SITE INVESTIGATION REPORT FOR THE CATTLEHEAD CDV SITE

United States Forest Service, Southern Region

Ozark St. Francis National Forest

Contract No. AG-43ZP-D-15-0007

Prepared for:

U.S. Department of Agriculture United States Forest Service, Southern Region Atlanta, Georgia 30309

Prepared by:

BMT Designers & Planners, Inc. 4401 Ford Avenue, Suite 1000 Alexandria, Virginia 22302

March 2019

TABLE OF CONTENTS

1. INTRODUCTION ...... 1

2. GENERAL BACKGROUND ...... 3

3. SITE LOCATION AND PHYSICAL SETTING ...... 4 3.1. Site Location ...... 4 3.2. Topography ...... 4 3.3. Geology ...... 4 3.4. Hydrogeology ...... 5 3.5. Surface Water ...... 6

4. DESKTOP DATA COLLECTION AND SITE RECONNAISSANCE ...... 7 4.1. Site Description ...... 7 4.2. Surrounding Property Description ...... 7 4.2.1. Sensitive Receptor Survey ...... 8 4.3. Historical Aerial Photograph Review ...... 9 4.4. Operational History and Contaminants of Potential Concern ...... 10 4.5. Previous Investigations ...... 11 4.6. Identification of Areas of Potential Concern ...... 11

5. ABBREVIATED PRELIMINARY ASSESSMENT/FIELD SCREENING ...... 13 5.1. Vat Water and Vat Soil/Sludge Sampling ...... 13 5.2. Surface and Shallow Subsurface Soil Sample Collection and Analytical Results ...... 14 5.2.1. XRF Analytical Results ...... 14 5.2.2. Verification of Screening Level Risk Assessment Results ...... 14 5.2.3. Fixed Laboratory Analytical Results ...... 15 5.2.4. Further Evaluation of the Soil to Groundwater Pathway ...... 16 5.3. Groundwater and Subsurface Soil Sample Collection and Analytical Results ...... 16 5.3.1. Subsurface Soil Sample Collection and Analytical Results ...... 17 5.3.2. Groundwater Sample Collection and Analytical Results ...... 18 5.4. Surface Water and Sediment Sample Collection and Analysis ...... 18 5.5. Screening Level Risk Assessment Summary ...... 18 5.5.1. Field Screening Level Risk Assessment ...... 18 5.5.2. Fixed Laboratory Results Screening Level Risk Assessment ...... 18

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TABLE OF CONTENTS

6. FOCUSED SITE INVESTIGATION ...... 20

7. FOLLOW-ON SOIL SAMPLING ...... 21 7.1. Follow-on Soil Sampling Activities and Results ...... 21

8. QUALITY ASSURANCE AND QUALITY CONTROL SUMMARY ...... 23 8.1. XRF Analysis Quality Assurance/Quality Control Samples ...... 23 8.2. XRF Data Comparability and Usability ...... 25 8.3. Evaluation of XRF Interferences ...... 26 8.4. Fixed Laboratory Analysis Quality Assurance/Quality Control Samples ...... 28 8.5. Data Validation ...... 29 8.5.1. Field Data Validation ...... 29 8.5.2. Laboratory Data Validation ...... 29 8.5.3. SVOC Resampling ...... 30 8.6. Deviations from the Sampling and Analysis Plan ...... 30

9. STREAMLINED RISK ASSESSMENT ...... 31 9.1. Human Health Risk Assessment ...... 31 9.1.1. Data Evaluation ...... 32 9.1.1.1. Selection of Data for Use in the Risk Assessment ...... 32 9.1.1.2. Selection of Contaminants of Potential Concern (COPCs) ...... 32 9.1.2. Exposure Assessment ...... 35 9.1.2.1. Exposure Scenarios ...... 35 9.1.2.2. Exposure Point Concentrations (EPCs) ...... 35 9.1.2.3. Calculation of Dermal and Ingestion Exposures to Toxaphene in Soils ...... 35 9.1.3. Toxicity Assessment ...... 36 9.1.3.1. Non-Carcinogenic Contaminants ...... 36 9.1.3.2. Carcinogenic Contaminants ...... 36 9.1.4. Human Health Risk Characterization ...... 36 9.1.4.1. Cancer Risks ...... 36 9.1.4.2. Non-Carcinogenic Risks ...... 37 9.1.4.3. Radiological Risks ...... 37 9.1.4.4. Human Health Risk Summary ...... 38 9.2. Ecological Risk Assessment ...... 38 9.2.1. Problem Formulation ...... 38

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TABLE OF CONTENTS

9.2.1.1. Selection of Ecological COPCs ...... 39 9.2.1.2. Identification of Ecological Exposure Scenarios ...... 39 9.2.2. Ecological Exposure ...... 39 9.2.3. Toxicity Assessment ...... 40 9.2.4. Ecological Risk Characterization ...... 40

10. SUMMARY AND CONCLUSIONS ...... 42

11. REFERENCES ...... 46

TABLES

Table 1 Cattle Head Site Location Summary ...... 4 Table 2 Comparison of Arsenic Fixed Laboratory and XRF Analytical Results ...... 15 Table 3 Summary of Arsenic and OC Pesticide Analytical Results for the Deep Soil Boring ...... 17 Table 4 Calibration Verification Results ...... 24 Table 5 Field Precision Verification Results ...... 25 Table 6 Summary of Lead and Arsenic Fixed Laboratory Analytical Results ...... 27 Table 7 Toxaphene Concentrations in Soils ...... 32 Table 8 Summary of HHRA Risk Characterization Results ...... 38 Table 9 Ecological Soil Toxicity Values for Toxaphene (mg/kg soil) ...... 41

FIGURES

Figure 1: Site Location Map Figure 2: 7.5-Minute Topographic Map Figure 3: Arkansas Physiographic Province Map Figure 4: Surficial Soil Map Figure 5: Subsurface Geology Map Figure 6: Site Map Figure 7: Sample Location Map Figure 8: Arsenic Tag Map Figure 9: 2017 Follow-on Sampling Sample Location Map Figure 10: 2017 Follow-on Sampling Toxaphene Tag Map

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APPENDICES

Appendix A Program-Specific Soil Screening Levels Information Sheet Appendix B CDVMP Site Investigation Flow Chart Appendix C Select Site Photographs Appendix D Sensitive Receptor Summary Appendix E Environmental Database Report Appendix F Historical Aerial Photographs Appendix G Analytical Results Summary Appendix H Complete Laboratory Analytical Results Appendix I Soil Boring Logs Appendix J XRF and Fixed Laboratory Analytical Results Correlation and Regression Analysis Summary Appendix K Field Change Request Forms Appendix L HHRA Rags D Tables Appendix M Toxaphene ProUCL Output

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LIST OF ACRONYMS

%D Percent Difference μg/L micrograms per liter AAS Arkansas Archaeological Society AGS Arkansas Geological Survey AOPCs Areas of Potential Concern APA Abbreviated Preliminary Assessment AWQC Ambient Water Quality Criteria bgs below ground surface BMT BMT Designers & Planners, Inc. CDV Cattle Dip Vat CDVMP Southern Region Cattle Dip Vat Management Program CERCLA Comprehensive Environmental Response, Compensation, and Liability Act COPC Contaminant of Potential Concern EB Equipment Rinsate Blank EE/CA Engineering Evaluation and Cost Analysis EDR Environmental Data Resources EPA U.S. Environmental Protection Agency fbgs feet below ground surface FS Forest Service FSI Focused Site Investigation GPS Global Positioning System HASP Site-Specific Health and Safety Plan in inches LLOD Lower Limit of Detection mg/kg milligrams per kilogram mg/L milligrams per liter LCS Laboratory Control Sample MCL Maximum Contaminant Level MS/MSD Matrix Spike/Matrix Spike Duplicate NRCS Natural Resources Conservation Service NWI National Wetlands Inventory OC Organochlorine PAH polynuclear aromatic hydrocarbon pH negative of the log10 of the concentration (moles per liter) of hydrogen ions PR Presumptive Remedy for Metals-In-Soils Sites

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LIST OF ACRONYMS (Continued)

QA/QC Quality Assurance/Quality Control QAPP Quality Assurance Program Plan R Correlation Coefficient r2 Coefficient of Determination RSD Relative Standard Deviation RML EPA Region 4 Removal Management Level SAP Sampling and Analysis Plan SDWA Safe Drinking Water Act SI Site Investigation SPLP Synthetic Precipitation Leachate Procedure SVOC Semivolatile Organic Compound USDA U.S. Department of Agriculture USFWS U.S. Fish and Wildlife Service USGS U.S. Geological Survey XRF X-ray Fluorescence

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1. INTRODUCTION

Site Investigations (SIs) were performed on the Cattle Head cattle dip vat (CDV) site (site no. 3PP657) located in the Big Piney Ranger District of the Ozark National Forest in Pope County, Arkansas as part of the U.S. Department of Agriculture (USDA) Forest Service (FS) Southern Region Cattle Dip Vat Management Program (CDVMP). The SI was completed under FS’ CERCLA authority in accordance with the provisions of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). All SI activities were carried out in compliance with the CDVMP Quality Assurance Program Plan (QAPP) (FS, 2015) and the Site-Specific Sampling and Analysis Plans (FS, 2015a and FS, 2017).

The initial Cattlehead Vat SI was performed 2015 as part of the FS CDVMP. Follow-on delineation soil sampling was completed in 2017 based on the results from the 2015 SI. This report expands on the earlier investigation efforts through the completion of a “streamlined” risk assessment to quantify potential human and ecological exposures to toxaphene in surficial soils at the site. In addition, conclusions and recommendations regarding the presence of toxaphene in soil have been added.

The primary goal of the CDVMP is to protect recreating populations and Forest personnel from potential chronic exposure to chemicals that might remain at former CDV sites and to ensure contaminated soils, if any, are not impacting groundwater. In order to achieve this goal, this SI is focused on the identification of potential hazards through field screening for historically used metals-based pesticides (i.e., lead and arsenic) using a field portable X-ray Fluorescence (XRF) analyzer, comparison to CDVMP-specific screening criteria, and determination of the need to implement a Presumptive Remedy (PR) for Metals-In- Soils Sites developed by United States Environmental Protection Agency (EPA) (EPA, 1999). Based on the expected co-location of arsenic with other contaminants of potential concern (COPCs), the presence of arsenic measured by real-time XRF analysis is used as an indicator for the potential presence of other COPCs.

Two risk-based CDVMP-specific screening criteria for arsenic in soil were developed based on potential exposure scenarios and guidance for low-level threat and principal threat waste (EPA, 1991a). The low- level threat screening criterion for arsenic is 456 milligrams per kilogram (mg/kg). The detection of arsenic at concentrations greater than or equal to this criterion triggers characterization of the extent of elevated concentrations of arsenic in soil and indicates the potential need for the implementation of the containment presumptive remedy. The second screening criterion is the principal threat waste screening criterion of 4,560 mg/kg. The detection of arsenic at concentrations greater than or equal to this criterion triggers the potential need for the implementation of soil treatment and requires the collection of additional data to support the design and implementation of the treatment presumptive remedy or the development and evaluation of other remedial options. More information regarding the presumptive remedy, program

CDVMP Site Investigation at the Cattle Head CDV, Ozark National Forest (Update) Page 1 Task Order No. AG-43ZP-D-15-0007 March 2019 specific soil screening levels, and distinction between low-level versus principal threat waste is provided in Appendix A. A flow chart summarizing the CDVMP Site Investigation requirements is included as Appendix B.

The SI included the following activities:  Review of Regional and Site-Specific Environmental Setting  Review of Operational History and Previous Site Investigations  Historical Aerial Photography Review and Identification of Areas of Potential Concern (AOPCs)  Evaluation of Potential Receptors  Abbreviated Preliminary Assessment Field Screening  Groundwater Quality Assessment

This document is organized in the following order:  Section 1 - Introduction  Section 2 - General Background  Section 3 - Site Location and Physical Setting  Section 4 - Desktop Data Collection and Site Reconnaissance  Section 5 - Abbreviated Preliminary Assessment/Field Screening  Section 6 - Focused Site Investigation  Section 7 - Quality Assurance and Quality Control Summary  Section 8 - Follow-on soil sampling  Section 9 – Streamlined Risk Assessment  Section 10 - Summary and Conclusions  Section 11 - References

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2. GENERAL BACKGROUND

Between 1906 and 1943, cattle dipping vats (CDVs) were constructed throughout the southern United States as part of the Cattle Fever Tick (Boophilus microplus and B. annulatus) Eradication Program. The program was aimed at the eradication of the tick responsible for transmitting the ‘Texas Fever’ disease (bovine babesiosis) among cattle herds. After a 36-year campaign, cattle fever ticks were declared eradicated from the U.S. in 1943; however, dipping reportedly persisted in some areas until the 1960s.

Arsenic-based pesticide solutions were used in conjunction with dip vats and became well established as the preferred method for cattle treatment. In the 1940s, organochlorine (OC) pesticides were reportedly added to the arsenical pesticide solutions to increase effectiveness. Historically, spent arsenical and OC pesticide solutions were pumped out of the vat and into an unlined evaporation pit located in close proximity to the vat and allowed to evaporate. In some cases, spent dip solution was discharged directly to adjacent streams or intermittent drainage features (Pasquill, 2012).

Former CDV sites have been identified within FS Southern Region’s National Forests, which are designated for recreational use and commercial logging. Typically, there is no fencing limiting public access to the potentially contaminated former CDV sites. CDV sites within the Southern Region National Forests are generally similar in size and construction and may have been used from approximately 1900 to 1960 for the treatment of livestock. CDVs were typically concrete or wood-lined basins constructed in pastures or cattle-loading areas that were filled with pesticides. Individual cattle were driven into the CDV where they were immersed in the pesticide solution before exiting the basin at the opposite end onto a drip pad. The identified historical CDV sites are now abandoned and may pose human health and environmental risks due to residual concentrations of metals and pesticides potentially present in environmental media at the sites.

In general, many of these CDV sites are similar in their setting, design and construction, types of chemicals used, and extent of contamination. Investigation of numerous CDV sites across the Southeast has frequently found arsenic and in some locations, OC pesticides in soils. These COPCs have also been found in groundwater at some locations. The CDVMP was implemented to systematically assess the presence, extent, and potential risk posed by residual contamination at CDV sites within the FS Southern Region’s National Forests.

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3. SITE LOCATION AND PHYSICAL SETTING

3.1. Site Location The Cattle Head site is located off Forest Road 1375, approximately 0.75-mile east of the intersection of the Forest Road 1375 and Broomfield Road in the Ozark National Forest, Arkansas. The intersection of Forest Road 1375 and Broomfield Road is immediately southeast of the intersection of Broomfield Road and Bibler Hill Road. The general geographic information for the Cattle Head site including the site location (coordinates), county, ranger district, United States Geological Survey (USGS) 7.5-minute topographic quadrangle, and site coordinates are summarized in Table 1. A site location map depicting the location of the Cattle Head site is included as Figure 1.

Table 1: Cattle Head Location Summary

Ranger Easting Northing Town- USGS State I.D. Name Latitude Longitude Range Section County District (m) (m) ship Quad*

Big Piney 3PP657 Cattle Head 35.475717° -93.056580° 494,867 3,925,801 T10N R19W 31 Pope Dover

*7.5 Minute Topographic Quadrangle Map, Dover Quadrangle (USGS, 1993)

3.2. Topography The Cattle Head CDV site is located on the flat middle slope of an upland area of the Arkansas Valley Hills. The topography of the site slopes down slightly to the northeast and the topography of the surrounding area is variable with hilltops and valleys throughout the area. The Cattle Head CDV site has an approximate elevation of 595 feet above sea level. The site location is depicted on the USGS 7.5- Minute Topographic Map, Dover Quadrangle (USGS, 1993). An excerpt from the 7.5-minute topographic map depicting the Cattle Head CDV site location is included as Figure 2.

3.3. Geology The Cattle Head CDV site is located within the Arkansas Valley Physiographic region of the interior highlands. The Arkansas River Valley region is a synclinorium, a regional geological structure of general synclinical (troughs and valleys) series of smaller folds. It lies between dipping rocks of the Boston Mountains to the north and the highly folded rocks of the Ouachita Mountains to the south. Alluvial deposits overlie consolidated rocks along the Arkansas River and its major tributaries (Kresse et al., 2014). Within the Arkansas Valley region, the Cattle Head site is located within the Arkansas Valley Hills Physiographic Province. The surface rocks in this region consist of a sequence of coal-bearing sandstones and shales. Once flat-lying, these Pennsylvanian sedimentary rocks have been compressed into well-developed east-west trending open folds (anticlines and synclines) and faults, which gradually

CDVMP Site Investigation at the Cattle Head CDV, Ozark National Forest (Update) Page 4 Task Order No. AG-43ZP-D-15-0007 March 2019 diminish northward into the Ozark Plateau Region (AGS, 2015). The location of the Cattle Head CDV site is depicted on the Arkansas Physiographic Province map in Figure 3.

Surficial geology at the Cattle Head CDV site is the Nella Loam, a well-drained gravelly fine sandy loam common on hillside slopes derived from sandstone and shale. Upper layers of surficial soil are predominantly composed of gravelly fine sandy loam with deeper soils (greater than 21 inches) having a greater clay content. At depths greater than 43 inches, the Nella series has a greater cobble content (NRCS, 2016). The description of the Nella Loam is consistent with the observed surficial soil lithology at the site that was identified as dark brown to light brown gravelly fine sandy loam. A surficial soil map for the Cattle Head CDV site is included as Figure 4.

The specific geologic formation underlying the Cattle Head CDV site is the Atoka formation. The Atoka formation is a sequence of marine, mostly tan to gray, silty sandstones and grayish-black shales. It is the surface rock of the Boston Mountains and dominates the exposures in the Arkansas River Valley. The unit locally contains discontinuous streaks of coal and coaly shale in the Boston Mountains and Arkansas River Valley. The formation is conformable with the Bloyd Shale in the Boston Mountains and the Johns Valley Shale in the Ouachita Mountains. The unit may attain a thickness of 25,000 feet in the Ouachita Mountains, although only largely incomplete sections are known (AGS, 2015). Bedrock outcrops were not observed at the Cattle Head CDV site or the surrounding vicinity. A subsurface geology map for the Cattle Head CDV site is included as Figure 5.

3.4. Hydrogeology Aquifers of the interior highlands are discontinuous and generally occur in shallow, fractured, well- indurated, structurally modified bedrock. These aquifers generally have low yield and surface water is the predominant source of potable supply in this region; however, withdrawal wells are used for domestic supply. Aquifers of the interior highlands occur within 11 different formations including sandstone, siltstone, and shale formations of the Upper Mississippian and Pennsylvanian Age. These aquifers are collectively referred to as the Western Plains confining system due to the presence of low permeability shale and siltstone formations that impede the flow of water to and from the underlying Springfield Plateau aquifer. The Western Interior Plains confining system is relatively thin in the upper section of the Boston Mountains Plateau physiographic region, thickening to the south as it approaches the Arkansas River (Kresse et al., 2014).

Aquifers within the Western Interior Plains confining system vary locally and typically have low well yield; however, they were historically used for domestic and livestock supply prior to the development of surface water resources. Groundwater is present in fractures associated with the underlying formations and the quantity of groundwater available is related directly to the density, size, openness, and degree of

CDVMP Site Investigation at the Cattle Head CDV, Ozark National Forest (Update) Page 5 Task Order No. AG-43ZP-D-15-0007 March 2019 interconnection of fractures. Groundwater flow paths are short and topographically controlled (from hilltops to valleys) within relatively small watersheds (Kresse et al., 2014). Based on topography at the site (Section 3.2), groundwater is expected to flow through bedrock fractures following local topography. Groundwater was not encountered at the Cattle Head CDV site during the advancement of the deeper soil boring, which encountered refusal at a depth of 4 feet bgs (Section 5).

According to an environmental records search, there are no groundwater withdrawal wells located within 1-mile of the site (EDR, 2015). Based on information provided by the Forest Service, there are no reported or observed groundwater withdrawal wells historically located in the vicinity of the Cattle Head CDV site.

3.5. Surface Water The Cattle Head CDV site is located in the Little Creek – Illinois Bayou Watershed, which is considered a Class 2 watershed and is considered to be functioning at risk (FS Region 8, 2015). Class 2 watersheds exhibit moderate geomorphic, hydrologic, and biotic integrity relative to their natural potential condition.

