 CERCLIS No. LAN000607014 Sample Results No samples were collected. 7.3 AREA of INVESTIGATION ± Surface Impoundments The surface impoundments within the Mossville AOI are AIs and receptors since allegations have been made that at least one of the ponds (Pond C) has been used for disposal (Figure 1, Figure 2). Pond A is located west of Princess Street and north of Duke Street. The pond is approximately 400 feet by 550 feet, with an unknown depth. Pond B is located north of East Burton Street, east of Edna Hardy Lane and west of Benjamin Street. The irregular shaped impoundment is approximately 900 feet in length south-north, and ranges from 75 to 300 feet in width, with an unknown depth. There are actually three impoundments at Pond C, located east of Coach Williams Drive. The impoundments are approximately 600 by 470 feet, 400 by 350 feet, and 500 by 300 feet, with unknown depths. None of the impoundments appear to be natural. The dates of construction and details about the construction of the impoundments have not been determined. Pond C is actively used as a source of soil for building in the Lake Charles area, and it is likely that all of the ponds were originally constructed for this purpose. 7.3.1 Sample Locations Sediment and surface water samples were collected from each of the ponds (Figure 5). A fish sample was collected from Pond C. The ponds are also receptors for the surface water pathway, and samples are discussed in detain in section 8.2. 7.3.2 Sample Results Sample results are discussed in section 8.2. Site Inspection Report 27 Date Mossville 8 CERCLIS No. LAN000607014 MIGRATION/EXPOSURE PATHWAYS AND RECEPTORS The following subsections descrLEH PLJUDWLRQ SDWKZD\V DQG SRWHQWLDO 5HFHSWRUV ZLWKLQ WKH VLWH¶V range of influence (Figures 5, 6, 7 and 8). This section discusses the groundwater migration pathway, the surface water migration pathway, the soil exposure pathway, and the air migration pathways. 8.1 GROUNDWATER MIGRATION PATHWAY The target distance limit (TDL) for the groundwater migration pathway is a 4-mile radius that extends from the sources at the site. Figure 6 depicts the groundwater 4-mile TDL. 8.1.1 Geologic Setting Calcasieu Parish in Louisiana is located within the Gulf Coastal Plain, which is composed of sediment deposits of Recent age laid down in the Gulf of Mexico and in the valleys of streams. The deposits generally consist of fine sand, silt, clay and a few lenses of coarse sand. Limited use aquifers are located in sand zones within these deposits. The Pleistocene deposits which underlie the recent deposits were laid down during glacial retreats. The system of aquifers formed by the Pleistocene deposits has been named the Chicot Aquifer. The aquifer consists of thick deposits of gravel, sand and clay. The material generally becomes coarser with depth. The sediments forming this plain slope gently towards the Gulf of Mexico. The principal fresh water-bearing zones in WKH &KLFRW $TXLIHU DUH WKH ³ DQG ´ IRRW VDQGV QDPHG IRU WKH depth at which they occur in the industrial area of Lake Charles, generally south and east of Mossville. These sands are separate hydrologic units at Lake Charles, but become one unit QRUWK RI WKH SDULVK 7KH EDVH RI WKH ³ ´ IRRW VDQG DW IHHW EHORZ VHD OHYHO LQ /DNH &KDUOHV marks the base of the Chicot Aquifer, below which begins the Pliocene Foley Formation. The Evangeline Aquifer, consisting of a series of fine and medium sand, silt and clay is found within the Foley Formation. Pliocene deposits at Lake Charles are considered to be approximately 1,800 feet thick, and dip to the south (Ref. 51, pp. 8-11). Site Inspection Report 28 Date Mossville CERCLIS No. LAN000607014 The average annual rainfall in Calcasieu Parish is 55.8 inches, and the net precipitation is between 15 to 30 inches per year (Ref. 52, p. 1; Ref. 2, Figure 3-2, Table 3-4). 8.1.2 Aquifer System Sands in the Recent deposits recharge by migration of rainfall onto the surface of the water levels in these sands usually rise after rainfall events. Near streams and rivers, groundwater levels also tend to rise and fall with the rise and fall of stream levels, both from rainfall and tidal influence, indicating hydraulic connection between the aquifers and the streams (Ref. 51, p. 22). Wells in the Recent deposits are typically 50 foot or less in depth, and produce water at a rate of 2 to 3 gallons per minute (gpm) (Ref. 51, p. 26). Recharge of the Chicot Aquifer occurs at its outcrops in Beauregard, Allen, Rapides and Evangeline Parishes, north of Calcasieu Parish (Ref. 51, p. 22). Wells in the Chicot Aquifer are typically under an artesian head, and interconnection between the different sands is present, dependent on the quality of the clay separating the sand at specific locations (Ref. 51, pp. 22, 58 7KH SULQFLSDO ZDWHU SURGXFLQJ ]RQHV LQ WKH &KLFRW $TXLIHU DUH WKH ³ DQG ´ IRRW sands, although there are some shallower zones of production (Ref. 51, p. 26). These shallow wells typically have yields of less than 100 gpm (Ref. 16, pp. 26-27 7KH WRS RI WKH ³ IRRW´ sand varies considerably in depth (85 ± 175 feet) below the surface and thickness (20 ± 200 feet), and dips southward at 4-10 feet per mile. In the vicinity of the Mossville AOI, the sand is reportedO\ IHHW WKLFN DW D GHSWK RI IHHW 5HFKDUJH LQ WKH ³ IRRW´ VDQG RFFXUV LQ northern Calcasieu and southern Beauregard Parishes. The sands grade from fine to medium DW WKH WRS WR FRDUVH VDQG WR JUDYHO DW WKH EDVH :DWHU IURP WKH ³ IRRW´ VDQG Ls used for domestic and irrigation purposes, although there is also industrial use. Yields vary depending on location, but range from 1,800 to 4,500 gpm (Ref. 51, pp. 27-30). The Evangeline Aquifer nears the surface in northern Beauregard, Allen and Evangeline Parishes, where the aquifer is recharged. Few wells in Calcasieu Parish are completed in the Evangeline Aquifer. The Evangeline is more commonly utilized to the north where it is shallower (Ref. 51, pp. 37-40). Site Inspection Report 29 Date Mossville CERCLIS No. LAN000607014 Both the Chicot and Evangeline aquifers are under artesian heads, although neither aquifer has artesian flow at the surface. Water levels in the Chicot Aquifer have declined due to pumping (Ref. 51, pp. 44-55). Due to groundwater contamination at the chemical plants within the Calcasieu Estuary, there are numerous ongoing groundwater monitoring and remediation actions being conducted (Ref. 15; Ref. 16; Ref. 53). Plants operated by Georgia Gulf and Sasol North American are located adjacent to the east side of the Mossville AOI, and are the most likely to impact groundwater within the AOI. Four water bearing zones within the Recent deposits have been identified on WKH 6DVRO IDFLOLW\ 5HI WKH ³ IRRW ´ ³ IRRW ´ ³ IRRW´ DQG ³ IRRW´ VDQGV 7KHVH IRXU zones, along with the ³ IRRW´ ]RQH LQ WKH &KLFRW $TXLIHU DUH DOO PRQLWRUHG DV SDUW RI WKH Consent Agreement between Vista (the predecessor of Sasol) and LDEQ (Ref. 14). Monitoring under WKH &RQVHQW $JUHHPHQW 3OXPH LQ WKH ³ IRRW´ ³ IRRW´ DQG ³ IRRW´ ]RQHV Ls DOVR FRQGXFWHG RQ &RQRFR¶V IDFLOLW\ 5HI 16). 