The nearest perennial surface water features are three (3) man-made ponds located within 0.25 miles of the site. The Illinois Bayou is located approximately 1 mile east of the site. Several intermittent streams that ultimately discharge to the Illinois Bayou was identified on the USGS topographic map within 0.5 miles of the site (USGS, 1993). There is no clear conveyance (e.g., channels or drainage features) from the Cattle Head CDV site to the man-made ponds or ephemeral streams identified in the vicinity.

The Cattle Head CDV site is located outside of a designated floodplain. The eastern most extent of a 500- year floodplain associated with the Illinois Bayou and its tributaries is located approximately 0.75 miles south of the Cattle Head CDV site (EDR, 2015). The three ponds in the vicinity of the site were identified as a man-made freshwater palustrine unconsolidated bottom ponds that are permanently flooded. No other wetlands were identified in the vicinity of the Cattle Head CDV site (USFWS, 2016).

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4. DESKTOP DATA COLLECTION AND SITE RECONNAISSANCE

On August 29, 2015, a reconnaissance of the Cattle Head CDV site and the surrounding area was conducted by BMT Designers & Planners, Inc. (BMT). The inspection included the identification of the vat structure and site features, site access and conditions, and surrounding properties. Additional desktop data collection activities including an environmental database search, review of the operational history of the site, historical aerial photograph review, a review of previous investigations, and the identification or potential receptors were completed. Desktop data collection and site reconnaissance activities are summarized in the following subsections. Ultimately, the site reconnaissance and desktop data collection effort resulted in the identification of areas of potential concern (AOPCs) and contaminants of potential concern (COPCs) that were considered in the selection of sampling locations and analyses during the first phase of the Site Investigation, referred to as the Abbreviated Preliminary Assessment (APA) (Section 5).

4.1. Site Description The Cattle Head CDV site is located on the middle slope of a hill in an uplands area of the Arkansas River Valley. The site is located within the Ozark National forest and is on federally owned land. The vat structure is located north of Forest Road 1375 at 35° 28' 32.40" N and 93° 3' 23.68" W. The vat structure is constructed with concrete and is approximately 31 feet long by 3.5 feet wide by 4 feet deep and has a wood and metal canopy. Both the vat and canopy structure are in good condition. There was no evidence of former fence lines or other structures associated with the site. Based on an aerial photograph analysis (Section 4.3), the total area of the site (e.g., the vat structure, drip pad, and holding pen areas) may be as large as 1.3 acres. Access to the site is from Forest Road 1375 from the south.

During the site reconnaissance, the Cattle Head CDV was inspected and site features including the vat structure and canopy were identified. There was no drip pad identified associated with the Cattle Head vat structure. An area of mounded material was identified immediately south of the vat structure. This mound was inspected and contains cobbles with some sandy soil that is consistent with observed site lithology. Based on the mound contents and its proximity to the vat structure, this mound may have been created with soil excavated during vat construction. There was no evidence of disposal or storage of pesticide solutions or clear conveyances from the site. Site features are depicted on a Site Map included as Figure 6. Select site photographs are included as Appendix C.

4.2. Surrounding Property Description During desktop data collection and Site reconnaissance, surrounding properties and land use were noted. No improved property or structures were identified within ¼-mile of the site. No residences, schools or

CDVMP Site Investigation at the Cattle Head CDV, Ozark National Forest (Update) Page 7 Task Order No. AG-43ZP-D-15-0007 March 2019 daycare centers were identified within 0.25 miles of the site. The nearest residence is located approximately 0.45 miles northeast of the Cattle Head CDV site.

4.2.1. Sensitive Receptor Survey A sensitive receptor survey was completed to identify potential receptors located within the vicinity of the Cattle Head CDV site. The sensitive receptor survey included the identification of residences, schools, daycare centers, parks or recreation areas, ecological receptors, surface water bodies, and groundwater withdrawal wells located within 0.25 miles of the site. Sensitive receptor survey findings are presented below and summarized in the sensitive receptor form included as Appendix D.  There are no residential properties are located within 0.25 miles of the CDV site. The nearest residences were identified approximately 0.5 miles to the northeast and south-southeast of the site.  There were no groundwater withdrawal wells identified within 0.25 miles of the CDV site. A commercially available Environmental Data Resources environmental database report was obtained to search groundwater withdrawal databases for groundwater withdrawal wells located within 1-mile of the Cattle Head site. The database search included a review of the Federal USGS well database, the Federal Reporting Database System for Public Water Systems, and the state well database. No groundwater withdrawal wells were identified within 1-mile of the Cattle Head CDV Site. The Environmental Database Report for the Cattle Head site is included as Appendix E. Based on information provided by FS personnel, there is reportedly a groundwater withdrawal well located approximately 4,000 feet south of the site.  There were no schools or daycare centers identified within 0.25 miles of the CDV site.  The Cattle Head CDV site is located within the Ozark National Forest. Due to the recreational use of the national forest, potential recreating populations are considered receptors for the site. No other parks or recreation areas were identified within 0.25 miles of the Cattle Head CDV site.  Three (3) small ponds were identified within 0.25 miles of the site. The nearest ponds are located approximately 550 feet northeast and southeast of the site. Several ephemeral tributaries that flow toward the Illinois Bayou were identified within 0.5 miles of the site. The Illinois Bayou is located approximately 1 mile east of the site. No other surface water features were identified within the vicinity of the Cattle Head CDV site.  Three (3) small ponds were identified within 0.25 miles of the site. These ponds are identified as a man-made freshwater palustrine unconsolidated bottom ponds that are and permanently flooded US Fish and Wildlife Service (USFWS) in the National Wetlands Inventory (NWI) (USFWS, 2015). A NWI map is included in Appendix D.  Threatened and endangered species have been identified in the Ozark and St. Francis National Forests. The following threatened species have been identified: Bald Eagle, Ozark Cavefish, Magazine Mtn. Shagreen (snail), Geocarpon (plant), American Alligator. The following

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endangered species have been identified Gray Bat, Indiana Bat, Ozark Big-Eared Bat, American Burying Beetle, Interior Least Tern, and the Fat Pocketbook Mussel (FS, 2016). There are no reported occurrences of threatened or endangered species at the site.

Based on the review of sensitive receptors, the Ozark National Forest was identified for recreational use and potential recreating populations were identified as potential receptors. Three (3) ponds were identified within 0.25 miles of the site. No other sensitive receptors, sensitive environments, or ecological receptors were identified at or within the vicinity of the site.

4.3. Historical Aerial Photograph Review Historical aerial photographs of the Cattle Head site and surrounding area from 1936 were provided by the Forest Service and aerial photographs from 1941 were acquired from the National Air Survey Center Corporation. The 1941 aerial photographs were digital copies of aerial photographs in the National Archives Collection. Observations gathered from the review of the aerial photography were limited to a monoscopic evaluation of digitally-reproduced images of the original photography. Historic topographic map coverage for the Cattle Head CDV site was not available. Historical aerial photographs are summarized below and included as Appendix F.

December 31, 1936 The 1936 aerial photograph is a high elevation black and white photograph with coverage of the Cattle Head CDV site and the surrounding area. The vat structure, drip pad, and any supporting structures (e.g., holding pens) were not identifiable; however, there appears to be a fence surrounding the small tract of land that is the location of the vat. A white rectangular feature at the location of the vat is visible; however, image quality is not sufficient to clearly identify the vat structure or associated canopy. The small tract of land that the vat is located on is separated from a larger tract of cleared land to the north and northwest by what appears to be a fence and is separated from small tract of land to the south by the Forest Road 1375. The tract of land with the vat (north of Road 1375) is approximately 255 by 225 feet and has an approximate area of 57,375 square feet or 1.3 acres.

Large tracts of cleared land are located immediately north and west of the site. These tracts also contain several structures and fenced areas. A third large tract of cleared land is located to the southwest across a wooded area. These tracts of land appear to be used for pastureland or other agricultural purposes. Other surrounding areas are forested. There is no evidence of the three (3) ponds currently located in the vicinity of the site or other surface water features. Several drainage courses are evident on or adjacent to the agricultural fields located northeast and southeast of the site.

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The presence of several structures and cleared land suggests that the infrastructure necessary for agriculture, including livestock farming, is present in the vicinity of the Cattle Head CDV site at the time of the 1936 coverage.

October 11, 1941 The 1941 aerial photograph is a high elevation black and white photograph with coverage of the Cattle Head CDV site and the surrounding area. The vat structure, drip pad, and supporting structures (e.g., holding pens) are not identifiable. The site and surrounding properties appear unchanged from the 1936 coverage. A small disturbance in the location of the pond currently located approximately 550 feet northeast of the site is visible; however, it does not appear to be a pond in this coverage. No other evidence of surface water or drainage features in the vicinity of the site is evident in this coverage. The Cattle Head CDV site and the surrounding land appear to be used for agricultural purposes that may include livestock farming at the time of this coverage.

4.4. Operational History and Contaminants of Potential Concern As indicated in Section 2, between 1906 and 1943, CDVs were constructed throughout the southern United States as part of the Cattle Fever Tick (Boophilus microplus and B. annulatus) Eradication Program. The program was aimed at the eradication of the tick responsible for transmitting the ‘Texas Fever’ disease (bovine babesiosis) among cattle herds. After a 36-year campaign, cattle fever ticks were declared eradicated from the U.S. in 1943; however, dipping reportedly persisted in some areas until the 1960s (Pasquill, 2012).

Arsenic-based pesticide solutions were used in conjunction with dip vats and became well established as the preferred method for cattle treatment. In the 1940s, OC pesticides were reportedly added to the arsenical pesticide solutions to increase effectiveness and fuel oil, kerosene, and other petroleum products may have been used as carriers. Historically, spent dip solution was pumped out of the vat and into an unlined evaporation pit located in close proximity to the vat and allowed to evaporate. In some cases, spent dip solution was discharged directly to adjacent streams or intermittent drainage features (Pasquill, 2012).

Based on conditions found at numerous other CDV sites both on and off USDA FS land, arsenic in soils is the primary contaminant of potential concern (COPC) expected. Secondary COPCs include OC pesticides and polynuclear aromatic hydrocarbons (PAHs) which may be collocated with arsenic. Specific COPCs for the Cattle Head CDV site include:

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Contaminants of Potential Concern . Arsenic . DDD . Gamma BHC (Lindane) . Aldrin . DDE . Gamma Chlordane . Alpha Chlordane . Endrin . Heptachlor Epoxide . Alpha BHC . Endrin Ketone . Methyloxychlor . Beta BHC . Endrin Aldehyde . PAHs . Delta BHC . Endosulfan I . Toxaphene . Dieldrin . Endosulfan II

Based on the review of historical aerial photography, site inspection, and desktop data collection, there is evidence of agricultural activity in the vicinity of the Cattle Head CDV site from the late 1800’s through the early 1940’s. There is no specific information available on the frequency or duration of cattle dipping activities. As a result, all primary and secondary COPCs were retained for the Cattle Head CDV site.

4.5. Previous Investigations Prior to the 2015 SI there were no previous environmental investigations conducted on the Cattle Head CDV site. A Dip Vat Heritage Report was completed by the Arkansas Archaeological Survey (AAS) for the Cattle Head site in 2004 (AAS, 2004). The following is a summary of notable findings from the Cattle Head CDV site Heritage Report:  The Cattle Head CDV site had poor ground visibility (less than 25%) as a result of pine litter, brush, vines, and briers.  Vegetation at the site was observed to consist of pine and mixed hardwoods.  The vat structure and site were observed to be in good condition and was filled with water at the time of the inspection.  There was no evidence of other structures identified in historical aerial photography. It is suspected that the associated structures were razed to support the logging activities in the area.  The vat canopy or roof structure was intact and was constructed with wood and a metal roof.  A small depression was identified approximately 42 feet west-southwest of the vat.  Shovel test pits were not completed at the site due to the potential presence of contaminants in soil.

4.6. Identification of Areas of Potential Concern Based on the results of desktop data collection activities and the site inspection, the following AOPCs were identified for the Cattle Head CDV site:  Water and soil/sludge located within the vat.  Areas where the spent cattle-dip solution and/or sludge may have been disposed of including the depression identified in the vicinity of the vat (AAS, 2004).

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 Around the vat where dip solution may have splashed.  The drip pad, the area where cattle exited the vat, and holding pen areas.

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5. ABBREVIATED PRELIMINARY ASSESSMENT/FIELD SCREENING

The Abbreviated Preliminary Assessment (APA) is the first phase of investigation and is intended to assess the presence of contamination associated with former CDV activities and to determine the need for further investigation based on potential risk associated with identified contamination. The APA was implemented at the Cattle Head CDV site in 2015 and included the assessment of all environmental media at the site including surface soil, subsurface soil, and the vat contents through the collection and analysis of discrete samples. Surface water and sediment samples were not collected as part of the APA at the Cattle Head CDV site because the nearest water bodies (man-made ponds) are located over 550 feet from the site and there are no clear conveyances from the site to the ponds. Groundwater samples were not collected at the Cattle Head CDV site due to the presence of bedrock at depths shallower than the water table.

Sample locations were biased toward areas that were identified as AOPCs. APA details including the number and locations of samples from each media, field measurement results, and fixed laboratory analytical results are presented in the following subsections. Additionally, the screening level risk assessment process for determining the need for further investigation (e.g., a Focused Site Investigation [FSI] [Section 6]) is also detailed in this section. All APA activities were carried out pursuant to the approved Site-Specific Sampling and Analysis Plan (FS, 2015a), and the CDVMP QAPP (FS, 2015), and the Site-Specific Health and Safety Plan (HASP) (Appendix F of FS, 2015a).

Follow-on sampling was conducted in 2017 at the site to delineate the extent of toxaphene contamination in soils that were identified in 2015. All follow-on sampling activities were carried out pursuant to the approved 2017 CDVMP Site-Specific Sampling and Analysis Plan (FS, 2017), and the CDVMP QAPP (FS, 2015), and the Site-Specific Health and Safety Plan (HASP) (FS, 2017a). Follow-on sampling activities and results are described in section 7.

5.1. Vat Water and Vat Soil/Sludge Sampling During the APA, the vat structure was identified and inspected. Standing water was observed in the vat structure and one (1) grab sample (3PP657-VW01) was collected and submitted for laboratory analysis of dissolved arsenic via EPA Method 6010 and OC pesticides via EPA Method 8081. The dissolved arsenic sample aliquot was lab filtered prior to analysis. A total arsenic sample was not collected from the vat structure. Dissolved arsenic was detected in the vat water sample at a concentration of 0.37 milligrams per liter (mg/L). The dissolved arsenic concentration in vat water was greater that the Safe Drinking Water Act (SDWA) maximum contaminant level (MCL) of 10 micrograms per liter (µg/L) and the EPA Region 4 Removal Management Level (RML) for residential tap water of 5.2 µg/L. The OC pesticides 4,4’-DDT, alpha-BHC, beta-BHC, endosulfan II, endrin, endrin aldehyde, and gamma-BHC (lindane) were detected

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A sediment/sludge sample was not collected from the vat structure due to the unconsolidated nature of the material at the bottom of the vat. During sample collection efforts, only fresh leaf litter was collected in the grab sample and sediment could not be collected.

5.2. Surface and Shallow Subsurface Soil Sample Collection and Analytical Results As part of the APA, a total of nine (9) soil borings (3PP657-SB01 through 3PP657-SB09) were advanced with a hand auger to a total depth of 12 inches (in) below ground surface (bgs). Soil lithology was recorded on a field sample collection sheet and soil samples were collected from two intervals (0 to 6 and 6 to 12 in bgs) from each boring. GPS coordinates for each boring location were also recorded in the field sample collection sheet. Soil sample locations are depicted on the sample location map included as Figure 7.

5.2.1. XRF Analytical Results Soil samples from each interval were homogenized in a disposable plastic bag and analyzed in the field with a field portable XRF analyzer for arsenic via EPA Method 6200. XRF analysis was completed with Delta Class Plus XRF analyzer (DCC-6000) in accordance with the operating instruction (Innov-X Systems, Inc., 2010) and quality assurance procedures detailed in the CDVMP QAPP (FS, 2015). Vegetation was removed from the 0 to 6 in bgs sample interval prior to sample homogenization and analysis. In addition to soil analysis via XRF, soil pH and percent moisture was measured in the field using Kelway® Soil pH and Moisture Meter and recorded in the field sample collection sheet.

Arsenic was detected at concentrations ranging from 10.2 ± 1.0 to 154 ± 2.0 mg/kg. Arsenic was not detected in surface soil (0 to 6 in) and or shallow subsurface soil (6 to 12 in) at concentrations greater than the CDVMP low-level threat waste screening criterion of 456 mg/kg. Surface soil and shallow subsurface soil sampling results for arsenic are presented on a Tag Map included as Figure 8. Complete XRF analytical results are included in Appendix G.

5.2.2. Verification of Screening Level Risk Assessment Results Arsenic was not detected in surface soil or shallow subsurface soil at concentrations greater than the CDVMP low-level threat waste screening criterion of 456 mg/kg. As a result, no verification sampling was required for the Cattle Head site.

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5.2.3. Fixed Laboratory Analytical Results In order to confirm the results of the XRF analysis, a total of two (2) soil samples were submitted for fixed laboratory analysis of arsenic, iron and lead via EPA Method 6010 and OC pesticides via EPA Method 8081A. The soil samples selected for confirmation analysis from the Cattle Head CDV site were 3PP657- SB01 at 0 to 6 inches bgs and 3PP657-SB03 at 6 to 12 inches bgs. Samples were selected from the upper and lower range of concentrations measured by the XRF. Fixed laboratory arsenic analytical results for the selected samples are compared to their corresponding XRF results in Table 2. A review of the accuracy and usability of the arsenic results via XRF and is included in Section 7.

Table 2: Comparison of Arsenic Fixed Laboratory and XRF Analytical Results Sample Identification and Depth Fixed Laboratory Analysis XRF Analysis Arsenic Result Interval (bgs) Arsenic Result (mg/kg) (mg/kg) 3PP657-SB01 (0-6 in) 220 154 ± 2.0 3PP657-SB03 (6-12 in) 11.0 10.2 ± 1.0

The OC pesticide toxaphene was detected in confirmation sample 3PP657-SB01-0-6” at a concentration of 2,400,000 µg/kg (2,400 mg/kg). Toxaphene was detected in the soil sample 3PP657-SB01-0-4’, which was collected from the same location as 3PP657-SB01-0-6”, at a concentration of 69,000 µg/kg (69 mg/kg). Toxaphene was also detected in soil sample 3PP657-SB03-6-12” at a concentration of 410 µg/kg (0.410 mg/kg). The residential RML for toxaphene is 49,000 µg/kg (49 mg/kg). No other OC pesticides were detected in the confirmation samples.

In addition to OC pesticide and arsenic analysis, the soil sample with the greatest arsenic XRF result (3PP657-SB01-0-6”) was submitted for laboratory analysis of semivolatile organic compounds (SVOCs) via EPA Method 8270 and for arsenic analysis via EPA Method 6010 with extraction via the synthetic precipitation leachate procedure (SPLP) via EPA Method 1312.

SVOCs were not detected in confirmation sample 3PP657-SB01-0-6”. SVOC detection limits were less than RMLs for all analytes. A laboratory quality assurance infraction was identified for the SVOC results and 61 of 72 analytes on the SVOC target analyte list were rejected and were “R” qualified. Soil sample 3PP657-SB01-0-6” was resampled in November 2015 and was submitted for laboratory analysis of SVOCs. SVOCs were not detected in recollected confirmation sample 3PP618-SB01-0-6”. SVOC detection limits were less than RMLs for all analytes.

The SPLP extraction procedure is intended to simulate arsenic leachate from soils exposed to precipitation in the natural environment (as opposed to landfill conditions) and provides an indication of the potential migration of arsenic from soil to soil pore water. Arsenic was detected in the SPLP leachate

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A summary of analytical results for the soil samples are included in Appendix G and the complete laboratory analytical report is included as Appendix H.