10 Foot Sand 0RQLWRULQJ DQG UHFRYHU\ ZHOOV DUH ORFDWHG ZLWKLQ WKH ³ IRRW´ VDQG RQ WKH 6DVRO IDFLOLW\ 7KH rd quarter 2009 monitoring results indicate that the flow in this zone is generally to the south. The historic potentiometric surface has been between 5 and 14 feet above mean sea level (msl); however, pumping from the recovery wells has resulted in a lower potentiometric surface in the recent past. The extent of the zone appears to be limited to the northwest portion of the Sasol facility. The westward extent of the zone is not known, and stratigraphic studies indicated that the sands are not laterally continuous (Ref. 53, p. 3). This zone has not been described on the Conoco facility (Ref. 15). 25 Foot Sand *URXQGZDWHU IORZ LQ WKH ³ IRRW´ VDQG LV GRPLQDWHG E\ WKH SXPSLQJ RI WKH UHFRYHU\ ZHOOV RQ WKH Sasol facility. The natural southern gradient has been reversed to the north on the southern portion of the Sasol facility and on the Conoco facility. Potentiometric surfaces in this zone have historically ranged from +13 to -1 foot above msl. 7KH ³ IRRW´ VDQG LV EHOLHYHG WR EH LQ hydraulic connection with Bayou Verdine which passes through the Conoco facility south of Old Spanish Trail (Ref. 53, pp. 3-4). As with the ³10 foot´ sand, the westward extent of the zone has Site Inspection Report 30 Date Mossville CERCLIS No. LAN000607014 not been determined. On the Conoco facility south of the bayou, flow is north and east toward to bayou (Ref. 15, p. 23). 50 Foot Sand ,Q WKH ³ IRRW´ VDQG KLVWRULFDO JURXQGZDter flow has been toward the west-southwest, but pumping at recovery wells has altered the flow on the Sasol facility toward the recovery wells (Ref. 53, pp. 4-5). The westward extent of the ³50 foot´ sand has not been determined. Flow to the southwest occurs on the Conoco facility, where the potentiometric surface is -2 to -4 feet below msl (Ref. 15 S 7KLV ]RQH ZDV RULJLQDOO\ GHVFULEHG DV WKH ³ORZHU -IRRW´ VDQG DV WKHUH DUH GLVFRQWLQXRXV VDQG VLOW OD\HUV LQ ZKDW ZDV GHVFULEHG DV WKH ³XSSHU -fRRW´ VDQG 80 Foot Sand 7KH ³ IRRW´ VDQG OD\HU FRQVLVWV RI GLVFRQWLQXRXV VDQG\ OHQVHV DQG VWULQJHUV ZLWK D OLPLWHG areal extent. Flow is to the southwest with a historic potentiometric surface of 2.6 to -10.3 feet msl. The layer is continuous in the western portion of the Sasol plant and within the eastern portion of the AOI, and was not identified on the Conoco facility (Ref. 53, p. 5; Ref. 15, p. 23). This layer has shown the greatest extent of groundwater contamination (Figure 4). 200 Foot Sand ThH ³ IRRW´ VDQG OD\HU IORZV WR WKH VRXWK-southwest with a potentiometric surface of -30.71 to -33.79 foot below MSL (Ref. 53, p. 5). Reported flow direction on the ConocoPhillips facility is also to the southwest (Ref. 15, p. 23). 500 Foot Sand 7KH ³ IRRW´ VDQG LV WKH SULQFLSDO DTXLIHU LQ WKH SDULVK 7KH DTXLIHU UDQJHV LQ WKLFNQHVV IURP 25 to 310 feet, at depths of 165 to 590 feet bgs. In the vicinity of Mossville, this sand is reported to be encountered at a depth of 390 feet bgs, and is 170 feet thick. The recharge area outcrops in central Beauregard and Allen Parishes, and the sand dips southward at about 18 feet per PLOH 7KH ³ IRRW´ VDQG LV WDSSHG IRU SXEOLF VXSSO\ LUULJDWLRQ DQG LQGXVWULDO XVH \LHOGLQJ to 3,800 gpm. The City of Sulfur reportedly obtains its public supply from this sand. The public ZDWHU VXSSO\ LQ 0RVVYLOOH LV REWDLQHG IURP WKH ³ IRRW´ VDQG 7KH ³ IRRW´ VDQG UDQJHV IURP fine sand at the top to coarse sand and gravel at the base (Ref. 51, pp. 30-34). 700 Foot Sand Site Inspection Report 31 Date Mossville CERCLIS No. LAN000607014 7KH ³ IRRW´ VDQG LV XVHG E\ LQGXVWULHV DQG LUULJDWRUV DQG LV WKH SULPDU\ GULQNLQJ ZDWHU VRXUFH IRU WKH &LW\ RI /DNH &KDUOHV 7KH ³ IRRW´ VDQG UDQJHV LQ WKLFNQHVV IURP WR IHHW ZLWKLQ the parish. In the vicinity of Mossville, the sand is found at a depth of 700 feet bgs and is 220 feet thick. The sand dips southward at 10 feet per mile, but varies depending on location. The material consists of fine to coarse sands (top to bottom) (Ref. 51, pp. 34-37). 8.1.3 Drinking Water Receptors START conducted a water well survey utilizing the Louisiana Department of Transportation (LDOT) website to determine the number of registered water wells located within the 4-mile radius of the Mossville AOI. The LDOT registered water well database contains information pertaining to public supply, domestic, irrigation, industrial, rig supply, and monitoring wells (Ref. 21). Review of the database indicates an active total of six public supply wells, two private domestic wells, one irrigation well, and 25 monitoring/recovery/piezometer wells registered within the AOI, and several wells that have been plugged and abandoned (Table 8). Two of the public supply wells are utilized by the Mossville Water Works District 2 to provide water within the Mossville AOI (Ref. 56). Within a 4-mile radius of the AOI, 100 public supply wells, 467 private domestic wells, 17 irrigation wells, 126 industrial supply wells, and 1,032 monitoring/recovery/observation/piezometer wells have been registered (Ref. 56). The public supply wells and their distances to the Mossville AOI are shown in Table 9 Public wells within the 4-mile radius are utilized by parish water districts and the cities of Sulphur, Lake Charles and Westlake. All but three of the identified municipal water wells within the Mossville AOI and within 4 miles of WKH 0RVVYLOOH $2, DUH GUDZLQJ ZDWHU IURP WKH ³ IRRW´ VDQG RI WKH &KLFRW DTXLIHU Ref. 56). One well owned by the City of Westlake and two wells utilized by the Louisiana (LA) State Park system draw ZDWHU IURP WKH ³ IRRW´ VDQG RI WKH &KLFRW DTXLIHU Ref 56). The service area of the Mossville Waterworks District 2 includes the majority of the Mossville AOI, excluding only the area south of the Union Pacific railroad tracks and north of US Hwy 90. The number of connections to the Mossville Waterworks District 2 is 371 (337 residential) (Ref. Site Inspection Report 32 Date Mossville CERCLIS No. LAN000607014 70) and the system serves 879 (Ref. 23, Ref. 25) persons. Water District 2 utilizes two (2) drinking water wells, depths ranging from 425 feet bls to 458 feet bls (Table 8, Ref. 70). The municipal wells are located at the waterworks situated north of the Jacob Rigmaiden Center, near the center of the Mossville AOI (Figure 5). The City of Sulphur water system, utilizing six wells, provides potable water to the residents of Sulphur. The number of connections to the Sulphur water system is 7,896, providing water to approximately 21,000 persons (Ref. 71). One well at a depth of 580 feet bls is located between ! and " mile of the Mossville AOI. One well at a depth of 580 feet bls is located between " and 1 mile of the AOI. Two wells at depths of 533 and 540 feet bls are located between 2 and 3 miles of the Mossville AOI. The remaining two wells at depths of 578 and 544 feet bls are located between 3 and 4 miles of the AOI. The City of Westlake water system, utilizing five wells, supplies potable water to the residents of Westlake. The number of connections to the Westlake water system is 1,750, serving a population of approximately 7,000 (Ref. 71). Two of the wells used by Westlake are located between 1 and 2 miles of the Mossville AOI, at depths of 527 and 537 feet bls. LDOT registration also lists an additional well with a depth of 240 feet bls, which may not be in use. The three remaining Westlake wells, with depths of 511, 552, and 558 feet bls, are located between 2 and 3 miles of the AOI. The Calcasieu Parish Waterworks District 4, utilizing two wells, supplies potable water to the residents of north Westlake. The number of connections to the water system is 1700, serving a population of approximately 1600 (Ref. 70). Both of the wells used by District 4 are located between 2 and 3 miles of the Mossville AOI, at depths of 492 and 480 feet bls. Two wells owned by the LA State Park system are located between 3 to 4 miles of the Mossville AOI. Lake Charles HA owns one well located between 2 and 3 miles of the AOI and one well Site Inspection Report 33 Date Mossville CERCLIS No. LAN000607014 between 3 and 4 miles of the AOI (Ref. 56). Usage of these wells has not been determined. Numerous other public supply wells, designated for commercial use, are located within the 4 mile target distance radius (Ref. 56). Estimated number of population served by municipal wells by distance ring (see Appendix F for calculations) is 879 (0 to 0.25 miles), 3,500 (>0.25 to 0.5 miles), 3,500 (>0.5 to 1 mile), 2,800 (>1 to 2 miles), 12,800 (>2 to 3 miles) and 7,000 (>3 to 4 miles). It should be noted that municipal drinking water users may be overestimated due to the fact that the number of connections could include businesses. According to the LDOT water well database, a total of 443 active private drinking water wells are located within the 4-mile radius (Table 10; Ref. 56). Domestic or private water wells within the 4-mile radius include 3 wells drawing from alluvial aquifers, 45 wells drawing from the recent DJH GHSRVLWV ZHOOV GUDZLQJ IURP WKH ³ IRRW´ VDQG RI WKH &KLFRW DTXLIHU ZHOOV GUDZLQJ IURP WKH ³ IRRW´ VDQG RI WKH &KLFRW DTXLIHU RQH ZHOO GUDZLQJ IURP WKH ³ VDQG´ RI the Chicot aquifer, and 33 wells of unknown depth (Ref. 56). Two of the wells are located within the Mossville AOI. Estimated population served by private wells by distance ring (see Appendix F for calculations) in the recent deposits is 13 (>1 to 2 miles), 33 (>2 to 3 miles) and 69 (>3 to 4 miles). Usage in the alluvial aquifers is ! WR PLOHV ,Q WKH ³ ´ IRRW VDQG usage is 23 (0 to 0.25 miles), 10 (>0.25 to 0.5 miles), 8 (>0.5 to 1 mile), 99 (>1 to 2 miles), 148 ! WR PLOHV DQG ! WR PLOHV ,Q WKH ³ ´ IRRW VDQG usage is 3 (0 to 0.25 miles), 3 (>0.25 to 0.5 miles), 3 (>0.5 to 1 mile), 25 (>1 to 2 miles), 53 (>2 to 3 miles), and 176 (>3 to 4 PLOHV $Q HVWLPDWHG SHUVRQV XVH ZDWHU IURP WKH ³ ´ IRRW VDQG IURP EHWZHHQ WR miles from the AOI. The identified target water wells within the 4-mile radius ranged in depth from 13 feet bgs to 698 feet bgs 7KH WDUJHW ZHOOV ZHUH VFUHHQHG LQ WKH 5HFHQW GHSRVLWV DQG WKH ³ DQG IRRW´ sands of the Chicot Aquifer (Ref. 56). Totals by distance for groundwater usage, both municipal and residential, are included in Table 11. Site Inspection Report 34 Date Mossville CERCLIS No. LAN000607014 The LDOT water well survey indicates the presence of seventeen (17) registered irrigation wells screened in the Chicot aquifer within a 4 mile radius of the Mossville AOI (Ref. 56, pp. 2122 and 30-31). The Mossville Waterworks District 2, Calcasieu Parish Waterworks District 4, City of Sulphur and City of Westlake water systems are all located within a State approved wellhead protection area (Ref. 69). 8.1.4 Sample Locations and Results Groundwater samples were collected from Mossville Water System Well 1, Mossville Water System Well 2 (with a duplicate), from a residential well located on Parcel 36 (with a duplicate) and a residential well located on Parcel 40 (Figure 5, Table 2). All sample locations are within the AOI. Samples from the two water system wells were analyzed for all parameters. Samples from the two residential wells were analyzed for all parameters except dioxins. In addition to the groundwater samples collected directly from the wells, samples were also collected from residential taps and from monitoring taps within the Mossville distribution system to address the concerns of the residents raised during public meetings (Figure 5, Table 2). Samples collected from Parcel 01, Parcel 06, Parcel 09, Parcel 15, Parcel 18, Parcel 25, Parcel 30, Mossville Distribution Tap 1, Mossville Distribution Tap 2 (dioxin duplicate), Mossville Distribution Tap 3, Mossville Distribution Tap 4 and Mossville Distribution Tap 5 were analyzed for all parameters. Samples collected from Parcel 02 (duplicate), Parcel 03, Parcel 04, Parcel 05, Parcel 07, Parcel 08, Parcel 10, Parcel 11, Parcel 12 (duplicate), Parcel 13, Parcel 14, Parcel 16, Parcel 17, Parcel 21, Parcel 22 (duplicate), Parcel 23, Parcel 24, Parcel 26, Parcel 27, Parcel 28, Parcel 29, Parcel 31, Parcel 34, Parcel 39 and Parcel 49 were analyzed for all parameters except dioxin. Samples from Parcel 16A (and its duplicate) were analyzed for coliforms only. Site Inspection Report 35 Date Mossville CERCLIS No. LAN000607014 Soil gas samples were collected at Parcel 30 (4 samples), Parcel 31 (3 samples) and Parcel 32 (2 samples). Samples were analyzed for VOCs. For the well samples, in comparison to the water sample collected at Parcel 38 and MCLs, no analytes were detected at significant/elevated concentrations in any of the groundwater samples. Complete sample results are included in Table 12. For the distribution system samples, in comparison to the water sample collected at Parcel 38 and MCLs, no analytes were detected at significant/elevated concentrations. Coliforms (8 cfu/100 ml) were detected in the sample from Parcel 16 but were not detected when the location was re-sampled. Complete sample results are included in Table 13. EPA conducted an evaluation of the Mossville Water System with the objective of documenting the current compliance status with the requirements of the Safe Drinking Water Act and the ability of the water system to achieve future compliance (Ref. 76). The evaluation investigated the operations, management and infrastructure of the system. Concentrations of iron and manganese in samples collected from the two system wells exceeded secondary MCLs, however concentrations in samples of treated water were below MCLs. Low levels of disinfection byproducts, below EPA limits, were detected in treated water samples. The evaluation noted deficiencies with the location of a septic system in relation to one of the wells, the capacity of the filtration system, and a lack of flush valves on the dead-end lines in the system. The evaluation concluded that the water system is in compliance with all drinking water requirements of the National Primary Drinking Water Regulations. Potential problems