5.2.4. Further Evaluation of the Soil to Groundwater Pathway Arsenic was detected via XRF and fixed laboratory analysis in soil sample 3PP657-SB01-0-6” (arsenic SPLP leachate result of 0.1 mg/L) at concentrations of 154 ± 2.0 and 220 mg/kg, respectively. Soil sample 3PP657-SB01-6-12” was collected from a depth of 6 to 12 in bgs, immediately below soil sample 3PP657-SB01-0-6”, and a composite soil sample was collected from 0 to 4 feet from the same borehole (Section 5.3). Arsenic was detected in the 6 to 12 in increment, and composite samples at concentrations of 142 ± 2.0 and 53.0 ± 1.4 mg/kg, respectively. Arsenic concentrations generally decrease with depth, suggesting that that the vertical migration of arsenic under site conditions is limited.

Groundwater is expected to occur in bedrock fractures underlying the Cattle Head CDV site (Section 3.4). During the advancement of a deep soil boring for the collection of groundwater samples, shale bedrock was encountered at a depth of 4 feet bgs and groundwater was not present in overburden material (Section 5.3). There is over 3 feet of unconsolidated material between soil sample 3PP657-SB01-0-6” and the underlying interface between unconsolidated soil and bedrock.

Based on the observed decrease in arsenic concentrations with depth and the depth to the interface between unconsolidated soil and bedrock, it is not expected that leachate from site soils will impact groundwater. Additionally, groundwater receptors (e.g., withdrawal wells) were not identified in the vicinity of the Cattle Head site.

5.3. Groundwater and Subsurface Soil Sample Collection and Analytical Results As part of the APA, one (1) deep soil boring was advanced using Geoprobe® direct push technology for the collection of subsurface soil samples and the collection of a single groundwater sample at the Cattle Head site. The location of the deep soil boring was determined in the field based on APA surface and shallow subsurface soil sample analytical results (via XRF), the location of the vat, and other site features. The location selected for the advancement of the deep boring was the location with the maximum arsenic result (3PP657-SB01). The location of the deep soil boring is depicted in Figure 7. Groundwater and subsurface soil sampling results are presented on a Tag Map included as Figure 8.

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5.3.1. Subsurface Soil Sample Collection and Analytical Results Continuous soil cores were collected during the advancement of the deep soil boring (3PP657-SB01). Soil boring lithology was logged as the borehole was advanced for the identification of the water table or perched water bearing zones. Subsurface lithology was described as dark brown to light brown sandy loam with some shale gravel. Refusal was encountered at a depth of approximately 4 feet bgs and weathered shale bedrock was present from 3.5 to 4 ft bgs. A second borehole was advanced adjacent to 3PP657-SB01 and refusal was encountered at 3 ft bgs due to the presence of shale bedrock. Bedrock fragments were observed in the soil core at the terminal depth of the borehole. Groundwater was not encountered during deep borehole advancement. A soil boring log for the deep borehole is included as Appendix I.

Arsenic was not detected at concentrations greater than 456 mg/kg in surface or shallow subsurface soil samples collected from soil boring 3PP657-SB01. As a result, no additional discrete soil samples were collected from soil boring 3PP657-SB01. A composite soil samples was collected from 0 to 4 feet bgs for arsenic analysis via XRF. In order to confirm the results of the XRF analysis, subsurface soil sample 3PP618-SB15-0-4’ was submitted for fixed laboratory analysis of arsenic, iron and lead via EPA Method 6010 and OC pesticides via EPA Method 8081A. Iron and lead results are discussed in Section 7 and a summary of arsenic and OC pesticide analytical results and OC pesticide fixed laboratory analytical results from the deep borehole is provided in Table 3.

Table 3: Summary of Arsenic and OC Pesticide Analytical Results for the Deep Soil Boring Depth Sample Type XRF Analysis Fixed Laboratory Fixed Laboratory Sample Identification Interval (discrete or Arsenic Result Analysis Arsenic Analysis OC Pesticide (bgs) composite) (mg/kg) Result (mg/kg) Result (µg/kg) 3PP618-SB01-0-4’ 0 to 4 ft Composite 53.0 ± 1.4 81.0 Toxaphene* (69,000 µg/kg) NA – Not Analyzed *No other OC pesticides were detected

Subsurface soil sample 3PP657-SB01-0-4’ was submitted for arsenic analysis via EPA Method 6010 with extraction via the SPLP by EPA Method 1312. The SPLP extraction procedure is intended to simulate arsenic leachate from soils exposed to precipitation in the natural environment (as opposed to landfill conditions). Arsenic was detected at a concentration of 0.19 mg/L in the SPLP leachate from sample 3PP657-SB01-0-4’. The RML and MCL for arsenic are 5.2 and 10 µg/L, respectively. As a result, arsenic in soil may have the potential to impact groundwater and further evaluation of the soil to groundwater pathway is needed.

A summary of analytical results for subsurface soil samples is included in Appendix G and the complete laboratory analytical report is included as Appendix H.

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5.3.2. Groundwater Sample Collection and Analytical Results A groundwater sample was not collected at the Cattle Head Vat site as part of the APA due to site specific conditions. Two (2) soil borings were advanced in an effort to collect a groundwater samples at the site. Bedrock was encountered in the borings at depths of 3 and 4 feet bgs. Groundwater was not encountered in the unconsolidated overburden soils. Consistent with the description of aquifers in the interior highlands (Section 3.4), groundwater underlying the site is likely present in fractures within the underlying bedrock and could not be sampled using Geoprobe® direct push technology. Drilling methods capable of advancing boreholes through the underlying consolidated rock are needed for the collection of groundwater samples at the Cattle Head Vat site.

5.4. Surface Water and Sediment Sample Collection and Analysis Three (3) small ponds are located within ¼ mile of the Cattle Head CDV site and represent potential ecological receptors. The nearest ponds are located approximately 550 feet northeast and southeast of the vat site. There are no clear conveyances between the site and any of the ponds. No other perennial or ephemeral surface water features were identified in the vicinity if the site. As a result, surface water and sediment samples were not collected as part of the investigation of the Cattle Head site.

5.5. Screening Level Risk Assessment Summary A screening level risk assessment was completed in the field to determine whether further investigation, verification sampling and a Focused Site Investigation (FSI), is required for the Cattle Head site based on real-time arsenic results for soil. Additionally, this field screening level risk assessment was used to identify soil samples to be submitted for fixed laboratory analysis of arsenic, lead, iron, OC pesticides, and SVOCs. A second screening level risk assessment was completed comparing fixed laboratory analytical results to the CDVMP-specific screening criteria for arsenic, EPA Region 4 RMLs, and other applicable criteria for detected OC pesticides and SVOCs. The following sections summarize the screening level risk assessments.

5.5.1. Field Screening Level Risk Assessment In accordance with the CDVMP, site specific soil results for arsenic were compared to the both CDVMP- specific low-level threat screening criteria for arsenic of 456 mg/kg and the principal threat waste screening level for arsenic of 4,560 mg/kg (Appendix A). The maximum detected concentration of arsenic in soil was 154 ± 2.0, less than the CDVMP-specific low-level threat screening criteria. As a result, verification sampling and a FSI were not required for the Cattle Head site.

5.5.2. Fixed Laboratory Results Screening Level Risk Assessment The results of the field screening level risk assessment for arsenic were used to select the soil samples submitted for fixed laboratory analysis of OC pesticides and SVOCs (Section 5.1 and 5.2). Soil samples

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3PP657-SB01-0-6” and 3PP657-SB03-6-12” were submitted for fixed laboratory analysis of arsenic, lead, iron, OC pesticides, and SVOCs. A screening level risk assessment was completed by comparing fixed laboratory analytical results for lead, iron, OC pesticides and SVOCs to EPA Region 4 RMLs for residential soil. The EPA Region 4 RMLs are chemical-specific concentrations for individual contaminants in tap water and soil that may be used to support the decision to undertake a removal action or further investigation. The RML table used for the screening level risk assessment for the Cattle Head site is dated July 2015 and corresponds to a 10-4 risk level for carcinogens and a hazard quotient of 1 for non- carcinogens. Arsenic fixed laboratory analysis results were compared to CDVMP-specific screening criteria in Sections 5.2.3 and 5.3.1.

Iron was detected in soil at concentrations ranging from 19,000 to 41,000 mg/kg. Iron was not detected at concentrations greater than its residential soil RML (55,000 mg/kg). Lead was detected in soil at concentrations ranging from 11 to 23 mg/kg. Lead was not detected at concentrations greater than its residential soil RML (400 mg/kg). Iron and lead results are evaluated relative to XRF data quality and usability in Section 7.

The OC pesticide toxaphene was detected in soil at concentrations ranging from 410 to 2,400,000 µg/kg in soil samples 3PP657-SB03-6-12” and 3PP657-SB01-0-6”, respectively. Toxaphene was detected in the composite sample collected from soil boring SB01 (3PP657-SB01-0-4’) at a concentration of 69,000 µg/kg. The RML for toxaphene is 49,000 µg/kg. No other OC pesticides were detected in soil samples collected from the Cattle Head site.

The OC pesticides 4,4’-DDT, alpha-BHC, beta-BHC, endosulfan II, endrin, endrin aldehyde, and gamma- BHC (lindane) were detected in the vat water sample. The OC pesticides alpha-BHC and endrin were detected at concentrations greater than their respective Ambient Water Quality Criteria (AWQC). Toxaphene was not detected in the vat water sample at a detection limit of 0.77 µg/L.

SVOCs were not detected in soil samples collected from the Cattle Head site in August 2015. During data validation, an infraction in laboratory analytical procedures was identified. As a result, SVOC results were qualified as rejected data and are not considered useable for site management decisions. SVOC samples were recollected in November of 2015. SVOCs were not detected in the soil sample collected in November 2015. Laboratory detection limits for all SVOCs are less than their respective RMLs. SVOCs are not present in soil at the Cattle Head site at concentrations greater than their residential soil RMLs.

A summary of detected OC pesticides and SVOCs, including a comparison to their respective RMLs, is included in Appendix G. Complete OC pesticide and SVOC analytical results are included in Appendix H.

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6. FOCUSED SITE INVESTIGATION

Based on the results of the APA, a Focused Site Investigation was not completed for the Cattle Head site.

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7. FOLLOW-ON SOIL SAMPLING

Follow-on soil sampling was conducted in 2017 at the Cattle Head CDV site and included the collection of soil in the immediate vicinity of the vat. Follow-on soil sampling was initiated to delineate the horizontal and vertical extent of soil with concentrations of toxaphene above EPA Region IV RMLs.

All follow-on sampling activities were carried out pursuant to the approved 2017 CDVMP Site-Specific Sampling and Analysis Plan (FS, 2017), and the CDVMP QAPP (FS, 2015), and the Site-Specific Health and Safety Plan (HASP) (FS, 2017a). Follow-on sampling activities and results are described in section 7.

7.1. Follow-on Soil Sampling Activities and Results As part of the follow-on delineation soil sampling, nine (9) soil borings (3PP657-SB11 through 3PP657- SB19) were advanced with a hand auger to a total depth of 24 in bgs. Soil samples were collected from two (2) discrete depth intervals (0 to 12 and 12 to 24 in bgs) from each boring. Soil sampling locations are shown in Figure 9.

Soil samples were submitted for laboratory analysis of OC pesticides via SW8081. All soil samples collected from 0 to 12 in bgs were analyzed. All samples collected from 12 to 24 in bgs were archived at the analytical laboratory for subsequent analysis based on the results of the shallower soil samples. Based on sampling results from the shallow soil samples, three (3) deeper soil samples were analyzed (3PP657-SB13, SB14 & SB18).

Toxaphene was detected at a maximum concentration of 100,000 µg/kg in 3PP657-SB14, which is located five (5) feet west of the vat egress, and four (4) feet east of 3PP657-SB01. Toxaphene was detected in SB01 at a concentration of 2,400,000 µg/kg in 2015. Except for a trace detection of Gamma- BHC (Lindane) in 3PP657-SB13, toxaphene was the only OC pesticide detected in follow-on sampling soil samples. All toxaphene results are shown in Figure 10.

The EPA Region IV RML for residential soil residential soil is 49,000 µg/kg for toxaphene. Toxaphene was detected in seven (7) out of nine (9) follow-on sampling borings, and detected above EPA Region IV RMLs in only one (1) soil boring (3PP657-SB14). Toxaphene appears to be present in surficial soils around the Cattlehead CDV site to a distance of at least fifteen (15) feet and an area of 150-300 square feet around the vat structure egress. Toxapehene concentrations exceeding the EPA Region IV RML are estimated to be present within six (6) to eight (8) feet from the vat egress and occupies an area of approximately 50-80 square feet.

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Toxaphene was present to depths of up 24 in bgs, and likely deeper. As described in Section 5.5.2, and shown in Figure 10, toxaphene was detected at a concentration of 2,400,000 µg/kg at a depth interval of 0 to 6 in bgs, and 69,000 µg/kg in a homogenized depth interval of 0 to 4 ft bgs.. All analytical data is presented in Appendix H.

An estimated soil volume of approximately twelve (12) to eighteen (18) cubic yards contains toxaphene at concentrations greater than the EPA Region IV RML.

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8. QUALITY ASSURANCE AND QUALITY CONTROL SUMMARY

Quality assurance for the CDVMP site investigation is implemented in accordance with the CDVMP QAPP (FS, 2015a). A primary goal of the Quality Assurance/Quality Control (QA/QC) aspect of the investigation is to ensure the quality and integrity of environmental samples, accuracy and precision of laboratory analyses, representativeness of results, and completeness of information generated by field activities at the Cattle Head site. QA/QC program aspects detailed in the following subsections include:  XRF QA/QC sample collection  XRF Confirmation Samples  Fixed laboratory analysis QA/QC sample collection  Data validation  Deviations from the approved work plan

8.1. XRF Analysis Quality Assurance/Quality Control Samples Arsenic analysis using a field portable XRF analyzer was completed at the Cattle Head site for the 2015 investigation. XRF analyzer calibration was completed in accordance with the requirements in the Delta Class Plus XRF analyzer (DCC-6000) user’s manual (Innov-X Systems, Inc., 2010) and the CDVMP QAPP each day the XRF analyzer was in operation (FS, 2015). As part of the APA, the following is a summary of calibration completed on the XRF analyzer:

Initial Calibration Initial calibration (also referred to as energy calibration) was automatically completed at instrument start up. There were no errors associated with initial calibration identified during instrument start up.

Instrument Calibration On August 29, 2015, a method blank consisting of silicon dioxide was analyzed (in the same plastic bag used for sample analysis) before analysis, once during the analysis of the first 20 samples, and once during the analysis of the second 20 samples. The method blank sample was not analyzed following analysis on August 29, 2015. The method blank analysis from before sample analysis on August 30, 2015 is considered in conjunction with instrument calibration completed on August 29, 2015. The instrument/method blank XRF results were all less than the lower limit of detection (LLOD) and corrective action was not required.

Calibration Verification On August 29, 2015, calibration verification (also referred to as standardization) was completed before analysis, once during the analysis of the first 20 samples, and once following analysis. Calibration

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Table 4: Calibration Verification Results Standard 2710a Standard 2711a XRF Standard Calculated XRF Standard Calculated Measurement Result Concentration Percent Result Concentration Percent (mg/kg) (mg/kg) Difference (mg/kg) (mg/kg) Difference August 29, 2015 Prior to 1,586 ± 16 1,540 ± 100 2.99% 121 ± 6 107 ± 5 13.08% Analysis Samples 0-20 1,608 ± 16 1,540 ± 100 4.42% 107 ± 6 107 ± 5 0.00% Following 1,616 ± 16 1,540 ± 100 4.94% 123 ± 6 107 ± 5 14.95% Analysis

Field Precision Verification On August 29, 2015, field precision verification consisting of 7 replicate measurements was completed on soil sample 3PP657-SB01-0-6”. Field precision verification results were used to calculate the relative standard deviation (RSD). The RSD provides an indication of the precision of the XRF measurement results and should be considered in conjunction with matrix variability. The acceptance criterion for precision is a RSD less than or equal to 20% (FS, 2015). Precision verification results %RSD were less than 20% on August 29, 2015. Field precision verification results are presented in Table 5.

Based on the precision verification results, the precision of the XRF measurements collected on August 29, 2015 meet acceptance criteria and no corrective action was required during XRF measurements.

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Table 5: Field Precision Verification Results Replicate No. XRF Result 1 154.0 ± 2.0 2 138.4 ± 2.0 3 131.5 ± 1.9 4 181.0 ± 3.0 5 159.0 ± 2.0 6 154.0 ± 3.0 7 149.0 ± 2.0 % RSD 10.41%

8.2. XRF Data Comparability and Usability In order to confirm the results of the XRF analysis, four (4) soil samples (including one duplicate sample) analyzed with the XRF at the Cattle Head site were submitted for fixed laboratory analysis of arsenic via EPA Method 6010. In accordance with EPA Method 6200, confirmation samples were selected from the lower, middle, and upper range of concentrations measured by the XRF (EPA, 2006). Soil samples selected for confirmation analysis and analytical results are presented in Section 5.

In order to evaluate the usability of the XRF data, a correlation analysis and regression analysis were performed on the fixed laboratory confirmation sample results and the corresponding XRF data. The correlation analysis is used to determine if there is a strong linear relationship between the XRF data and the corresponding laboratory analytical result. The correlation analysis on the XRF data and laboratory data for the Cattle Head site indicates a correlation coefficient (R) of 0.988. The closer the correlation coefficient is to 1 then the stronger the linear relationship between data sets. As a result, the Cattle Head site data has a strong linear relationship that supports the completion of a linear regression analysis for the evaluation of data usability.

The linear regression analysis was completed to determine if there is a significant linear relationship between the XRF data and the laboratory confirmation data. According to the QAPP, the coefficient of determination (r2) determined through the linear regression analysis is compared to acceptance criteria to determine the usability of XRF data. If r2 is greater than 0.7, then XRF results may be considered screening level data. If r2 is greater than 0.9, then XRF results could meet definitive level data criteria. The regression analysis of the XRF data and laboratory data for the Cattle Head site indicates a coefficient of determination (r2) of 0.9769. As a result, the XRF data collected for the Cattle Head site is considered definitive level data and is usable for site management decisions.

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The Cattle Head site was investigated as part of a CDVMP site investigation effort that included a total of seven (7) sites in the Ozark National Forest. XRF and fixed laboratory data was collected for each site. In order to complete a more robust statistical evaluation of the XRF and fixed laboratory analytical results, a correlation analysis and a regression analysis was completed using data from all seven (7) CDV sites and included a total of twenty-three (23) data points. The correlation analysis on the XRF data and laboratory data for all sites indicates a correlation coefficient (R) of 0.995, suggesting a strong linear relationship that supports the completion of a linear regression analysis for the evaluation of data usability. The regression analysis indicates a coefficient of determination (r2) of 0.9898. As a result, the XRF data collected for all seven (7) sites investigated as part of the 2015 CDVMP site investigation effort is considered definitive level data and is usable for site management decisions.

A summary of XRF data and the corresponding laboratory data and the results of the correlation and regression analyses are included as Appendix J.

8.3. Evaluation of XRF Interferences In addition to arsenic, confirmation sample laboratory analysis included lead and iron to evaluate potential interferences with XRF results. Soil moisture also has the potential to interfere with XRF analysis and was measured in soil at the time of sample collection.

Iron Iron is commonly present at high concentrations in the environment (EPA, 2006). At high concentrations, iron presents a potential interference for both XRF and fixed laboratory analysis of soil samples and is often used as a target reference element in XRF analysis. As indicated in Section 5.5.2, iron was detected in soil at concentrations ranging from 19,000 to 41,000 mg/kg. Based on the correlation analysis completed on the arsenic XRF and fixed laboratory results presented in Section 7.2, arsenic XRF results are well correlated with the corresponding fixed laboratory results. As a result, interference due to high concentrations of iron did not have negative effects on the arsenic XRF or fixed laboratory data quality and was not evaluated further.

Lead Lead is known to interfere with the measurement of arsenic via XRF analysis. Certain x-ray lines from different elements can be very close in energy and can cause interference by producing a severely overlapped spectrum. The presence of lead is known to severely interfere with arsenic determination by XRF (Kalnicky and Singhvi, 2001). Lead is measured from two x-ray spectral line (Pb Lα and Pb Lβ) and the Pb Lβ spectral line is typically used for lead analysis. Similarly, arsenic is measured from either of two spectral lines (As Kα or As Kβ) and the As Kα spectral line is typically used for analysis. The wavelength of the lead spectral line Pb Lα is similar to the arsenic spectral line As Kα and the energy difference

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Arsenic can also be measured from the As Kβ, which allows XRF analyzers to mathematically correct for the overlapping spectrum and the presence of lead; however, there are limitations associated with this mathematical correction (Innov-X Systems, Inc., 2010). When the ratio of lead to arsenic in a sample is 10:1 or more, arsenic concentrations cannot be efficiently calculated (EPA, 2006). This may result in reporting of a "non-detect" value for arsenic, regardless of the actual concentration present in the sample (User’s Manual). When the arsenic Kβ spectral line is used, sensitivity will be decreased by a factor of two to five times because the arsenic Kβ spectral line is less intense than the arsenic Kα spectral line which results in increased detection limits. A summary of the lead and arsenic fixed laboratory analytical results for the Cattle Head site is provided in Table 6.