identified include the financial issues (insufficient operating ration, debt coverage ratio and financial resources), excessive unaccounted for water, insufficient operational resources, undersized storage tank, potential contamination of the east well by a septic system and lack of sealing, lack of flush valves on dead-end lines, old greensand filters not operating properly, and problems with access in the buy-out area making operations difficult. Site Inspection Report 36 Date Mossville CERCLIS No. LAN000607014 For the soil gas samples, significant/elevated concentrations of toluene (40.99 ng) and total petroleum hydrocarbons (TPH) in the C5-9 gasoline range, 2949 ng) were detected in one of the samples from Parcel 30 and toluene (31.42 ng) was detected in a second sample from Parcel 30. Screening levels are 25 ng for toluene and 2,500 ng for TPH C5-C9. The C5-C9 range of TPH and toluene are typically associated with gasoline and are not in the plume of contaminated groundwater that originates from the SASOL facility. No target analytes were detected in the remaining two samples for Parcel 30 or in the samples from Parcel 31 or from Parcel 32. Complete sample results are included in Table 14. 8.2 SURFACE WATER MIGRATION PATHWAY The surface water migration pathway TDL begins at the probable point to entry (PPE) of surface water runoff from the site to a surface water body and extends downstream for 15 miles. Figure 7 depicts the surface water 15-mile TDL. 8.2.1 Overland Route Surface runoff from the eastern portion of the AOI flows into Bayou Verdine, a perennial surface water body, both directly and from drainage ditches (Figure 7; Ref. 5). The PPE (PPE 1) for Bayou Verdine is defined as the location where Bayou Verdine enters the AOI. Bayou Verdine flows southeast for approximately 3.25 miles, passing through the ConocoPhillips and Lyondell Chemical Facilities, until discharging into the Calcasieu River north of Coon Island (Figure 7, Ref. 5). The remaining 11.75 miles of the flow is within the Calcasieu River and the Calcasieu Ship Channel. The western portion of the AOI flows directly and from drainage ditches into Maple Fork, a perennial surface water body originating just north of the AOI, which flows for DSSUR[LPDWHO\ PLOHV WR WKH VRXWKHDVW LQWR %D\RX '¶,QGH )LJXUH 5HI 7KH 33( IRU 0DSOH Fork (PPE 2) is defined as the locations where Maple Fork enters the AO, %D\RX '¶,QGH IORZV approximately 2.5 miles southeast into the Calcasieu Ship Channel/Calcasieu River southwest of Coon Island, where the flow converges with the flow from Bayou Verdine. As the overland flow segments pass through the Mossville AOI and the source is contaminated soil, the overland Site Inspection Report 37 Date Mossville CERCLIS No. LAN000607014 flow distance is 0 feet (Figure 7). There are numerous active NPDES discharges to Bayou VerdiQH 0DSOH )RUN %D\RX '¶,QGH DQG WKH &DOFDVLHX 5LYHU &DOFDVLHX 6KLS &KDQQHO The Calcasieu River is under tidal influence (Ref. 18, p. 5; Ref. 58, p. 5), the in-water segment also extends northeast within the river for 11.75 miles (Ref. 2; Ref. 3; Ref. 58, p. 5). Flow rates are not measured. Due to the flat topography of the area, it is likely that Bayou Verdine, Bayou G¶,QGH DQG 0DSOH )RUN DUH DOVR XQGHU WLGDO LQIOXHQFH The two-year, 24-hour rainfall for the area of the site is approximately 5.0 to 5.5 inches (Ref. 57, p. 1). Mossville is situated within the Gulf Coast Prairies of Calcasieu Parish (Ref. 58, p. 1). The soils within the AOI are generally silt loams comprising 9 soil groups (Ref. 59, p. 10). The GuytonMesser silt loams, Kinder-Messer silt loams and Mowata-Vedrine silt loams are the most common soils in the AOI (Ref. 58, pp. 13-40; Ref. 59, pp. 12-21). The soils range from moderately-well drained to frequently flooded with slopes of 1 to 3 percent and generally have high water capacities. Soils range from 60 to 80 inches in thickness. Water transmissivity ranges from low to high (Ref. 59, pp. 12-29). Portions of the Mossville AOI along Bayou Verdine and Maple Fork are within the Federal Emergency Management Agency (FEMA) 100-year floodplain (Ref. 60). Based on observations during the site reconnaissance, there are no containment features that would prevent or contain a release in the event that the Mossville AOI becomes flooded. In addition to Maple Fork and Bayou Verdine, three surface impoundments are located within the area of interest. Pond A is located west of King Street, Pond B is located north of E. Burton Street, and Pond C is located east of Coach William Drive (Ref. 5, Figure 1, Figure 2). The three impoundments appear to be man-made, resulting from the excavation of sand/soil for use. There are no defined inflows into the impoundments. Due to the shallow depth to groundwater in the area, water levels in the impoundments are likely to be closely associated to the shallow groundwater. Site Inspection Report 38 Date Mossville CERCLIS No. LAN000607014 8.2.1.1 Sample Locations and Results Surface water and sediment samples were collected from Pond A. Surface water and sediment were collected from Pond B. Surface water (duplicate) and sediment (duplicate) were collected from Pond C (Figure 5, Table 15 and Table 17). Surface water and sediment samples were analyzed for all parameters (Table 2). No background sample was collected for the surface water, sediment or fish matrices. The sediment samples were compared to the results from the health-based benchmark. No analytes were detected at concentrations above MCL in the surface water samples. Complete surface water sample results are included in Table 15. Concentrations of arsenic in the sediment samples from all three ponds exceeded its EPA soil screening level (SSL) of 0.39 parts per million (ppm - milligram per kilogram ± [mg/kg]), however arsenic is a naturally occurring element and the sample concentrations were all less than the LDEQ background level of 12 ppm. Arsenic has not been identified in the releases from the plants. Benzo(a)pyrene was detected in Pond A at a concentration above its SSL of 15 micrograms per kilogram (ug/kg). The benzo(a)pyrene concentration was consistent with the local background. Complete sediment sample results are included in Table 17. Table 16 Pond Sediment Results Above SSLs Analyte SSL Local BKG Pond A Pond B Pond C Pond C/DUP Arsenic 0.39 mg/kg 1.1 mg/kg 3.3 mg/kg 9.9 mg/kg 1.1 mg/kg 2.0 mg/kg Benzo(a)pyrene 15 ug/kg 21 ug/kg 21 ug/kg Site Inspection Report 39 Date Mossville 8.2.2 CERCLIS No. LAN000607014 Drinking Water Receptors Surface water is not utilized for public supply in Calcasieu Parish (Ref. 58, p. 3), therefore this pathway was not evaluated. Drinking water is obtained from either municipal or domestic water wells screened in the Recent Deposits or Chicot Aquifers (Ref. 58, p. 3). 