Table 6: Summary of Lead and Arsenic Fixed Laboratory Analytical Results

Arsenic Lead Concentration Lead to Arsenic Sample Identification Concentration (mg/kg) Ratio (mg/kg)

3PP657-SB01-0-4' 14 49 0.29

3PP657-SB01-0-4' DUP 13 81 0.16

3PP657-SB01-0-6" 23 220 0.10

3PP657-SB03-6-12" 11 220 0.05

Average: 15.3 142.5 0.15

Based on fixed laboratory analytical results, the ratio of lead to arsenic at the Cattle Head site ranged from 0.05 to 0.29 with an average of 0.15. The maximum observed lead to arsenic ratio (0.29) and the average lead to arsenic ratio (0.15) are less than the 10:1 ratio where significant interferences are expected. As a result, lead is not considered to have interfered with the arsenic XRF results for the Cattle Head site.

Soil Moisture Soil moisture content may affect the accuracy of soil samples analysis via XRF. When the moisture content is between 5 and 20%, the overall error from moisture may be minimal. Soil moisture content may be a major source of error when soil samples are saturated (EPA, 2006). Percent relative saturation was measured in each soil sample at the time of sample collection. Percent relative saturation is a ratio of the moisture content relative to the relative saturation or field capacity. In order to determine the percent

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Based on the observed site lithology and published surficial lithology (Section 3.3), soil at the Cattle Head site is the Nella Loam which is a brown to light brown well-drained gravelly fine sandy loam (NRCS, 2016). As a result, the field capacity of the Cattle Head site soils was assumed to be 45%, consistent with published values for the field capacity of loam. The calculated percent moisture at the Cattle Head site ranged from 2.3 to 11.3%. The percent moisture for Cattle Head site soils was within the ideal range for XRF analysis and the potential interference resulting from moisture at this site is considered minimal.

Based on a review and analysis of potential interferences with arsenic analysis via XRF including iron, lead, and soil moisture, no interference was observed at the Cattle Head site. The correlation analysis between XRF and fixed laboratory analysis (Section 7.2) indicates that the arsenic XRF measurements are well correlated with the corresponding fixed laboratory analytical results. This supports the conclusion that interferences do not affect the accuracy or usability of the arsenic XRF results for the Cattle Head site.

8.4. Fixed Laboratory Analysis Quality Assurance/Quality Control Samples In accordance with the CDVMP QAPP, appropriate QA/QC samples were collected in the field from soil and water samples to assess sampling and analytical precision and accuracy, as well as any interference present in the sample matrices. Due to the small number of samples submitted for laboratory analysis from each site, QA/QC samples were collected based on the total number of samples collected from all seven (7) sites investigated as part of the 2015 CDVMP site investigation effort. QA/QC samples are applicable to fixed laboratory analyses and field measurements. Field measurement with an XRF via EPA Method 6200 requires a separate suite of QA/QC samples and tests detailed in Section 7.1.

QA/QC samples collected from solid media as part of the investigation included three (3) duplicate samples and one (1) matrix spike/matrix spike duplicate (MS/MSD) sample. Soil QA/QC samples were submitted for laboratory analysis applicable to the specific sample requirements detailed in the SAP and include SVOCs, OC pesticides, iron, lead, and arsenic.

QA/QC samples collected from liquid media as part of the investigation included one (1) duplicate sample and one (1) MS/MSD sample. Liquid media QA/QC samples were submitted for laboratory analysis of OC pesticides and dissolved metals.

As part of the follow-on delineation soil sampling, one (1) field duplicate and one (1) MS/MSD were collected from the cattlehead site and analyzed for OC pesticides.

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Equipment Rinsate Blanks (2015): Equipment rinsate blanks (EB) were collected to assess equipment decontamination (for reusable sample collection equipment only). A total of two (2) equipment rinsate blanks were collected from the hand auger and Geoprobe® direct push tooling following the decontamination of sampling equipment. The equipment blank collected from the hand auger was submitted for laboratory analysis of SVOCs, OC pesticides, iron, lead, and arsenic. The equipment blank collected from the Geoprobe® direct push tooling was submitted for laboratory analysis of OC pesticides, iron, lead, and arsenic. Equipment rinsate blanks were non-detect for all analytes except iron, which was identified in all equipment blank samples at concentrations ranging from 0.017 to 0.75 mg/L. The results of the equipment blank samples indicate that the equipment decontamination procedures implemented during the CDVMP site investigation were sufficient to prevent cross-contamination between samples.

Equipment Rinsate Blanks (2017): An EB was collected from the hand auger used for the follow-on delineation sampling at the conclusion of the 2017 CDVMP program. No OC Pesticides were detected on the EB collected from the hand auger.

8.5. Data Validation In accordance with the QAPP, data validation was completed on field and laboratory data (FS, 2015). The following subsection detail field and laboratory validation.

8.5.1. Field Data Validation The purpose of field data validation is to identify outliers (i.e., an observation that does not conform to the pattern established by other observations). Outliers may be the result of transcription errors or instrument breakdowns. Field data was reviewed by field team personnel at the time of collection and by the Field Operations Manager following the completion of the sampling program. Outliers were not identified in field data during validation and no action was required.

8.5.2. Laboratory Data Validation All laboratory analytical data was validated in accordance with EPA Stage 3 Data Validation as described in Guidance for Labeling Externally Validated Laboratory Analytical Data for Superfund Use, EPA-540-R- 08-005 (EPA, 2009). Stage 3 data validation consists of a verification and validation based on completeness and compliance checks of sample receipt conditions, sample results, instrument and batch QC, and recalculation of select sample and QC results. Data validation was conducted by the project Quality Assurance Officer. Data qualifiers were applied to analytical result where appropriate and validated analytical results are included in Appendix H. The complete data validation report is retained in project files and is available upon request.

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SVOC analytical data collected for was rejected (“R” qualified) due to a laboratory quality control infraction. The laboratory control sample (LCS), matrix-spike (MS), and matrix spike duplicate (MSD) associated with the samples were spiked with only 11 of the 72 target analytes. The sample results associated with the analytes not included in the LCS, MS, and MSD spike could not be evaluated for overall method bias or precision. Additionally, no historical data was available for the site for comparison. Based on professional judgment, sample results for the 61 missing target analytes were “R” qualified. Analytes that were evaluated in the batch and were not “R” qualified were: phenol, 2-chlorophenol, 1,4- dichlorobenzene, N-nitroso-di-n-propylamine, 1,2,4-trichlorobenzene, 4-chloro-3-methylphenol, acenaphthene, 4-nitrophenol, 2,4-dinitrotoluene, pentachlorophenol, and pyrene.

8.5.3. SVOC Resampling As a result of the “R” qualified data, select sites (including the Cattle Head site) were re-sampled for SVOC analysis in November 2015. In November 2015, a soil sample from the approximate location of 3PP657-SB01 was collected at a depth of 0 to 6 inches bgs. This sample location and depth corresponds with the maximum arsenic result at the site. SVOCs were not detected in soil sample 3PP657-SB01-0-6”. Analytical results for the resampling event are included in Appendix H.

One additional field duplicate sample was collected during the SVOC resampling event. One additional equipment blank was collected from the hand auger used for soil sample collection. SVOCs were not detected in the equipment blank.

8.6. Deviations from the Sampling and Analysis Plan During the implementation of the site investigation at the Cattle Head site, there were several deviations from the Site-Specific Sampling and Analysis Plan and/or the QAPP. Three (3) variances from the SAP and QAPP were reviewed and approved by the contractor Project Manager, Forest Service On-Site Coordinator, and the Field Operations Manager and were documented in the field logbook. The first variance was to reduce the minimum number of samples to be collected at each CDV site from a minimum of four (4) to 10% of the number of samples analyzed via XRF. The second field variance was to simplify the soil sample homogenization procedure prior to XRF analysis. A written field change request was completed for the approved changes. The completed field change request forms are included in Appendix K.

In addition to these documented changes, the vat water sample collected from the Cattle Head vat structure (3PP657-VW01) was submitted for dissolved arsenic only. The Site-specific SAP requires the collection of both total and dissolved samples for arsenic analysis. This deviation was the result of an error by the field sampling team.

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9. STREAMLINED RISK ASSESSMENT

Due to elevated levels of toxaphene in soil at the site, a streamlined risk assessment was developed to calculate potential risks to human and ecological receptors from this AOPC. A Streamlined Risk Assessment can be used to rapidly evaluate risks associated with potential removal actions at sites, and is consistent with EPA Guidance. The primary goal of the CDVMP is to protect recreating populations and Forest Service personnel from potential chronic exposure to chemicals that might remain at former CDV sites.

Low-Level and Principal waste screening levels were developed specifically for use in the CDVMP for arsenic in soils: however, there is no Low-Level and Principal waste screening level for toxpahene. This section therefore characterizes risks associated with toxaphene in soils at the Cattle Head CDV Site. The Risk Assessment (RA) includes an assessment of human health (Section 9.1) and ecological risks (section 9.2) for toxaphene in soils.

9.1. Human Health Risk Assessment A human health baseline risk assessment (HHRA) is an evaluation of cancer and non-cancer risks posed to humans by the release of hazardous substances, pollutants, and contaminants from a site without remediation. The approach for the HHRA for the Cattle Head CDV Site is based on EPA Region 4 HHRA guidance (EPA, 2018) and EPA’s Risk Assessment Guidance for Superfund (RAGS). RAGS is composed of six parts including EPA, 1989; EPA, 1991a; EPA, 1991b; EPA, 2001; EPA. 2004; EPA, 2009a and EPA, 2009b.

The components of the HHRA as depicted in the following subsections including:  Data Evaluation  Exposure Assessment  Toxicity Assessment  Risk Characterization

EPA recommends that the HHRA process be documented according to EPA RAGS Part D by the development of standard tables. These standard tables document the human health risk assessment process. These standard tables for the Cattle Head CDV Site are provided in Appendix L of this report. The scope of the Cattle Head CDV HHRA is limited to potential exposures for humans to toxaphene contamination in soils.

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9.1.1. Data Evaluation The first part of the HHRA process for Data Evaluation includes the selection of data suitable for use in the HHRA and the second part identifies Contaminants of Potential Concern.

9.1.1.1. Selection of Data for Use in the Risk Assessment In the case of this HHRA for the Cattle Head CDV Site data evaluation is limited to toxaphene in soils. Table 7 provides the results of the chemical analyses of toxaphene in soils from Site sampling activities as described in the SI report (BMT, 2018). Figure 10 shows the extent of toxaphene contamination in site soils.

Soil sample 3PP657-SB01-0-4” was not included in the data evaluation because this soil boring was collected from the same location as soil samples 3PP657-SB01-0-6” and homogenized.

Table 7. Toxaphene Concentrations in Soils Depth Toxaphene Location Date (inches) (mg/kg) 0-6 2,400 SB01 2015 0-12 0.410 SB03 2015 0-12 0.028 SB15 2017 0-12 0.200 SB12 2017 0-12 7.3 SB13 2017 0-12 100 SB14 2017 0-12 0.028 SB11 2017 0-12 0.360 SB16 2017 0-12 0.130 SB17 2017 0-12 2.5 SB18 2017 0-12 1.5 SB19 2017 12-24 5.2 SB13 2017 12-24 96 SB14 2017 12-24 3.4 SB18 2017

9.1.1.2. Selection of Contaminants of Potential Concern (COPCs) The occurrence, distribution and selection of COPCs in soils for the Cattle Head CDV Site is summarized in RAGS Part D Standard Table 2.1 (Appendix L). As previously described, the list of COPCs for the Cattle Head CDV Site is limited to toxaphene in soils. For each chemical detected in soil the maximum detected concentration is compared to the respective EPA Regional Screening Level (RSL) for Chemical Contaminants at Superfund Sites (November 2018) (EPA, 2018a) https://www.epa.gov/risk/regional- screening-levels-rsls. The RSLs used for comparison are chemical concentrations in residential soil

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Toxaphene is identified as a carcinogenic COPC in soils by the EPA; and no non-carcinogenic COPCs were identified for the Cattle Head CDV Site. Due to its nature and properties, toxaphene is a unique COPC, which requires some additional consideration. A summary description of toxaphene from the Agency for Toxic Substances and Disease Registry (ASTDR) is provided below:

Toxaphene is a manufactured pesticide comprising a complex mixture of hundreds of chlorinated terpenes. After DDT was banned from use in the United States in 1972, toxaphene became the most popular substitute. Control of pests on cotton crops was the principal use of toxaphene in the United States, although the pesticide was used to control a variety of insects on a range of crops and to eradicate undesirable fish species in some aquatic environments.

In November of 1982, EPA canceled the registration of toxaphene for most uses as a pesticide or pesticide ingredient. All registered uses of toxaphene mixtures in the United States and its territories were canceled in 1990. Toxaphene was widely released to the environment mainly as a result of its past use as an insecticide. Toxaphene has been transported over long distances in the atmosphere. The presence of toxaphene in surface waters of the Great Lakes has been attributed to aerial transport of the mixture from application sites in the southern United States.

Atmospheric toxaphene is transported back to soil and water surfaces by wet and dry deposition processes. Toxaphene strongly adsorbs to particles and is relatively immobile in soils. In water, toxaphene is strongly adsorbed to suspended particulates and sediments and is bioconcentrated by aquatic organisms to fairly high levels, with bioconcentration factors (BCFs) on the order of 4,200–60,000.

Toxaphene also appears to be biomagnified in aquatic food chains. The composition of technical toxaphene released to the environment has changed over time since toxaphene congeners degrade at different rates, resulting in what is commonly termed weathered toxaphene. Degradation proceeds mainly through dechlorination and dehydrochlorination resulting in a shift in composition toward lower chlorinated homologs. Presently, exposure to persistent toxaphene congeners and degradation products is the primary health concern for the general population. Toxaphene congeners that have been found to persist in fish, marine mammals, and human serum and breast milk include those

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identified as Parlars p-26, p-40/41, p-44, p-50, and p-62. Pooled results of studies that assessed levels of these congeners in human serum and/or breast milk indicate that p- 26, p-50, and p-62 comprise most of the total toxaphene body burden. The major source of exposure for the general population appears to be ingestion of low concentrations of persistent toxaphene congeners in food, particularly fish, and toxaphene-contaminated drinking water.

Subpopulations with increased potential for significant exposure to persistent toxaphene congeners include northern Native American groups that eat toxaphene-contaminated aquatic mammals, recreational or subsistence hunters in the southern United States that consume significant amounts of game animals (especially species like raccoons), and people who consume certain types of sport-caught fish (such as trout, salmon, herring, smelt, and walleye) from the Great Lakes. (ASTDR, 2014).

The ASTDR document provides some of the background on toxaphene’s history, and highlights some of the challenges of providing comprehensive risk assessments for the COPC. Each of the known 670 chemicals has different properties, including solubility in water, bioavailability, toxicity, and volatility. As toxaphene weathers within the environment, the more soluble and volatile fractions will be transported away, while the more organophilic and heavier portions will be retained in the soils. Toxaphene was primarily used in the 1960s and 1970s and was banned in the United States in 1990 and globally in 2001; therefore, all toxaphene encountered at CDV sites is expected to be highly weathered.

The human health and ecological uptake and toxicity assessments for toxaphene determined it is harmful to human health and the environment. Sources, including EPA’s Integrated Risk Information System (IRIS) database, have identified toxaphene as carcinogenic, though this designation has not yet been confirmed. It is assumed that different component chemicals may be carcinogenic or non-carcinogenic on an individual basis. Likewise, it is assumed that the toxicity values were developed using unweathered toxaphene, meaning that the toxicity and bioavailability of toxaphene at older sites may be significantly different than published values used in this HHRA. Though this HHRA is not able to assess the impacts of the weathering to toxaphene’s characteristics, it is noted that the most toxic fractions of mixtures (e.g. toxaphene, petroleum) are typically the more volatile and/or soluble fractions. The most volatile and/or soluble fractions will be (1) preferentially bound within organophilic substrates with high organic matter contents, (2) be preferentially transported from the location of contamination by dissolution into runoff, and/or (3) more quickly volatize into the environment and be lost from the site. Therefore, highly weathered toxaphene mixtures are more likely to have reduced toxicity compared to toxaphene mixtures as mixed and applied.”

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9.1.2. Exposure Assessment The exposure assessment estimates the magnitude, frequency, duration, and route of exposure for all potential human receptors. This process consists of two steps.  Identification of human health exposure scenarios; and  Quantifying exposures for each identified COPC for exposure medium for each exposure scenario.

9.1.2.1. Exposure Scenarios The Cattle Head CDV HHRA is limited to the most conservative exposure scenarios for human receptors. The exposure scenarios identified for human receptors include:  Potential Future Adult Residents exposed to toxaphene in soils via ingestion and dermal exposures.  Potential Future Child Residents exposed to toxaphene in soils via ingestion and dermal exposures.  Current and Future Outdoor Workers exposed to toxaphene in soils via ingestion and dermal exposures.

EPA HHRA guidance (RAGS; EPA, 1989) and EPA Region 4 guidance (EPA, 2018) require that a future residential exposure scenario be included with each risk assessment. The selection of HHRA exposure scenarios for the Cattle Head CDV Site is documented in RAGS Part D Standard Table 1 (Appendix L).

9.1.2.2. Exposure Point Concentrations (EPCs) EPA guidance identifies that the exposure term for HHRA should approximate a Reasonable Maximum Exposure (RME) as the 95% Upper Confidence Limit (UCL) of the arithmetic mean concentration of the COPC in an exposure medium (i.e. soil, groundwater, etc.). To assist in identification of the most appropriate RME UCL, EPA has developed ProUCL software. For each COPC identified in soils (in this case toxaphene only) at the Cattle Head CDV an Exposure Point Concentration (EPC) was calculated using EPA’s ProUCL v5.1 software (EPA, 2017). The ProUCL results are used to identify the most appropriate RME UCL for each toxaphene in soils in RAGS Part D Standard Table 3.1 in Appendix L. The ProUCL input and output files are included as Appendix M.

9.1.2.3. Calculation of Dermal and Ingestion Exposures to Toxaphene in Soils RAGS Part D Standard Table 4.1 (Appendix L) provides the parameters and equations used to quantify exposures for toxaphene in soils associated with dermal and ingestion exposures. Dermal and Ingestion exposure doses for toxaphene are reported in RAGs Part D Standard Tables 7.1, 7.2 and 7.3 (Appendix L) for future adult residents, future child residents and current/future outdoor site workers, respectively.

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9.1.3. Toxicity Assessment Toxicity assessment consists of two stages: hazard identification and dose-response assessment. Hazard identification evaluates if a COPC can cause a specific effect and if the adverse health effect occurs in humans. Hazard identification also evaluates the nature and strength of the evidence of causation. Dose- response assessment quantitatively evaluates toxicity information for the chemical to determine the relationship between the administered dose or concentration of the chemical and the incidence of an adverse effect in the exposed population. For non-carcinogens, the toxicity values, or reference doses (RfDs for oral and dermal exposures) are expressed in terms of a threshold value that is below which adverse effects are not expected to be observed. Toxicity values for carcinogens are known as cancer slope factors (CSFs) and are expressed in units of cancer incidence per unit dose of the chemical.

9.1.3.1. Non-Carcinogenic Contaminants RAGS Part D Standard Table 5.1 (Appendix L) is used to record the dermal and oral non-cancer toxicity data for each COPC used in an HHRA. RAGS Part D Standard Table 5.2 is used to record the inhalation non-cancer toxicity data for each COPC. For the Cattle Head CDV Site, RAGS Part D Standard Tables 5.1 and 5.2 are not used as there are no non-carcinogenic COPCs identified.