8.2.3 Human Food Chain Receptors Contamination within the Calcasieu River and Estuary, has prompted health advisories relating to the consumption of fish and shellfish from the estuary by LDEQ in 1992 and Louisiana Department of Health and Hospitals in 2000 (Ref. 61). Guidance used to issue the health advisories is included in Reference 62. Area residents and property owners indicate that fishing for consumption of bass, gar and catfish occurs in the three surface impoundments within the AOI (Ref. 63). Surface water resource usage occurs within Calcasieu Parish, primarily for rice farming (Ref. 58, p. 2). It has not been determined if water from the 15-mile TDL of the Calcasieu River is being used as a resource. 8.2.3.1 Sample Locations and Results A fish sample was collected from Pond C (Figure 5). The fish sample was analyzed for metals, PEST, PCB and dioxins. In the fish sample from Pond C, concentrations of 1,2,3,4,7,8-HxCDF (6.5 nanograms per kilogram - ng/kg), 1,2,3,7,8-PeCDF (0.27 ng/kg) and WHO-2005 TEQ (2.2903 ng/kg) exceed EPA screening levels (1,2,3,4,7,8-HxCDF (2.4 ng/kg), 1,2,3,7,8-PeCDF (0.24 ng/kg), WHO2005 TEQ (0.24 ng/kg)). Other dioxins and furans were detected in the sample, generally at concentrations below screening levels and below quantitation limits. Complete sample results are in Table 18. 8.2.4 Environmental Receptors According to the Louisiana Department of Wildlife and Fisheries, there are two (2) species of birds (red-cockaded woodpecker ± Picoides boreakus and bald eagle ±Haliaeetus leucocephalus) and one (1) species of mammal (red wolf ± Canis rufus) that are either federally Site Inspection Report 40 Date Mossville CERCLIS No. LAN000607014 or state-designated endangered or threatened species in Calcasieu Parish (Ref. 64, pp. 1-3). The location of the critical habitats for these designated endangered or threatened species has not been obtained. Wetlands are present along Bayou Verdine, Maple Fork and the Calcasieu River within the TDL, with an estimated 257,161 feet or 48.7 miles of wetlands frontage, calculated using ESRI ArcMap, Version 9.3, 2008 (Ref. 5; Figure 7). 8.2.4.1 Sample Locations and Results No samples were collected. 8.3 SOIL EXPOSURE PATHWAY The soil exposure pathway is evaluated based on the threat to resident and nearby populations from soil contamination within the first two feet of the surface. 8.3.1 Site Setting and Exposed Sources Mossville consists of residential and agricultural land, and small businesses located in an unincorporated area of Calcasieu Parish, north of US Highway 90, and north of Lake Charles, Louisiana. The AOI encompasses approximately 1.5 square miles. The area is north and west of a series of refineries and chemical plants (Figure 3, Ref. 65). No records of disposal of any chemicals within the AOI have been located; however, deposition of chemicals from air emissions from the refineries and chemical plants is likely to have occurred. Limited soil sampling has been conducted in the area; however, the analyses have been limited to dioxins and dioxin-like materials, with dioxin-like materials being detected. ATSDR concluded that dioxin concentrations in surface soils were not at levels of concern (Ref. 21, p. 46). The Calcasieu Parish School system has a facility within the AOI, and the Rigmaiden Recreation Center is located within the AOI (Figure 1). Site Inspection Report 41 Date Mossville 8.3.2 CERCLIS No. LAN000607014 Receptors There are over 1,600 parcels located within the AOI, and over 900 of these properties are residential or commercial (Ref. 66). One school administration building and one recreation center are also located within the AOI (Figure 1). Calcasieu Parish contains two (2) species of birds and one (1) species of mammal that have been designated as either federally- and/or state-endangered or threatened; however, the exact locations for critical habitats for these species have not been documented (Ref. 64, pp. 1 - 3). No terrestrial resource usage (commercial agriculture, commercial silviculture, or commercial livestock grazing/production) has been documented within the Mossville AOI or within 200 feet of the AOI (Ref. 2, Sec. 5.1.3.4). As previously stated, the AOI is located in an unincorporated area of Calcasieu Parish (Figures 1 and 2). According to U.S. Census tract data, the population within the Mossville AOI is 665, and the population within a 1-mile radius of the AOI is 6,287 (Ref. 67, Ref. 68). The AOI is accessible, and there is recreational use at the Rigmaiden Recreation Center on the AOI (Figure 1, Figure 6). 8.3.2.1 Sample Locations and Results Samples were collected from 51 parcels within the AOI. Samples collected from Parcel 01, Parcel 02 (duplicate), Parcel 03 Parcel 04, Parcel 05, Parcel 06, Parcel 07, Parcel 08, Parcel 09, Parcel 11, Parcel 12, Parcel 13, Parcel 14, Parcel 15, Parcel 16, Parcel 17, Parcel 18, Parcel 21, Parcel 22 (duplicate), Parcel 23, Parcel 24, Parcel 25, Parcel 26, Parcel 28, Parcel 29, Parcel 30, Parcel 31, Parcel 32 (duplicate), Parcel 33, Parcel 34, Parcel 39, Parcel 41, Parcel 42 (duplicate), Parcel 43, Parcel 44, Parcel 45, Parcel 46, Parcel 47, Parcel 48 and Parcel 49 were analyzed for all parameters. Samples collected for Parcel 27 and Parcel 36 were analyzed for all parameters except dioxins. Four samples were collected from Parcel 10 with one sample analyzed for all parameters and the remaining three analyzed for dioxins only. Five samples were collected from Parcel 50 with one sample analyzed for all parameters and Site Inspection Report 42 Date Mossville CERCLIS No. LAN000607014 the remaining four samples analyzed for dioxins only. Samples collected from Parcels 51, 52, 54, 55, 56 and 57 were analyzed for dioxins only (Table 2). Two metals (arsenic and lead), 5 SVOA PAHs (benzo(a)pyrene, benzo(b)fluoranthene, benzo(a)anthracene, dibenzo(a,h)anthracene and indeno(1,2,3-cd)pyrene) and Aroclor 1254 were detected in soil samples at concentrations greater than their SSLs (Table 19). Dioxins and furans were detected in all of the soil samples; however the TEQs for the samples did not exceed the residential soil PRG of 72 ppt TEQ that was proposed during the Dioxin Reassessment process and is still under review. This value is a non-cancer risk-based value that, in this case, would be roughly equivalent to an ELCR of 10-5. Arsenic concentrations were generally less than three times the local background from Parcel 38, and except at Parcel 4 (16.7 mg/kg), were less than LDEQ background of 12 ppm (mg/kg). The concentrations of benzo(a)pyrene were also generally less than CRQLs and within three times the local background, indicating that its presence is consistent with the local background. Parcel 10 is the only sample where all eight of the analytes were detected at concentrations exceeding SSLs. Evidence of a recent structure fire was noted at Parcel 10 which probably accounts for the high levels of the PAHs. Parcels 4, 5, 7, 13, 32 and 48 had multiple detects of PAHs greater than SSLs, and Parcel 46 had an Aroclor 1254 detect. The organics that are released from the plants (Section 2.4.1) were not detected, or were detected at very low concentrations, in the samples. Complete analytical results for the soil samples are included in Table 20. 