9.1.3.2. Carcinogenic Contaminants RAGS Part D Standard Table 6.1 (Appendix L) is used to record the dermal and oral cancer toxicity data used in the HHRA for toxaphene in soils. Table 6.1 provides cancer slope factors (CSFs) for oral and dermal exposures, oral adsorption efficiency for dermal exposures, and cancer weight of evidence for each soil COPC. RAGS Part D Standard Table 6.2 (Appendix L) provides CSFs and cancer weight of evidence for inhalation exposures. For the Cattle Head CDV Site, RAGS Part D Standard Table 6.2 is not used as inhalation exposures are not evaluated. The primary source of CSFs and weight of evidence classification of carcinogenic contaminants are obtained from EPA’s IRIS (https://www.epa.gov/iris). Secondary values that have been accepted by EPA are documented as part of the EPA RSLs (https://www.epa.gov/risk/regional-screening-levels-rsls) (EPA, 2018a).

9.1.4. Human Health Risk Characterization The final component of the HHRA is risk characterization. In this step, the exposure and toxicity assessments are integrated to produce a quantitative estimate of non-cancer hazards and cancer risks. Risks are calculated for individual COPCs. Risks are also calculated for overall risk assuming simultaneous exposures to all COPCs by a single receptor are additive.

9.1.4.1. Cancer Risks Carcinogenic risk is calculated as the product of the carcinogenic COPC specific CSF (from RAGS Part D Standard Tables 6.1 for oral and dermal exposures and 6.2 for inhalation exposures) and the calculated

CDVMP Site Investigation at the Cattle Head CDV, Ozark National Forest (Update) Page 36 Task Order No. AG-43ZP-D-15-0007 March 2019 intake (dose) for oral and dermal exposures or the estimated exposure concentration in are for inhalation exposures. Carcinogenic effects are expressed in terms of dimension-less numbers that represent the probability of a receptor (adult or child) developing cancer resulting from exposure to each COPC that is classified as a carcinogen. The estimated dose (or concentration for inhalation exposures) for each carcinogenic COPC is multiplied by the respective CSF to calculate the Incremental Lifetime Cancer Risk (ILCR) value. The expression is as follows:

ILCR = Intake (mg/kg-day or µg/cm3) × CSF (1/mg/kg-day or µg/cm3)

For simultaneous exposure to several carcinogens, the calculated ILCRs are summed within each pathway and then for all pathways to yield a total ILCR posed by the Site for each receptor. This approach represents the probability of developing a carcinogenic response, which is solely attributable to exposure to chemicals in excess of general background risk.

Based on the assumption that any exposure to a carcinogen poses some risk, zero risk is not achievable in a practical sense. To be protective of human health, EPA has specified that exposure to site-related carcinogens should be limited to result in an individual upper bound excess lifetime cancer risk not to exceed one in 10,000 or 1E-04. EPA has established the range from one in 10,000 (1E-04) to one in a million (1E-06) as the acceptable risk range. Cancer risks of one in a million or less are generally considered acceptable.

RAGS Part D Standard Tables 7.1, 7.2, and 7.3 (Appendix L) summarize the calculation of cancer risks for toxaphene in Cattle Head CDV Site surface soils. ILCR values for toxaphene are presented as well as a total ILCR across dermal, and ingestion exposure pathways in RAGS Part D Standard Table 9.1 for future adult residents, in Standard Table 9.2 for future child residents and Standard Table 9.3 for outdoor workers (Appendix L).

9.1.4.2. Non-Carcinogenic Risks RAGS Part D Standard Table 7 is also used to record risks associated to exposures to non-carcinogens. In the case of the Cattle Head CVP Site, no non-carcinogenic COPCs were retained for risk assessment and therefore non-carcinogenic risks are not assessed.

9.1.4.3. Radiological Risks RAGS Part D Standard Table 8 is used to record risks associated to exposures to radionuclides. In the case of the Cattle Head CVP Site, radionuclides are not found in surface soils and risks are not assessed.

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9.1.4.4. Human Health Risk Summary Table 8 provides an overall summary of the carcinogenic risks calculated for the selected scenarios; including future resident adults, future resident children and current/future outdoor site workers exposed to toxaphene in surface soils at the Cattle Head CDV Site via dermal contact and direct ingestion.

Risks associated with dermal absorption range from an ILCR of 2.4E-04 for outdoor workers to 5.4E-04 for the future resident child. These risk estimates are within the EPA’s acceptable cancer risk range of 1E- 04 to 1E-06. However, cancer risks associated with ingestion are above the EPA’s acceptable risks at ILCR values ranging from 7.1E-01 for the outdoor worker to 2.3E+00 for the future residential child exposure scenario (Table 8).

Table 8. Summary of HHRA Risk Characterization Results

ILCR ILCR Receptor Population Exposure Medium Total ILCR Dermal Absorption Ingestion Future Resident ‐ Adult Surface Soils 3.0E-04 7.1E-01 7.1E-01

Future Resident ‐ Child Surface Soils 5.4E-04 2.3E+00 2.3E+00

Current/Future - Worker Surface Soils 2.4E-04 5.7E-01 5.7E-01

Note: EPA Acceptable Carcinogenic Risk Range: 1E-04 to 1E-06.

9.2. Ecological Risk Assessment The ecological risk assessment (ERA) for the Cattle Head CDV is performed in accordance with national EPA guidance (EPA, 1997; 2001; 2005) and EPA Region 4 guidance (USEPA, 2018). The steps of the ecological risk assessment include the following:

 Problem Formulation  Ecological Exposure Assessment  Ecotoxicity Assessment  Ecological Risk Characterization

9.2.1. Problem Formulation Problem Formulation is the planning step of the ERA process that identifies the focus of the assessment including potential receptors, contaminated media, potential exposure pathways and toxicity endpoints that are the focus of the assessment. It is not possible to assess risks for all ecological species that may come into contact with contaminants in Site soils. The first step of the Problem Formulation process is to identify ecological COPCs and the second step is to identify the exposure pathways and endpoints that will be the focus of the ERA.

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9.2.1.1. Selection of Ecological COPCs The Ecological Screening Values (ESVs) used to identify COPCs for the Cattle Head CDV Site are identified from the EPA Region 4 Guidance for ERAs (EPA, 2018). For screening purposes, it is EPA Region 4 policy to use the ESVs as conservative values associated with a Hazard Quotient (HQ) of 1.0. The ESVs also are based on toxicological data that are associated with no observed adverse effect levels (NOAELs) for the test species.

For Toxaphene, EPA Region 4 ESVs are available for screening soils for potential risks to soil invertebrates, mammals and birds (EPA, 2018). These ESVs at 0.00015 mg/kg for soil invertebrates, 5.9 mg/kg for mammals and 4.1 mg/kg for birds are exceeded by the maximum detected concentration of Toxaphene in soils at the Cattle Head CDV Site of 2,400 mg/kg (Table 7 and Figure 10). Therefore, Toxaphene is selected as a COPC for ecological receptors in surface soil.

9.2.1.2. Identification of Ecological Exposure Scenarios It is not possible to assess risks for all ecological species that may come into contact with contaminants in site soils. Therefore, representative species of the mammalian and avian classes of organisms potentially exposed to soil contamination are selected for evaluation. EPA Region 4 guidance specifies that toxicity data be derived by a hierarchy (EPA, 2018). Toxicity data are not available for plants or soil invertebrates from the recommended sources for exposure to Toxaphene in soils. Therefore, these soil receptors are not selected for the assessment. The ecological exposure scenarios identified as the basis of the ERA for the Cattle Head CDV include the following:

 Exposure of mammalian omnivores to Toxaphene in soils and diet  Exposure of mammalian carnivores to Toxaphene in soils and diet  Exposure of avian omnivores to Toxaphene in soils and diet  Exposure of avian carnivores to Toxaphene in soils and diet

The following mammalian and avian representative species with data available from the Los Alamos Laboratory EcoRisk database (LANL, 2018) include the deer mouse (mammalian omnivore consuming 50% plants and 50% soil invertebrates), the gray fox (consuming 100% small mammals) and the robin (avian omnivore) and the American kestrel (avian carnivore).

9.2.2. Ecological Exposure Ecological receptors may be exposed to contaminants from soils as the result of the accumulation of contaminants in organisms that are part of their diet. They may also be exposed via incidental ingestion of the contaminated media. Exposure factors for wildlife are integrated with toxicity factors as described in Section 9.2.4.

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9.2.3. Toxicity Assessment As recommended by EPA Region 4 ERA Guidance (EPA, 2018) ecological toxicity values are identified from the Los Alamos Laboratory EcoRisk Database. This information is integrated as risk associated with soil concentrations as described in Section 9.2.4. Conservative toxicity values are based on no observed adverse effect concentrations (NOAELs) while less conservative toxicity values are based on observed adverse effect concentrations (LOAELs).

9.2.4. Ecological Risk Characterization Risks for ecological receptors are typically expressed as Hazard Quotients (HQs) for each representative species and COPC. The basic equation for calculation of Hazard Quotients (HQs) for wildlife ecological receptors is described as part of the Ecological Soil Screening Levels (Eco-SSLs) for Superfund (EPA, 2007) and is expressed as:

where:

HQj = Hazard quotient for contaminant (j) (unitless), Soilj = Concentration of contaminant (j) in soil (mg/kg dry weight), N = Number of different biota types in diet, Bij = Concentration of contaminant (j) in biota type (i) (mg/kg dry weight), Pi = Proportion of biota type (i) in diet, FIR = Food ingestion rate (kg food [dry weight]/ kg BW [wet weight] /day), AFij = Absorbed fraction of contaminant (j) from biota type (i) (for screening purposes set equal to 1), AFsj = Absorbed fraction of contaminant (j) from soil (s) (for screening purposes set equal to 1), TRVj = Toxicity reference value (mg/kg BW/day) Ps = Soil ingestion as proportion of diet, AUF = Area use factor (for screening purposes set equal to 1).

EPA Region 4 guidance (EPA, 2018) recommends the use of exposure and toxicity reference values (TRVs) from EcoSSL documents (if available) followed by the ECORISK database available from the Los Alamos National Laboratory (LANL, 2017). This database uses the same basic equation with conservative assumptions of absorbed fractions (AF) of 1 and AUF of 1. Options are available from the LANL ECORISK system to calculate safe soil concentrations of COPCs using no-observed effect level (NOAEL) TRVs and lowest-observed effect level (LOAEL) TRVs. The soil toxicity values for toxaphene in soils using the conservative exposure assumptions range from 7.8 mg/kg soil for the American robin 13,000 mg/kg soil for the gray fox (Table 9). The soil toxicity values for toxaphene using more realistic exposure assumptions of AF’s of 0.1 and an AUF of 0.25 (assumes the wildlife species spends 25% of the time foraging within the area of contamination). Using the more realistic exposure assumptions and a NOAEL TRV results in Toxaphene wildlife soil toxicity values ranging from 312 mg/kg soil to 520,000

CDVMP Site Investigation at the Cattle Head CDV, Ozark National Forest (Update) Page 40 Task Order No. AG-43ZP-D-15-0007 March 2019 mg/kg soil. The recommended soil concentration of toxaphene that would be protective of wildlife receptors is 312 mg/kg soil (i.e., the most conservative value within the range).

Table 9. Ecological Soil Toxicity Values for Toxaphene (mg/kg soil)

Conservative Realistic Exposure Exposure Assumptions Assumptions NOAEL LOAEL NOAEL LOAEL Receptor Class Representative Species TRV TRV TRV TRV Mammals Omnivore Deer Mouse 1.10E+01 1.10E+02 4.40E+02 4.40E+03 Carnivore Gray Fox 1.30E+03 1.30E+04 5.20E+04 5.20E+05 Birds Omnivore American robin 7.80E+00 7.80E+01 3.12E+02 3.12E+03 Carnivore American kestrel 5.50E+02 5.50E+03 2.20E+04 2.20E+05 Source: LANL, 2018. Search based on CAS RN for toxaphene of 8001-35-2. Searches based on only entering the chemical name "toxaphene" yield the wrong results.

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10. SUMMARY AND CONCLUSIONS

In August 2015, a Site Investigation (SI) was conducted at the Cattle Head site located in the Big Piney Ranger District of the Ozark National Forest, Pope County, Arkansas. The SI was initiated by completing a review of historical site documentation, desktop data collection, and a site reconnaissance. Based on the site-specific information collected, Areas of Potential Concern (AOPCs) were identified and a biased sampling program guided by real-time XRF analysis was implemented.

In November 2017, follow-on soil sampling was conducted at the Cattle Head site to delineate the extent of toxaphene contamination in soils that had been identified during the SI in 2015. The follow-on soil sampling was conducted as part of the 2017 CDVMP field effort.

The 2015 Site Investigation sampling program included the collection of surface and subsurface soil samples and vat water samples. Sample locations were selected based on identified AOPCs and were biased toward areas that had the greatest likelihood of being impacted by historical cattle dipping operations and/or the storage and disposal of pesticide solutions. The following is a summary of sampling results from the first phase of the Site Investigation sampling program:

 A total of nine (9) surface soil (0 to 6 inches) and nine (9) shallow subsurface soil samples (6 to 12 inches) were collected and analyzed for arsenic with a field portable XRF analyzer. Arsenic concentrations in soil ranged from 10.2 to 154 mg/kg with the maximum arsenic concentrations detected in soil samples from adjacent to the vat egress.

 Arsenic was not detected in surface or shallow subsurface soil at concentrations greater than the CDVMP-specific low-level threat screening criterion of 456 mg/kg. As a result, verification sampling was not completed at the Cattle Head site.

 The area adjacent to the vat egress was selected for the advancement of a subsurface soil boring (3PP657-SB01) and the collection of a groundwater sample. Refusal was encountered at 3 and 4 feet in 2 attempts to advance the borehole. A composite subsurface soil sample was collected from soil boring 3PP657-SB01 at 0 to 4’. Arsenic was detected via XRF analysis in the composite subsurface soil sample at a concentration of 53 mg/kg. The composite sample from the 0 to 4 foot interval was submitted for laboratory analysis of arsenic, lead, iron, and OC pesticides. Arsenic was detected at a concentration less than the CDVMP-specific low-level threat screening criterion. Iron and lead were detected at concentrations less than their respective RMLs.

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 The soil sample with the greatest arsenic XRF result and a subsurface soil sample (3PP657- SB01-0-6” and 3PP657-SB01-0-4’) were submitted for laboratory analysis of arsenic in leachate via SPLP. Additionally, a duplicate sample (3PP657-SB01-0-4’ DUP) was submitted for laboratory analysis of arsenic in leachate via SPLP. Arsenic was detected in the SPLP leachate sample 3PP657-SB01-0-6” at a concentration of 0.1 mg/L. Arsenic was detected in the subsurface soil SPLP leachate samples 3PP657-SB01-0-4’ and 3PP657-SB01-0-4’ DUP at concentrations of 0.17 and 0.19 mg/L, respectively.

 A correlation analysis and linear regression analysis was completed on XRF arsenic results and fixed laboratory analytical results to determine data usability. The correlation analysis and the regression analysis were completed using the Cattle Head CDV site data set and the data set from all seven (7) sites investigation during the 2015 CDV site investigation effort. The correlation and regression analysis concluded that both data sets has a strong linear relationship and that XRF data meets acceptance criteria for definitive level data and is usable for site management decisions.

 A groundwater sample was not collected from the Cattle Head CDV site due to the presence of bedrock above the water table.

 Standing water was observed in the vat structure and a vat water sample was collected from the Cattle Head CDV site. Dissolved arsenic was detected in the vat water sample at a concentration of 0.37 mg/L. The dissolved arsenic concentration in vat water was greater that the Safe Drinking Water Act (SDWA) maximum contaminant level (MCL) of 10 µg/L and the EPA Region 4 Removal Management Level (RML) for residential tap water of 5.2 µg/L. A total arsenic sample was not collected from the vat structure. The OC pesticides 4,4’-DDT, alpha-BHC, beta-BHC, endosulfan II, endrin, endrin aldehyde, and gamma-BHC (lindane) were detected in the vat water sample.

 Sediment was observed in the vat structure; however, a vat sediment sample was not collected due to the unconsolidated nature of the sediment material.

 Three (3) man-made ponds are located in the vicinity of the site. The nearest ponds are located approximately 550 feet northeast and southeast of the site. There are no clear conveyances from the site to the pond and no other surface water features were identified in the vicinity of the site. Surface water and sediment samples were not collected as part of the site investigation of the Cattle Head site.

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 The soil sample with the greatest arsenic XRF result and a subsurface soil sample (3PP657- SB01-0-6” and 3PP657-SB01-0-4’ respectively) were submitted for laboratory analysis of OC pesticides. Toxaphene was detected in the sample 3PP657-SB01-0-6” at a concentration of 2,400,000 µg/kg, and in 3PP657-SB01-0-4’ at a concentration of 69,000 µg/kg. The residential soil RML for toxaphene is 49,000 µg/kg.

 Follow-on sampling identified toxaphene in soils in seven (7) out of nine (9) soil borings. Toxaphene was detected at concentrations greater than the RML of 49,000 µg/kg in one (1) follow-on soil boring (3PP657-SB14), which is located 5 feet east of the vat egress. Follow-on soil sampling data combined with sampling data from the 2015 SI indicates that toxaphene is present in surficial soils at the Cattlehead site over an area of up to 300 square feet and is present at depths up to and greater than 24 in bgs. The total volume of soil with toxaphene concentrations exceeding EPA Region IV RMLs is estimated at twelve (12) to eighteen (18) cubic yards.

Arsenic was detected in soil at concentrations less than the CDVMP-specific low-level threat screening criterion of 456 mg/kg. As a result, verification sampling was not completed and the second phase of the site investigation program was not implemented at the Cattle Head site. The OC pesticide toxaphene was detected at concentrations greater than its residential RML in surface and subsurface soil samples. Additionally, several OC pesticides were detected in the vat water sample collected from the Cattle Head site.

An HHRA (Section 9.1) and an ecological risk screening (Section 9.2) were conducted to assess potential risks resulting from high levels of toxaphene in surficial soils at the Cattlehead Site. The HHRA identified unacceptable risks to future residential populations and site workers from dermal contact and incidental ingestion of soils at the site. For ecological risks, a conservative toxaphene soil concentration of 312 mg/kg was calculated as being protective of animal species such as small birds.

Conclusions Based on the results of the Site Investigation, arsenic is not present in Cattle Head site soil at concentrations greater than the CDVMP-specific low-level threat screening criterion of 456 mg/kg. Iron, lead, and SVOCs are not present in soil or vat sediment/sludge at concentrations greater than their respective EPA Region 4 residential RMLs.

Surface water, sediment, and groundwater samples were not collected at the Cattle Head site. Based on the location of the nearest surface water feature (a man-made pond) and the absence of conveyances from the Cattle Head site, further evaluation of surface water and sediment quality of the ponds located in

CDVMP Site Investigation at the Cattle Head CDV, Ozark National Forest (Update) Page 44 Task Order No. AG-43ZP-D-15-0007 March 2019 the vicinity of the Cattle Head site is not required. No other sensitive environments or ecological receptors were identified in the vicinity of the site.

The arsenic concentrations detected in leachate via SPLP (maximum of 0.19 mg/L) suggests that leachate from site soils has the potential to impact groundwater. As a result, further investigation of the soil to groundwater pathway was completed. Based on the observed decrease in arsenic concentrations with depth and the depth to the interface between unconsolidated soil and bedrock, it is not expected that leachate from site soils will impact groundwater.

Between 2015 and 2017, the OC pesticide toxaphene was detected in nine (9) soil borings. Toxaphene was detected at a maximum concentration of 2,400,000 µg/kg (2,400 mg/kg) immediately adjacent to the vat egress and at depths of up to four (4) feet bgs. It appears that the toxaphene exceedances are limited to approximately 200-400 square feet of ground immediately adjacent to the vat structure egress.

Unacceptable risks to human and ecological receptors were estimated based on high concentrations of toxaphene in surficial soils that were identified in 2015 and 2017. These risks will require remedial action to correct. Potential remedial actions include: soil immobilization, or soil removal. The limited horizontal extents of identified toxaphene contamination in soils would limit the scale of potential remedial options.