8.4 AIR MIGRATION PATHWAY The air migration pathway TDL is a 4-mile radius that extends from sources at the site (Figure 6). 8.4.1 Human Receptors The Mossville AOI consists of residential and commercial lots within a one and a half square mile area of Calcasieu Parish (Ref. 66). The site is located in the vicinity of numerous chemical plants and refineries (Ref. 65). The chemical plants and refineries Site Inspection Report 43 Date Mossville CERCLIS No. LAN000607014 are active facilities with ongoing permitted releases under the Clean Air Act (CAA). Air sampling was not conducted during the Site Inspection. An evaluation of unpermitted air releases may result in an observed release to the air migration pathway. The sampling design for the SI focused on the collection and analysis of soil samples that may have been impacted from past activities. Potential contaminants of concern include the contaminants from the chemical plants which may accumulate in the soil within the Mossville AOI. A review of the 2009 Toxic Release Inventory (TRI) indicated that thirty-three industries located in Westlake, Sulphur, Lake Charles, and Carlyss, Louisiana, reported releases. Top Five Industries with Releases(pounds of total chemicals) Chemical Waste Management, Sulphur, LA 4,141,920 lbs Louisiana Pigment, Westlake 3,071,993 lbs Firestone Polymers 1,281,600 lbs Conoco Philips, Lake Charles Refinery, Westlake 1,222,121 lbs Citgo Petroleum Corp, Westlake 1,076,336 lbs Nineteen facilities operate in the Mossville area. Six of the facilities have high priority air violations: Louisiana Pigment, Firestone Synthetic Rubber and Latex/Polymers Lake Charles, Conoco Phillips Lake Charles Refinery, Citgo Petroleum Corp, PPG Industries, and Sasol (Condea Vista). Four of the five top emitters are also high priority violators. According to U.S. Census tract data, the population within the Mossville AOI is 665, and within a 1-mile radius of the AOI is 6,287 (Ref. 67, Ref. 68). Site Inspection Report 44 Date Mossville 8.4.2 CERCLIS No. LAN000607014 Environmental Receptors No terrestrial resource usage (commercial agriculture, commercial silviculture, or commercial livestock grazing/production) has been documented within the Mossville AOI or within " mile of the AOI (Ref. 2, Sec. 5.1.3.4). Wetland acreage on and within ! mile of the site, is 92.93 acres, within ! to " mile is 74.31 acres, " to 1 mile is 120.02 acres, 1 to 2 miles is 232.54 acres, 2 to 3 miles is 1964.59 acres, and 3 to 4 miles is 2470.44 acres, calculated using ESRI ArcMap, Version 9.3, 2008 (Figure 8). 8.4.2.1 Sample Locations and Results No air samples were collected. Site Inspection Report 45 Date Mossville 9 CERCLIS No. LAN000607014 SUMMARY AND CONCLUSIONS Mossville AOI is a residential community located west and northwest of a concentration of chemical plants in Westlake and northern Lake Charles, Louisiana. The AOI encompasses approximately 1.5 square miles. The majority of the land use is residential, with a few commercial entities, churches, a recreation center and a school. Sampling was conducted on multiple occasions. From April 26 to May 1, 2010, groundwater samples were collected from two public supply wells and from two residential wells and water samples were collected from five system monitoring taps and from 34 residences. Surface water and sediment samples were collected from three pond and soil samples were collected from 45 properties. Three water samples were collected from residential properties on May 12 and 13, 2010, to confirm coliform results from the initial samples. Ten soil gas samples were collected from five properties from May 12 to May 19, 2010. A single fish sample was collected on May 20, 2010. After the original dioxin analysis was rejected for QA issues, re-sampling was conducted from August 16 to 20, 2010 for dioxin analysis only. Groundwater samples were collected from the two public supply wells, and water samples were collected from the five system taps and from eight residences. Surface water and sediment samples were collected from the three ponds and soil samples were collected from 49 properties, including 6 properties not previously sampled. 9.1 SOURCES The primary source of contamination within the AOI is soil which may have been contaminated by deposition from air emissions from the chemical plants. Ponds which may have been used for disposal of materials from the chemical plants are the second potential source which was evaluated. Site Inspection Report 46 Date Mossville 9.2 CERCLIS No. LAN000607014 RECEPTORS Ground Water Receptors for the groundwater pathway include all of the residents who obtain their drinking water from the Mossville Public Supply system. No significant/elevated concentrations of any analytes were detected in the groundwater samples collected from either the public supply or private wells, or in any of the samples collected from residences or taps within the distribution system. Low concentrations of trihalomethanes (treatment byproducts) were detected in the distribution system samples. Soil gas samples did not contain contaminants associated with the plume of contaminated groundwater from the SASOL facility underlying the AOI. Surface Water In the surface water pathway, concentrations of 1,2,3,4,7,8-HxCDD, 1,2,3,7,8-PeCDF and the WHO-2005 TEQ exceed the lifetime excess cancer risk range specified by the Superfund program in the fish sample collected for analysis. No analytes were detected in the water samples at concentrations exceeding MCLs. Arsenic was detected at concentrations above its SSL in the sediment samples from all three ponds; however the concentrations reflect the local and LDEQ backgrounds for arsenic. Benzo(a)pyrene was detected at a concentration greater than its SSL in the sediment sample from Pond A, but the concentration was reflective of the local soil background concentration. Dioxins and furans were detected in the sediment samples, but the TEQ concentration did not exceed the residential soil PRG of 72 ppt TEQ that was proposed during the Dioxin Reassessment process and is still under review. This value is a non-cancer risk-based value that, in this case, would be roughly equivalent to an ELCR of 105. Soil Exposure For the soil exposure pathway, numerous dioxins and furans were detected in samples that were collected, however the TEQ concentration calculated for the samples did not exceed the residential soil PRG of 72 ppt TEQ that was proposed during the Dioxin Reassessment process and is still under review. This value is a non-cancer risk-based value that, in this case, would be roughly equivalent to an ELCR of 10-5. Arsenic concentrations exceed SSLs in all of the Site Inspection Report 47 Date Mossville CERCLIS No. LAN000607014 samples; however the concentrations are consistent in all of the samples and probably are representative of the local background. Multiple PAHs with concentrations exceeding their SSLs were detected in Parcels 4, 5, 7, 10, 13, 32 and 48, and benzo(a)pyrene was detected at concentrations above its SSL in the results for 18 additional parcels. Most results are consistent with the local background collected from Parcel 38, however concentrations of lead detected at Parcel 10 and the aroclors 1254 detected at Parcels 10 and 46 are unique. Higher concentrations of PAHs were detected in the samples from Parcels 4, 10, 32 and 48. Air Pathway Air sampling was not conducted during the Site Inspection. An evaluation of unpermitted air releases may result in an observed release to the air migration pathway. 