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11. REFERENCES

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Arkansas Geologic Survey, 2015. Physiographic Regions of Arkansas. Retrieved Online May 2015: Arkansas Geologic Survey, 2015: http://www.geology.ar.gov/education/ozark_plateaus.htm

ASTDR, 2014. Toxicological Profile for Toxaphene. October

Eisler, R. and J. Joacknow. 1985. Toxaphene Hazards to Fish, Wildlife and Invertebrates: A Synoptic Review. Biological Report 85(1.4) Contaminant Hazard Reviews. Report No. 4.

Environmental Data Resources, 2015. The EDR Geocheck Report for the Cattle Head site. May.

EPA. 1989. EPA Risk Assessment Guidance for Superfund (RAGs). Part A Volume 1; Human Health Evaluation Manual. EPA 540/1-89/002.

EPA, 1991a. A Guide to Principal Threat and Low Level Threat Wastes: Quick Reference Fact Sheet. November

EPA. 1991b. RAGS Part B Development of Risk-based Preliminary Remediation Goals, Interim EPA/540/R-92/003.

EPA. 1991c. RAGS Part C: Risk Evaluation of Remedial Alternatives. EPA/540/R-92/003

EPA. 1994. Role of the Ecological Risk Assessment in the Baseline Risk Assessment. Final. OSWER Directive #9285.7-17. http://www.epa.gov/oswer/riskassessment/ecou/pdf/v2no1.pdf

EPA. 1997. Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessments - Interim Final. OSWER Directive 9285.7-25 EPA/540/R-97/006. https://semspub.epa.gov/work/11/157941.pdf

EPA, 1999. Presumptive Remedy for Metals-in-Soils Sites: Quick Reference Guide. September.

EPA. 2001. RAGS Part D: Standardized Planning, Reporting, and Review of Superfund Risk Assessments.

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EPA. 2004. RAGS Part E: Supplemental Guidance for Dermal Risk Assessment EPA/540/R/99/005.

EPA, 2006. Innovative Technology Verification Report: XRF Technologies for Measuring Trace Elements in Soil and Sediment. EPA/540/R-06/003. February.

EPA, 2009. Guidance for Labeling Externally Validated Laboratory Analytical Data for Superfund Use. EPA-540-R-08-005. January.

EPA. 2014. Human Health Evaluation Manual, Supplemental Guidance: Update of Standard Default Exposure Factors. OSWER Directive 9200.1-120.EPA.

EPA. 2017. EPA’s ProUCL v5.1 software.

EPA. 2018. Region 4 Human Health Risk Assessment Supplemental Guidance. Scientific Support Section Superfund Division EPA Region 4. March 2018 Update.

EPA. 2018. EPA Regional Screening Levels (RSLs) for Chemical Contaminants at Superfund Sites (November 2018) https://www.epa.gov/risk/regional-screening-levels-rsls.

EPA. 2018. EPA Region 4 Ecological Risk Assessment Supplemental Guidance. Scientific Support Section Superfund Division EPA Region 4. March 2018 Update.

FS, 2015. Quality Assurance Program Plan for the Cattle Dip Vat Management Program. Final. May.

FS, 2015a. Site Specific Sampling and Analysis Plan, Field Screening and Focused Site Investigation for Seven Cattle Dip Vat Sites in the Ozark National Forest. Final. August.

FS, 2016. Forest Fact Sheet for the Ozark-St. Francis National Forests. Retrieved online February 2016: http://www.fs.usda.gov/detail/osfnf/about-forest/?cid=STELPRDB5211872

FS, 2017. Site Specific Sampling and Analysis Plan, Field Screening and Focused Site Investigation for Ten Cattle Dip Vat Sites in the Ozark National Forest. Final. October.

FS, 2017a. Site Health and Safety Plan for Ten Cattle Dip Vat Sites in the Ozark National Forest. Final. October.

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FS Region 8, 2015. Forest Service Region 8 Environmental Compliance and Protection (ECAP) Program CDV Maps. April.

Innov-X Systems, 2010. User Manual Delta™ Family: Handheld XRF Analyzer. June. Retrieved online February 2015: http://usenvironmental.com/download/manuals/Olympus%20- %20Delta%20User%20Manual.pdf

Kalnicky and Singhvi, 2001. Field portable XRF analysis of environmental samples. May

Kresse, T.M., Hays, P.D., Merriman, K.R., Gillip, J.A., Fugitt, D.T., Spellman, J.L., Nottmeier, A.M., Westerman, D.A., Blackstock, J.M., and Battreal, J.L., 2014. Aquifers of Arkansas—Protection, Management, and Hydrologic and Geochemical Characteristics of Groundwater Resources in Arkansas. U.S. Geological Survey Scientific Investigations Report 2014–5149. Retrieved online May 2015: http://dx.doi.org/10.3133/sir20145149

Los Alamos National Laboratory’s (LANL). 2017. ECORISK Database (Release 4.1), LA-UR-17-26476. LANL. Los Alamos, New Mexico. LANL 2017, 602538.

Natural Resource Conservation Service, 2016. Web Soil Survey National Cooperative Soil Survey Custom Soil Map for the Cattle Head site. March.

Pasquill, 2012. Arsenic and Old Bovine Lace - History of the Cattle Tick Eradication Program in the South. September.

USFWS, 2015. National Wetlands Inventory Map for the Cattle Head Vat. November.

USGS, 1993. 7.5 Minute Topographic Quadrangle Map, Dover Quadrangle. June.

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CATTLEHEAD FIGURES

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1402 àÁ 27 l p s C 25 l 30 28 ve 30 r u 29 ãÄ ra HOLLOW 1815 u 1802A G 25 àÁ C S S 25 Maupin Flat 1805A h le 27 29 26 al 1813 tt r 93237A 26 1805B ãÄ 27 y L i ãÄ Newton b MOCCASIN GAP B 1800A ãÄ àÁ 28 MOCCASIN 28 e a ãÄ Knob MULTI-USE TRAIL 30 te Waldo 29 B 34 GAP e 32 S 1813 M p 35 Russell 1800 a u 33 36 32 33 tn àÁ 31 r r D àÁ s 3PP522 34 Cem Tom 34 32 3PP618 r BM 1600 WAINSCOTT 31 y 31 36 1823 93237A 1814 35 ãÄ 36 1805 àÁ BOTTOMS PINEY àÁ 35 1310 32 33 àÁ 1807 h àÁ tn ãÄ 1816 t M àÁ WALDO MTN OVERLOOK 93706A àÁ r r n ow o C 4 r 1 5 M 4 Cr B 3 Hill C 1824 E 6 5 2 6 " àÁ ShermanN e l i 1813 LONG " m l 5 is 145 l 3 2 Illino 123 àÁ 6 Cem àÁ1328 Fk POOL 1816 A NM Strawberry 1 1804 4 1371 B Newton 2 C H «¬ àÁ 1 a àÁ d The 3 y e" 1800D 6 àÁ a " o o 4 w ãÄ t u 1813 m l 8 o Narrows J s ak e 1818 n e àÁ D s C s 5 M r n 9 9 r i W àÁ o 12 7 7 9 7 11 r 11 y u 10 8 àÁ1800 8 n M C 119 10 use t n C Ho 8 9 a 118 t 1800F H M M M 10 ck 1310 N r i 120 s ãÄ o o n an 12 R l NM Ev 1805 àÁ t NM àÁ 11 12 n r e Middle Mtn C l No t 16 13 l rth 17 t ARKANSAS vi Granny o i 15 Le H F 14 18 16 15 k L B Gap ap I 8 17 14 Cr r ranny G l Tater 13 G li 164 iney n P 14 13 18 o 16 «¬ Hill C 15 17 i r 17 16 s Hagarville 18 B ¤£ àÁ £ a 1310 71 19 20 ¤63 20 21 22 23 24 47 Walnut y T H o NM 14 1001C 1001A n o ! n 21 l u ( i 22 23 150 h n o Fayetteville ta ! 24 NM 20 t s ( r ãÄ ãÄ p un Ridge NM 19 e 19 E Mo e M 21 22 21 lony Kn b 23 24 20 Co o 1001 29 Bald àÁ 165 Ozark-St.ttle Francis National26 Forest i 28 27 28 Knob NM L ey 25 30 7 in "eC 29 26 n " Map Area 27 26 «¬ P i 29 «¬ 20 30 27 a C 28 is t Holman"e 55 167 25 NM o 25 n "eC lin u C M 30 Il e ¸¥¹ N " 24 28 o "C g 29 M "e "eC i M 3PP657 B N J Lutherville

a n C n Lit 33 o "e i tle (! c ps 34 35 " 32 23 32 k m 40 36 31 a 36 er s ho 33 t 34 og NM 173 22 T 35 o ¸¥¹ n o Fort Smith B Hol 32 33 36 M 32 n N ! M s u N ( 164 s Russellville 34 35 19 47 o u B 31 e"C31 33 m «¬ NM l NM M " u f ¤£ C 3 f 64 (! r Creek 23 23 y NM n M B N r lo Memphis a er Dardennell o ov k n St C e c e h Reservoir Cr 164 Ross C u 40 r «¬ Sub-Basin yo (! ¸¥¹ o is a le Scottsville o lino B tt R ¤£ Il Li 27 (HUC 8) os Little Rock 79 ke 359 359 s L d «¬ M Legend ee «¬ tn n «¬ Pleasant (! so M C C l o B Pin r "e i ProjectPiney Locations un Valley i ey ee W t Cre g Hot Springs k ain ek B NHD Sub-Basin (HUC 8) r ¤£70 (! Pine Bluff Watersheds Functioning at Risk Contaminant of Concern: National Forest Arsenic Map Extent «¬27 ¤£ CO Augsburg 333 71 CO ¤£ M 167 ¤£ Aug b «¬

Cattle Head

Figure 2: 7.5 Minute Topographic Map Cattle Head, Site No. 3PP657 Ozark National Forest, Pope County, Arkansas N35°28'31.54", W 93°3'23.21" 7.5 Minute Topographic Map Dover Quadrangle Scale: 1” = 1,850 feet Source: USGS, 1993

Ozark Highlands Ü Boston Mountains

Cattle Head

Arkansas Valley

Mississippi Alluvial Plain

View Area Ouachita Mountains Ozark Highlands Boston Mountains Mississippi Alluvial Plain Arkansas Valley

Ouachita Mountains South

Central South Central Plains Plains

Legend Tertiary Uplands Central Hills, Ridges, and Valleys Upper Boston Mountains Western Lowlands Holocene Meander Belts Floodplains and Low Terraces Fourche Mountains Lower Boston Mountains Western Lowlands Pleistocene Valley Trains Pleistocene Fluvial Terraces Western Ouachitas Springfield Plateau Arkansas/Ouachita River Holocene Meander Belts Cretaceous Dissected Uplands Scattered High Ridges and Mountains Dissected Springfield Plateau-Elk River Hills Arkansas/Ouachita River Backswamps Blackland Prairie Arkansas River Floodplain White River Hills Athens Plateau Arkansas Valley Hills Central Plateau Central Mountain Ranges Arkansas Valley Plains Grand Prairie Source: Arkasas Gis Office, http://gis.arkansas.gov/ Figure 3: Arkansas Physiographic Map Cattle Head Site Ozark National Forest 05 10 20 30 40 50 60 Site ID: 3PP657 Miles

Cattle Head Vat

Map Unit Symbol Map Unit Name 24 Mountainburg gravelly fine sandy loam, 8 to 12 percent slopes 29 Nella gravelly fine sandy loam, 3 to 8 percent slopes 31 Nella gravelly fine sandy loam, 12 to 20 percent slopes 35 Nella-Mountainburg association, rolling

Figure 4: Surficial Geology Map Cattle Head Ozark National Forest, Pope County, Arkansas Site Identification No. 3PP657 N35°28'32.40", W 93°3'23.68" Source: USDA Web Soil Survey (NRCS, 2016) Approximate Scale: 1” = 130 feet

Cattle Head

Figure 5: Subsurface Geology Map Cattle Head Site Ozark National Forest Site Identification No. 3PP657 N35° 28' 31.5" W93° 3' 23.2" Source: Geologic Map of Arkansas (USGS, 1993) Approximate Scale: 1” = 3.0 miles

Boring ID Depth XRF Result Boring ID Depth XRF Result Boring ID Depth XRF Result 0-6" 23.1 +/- 1.1 0-6" 45.4 +/- 1.1 0-6" 68.7 +/- 2 Boring ID Depth XRF Result SB07 SB08 SB06 0-6" 14.1 +/- 1.0 6-12" 14.8 +/- 1 6-12" 77 +/- 1.6 6-12" 61.7 +/- 1 SB03 6-12" 10.2 +/- 1.0 Lab Analytical Results (mg/kg) Arsenic 6-12" 11 Toxaphene 6-12" 0.410

Boring ID Depth XRF Result 0-6" 22.6 +/- 1.1 SB04 6-12" 12.7 +/- 1.1

Boring ID Depth XRF Result 0-6" 144 +/- 2.0 SB02 6-12" 112.2 +/- 1.8 Boring ID Depth XRF Result 0-6" 29.3 +/- 1 SB09 Boring ID Depth XRF Result 6-12" 18.3 +/- 1 0-6" 154 +/- 2 SB01 6-12" 142 +/- 2.0 Lab Analytical Results (mg/kg) Arsenic 0-6" 220 Toxaphene 0-6" 2,400 Boring ID Depth XRF Result SB01 0-4' 53 +/- 1.4 Lab Analytical Results (mg/kg) Arsenic 0-4' 81 Toxaphene 0-4' 69

Boring ID Depth XRF Result 0-6" 16.2 +/- 1 SB05 6-12" 13.2 +/- 1

SB14 SB11 SB03 Toxaphene (µg/kg) Toxaphene (µg/kg) Toxaphene (µg/kg) 0-12" 100,000 0-12" ND 6-12" 410 12-24" 96,000

SB12 Toxaphene (µg/kg) 0-12" 200

SB18 Toxaphene (µg/kg) 0-12" 2,500 12-24" 3,400 SB13 Toxaphene (µg/kg) 0-12" 7,300 12-24" 5,200

SB15 SB19 Toxaphene (µg/kg) Toxaphene (µg/kg) 0-12" ND 0-12" 1,500

SB16 SB01 SB17 Toxaphene (µg/kg) Toxaphene (µg/kg) Toxaphene (µg/kg) 0-12" 360 0-6" 2,400,000 0-12" 130 0-4' 69,000

APPENDIX A

Information Sheet on Program-Specific Soil Screening Levels

Attachment A ‐ Information Sheet on Program‐Specific Soil Screening Levels

The primary objective of the USDA FS Southern Region Cattle Dip Vat Management Program (CDVMP) is to remove any unacceptable risk to human health resulting from historic activities at over 120 CDV sites known to exist on U.S. Forest Service lands across the southeastern United States. Based on investigation of numerous other CDV sites, arsenic in soil is the primary concern, although presence of other pesticides that may have been used is also being evaluated. Where a removal action is needed, a secondary objective is to evaluate whether containment or treatment is indicated by the level of threat posed at the site. In order to achieve these objectives, the CDVMP incorporates two program‐specific screening levels. The following paragraphs explain how the screening levels were developed and will be used.

U.S. Environmental Protection Agency, Region 4 maintains a list of generic , risk‐based Removal Management Levels (RMLs) to help project managers decide when a removal action might be necessary. These generic RMLs are based on the methods used to calculate EPA's Regional Screening Levels. The generic list is published for both residential and industrial exposure scenarios using a 1 x 10‐4 risk level, the upper end of EPAs acceptable risk range. The CDVMP incorporates program‐specific, risk‐based soil screening levels that were calculated using EPA's Regional Screening Level calculator with a recreational exposure scenario. The program‐specific parameters input into EPA's calculator were based on the conservative assumption that recreators in all age groups would visit the abandoned cattle dip vat site once a week, for one hour, for 26 years. Although studies have shown that less than 25% of arsenic in soil ingested by animals (for the purpose of approximating bioavailability to humans) enters the bloodstream and is able to have an active effect on the body while the remaining 75% passes through the gastro‐intestinal tract remaining physiologically inert and is eliminated (EPA, Compilation and Review of Data on Relative Bioavailability of Arsenic in Soil, Dec 2012), the calculations were based on a very conservative assumption that bioavailability of the arsenic is 60%.

To achieve the primary and secondary objectives of the CDVMP, two screening levels were generated. First, to guide project management decisions on whether a removal action is necessary, a program‐ specific soil screening level of 456 mg/kg was calculated based on a x 10‐4 risk level, similar to EPA's RMLs. Then, a principal‐threat soil screening level of 4,560 mg/kg was calculated using a 10‐3 risk level as indicated by EPA's Presumptive Remedy for Metals‐In‐Soils sites (see Highlight 4 below). Details on these two calculations (input parameters and output levels) are included at the end of this information sheet. The lower level is used as a guide when deciding if a removal action is necessary to manage risk at the site and for triggering the second phase of investigation. The second, higher level is used as a guide when deciding if treatment vs. containment is necessary to mitigate the risk. The following two excerpts from EPA's Presumptive Remedy document help explain the remedy and how it is based on threat level. Reclamation of metals has been deleted from Highlight 1 as it is not a viable alternative for arsenic. Highlight 1 - The Metals-in-Soil Presumptive Remedy The presumptive remedy for principal threat metals-in-soil waste that is targeted for treatment is (see Highlight 4 for an explanation of principal threat wastes): Immobilization - Immobilization includes processes that change the physical or chemical properties that impact the leaching characteristics of a treated waste or decrease its bioavailability and concentration. This treatment locks metals within a solidified matrix (solidification) and/or converts the waste constituent into a more immobile form, usually by chemical reaction (stabilization). The process involves mixing a reagent (usually cement kiln dust, proprietary agents, cement, fly ash, blast furnace slag, bitumen) and generally solidifying the material with the contaminated soil. Reagents are selected based on soil characteristics and metal contaminants present. The treatment can be performed ex-situ or in-situ, and in either on- or off-site units. Immobilized materials generally are managed in a landfill with the associated containment barriers (e.g., caps). The presumptive remedy for low-level threat metals-in-soil waste that is not targeted for treatment is: Containment - Containment of metals-in-soil waste includes vertical or horizontal barriers. These remedial technologies can provide sustained isolation of contaminants and prevent mobilization of soluble compounds over long periods of time. They also reduce surface water infiltration, control odor and gas emissions, provide a stable surface over wastes, limit direct contact, and improve aesthetics. Institutional controls generally are used in conjunction with containment to further limit the potential for unintended access to the waste materials.

Highlight 4 - Description of Principal and Low-Level Threat Wastes Identification of principal threat and low-level threat wastes should occur, on a site-specific basis, when characterizing source materials. “Source material” is defined as material that includes or contains hazardous substances, pollutants, or contaminants that act as a reservoir for migration of contamination to ground water, surface water or air, or act as a source for direct exposure. Contaminated soil, sediments, and sludges can all be classified as source materials. Principal threat wastes are source materials considered to be highly toxic or highly mobile that generally cannot be reliably contained or would present a significant risk to human health or the environment should exposure occur. Examples include surface soil or subsurface soil containing high concentrations of contaminants of concern that are (or potentially are) mobile due to wind entrainment, volatilization, surface runoff, or sub-surface transport; and highly-toxic source material, such as soils containing significant concentrations of highly toxic materials. No “threshold level” of toxicity/risk has been established to equate to “principal threat.” However, where toxicity and

mobility of source material combine to pose a potential risk of 10-3 or greater, generally treatment alternatives should be evaluated. Low-level threat wastes generally include contaminated source material of low to moderate toxicity, such as surface soil containing contaminants of concern that generally are relatively immobile to air or ground water (i.e., non-liquid, low volatility, low leachability contaminants such as high molecular weight compounds) in the specific environmental setting; and low toxicity source material, such as soil and subsurface soil concentrations not greatly above reference dose levels or that present an excess cancer risk near the acceptable risk range. For more information, see A Guide to Principal Threat and Low Level Threat Wastes (9380.3-06FS, Nov. 1991). Site-specific 1 Recreator Equation Inputs for Soil

Variable Value TR (target cancer risk) unitless 1.0E-4 2 SArecsc (skin surface area - child) cm /day 2373 2 SArecsa (skin surface area - adult) cm /day 6032 2 SA0-2 (skin surface area - mutagenic) cm /day 2373 2 SA2-6 (skin surface area - mutagenic) cm /day 2373 2 SA6-16 (skin surface area - mutagenic) cm /day 6032 2 SA16-30 (skin surface area - mutagenic) cm /day 6032 2 SArecsa (skin surface area - adult) cm /day 6032 THQ (target hazard quotient) unitless 3 LT (lifetime - recreator) year 70

IFSrec-adj (age-adjusted soil ingestion factor) mg/kg 5460 DFSrec-adj (age-adjusted soil dermal factor) mg/kg 15360.8 IFSMrec-adj (mutagenic age-adjusted soil ingestion factor) mg/kg 24786.667 DFSMrec-adj (mutagenic age-adjusted soil dermal factor) mg/kg 63627.2 EF0-2 (exposure frequency) day/year 52 EF2-6 (exposure frequency) day/year 52 EF6-16 (exposure frequency) day/year 52 EF16-30 (exposure frequency) day/year 52 EFrecsc (exposure frequency - child) day/year 52 EFrecsa (exposure frequency - adult) day/year 52 EFrecsa (exposure frequency - adult) day/year 52 EFrecs (exposure frequency - recreator) day/year 52 IRS0-2 (soil intake rate) mg/day 200 IRS2-6 (soil intake rate) mg/day 200 IRS6-16 (soil intake rate) mg/day 100 IRS16-30 (soil intake rate) mg/day 100 IRSrecsc (soil intake rate - child) mg/day 200 IRSrecsa (soil intake rate - adult) mg/day 100

Output generated 09JUN2015:14:09:22 Site-specific 2 Recreator Equation Inputs for Soil

Variable Value

IRSrecsa (soil intake rate - adult) mg/day 100 ED0-2 (exposure duration) year 2 ED2-6 (exposure duration) year 4 ED6-16 (exposure duration) year 10 ED16-30 (exposure duration) year 10 EDrecsc (exposure duration - child) year 6 EDrecsa (exposure duration - adult) year 20 EDrecsa (exposure duration - adult) year 20 EDrecs (exposure duration - recreator) year 26 ET0-2 (exposure time) hr/day 1 ET2-6 (exposure time) hr/day 1 ET6-16 (exposure time) hr/day 1 ET16-30 (exposure time) hr/day 1 ETrecsc (exposure time - child) hr/day 1 ETrecsa (exposure time - adult) hr/day 1 ETrecsa (exposure time - adult) hr/day 1 ETrecs (exposure time - recreator) hr/day 1 BW0-2 (body weight) kg 15 BW2-6 (body weight) kg 15 BW6-16 (body weight) kg 80 BW16-30 (body weight) kg 80 BWrecsc (body weight - child) kg 15 BWrecsa (body weight - adult) kg 80 BWrecsa (body weight - adult) kg 80 2 AF0-2 (skin adherence factor) mg/cm 0.2 2 AF2-6 (skin adherence factor) mg/cm 0.2 2 AF6-16 (skin adherence factor) mg/cm 0.07 2 AF16-30 (skin adherence factor) mg/cm 0.07 2 AFrecsc (skin adherence factor - child) mg/cm 0.2

Output generated 09JUN2015:14:09:22 Site-specific 3 Recreator Equation Inputs for Soil

Variable Value 2 AFrecsa (skin adherence factor - adult) mg/cm 0.07 2 AFrecsa (skin adherence factor - adult) mg/cm 0.07 City (Climate Zone) PEF Selection Default

As (acres) PEF Selection 0.5 2 3 Q/Cwp (g/m -s per kg/m ) PEF Selection 93.77 3 PEF (particulate emission factor) m /kg 1359344438

A (PEF Dispersion Constant) 16.2302 B (PEF Dispersion Constant) 18.7762 C (PEF Dispersion Constant) 216.108 V (fraction of vegetative cover) unitless 0.5

Um (mean annual wind speed) m/s 4.69 Ut (equivalent threshold value) 11.32 F(x) (function dependant on Um/Ut) unitless 0.194 City (Climate Zone) VF Selection Default

As (acres) VF Selection 0.5 2 3 Q/Cwp (g/m -s per kg/m ) VF Selection 68.18 foc (fraction organic carbon in soil) g/g 0.006 3 ρb (dry soil bulk density) g/cm 1.5 3 ρs (soil particle density) g/cm 2.65

θw (water-filled soil porosity) L water/Lsoil 0.15 T (exposure interval) s 819936000 A (VF Dispersion Constant) 11.911 B (VF Dispersion Constant) 18.4385 C (VF Dispersion Constant) 209.7845

Output generated 09JUN2015:14:09:22 Site-specific 4 Recreator Screening Levels (RSL) for Soil ca=Cancer, nc=Noncancer, ca* (Where nc SL < 100 x ca SL), ca** (Where nc SL < 10 x ca SL), max=SL exceeds ceiling limit (see User's Guide), sat=SL exceeds csat, Smax=Soil SL exceeds ceiling limit and has been substituted with the max value (see User's Guide), Ssat=Soil inhalation SL exceeds csat and has been substituted with the csat

Ingestion Inhalation SF Unit Chronic Chronic Chronic Chronic CAS SFO Risk IUR RfD RfD RfC RfC -1 3 -1 3 Chemical Number Mutagen? VOC? (mg/kg-day) Ref (ug/m ) Ref (mg/kg-day) Ref (mg/m ) Ref

Arsenic, Inorganic 7440-38-2 No No 1.50E+00 I 4.30E-03 I 3.00E-04 I 1.50E-05 C

Soil Particulate Ingestion Dermal Inhalation Carcinogenic Volatilization Saturation Emission SL SL SL SL Factor Concentration Factor TR=1.0E-4 TR=1.0E-4 TR=1.0E-4 TR=1.0E-4 3 3 Chemical GIABS ABS RBA (m /kg) (mg/kg) (m /kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg)

Arsenic, Inorganic 1 0.03 0.6 - - 1.36E+09 5.20E+02 3.70E+03 1.43E+07 4.56E+02

Ingestion Dermal Inhalation Noncarcinogenic Ingestion Dermal Inhalation Noncarcinogenic SL SL SL SL SL SL SL SL Child Child Child Child Adult Adult Adult Adult Screening HQ=3 HQ=3 HQ=3 HI=3 HQ=3 HQ=3 HQ=3 HI=3 Level Chemical (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) Arsenic, Inorganic 7.90E+02 6.66E+03 1.03E+07 7.06E+02 8.42E+03 3.99E+04 1.03E+07 6.95E+03 4.56E+02 ca**

Output generated 09JUN2015:14:09:22 Site-specific 1 Recreator Equation Inputs for Soil

Variable Value TR (target cancer risk) unitless 1.0E-3 2 SArecsc (skin surface area - child) cm /day 2373 2 SArecsa (skin surface area - adult) cm /day 6032 2 SA0-2 (skin surface area - mutagenic) cm /day 2373 2 SA2-6 (skin surface area - mutagenic) cm /day 2373 2 SA6-16 (skin surface area - mutagenic) cm /day 6032 2 SA16-30 (skin surface area - mutagenic) cm /day 6032 2 SArecsa (skin surface area - adult) cm /day 6032 THQ (target hazard quotient) unitless 3 LT (lifetime - recreator) year 70

IFSrec-adj (age-adjusted soil ingestion factor) mg/kg 5460 DFSrec-adj (age-adjusted soil dermal factor) mg/kg 15360.8 IFSMrec-adj (mutagenic age-adjusted soil ingestion factor) mg/kg 24786.667 DFSMrec-adj (mutagenic age-adjusted soil dermal factor) mg/kg 63627.2 EF0-2 (exposure frequency) day/year 52 EF2-6 (exposure frequency) day/year 52 EF6-16 (exposure frequency) day/year 52 EF16-30 (exposure frequency) day/year 52 EFrecsc (exposure frequency - child) day/year 52 EFrecsa (exposure frequency - adult) day/year 52 EFrecsa (exposure frequency - adult) day/year 52 EFrecs (exposure frequency - recreator) day/year 52 IRS0-2 (soil intake rate) mg/day 200 IRS2-6 (soil intake rate) mg/day 200 IRS6-16 (soil intake rate) mg/day 100 IRS16-30 (soil intake rate) mg/day 100 IRSrecsc (soil intake rate - child) mg/day 200 IRSrecsa (soil intake rate - adult) mg/day 100

Output generated 09JUN2015:14:16:11 Site-specific 2 Recreator Equation Inputs for Soil

Variable Value

IRSrecsa (soil intake rate - adult) mg/day 100 ED0-2 (exposure duration) year 2 ED2-6 (exposure duration) year 4 ED6-16 (exposure duration) year 10 ED16-30 (exposure duration) year 10 EDrecsc (exposure duration - child) year 6 EDrecsa (exposure duration - adult) year 20 EDrecsa (exposure duration - adult) year 20 EDrecs (exposure duration - recreator) year 26 ET0-2 (exposure time) hr/day 1 ET2-6 (exposure time) hr/day 1 ET6-16 (exposure time) hr/day 1 ET16-30 (exposure time) hr/day 1 ETrecsc (exposure time - child) hr/day 1 ETrecsa (exposure time - adult) hr/day 1 ETrecsa (exposure time - adult) hr/day 1 ETrecs (exposure time - recreator) hr/day 1 BW0-2 (body weight) kg 15 BW2-6 (body weight) kg 15 BW6-16 (body weight) kg 80 BW16-30 (body weight) kg 80 BWrecsc (body weight - child) kg 15 BWrecsa (body weight - adult) kg 80 BWrecsa (body weight - adult) kg 80 2 AF0-2 (skin adherence factor) mg/cm 0.2 2 AF2-6 (skin adherence factor) mg/cm 0.2 2 AF6-16 (skin adherence factor) mg/cm 0.07 2 AF16-30 (skin adherence factor) mg/cm 0.07 2 AFrecsc (skin adherence factor - child) mg/cm 0.2

Output generated 09JUN2015:14:16:11 Site-specific 3 Recreator Equation Inputs for Soil

Variable Value 2 AFrecsa (skin adherence factor - adult) mg/cm 0.07 2 AFrecsa (skin adherence factor - adult) mg/cm 0.07 City (Climate Zone) PEF Selection Default

As (acres) PEF Selection 0.5 2 3 Q/Cwp (g/m -s per kg/m ) PEF Selection 93.77 3 PEF (particulate emission factor) m /kg 1359344438

A (PEF Dispersion Constant) 16.2302 B (PEF Dispersion Constant) 18.7762 C (PEF Dispersion Constant) 216.108 V (fraction of vegetative cover) unitless 0.5

Um (mean annual wind speed) m/s 4.69 Ut (equivalent threshold value) 11.32 F(x) (function dependant on Um/Ut) unitless 0.194 City (Climate Zone) VF Selection Default

As (acres) VF Selection 0.5 2 3 Q/Cwp (g/m -s per kg/m ) VF Selection 68.18 foc (fraction organic carbon in soil) g/g 0.006 3 ρb (dry soil bulk density) g/cm 1.5 3 ρs (soil particle density) g/cm 2.65

θw (water-filled soil porosity) L water/Lsoil 0.15 T (exposure interval) s 819936000 A (VF Dispersion Constant) 11.911 B (VF Dispersion Constant) 18.4385 C (VF Dispersion Constant) 209.7845

Output generated 09JUN2015:14:16:11 Site-specific 4 Recreator Screening Levels (RSL) for Soil ca=Cancer, nc=Noncancer, ca* (Where nc SL < 100 x ca SL), ca** (Where nc SL < 10 x ca SL), max=SL exceeds ceiling limit (see User's Guide), sat=SL exceeds csat, Smax=Soil SL exceeds ceiling limit and has been substituted with the max value (see User's Guide), Ssat=Soil inhalation SL exceeds csat and has been substituted with the csat

Ingestion Inhalation SF Unit Chronic Chronic Chronic Chronic CAS SFO Risk IUR RfD RfD RfC RfC -1 3 -1 3 Chemical Number Mutagen? VOC? (mg/kg-day) Ref (ug/m ) Ref (mg/kg-day) Ref (mg/m ) Ref

Arsenic, Inorganic 7440-38-2 No No 1.50E+00 I 4.30E-03 I 3.00E-04 I 1.50E-05 C

Soil Particulate Ingestion Dermal Inhalation Carcinogenic Volatilization Saturation Emission SL SL SL SL Factor Concentration Factor TR=1.0E-3 TR=1.0E-3 TR=1.0E-3 TR=1.0E-3 3 3 Chemical GIABS ABS RBA (m /kg) (mg/kg) (m /kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg)

Arsenic, Inorganic 1 0.03 0.6 - - 1.36E+09 5.20E+03 3.70E+04 1.43E+08 4.56E+03

Ingestion Dermal Inhalation Noncarcinogenic Ingestion Dermal Inhalation Noncarcinogenic SL SL SL SL SL SL SL SL Child Child Child Child Adult Adult Adult Adult Screening HQ=3 HQ=3 HQ=3 HI=3 HQ=3 HQ=3 HQ=3 HI=3 Level Chemical (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) Arsenic, Inorganic 7.90E+02 6.66E+03 1.03E+07 7.06E+02 8.42E+03 3.99E+04 1.03E+07 6.95E+03 7.06E+02 nc

Output generated 09JUN2015:14:16:11

APPENDIX B

CDVMP Site Investigation Flow Chart

CDV Management Program Site Investigation Flow Chart

Sampling and Analysis Plan Development: Desktop data collection Site Identification Site Inspection Previous investigations Historical aerial photograph Soil sample collection at six inch review intervals until two consecutive samples are below CDVMP specific low-level screening criterion of Identify AOPCs and 456 mg/kg. COPCs

Collect subsurface soil Conduct Abbreviated and groundwater Preliminary Assessment samples.

Collect surface and shallow subsurface soil samples for XRF and fixed laboratory analysis. Is vat structure Yes Evaluate the need to install present? permanent groundwater Collect Vat Water monitoring wells. and Vat Sediment Is a surface Samples No water feature Is arsenic present in vicinity No Further of CDV site? present at concentrations Yes greater than the CDVMP Action No specific low-level screening criterion of 456 mg/kg. No No Further Collect Surface Action Water and No Further Sediment Action Samples Yes

Confirmation Evaluation of Containment: Conduct Focused Site Sampling No Mobility Assessment Investigation Geotechnical Analysis

Yes

Is arsenic Is an area confirmed to present above the have arsenic Determine extent principal threat waste concentrations greater of arsenic in soil. than 456 mg/kg screening criterion of 4,560 mg/kg? Evaluation of Containment with S/I: Mobility Assessment Geotechnical Analysis Yes No Arsenic Speciation Analysis Treatability Study No Further Redox Potential Action

February 2016 Page 1

APPENDIX C

Select Site Photographs

Photograph 1 Cattle Head 3PP657

Ozark National Forest

35° 28' 31.5438"N 93° 3' 23.2128"W

7/29/2015 @ 15:50

Photographer: David Schanzle

Weather Conditions: ~70°F and sunny

Description: View of vat ingress from the east with wooden canopy.

Photograph 2 Cattle Head 3PP657

Ozark National Forest

35° 28' 31.5438"N 93° 3' 23.2128"W

7/29/2015 @ 15:55

Photographer: David Schanzle

Weather Conditions: ~70°F and sunny

Description: View of southern side of vat structure and canopy facing west.

1 of 3 Photograph 3 Cattle Head 3PP657

Ozark National Forest

35° 28' 31.5438"N 93° 3' 23.2128"W

8/29/2015 @ 12:40

Photographer: David Schanzle

Weather Conditions: ~70°F and partly cloudy

Description: XRF analysis of the homogenized soil samples.

Photograph 4 Cattle Head 3PP657

Ozark National Forest

35° 28' 31.5438"N 93° 3' 23.2128"W

8/29/2015 @ 14:16

Photographer: Doug Kmiotek

Weather Conditions: ~70°F and partly cloudy

Description: Pre-homogenized soil core sample.

2 of 3 Photograph 5 Cattle Head 3PP657

Ozark National Forest

35° 28' 31.5438"N 93° 3' 23.2128"W

8/29/2015 @ 15:00

Photographer: Doug Kmiotek

Weather Conditions: ~70°F and partly cloudy

Description: Advancement of the deep soil boring adjacent to vat structure using Geoprobe® direct push technology.

Photograph 6 Cattle Head 3PP657

Ozark National Forest

35° 28' 31.5438"N 93° 3' 23.2128"W

7/15/201 @ 13:07

Photographer: Forest Service

Weather Conditions: Unknown

Description: View of vat with standing water underneath vat canopy.

3 of 3

APPENDIX D

Sensitive Receptor Summary

ABBREVIATED PRELIMINARY ASSESSMENT - Sensitive Receptor Form Site Name: Cattle Head Site Identification No.: 3PP657 Site Location: 35° 28' 31.5438"N, 93° 3' 23.2128"W National Forest: Ozark National Forest Date: August 29, 2015

Residential Properties located within 1/4 mile of the site: There are no residential properties located within 1/4 mile of the site. The nearest residences are located approximately 0.5 miles to the northeast and 0.55 miles to the south-southeast.

Groundwater Withdrawal Wells located within 1/4 mile of the site: There are no known groundwater withdrawl wells located within 1/4 mile of the site. An environmental database search that included a search of the USGS well database, the Federal Reporting Database System for Public Water Systems, and the state well database indicated there were no groundwater withdrawl wells located within 1 mile of the site.

Schools and Daycare Centers located within 1/4 mile of the site: There are no schools or daycare centers located within 1/4 mile of the site.

Parks or recreation areas located within 1/4 mile of the site: This site is located within a national forest, which is designated as a recreational area.

Surface Water Bodies located within 1/4 mile of the site: There are three ponds located within 1/4 mile of the site, each pond is circular in shape and approximately 100-120 feet in diameter. One pond is located 550 feet southeast of the site, a second pond is located 550 feet northeast of the site and a third pond is located 1,150 feet southwest of the site. No other surface water features were identified within 1/4- mile of the site. The Illinois Bayou is located approximately 1 mile east of the site.

Ecological receptors identified within 1/4 mile of the site: The three ponds located in the vicnity of the site are identfified as a freshwater ponds by the USFWS in the NWI. These ponds are decribed as palustrine unconsolidated bottom ponds that are man made and permanently flooded. There are no wildlife refuges within 1/4 mile of the site. The following endangered species have been identified in the Ozark-St. Francis National Forest: Gray Bat, Indiana Bat, Ozark Big-Eared Bat, American Burying Beetle, Interior Least Tern, and the Fat Pocketbook Mussel. The following Threatened Species have been identified in the Ozark-St. Francis National Forest: Bald Eagle, Ozark Cavefish, Magazine Mtn. Shagreen (snail), Geocarpon (plant), American Alligator. There are no reported occurrences of threatened or endangered species at the site. Cattle Head Vat

Nov 12, 2015

This map is for general reference only. The US Fish and Wildlife Service is not responsible for the accuracy or currentness of the base data shown on this map. All wetlands related data should be used in accordance with the layer metadata found on the Wetlands Mapper web site. User Remarks:

APPENDIX E

Environmental Database Report

Cattle Head Liberty Hector, AR 72843

Inquiry Number: 4284895.1s May 05, 2015

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6 Armstrong Road, 4th floor Shelton, CT 06484 Toll Free: 800.352.0050 www.edrnet.com

FORM-NULL-CCA TABLE OF CONTENTS

SECTION PAGE

GEOCHECK ADDENDUM

Physical Setting Source Addendum A-1 Physical Setting Source Summary A-2 Physical Setting SSURGO Soil Map A-5 Physical Setting Source Map A-12 Physical Setting Source Map Findings A-13 Physical Setting Source Records Searched PSGR-1

Thank you for your business. Please contact EDR at 1-800-352-0050 with any questions or comments.