9.3 CONCLUSIONS Groundwater used for public and residential use within the Mossville AOI has not been impacted by chemical contamination, based on the results of samples collected from the wells and the distribution system. Soil gas sampling indicates that the plumes of contaminated groundwater on the eastern portion of the AOI are not impacting the remaining residents within the Bel Air Subdivision. Surface water within the AOI (ponds) contains contaminants at concentrations above health based limits; however the concentrations are within the range of the native background for the area. Fish in the ponds are likely to exceed health based limits for dioxins. It does not appear that the ponds have been used for disposal of hazardous materials. While the presence of dioxins and furans is widespread in the soils within the AOI, TEQs calculated based on these concentrations are all below the residential soil PRG of 72 ppt TEQ that was proposed during the Dioxin Reassessment process and is still under review. This value is a non-cancer risk-based value that, in this case, would be roughly equivalent to an ELCR of 10-5. Dioxins and furans are all naturally occurring, the natural background resulting from the incomplete combustion of various materials, including wood. The mean TEQ for all Site Inspection Report 48 Date Mossville CERCLIS No. LAN000607014 samples is 6.70 ppt, and only three sample concentrations exceed three standard deviations of the mean, two samples from Parcel 10 and the sample from Parcel 46. The highest concentrations of PAHs were also detected in the sample from Parcel 10, as were lead and aroclors 1254. It was noted that a structure fire had occurred on this parcel, which is likely to account for the high concentrations present. Arsenic was detected at low concentrations, exceeding its EPA SSL, in almost all of the samples, however concentrations are likely to reflect the local background as most sample concentrations were within three times the concentration detected in the background sample, and were less than the LDEQ background for the area. Low concentrations of PAHs were detected in the majority of the samples, with benzo(a)pyrene concentrations exceeding its EPA SSL. As with dioxins, there is a natural background of PAHs due to incomplete combustion. As with arsenic, concentrations reflect the local background concentration. Chlorinated and aromatic compounds that are emitted in the permitted releases from the surrounding facilities were not detected in the soil samples. Site Inspection Report 49 Date Mossville 10 1. CERCLIS No. LAN000607014 REFERENCES U.S. Environmental Protection Agency. Guidance for Performing Site Inspections Under CERCLA, September 1991. Excerpt Cover Page: Total Pages: 1. 2. U.S. EPA. Hazard Ranking System (HRS); Final Rule. 40 CFR, Part 300, pp. 5153251667. December 14, 1990. Excerpt Cover Page: Total Pages: 1. 3. U.S. EPA. Hazard Ranking System Guidance Manual; 9345.1-07, PB92-963377, EPA 540R-92-026. November 1992. Excerpt Cover Page: Total Pages: 1. 4. U.S. EPA, Office of Solid Waste and Emergency Response. Superfund Chemical Data Matrix. Prepared in January 2004. REFERENCE NOT INCLUDED. 5. United States Geological Survey Topographic Map: Buhler Quadrangle, LouisianaCalcasieu Parish. 7.5 Minute Series (Topographic). 1.24,000 scale. 1998; Westlake Quadrangle, Louisiana-Calcasieu Parish. 7.5 Minute Series (Topographic). 1.24,000 scale. 1996; Moss Lake Quadrangle, Louisiana-Calcasieu Parish. 7.5 Minute Series (Topographic). 1.24,000 scale. 1994. Total Pages: 3. 6. Calcasieu Parish, Louisiana ± Database and GIS files, 2009 Property Tax Records. 7. Agency for Toxic Substances and Disease Registry (ATSDR). Health Consultation, Exposure Investigation Report, Calcasieu Estuary Lake Charles, Calcasieu Parish Louisiana. November 19, 1999. Total Pages: 33. 8. Louisiana Oil Spill Coordinators Office. Aerial photographs: February & March, 1998, 2004. Total Pages: 1. 9. ATSDR. Serum Dioxin Levels in Residents of Calcasieu Parish, Louisiana. October 2005 Total Pages: 158. 10. Louisiana Department of Environmental Quality. Map ± Public Notice LDEQ PPG Industries, Inc. Lakes Charles Chemical Complex, Public Hearing and Request for Public Comment on Draft Post-Closure/HSWA Renewal Permit. August 18, 2009. Total Pages: 1. Site Inspection Report 50 Date Mossville CERCLIS No. LAN000607014 11. Mossville Environmental Action Now, Inc. et al. Industrial Sources of Dioxin Poisoning in 0RVVYLOOH /RXLVLDQD $ 5HSRUW %DVHG RQ WKH *RYHUQPHQW¶V 2ZQ 'DWD 5HYLVHG -XO\ 2007. Total Pages: 29. 12. CH2M Hill. 2007 Annual Groundwater Monitoring Report, Sasol North America Inc., Lake Charles Chemical Complex, LAR 000041087, AI#3271, March 2008. 13. Sasol North American, Inc. Letter/Report to Keith Casanova LDEQ: Lake Charles Chemical Complex, Groundwater Quarterly Progress Report Third Quarter 2009 Compliance Order Dated March 31, 1986. October 20, 2009. Total Pages: 15. 14. Letter from LDEQ to Vista Chemical Company (now Sasol) with attached March 21, 1986 Order. March 31, 1986. Total Pages: 6. 15. URS Corporation. 3rd Quarter 2009 Groundwater Monitor Well Sampling Report Agency Interest Number 2538, Lake Charles Refinery West End Project. September 30, 2009 Total Pages: 235. 16. CH2M Hill. 2008 Annual Groundwater Monitoring Report, Sasol North America Inc., Lake Charles Chemical Complex, LAR 000041087, AI#3271, February 2009. 17. ATSDR. Health Consultation Calcasieu Parish (Calcasieu Estuary) Lake Charles, Calcasieu Parish, Louisiana. October 16, 1998. Total Pages: 13. 18. U.S. EPA, Calcasieu Estuary Remedial Investigation, Executive Summary. 2003. Total Pages: 59. 19. ATSDR. Health Consultation Calcasieu Estuary Water Sampling Evaluation Calcasieu Parish, Louisiana. March 9, 2005 Total Pages: 28. 20. ATSDR. Health Consultation Calcasieu Estuary Sediment Sample Evaluation Calcasieu Parish, Louisiana. March 9, 2005. Total Pages: 25. Site Inspection Report 51 Date Mossville CERCLIS No. LAN000607014 21. ATSDR. Health Consultation Follow-Up Exposure Investigation Calcasieu Estuary (a/k/a Mossville) Lake Charles, Calcasieu Parish, Louisiana. March 13, 2006. Total Pages: 110 22. Dynamac Corporation. Quality Assurance Sampling Plan for Mossville, Sulphur, Calcasieu Parish, Louisiana. April 16, 2010. Total Pages: 247. 23. From: David Anderson START PM, To: Brenda Cook SAM USEPA. Subject: Amendment to QASP, Proposed additional sample locations at Mossville. August 12, 2010. Total Pages: 1. 24. Dynamac Corporation. Field Logbooks, Mossville, Sulphur, Calcasieu Parish, Louisiana. October 27, 2009 to August 19, 2010. Total Pages 51. 25. Dynamac Corporation. Field Data Sheets, Mossville, Sulphur, Calcasieu Parish, Louisiana. April 26, 2010 to August 19, 2010. Total Pages 123. 26. Beacon Environmental Services, Inc. Field Kit Guide for Passive Soil-Gas Investigations. Undated. Total Pages: 7. 27. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG MF3G94. May 24, 2010. Total Pages: 331. 28. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG MF3GE4. May 20, 2010. Total Pages: 321. 29. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG MF3GE5. May 24, 2010. Total Pages: 381. 30. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG MF3GH5. May 24, 2010. Total Pages: 296. 31. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG MF3GH6. May 21, 2010. Total Pages: 276. Site Inspection Report 52 Date Mossville CERCLIS No. LAN000607014 32. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG MF3GK3. May 24, 2010. Total Pages: 309. 33. USEPA Region 6 Laboratory. Data package. Project 10SF149. June 3, 2010. Total Pages 396. 34. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG F3GE4. May 21, 2010. Total Pages: 2246. 35. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG F3GF1. May 24, 2010. Total Pages: 2143. 36. ALS Laboratory Group (Datachem). Data package and SEDD, Case 40027, SDG F3GH8. May 21, 2010. Total Pages: 1554. 37. Cape Fear Analytical. Data package, Case 40347, EPDAC D100. October 10, 2010. Total Pages: 1108. 38. Cape Fear Analytical. Data package, Case 40347, EPDAC D116. October 14, 2010. Total Pages: 418. 39. Cape Fear Analytical. Data package, Case 40347, EPDAC D111. October 2, 2010. Total Pages: 1004. 40. Cape Fear Analytical. Data package, Case 40347, EPDAC D141. October 2, 2010. Total Pages: 755. 41. Cape Fear Analytical. Data package, Case 40347, EPDAC D164. October 2, 2010. Total Pages: 1085. 42. Cape Fear Analytical. Data package, Case 40347, EPDAC D202. October 6, 2010. Total Pages: 1044. 43. Accutest Laboratories. Data package, Project T51593. April 27, 2010. Total Pages 16. Site Inspection Report 53 Date Mossville CERCLIS No. LAN000607014 44. Accutest Laboratories. Data package, Project T51673. April 27, 2010. Total Pages 23. 45. Accutest Laboratories. Data package, Project T51728. April 28, 2010. Total Pages 30. 46. Accutest Laboratories. Data package, Project T51861. April 29, 2010. Total Pages 35. 47. Accutest Laboratories. Data package, Project T52523. May 12, 2010. Total Pages 14. 48. Accutest Laboratories. Data package, Project T52629. May 13, 2010. Total Pages 13. 49. Test America. Data package and SEDD, Project G0E27060. June 22, 2010. Total Pages 770. 50. Beacon Environmental Services, Inc. Passive Soil Gas Survey Analytical Report, Project 2322. December 7, 2010. Total Pages 14. 51. Harder, Alfred H. The Geology and Ground-Water Resources of Calcasieu Parish, Louisiana. Geological Water-Supply Paper 1448. 1960. Total Pages: 117. 52. U.S. Department of Commerce, National Oceanic and Atmospheric Administration. Historical Weather and Rainfall Data: Climatic Atlas of the United States. 1993. Total Pages: 3. 53. Sasol North American, Inc. Letter/Report to Keith Casanova LDEQ: Lake Charles Chemical Complex, Groundwater Quarterly Progress Report Third Quarter 2009 Compliance Order Dated March 31, 1986. October 20, 2009. Total Pages: 15. 54. See Reference 15. 55. See Reference 14. 56. Louisiana Department of Transportation and Development (DOTD) Website for Statewide Water Well Registration Data. Registered Water Wells. Public Works and Water Resources Division. Water Resources Section. Accessed at http://dotd.state.la.us. Accessed 2 January 2007. Total Pages: 4. Site Inspection Report 54 Date Mossville CERCLIS No. LAN000607014 57. U.S. Department of Commerce. Technical Paper No. 40. Rainfall Frequency of the United States. May 1961. Total Pages: 2. 58. U.S. Department of Agriculture. Soil Conservation Service. Soil Survey of Calcasieu Parish, Louisiana. Issued June, 1988. Total Pages: 173. 59. U.S. Department of Agriculture. Natural Resources Conservation Service. Custom Soil Resource Report for Calcasieu Parish, Louisiana Mossville Community Soils: Accessed from http://websoilsurvey.nrcs.usda.gov . Accessed on December 16, 2009. Total Pages: 23. 60. Federal Emergency Management Agency. Flood Insurance Rate Maps, Calcasieu Parish, Louisiana. Accessed at http://msc.fema.gov/webapp/wcs/stores/servelet/. Accessed on January 5, 2010. Total Pages: 8. 61. Louisiana Department of Environmental Quality. Human Health Protection through fish Consumption Swimming Advisories in Louisiana. Accessed from www.deq.louisiana.gov. Accessed on February 2, 2010. 62. Louisiana Department of Health and Hospitals. Fish and Shell Fish Consumption/Health Advisories Based on Guidelines entitled Protocol for Issuing Health Advisories and Bans Based on Chemical Contamination of Fish/Shellfish in Louisiana), Office of Public Health, New Orleans, Louisiana. January, 1997. 63. Record of Communication. Re: Fisheries in area ponds. To: File. From: David Anderson, START. July 7, 2010. Total Pages: 1. 64. Louisiana Department of Wildlife and Fisheries. Threatened and Endangered Table. Accessed at www.wlf.louisiana.gov. Accessed January 6, 2010. Total Pages: 5. 65. See Reference 10. 66. See Reference 6. Site Inspection Report 55 Date Mossville CERCLIS No. LAN000607014 67. U.S. Census Bureau. American FactFinder: Calcasieu Parish, Louisiana. Accessed at http://factfinder.census.gov/servelet/. Accessed on December 29, 2009. Total Pages: 2. 68. ESRI: Tele Atlas North America, Inc./Geographic Data Technology, Inc., 2005. 69. Louisiana Department of Environmental Quality, List of Public Water Supply Systems With Approved Wellhead Protection Programs, Accessed at www.deq.louisiana.gov. Accessed January 6, 2010. Total Pages: 9. 70. David Anderson, Memorandum to File. Water Works District 2 (Mossville) and 4 (Westlake) information, January 28, 2009. 71. U.S. Environmental Protection Agency: Water system information, Westlake and Sulphur, Louisiana. 2010. 72. U.S. EPA. Final Analytical Report, Mossville, Sample Collection Date 8/21/2009. Report Date 8/26/2009. 73. U.S. Environmental Protection Agency. Regional Screening Level (RSL) Summary Table May 2010. Accessed from www.epa.gov/region6/6pd/rcra_c/pd-n/screen/htm. Accessed May, 2010. Total Pages: 104. 74. U.S. Environmental Protection Agency. Dioxin Testing in the Mossville Public Water System. June 1999. 75. Federal Register. Notice of Lodging of Consent Decree Under the Comprehensive Environmental Response, Compensation, and Liability Act and the Clean Water Act. October 19, 2009. 76. U.S. Environmental Protection Agency. Drinking Water Contaminants, Maximum Contaminant Levels (MCLs). Accessed from www.EPA.gov/safewater/contaminants/index.html. Accessed January 14, 2010. Total Pages: 16. Site Inspection Report 56 Date FIGURES TABLES APPENDICES