Disclaimer - Copyright and Trademark Notice This Report contains certain information obtained from a variety of public and other sources reasonably available to Environmental Data Resources, Inc. It cannot be concluded from this Report that coverage information for the target and surrounding properties does not exist from other sources. NO WARRANTY EXPRESSED OR IMPLIED, IS MADE WHATSOEVER IN CONNECTION WITH THIS REPORT. ENVIRONMENTAL DATA RESOURCES, INC. SPECIFICALLY DISCLAIMS THE MAKING OF ANY SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR PURPOSE. ALL RISK IS ASSUMED BY THE USER. IN NO EVENT SHALL ENVIRONMENTAL DATA RESOURCES, INC. BE LIABLE TO ANYONE, WHETHER ARISING OUT OF ERRORS OR OMISSIONS, NEGLIGENCE, ACCIDENT OR ANY OTHER CAUSE, FOR ANY LOSS OF DAMAGE, INCLUDING, WITHOUT LIMITATION, SPECIAL, INCIDENTAL, CONSEQUENTIAL, OR EXEMPLARY DAMAGES. ANY LIABILITY ON THE PART OF ENVIRONMENTAL DATA RESOURCES, INC. IS STRICTLY LIMITED TO A REFUND OF THE AMOUNT PAID FOR THIS REPORT. Purchaser accepts this Report "AS IS". Any analyses, estimates, ratings, environmental risk levels or risk codes provided in this Report are provided for illustrative purposes only, and are not intended to provide, nor should they be interpreted as providing any facts regarding, or prediction or forecast of, any environmental risk for any property. Only a Phase I Environmental Site Assessment performed by an environmental professional can provide information regarding the environmental risk for any property. Additionally, the information provided in this Report is not to be construed as legal advice. Copyright 2015 by Environmental Data Resources, Inc. All rights reserved. Reproduction in any media or format, in whole or in part, of any report or map of Environmental Data Resources, Inc., or its affiliates, is prohibited without prior written permission. EDR and its logos (including Sanborn and Sanborn Map) are trademarks of Environmental Data Resources, Inc. or its affiliates. All other trademarks used herein are the property of their respective owners.

TC4284895.1s Page 1 ® GEOCHECK - PHYSICAL SETTING SOURCE REPORT

TARGET PROPERTY ADDRESS

CATTLE HEAD LIBERTY HECTOR, AR 72843

TARGET PROPERTY COORDINATES

Latitude (North): 35.4754 - 35° 28’ 31.44’’ Longitude (West): 93.0564 - 93° 3’ 23.04’’ Universal Tranverse Mercator: Zone 15 UTM X (Meters): 494883.2 UTM Y (Meters): 3925567.8 Elevation: 596 ft. above sea level

USGS TOPOGRAPHIC MAP

Target Property Map: 35093-D1 DOVER, AR Most Recent Revision: 1993

EDR’s GeoCheck Physical Setting Source Addendum is provided to assist the environmental professional in forming an opinion about the impact of potential contaminant migration.

Assessment of the impact of contaminant migration generally has two principal investigative components:

1. Groundwater flow direction, and 2. Groundwater flow velocity.

Groundwater flow direction may be impacted by surface topography, hydrology, hydrogeology, characteristics of the soil, and nearby wells. Groundwater flow velocity is generally impacted by the nature of the geologic strata.

TC4284895.1s Page 1 ® GEOCHECK - PHYSICAL SETTING SOURCE SUMMARY

GROUNDWATER FLOW DIRECTION INFORMATION Groundwater flow direction for a particular site is best determined by a qualified environmental professional using site-specific well data. If such data is not reasonably ascertainable, it may be necessary to rely on other sources of information, such as surface topographic information, hydrologic information, hydrogeologic data collected on nearby properties, and regional groundwater flow information (from deep aquifers).

TOPOGRAPHIC INFORMATION Surface topography may be indicative of the direction of surficial groundwater flow. This information can be used to assist the environmental professional in forming an opinion about the impact of nearby contaminated properties or, should contamination exist on the target property, what downgradient sites might be impacted.

TARGET PROPERTY TOPOGRAPHY General Topographic Gradient: General West

SURROUNDING TOPOGRAPHY: ELEVATION PROFILES 842 797 728 720 711 694 672 658 651 612 604 596 579 576 514 476 468 462 461 Elevation (ft)

North South TP 736 687 670 638 629 619 619 618 617 615 605 596 586 584 558 545 522 473 471 Elevation (ft)

West East TP 0 1/2 1 Miles ✩Target Property Elevation: 596 ft.

Source: Topography has been determined from the USGS 7.5’ Digital Elevation Model and should be evaluated on a relative (not an absolute) basis. Relative elevation information between sites of close proximity should be field verified.

TC4284895.1s Page 2 ® GEOCHECK - PHYSICAL SETTING SOURCE SUMMARY

HYDROLOGIC INFORMATION Surface water can act as a hydrologic barrier to groundwater flow. Such hydrologic information can be used to assist the environmental professional in forming an opinion about the impact of nearby contaminated properties or, should contamination exist on the target property, what downgradient sites might be impacted.

Refer to the Physical Setting Source Map following this summary for hydrologic information (major waterways and bodies of water).

FEMA FLOOD ZONE FEMA Flood Target Property County Electronic Data POPE, AR YES - refer to the Overview Map and Detail Map

Flood Plain Panel at Target Property: 05115C - FEMA DFIRM Flood data

Additional Panels in search area: Not Reported

NATIONAL WETLAND INVENTORY NWI Electronic NWI Quad at Target Property Data Coverage NOT AVAILABLE YES - refer to the Overview Map and Detail Map

HYDROGEOLOGIC INFORMATION Hydrogeologic information obtained by installation of wells on a specific site can often be an indicator of groundwater flow direction in the immediate area. Such hydrogeologic information can be used to assist the environmental professional in forming an opinion about the impact of nearby contaminated properties or, should contamination exist on the target property, what downgradient sites might be impacted.

AQUIFLOW® Search Radius: 1.000 Mile.

EDR has developed the AQUIFLOW Information System to provide data on the general direction of groundwater flow at specific points. EDR has reviewed reports submitted by environmental professionals to regulatory authorities at select sites and has extracted the date of the report, groundwater flow direction as determined hydrogeologically, and the depth to water table.

LOCATION GENERAL DIRECTION MAP ID FROM TP GROUNDWATER FLOW Not Reported

TC4284895.1s Page 3 ® GEOCHECK - PHYSICAL SETTING SOURCE SUMMARY

GROUNDWATER FLOW VELOCITY INFORMATION Groundwater flow velocity information for a particular site is best determined by a qualified environmental professional using site specific geologic and soil strata data. If such data are not reasonably ascertainable, it may be necessary to rely on other sources of information, including geologic age identification, rock stratigraphic unit and soil characteristics data collected on nearby properties and regional soil information. In general, contaminant plumes move more quickly through sandy-gravelly types of soils than silty-clayey types of soils.

GEOLOGIC INFORMATION IN GENERAL AREA OF TARGET PROPERTY Geologic information can be used by the environmental professional in forming an opinion about the relative speed at which contaminant migration may be occurring.

ROCK STRATIGRAPHIC UNIT GEOLOGIC AGE IDENTIFICATION

Era: Paleozoic Category: Stratifed Sequence System: Pennsylvanian Series: Atokan and Morrowan Series Code: PP1 (decoded above as Era, System & Series)

Geologic Age and Rock Stratigraphic Unit Source: P.G. Schruben, R.E. Arndt and W.J. Bawiec, Geology of the Conterminous U.S. at 1:2,500,000 Scale - a digital representation of the 1974 P.B. King and H.M. Beikman Map, USGS Digital Data Series DDS - 11 (1994).

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EDR Inc.EDR Inc. ® GEOCHECK - PHYSICAL SETTING SOURCE SUMMARY

DOMINANT SOIL COMPOSITION IN GENERAL AREA OF TARGET PROPERTY

The U.S. Department of Agriculture’s (USDA) Soil Conservation Service (SCS) leads the National Cooperative Soil Survey (NCSS) and is responsible for collecting, storing, maintaining and distributing soil survey information for privately owned lands in the United States. A soil map in a soil survey is a representation of soil patterns in a landscape. The following information is based on Soil Conservation Service SSURGO data.

Soil Map ID: 1

Soil Component Name: Nella

Soil Surface Texture: gravelly loam

Hydrologic Group: Class B - Moderate infiltration rates. Deep and moderately deep, moderately well and well drained soils with moderately coarse textures.

Soil Drainage Class: Well drained

Hydric Status: Not hydric

Corrosion Potential - Uncoated Steel: Moderate

Depth to Bedrock Min: > 0 inches

Depth to Watertable Min: > 0 inches

Soil Layer Information Saturated Boundary Classification hydraulic Layer Upper Lower Soil Texture Class AASHTO Group Unified Soil conductivity Soil Reaction micro m/sec (pH)

1 9 inches 16 inches gravelly loam Silt-Clay COARSE-GRAINED Max: 42 Max: 5.5 Materials (more SOILS, Sands, Min: 14 Min: 4.5 than 35 pct. Sands with fines, passing No. Silty Sand. 200), Silty Soils. 2 16 inches 72 inches gravelly clay Silt-Clay COARSE-GRAINED Max: 14 Max: 5.5 loam Materials (more SOILS, Sands, Min: 4 Min: 4.5 than 35 pct. Sands with fines, passing No. Clayey sand. 200), Clayey Soils. 3 0 inches 9 inches gravelly fine Silt-Clay COARSE-GRAINED Max: 42 Max: 5.5 sandy loam Materials (more SOILS, Sands, Min: 14 Min: 4.5 than 35 pct. Sands with fines, passing No. Silty Sand. 200), Silty Soils.

TC4284895.1s Page 5 ® GEOCHECK - PHYSICAL SETTING SOURCE SUMMARY

Soil Map ID: 2

Soil Component Name: Nella

Soil Surface Texture: gravelly loam

Hydrologic Group: Class B - Moderate infiltration rates. Deep and moderately deep, moderately well and well drained soils with moderately coarse textures.

Soil Drainage Class: Well drained

Hydric Status: Not hydric

Corrosion Potential - Uncoated Steel: Moderate

Depth to Bedrock Min: > 0 inches

Depth to Watertable Min: > 0 inches

Soil Layer Information Saturated Boundary Classification hydraulic Layer Upper Lower Soil Texture Class AASHTO Group Unified Soil conductivity Soil Reaction micro m/sec (pH)

1 9 inches 16 inches gravelly loam Silt-Clay COARSE-GRAINED Max: 42 Max: 5.5 Materials (more SOILS, Sands, Min: 14 Min: 4.5 than 35 pct. Sands with fines, passing No. Silty Sand. 200), Silty Soils. 2 16 inches 72 inches gravelly clay Silt-Clay COARSE-GRAINED Max: 14 Max: 5.5 loam Materials (more SOILS, Sands, Min: 4 Min: 4.5 than 35 pct. Sands with fines, passing No. Clayey sand. 200), Clayey Soils. 3 0 inches 9 inches gravelly fine Silt-Clay COARSE-GRAINED Max: 42 Max: 5.5 sandy loam Materials (more SOILS, Sands, Min: 14 Min: 4.5 than 35 pct. Sands with fines, passing No. Silty Sand. 200), Silty Soils.

Soil Map ID: 3

Soil Component Name: Mountainburg

Soil Surface Texture: gravelly fine sandy loam

Hydrologic Group: Class D - Very slow infiltration rates. Soils are clayey, have a high water table, or are shallow to an impervious layer.

Soil Drainage Class: Well drained

TC4284895.1s Page 6 ® GEOCHECK - PHYSICAL SETTING SOURCE SUMMARY

Hydric Status: Not hydric

Corrosion Potential - Uncoated Steel: Low

Depth to Bedrock Min: > 38 inches

Depth to Watertable Min: > 0 inches

Soil Layer Information Saturated Boundary Classification hydraulic Layer Upper Lower Soil Texture Class AASHTO Group Unified Soil conductivity Soil Reaction micro m/sec (pH)

1 0 inches 1 inches gravelly fine Granular COARSE-GRAINED Max: 42 Max: 6 Min: sandy loam materials (35 SOILS, Sands, Min: 14 4.5 pct. or less Sands with fines, passing No. Silty Sand. 200), Silty, or Clayey Gravel and Sand. 2 1 inches 5 inches gravelly fine Granular COARSE-GRAINED Max: 42 Max: 6 Min: sandy loam materials (35 SOILS, Sands, Min: 14 4.5 pct. or less Sands with fines, passing No. Silty Sand. 200), Silty, or Clayey Gravel and Sand. 3 5 inches 14 inches very gravelly Granular COARSE-GRAINED Max: 42 Max: 5.5 loam materials (35 SOILS, Gravels, Min: 14 Min: 4.5 pct. or less Gravels with passing No. fines, Clayey 200), Silty, or Gravel Clayey Gravel and Sand. 4 14 inches 18 inches unweathered Not reported Not reported Max: 1.4 Max: Min: bedrock Min: 0.42

Soil Map ID: 4

Soil Component Name: Nella

Soil Surface Texture: gravelly loam

Hydrologic Group: Class B - Moderate infiltration rates. Deep and moderately deep, moderately well and well drained soils with moderately coarse textures.

Soil Drainage Class: Well drained

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Hydric Status: Not hydric

Corrosion Potential - Uncoated Steel: Moderate

Depth to Bedrock Min: > 38 inches

Depth to Watertable Min: > 0 inches

Soil Layer Information Saturated Boundary Classification hydraulic Layer Upper Lower Soil Texture Class AASHTO Group Unified Soil conductivity Soil Reaction micro m/sec (pH)

1 9 inches 16 inches gravelly loam Silt-Clay COARSE-GRAINED Max: 42 Max: 5.5 Materials (more SOILS, Sands, Min: 14 Min: 4.5 than 35 pct. Sands with fines, passing No. Silty Sand. 200), Silty Soils. 2 16 inches 72 inches gravelly clay Silt-Clay COARSE-GRAINED Max: 14 Max: 5.5 loam Materials (more SOILS, Sands, Min: 4 Min: 4.5 than 35 pct. Sands with fines, passing No. Clayey sand. 200), Clayey Soils. 3 0 inches 9 inches gravelly fine Silt-Clay COARSE-GRAINED Max: 42 Max: 5.5 sandy loam Materials (more SOILS, Sands, Min: 14 Min: 4.5 than 35 pct. Sands with fines, passing No. Silty Sand. 200), Silty Soils.

Soil Map ID: 5

Soil Component Name: Leadvale

Soil Surface Texture: silt loam

Hydrologic Group: Class C - Slow infiltration rates. Soils with layers impeding downward movement of water, or soils with moderately fine or fine textures.

Soil Drainage Class: Moderately well drained

Hydric Status: Partially hydric

Corrosion Potential - Uncoated Steel: Moderate

Depth to Bedrock Min: > 0 inches

Depth to Watertable Min: > 61 inches

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Soil Layer Information Saturated Boundary Classification hydraulic Layer Upper Lower Soil Texture Class AASHTO Group Unified Soil conductivity Soil Reaction micro m/sec (pH)

1 0 inches 5 inches silt loam Silt-Clay FINE-GRAINED Max: 14 Max: 5.5 Materials (more SOILS, Silts and Min: 4 Min: 4.5 than 35 pct. Clays (liquid passing No. limit less than 200), Silty 50%), Lean Clay. Soils. FINE-GRAINED SOILS, Silts and Clays (liquid limit less than 50%), silt. 2 5 inches 24 inches silty clay loam Silt-Clay FINE-GRAINED Max: 14 Max: 5.5 Materials (more SOILS, Silts and Min: 4 Min: 4.5 than 35 pct. Clays (liquid passing No. limit less than 200), Silty 50%), Lean Clay Soils. 3 24 inches 55 inches silty clay loam Silt-Clay FINE-GRAINED Max: 4 Max: 5.5 Materials (more SOILS, Silts and Min: 0.42 Min: 4.5 than 35 pct. Clays (liquid passing No. limit less than 200), Clayey 50%), Lean Clay Soils. 4 55 inches 72 inches silty clay loam Silt-Clay FINE-GRAINED Max: 4 Max: 5.5 Materials (more SOILS, Silts and Min: 0.42 Min: 4.5 than 35 pct. Clays (liquid passing No. limit less than 200), Clayey 50%), Lean Clay Soils.

Soil Map ID: 6

Soil Component Name: Linker

Soil Surface Texture: fine sandy loam

Hydrologic Group: Class B - Moderate infiltration rates. Deep and moderately deep, moderately well and well drained soils with moderately coarse textures.

Soil Drainage Class: Well drained

Hydric Status: Not hydric

Corrosion Potential - Uncoated Steel: Low

Depth to Bedrock Min: > 89 inches

Depth to Watertable Min: > 0 inches

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Soil Layer Information Saturated Boundary Classification hydraulic Layer Upper Lower Soil Texture Class AASHTO Group Unified Soil conductivity Soil Reaction micro m/sec (pH)

1 0 inches 5 inches fine sandy loam Silt-Clay COARSE-GRAINED Max: 14 Max: 5.5 Materials (more SOILS, Sands, Min: 4 Min: 3.6 than 35 pct. Sands with fines, passing No. Clayey sand. 200), Silty COARSE-GRAINED Soils. SOILS, Sands, Sands with fines, Silty Sand. 2 5 inches 9 inches loam Silt-Clay COARSE-GRAINED Max: 14 Max: 5.5 Materials (more SOILS, Sands, Min: 4 Min: 3.6 than 35 pct. Sands with fines, passing No. Clayey sand. 200), Clayey Soils. 3 9 inches 25 inches loam Silt-Clay COARSE-GRAINED Max: 14 Max: 5.5 Materials (more SOILS, Sands, Min: 4 Min: 3.6 than 35 pct. Sands with fines, passing No. Clayey sand. 200), Clayey Soils. 4 25 inches 35 inches gravelly fine Silt-Clay COARSE-GRAINED Max: 14 Max: 5.5 sandy loam Materials (more SOILS, Sands, Min: 4 Min: 3.6 than 35 pct. Sands with fines, passing No. Clayey sand. 200), Clayey Soils. 5 35 inches 37 inches unweathered Not reported Not reported Max: 1.4 Max: Min: bedrock Min: 0.42

LOCAL / REGIONAL WATER AGENCY RECORDS

EDR Local/Regional Water Agency records provide water well information to assist the environmental professional in assessing sources that may impact ground water flow direction, and in forming an opinion about the impact of contaminant migration on nearby drinking water wells.

WELL SEARCH DISTANCE INFORMATION

DATABASE SEARCH DISTANCE (miles) Federal USGS 1.000 Federal FRDS PWS 1.000 State Database 1.000

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FEDERAL USGS WELL INFORMATION LOCATION MAP ID WELL ID FROM TP No Wells Found

FEDERAL FRDS PUBLIC WATER SUPPLY SYSTEM INFORMATION LOCATION MAP ID WELL ID FROM TP No PWS System Found

Note: PWS System location is not always the same as well location.

STATE DATABASE WELL INFORMATION LOCATION MAP ID WELL ID FROM TP No Wells Found

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6 6 5 0 0 6 7 2 0 8 0 0 8 0 0 6 6 0 8 6 0 0 6 8 6 4 0 0 0 6 0 0 2 0 8 6 4 4 0 4 7 6 0 6 0 4 2

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6 6 0 6 8 0 6 0 0 0 6 4 0 560 6 0 4 0 0 0

5 8 5 6 5 6 4 4 2 0 0 0 7 06 0 0 6 2 5 0 0 2 0 6 680 5 6 6 6 6 8 0 4 0 4 0 0 0 0 0 6 0 4 6 0 6 5 5 2 0 0 4 8 6 5 2 0 5 6 0 0 0 0 2 0 4 5 6 0 8 4 0 8 0 5 0 6 6 2 0 5

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EDR Inc.EDR Inc. GEOCHECK ® - PHYSICAL SETTING SOURCE MAP FINDINGS RADON

AREA RADON INFORMATION

State Database: AR Radon

Radon Test Results

Total Meas Mean Geom mean Median Std Dev Max % Sites>4 pCi/L % Sites>20 pCi/L ______

57 1.3 0.7 0.7 1.7 78.3 0

Federal EPA Radon Zone for POPE County: 3 Note: Zone 1 indoor average level > 4 pCi/L. : Zone 2 indoor average level >= 2 pCi/L and <= 4 pCi/L. : Zone 3 indoor average level < 2 pCi/L.

Federal Area Radon Information for Zip Code: 72843 Number of sites tested: 3 Area Average Activity % <4 pCi/L % 4-20 pCi/L % >20 pCi/L

Living Area - 1st Floor 0.500 pCi/L 100% 0% 0% Living Area - 2nd Floor Not Reported Not Reported Not Reported Not Reported Basement Not Reported Not Reported Not Reported Not Reported

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TOPOGRAPHIC INFORMATION

USGS 7.5’ Digital Elevation Model (DEM) Source: United States Geologic Survey EDR acquired the USGS 7.5’ Digital Elevation Model in 2002 and updated it in 2006. The 7.5 minute DEM corresponds to the USGS 1:24,000- and 1:25,000-scale topographic quadrangle maps. The DEM provides elevation data with consistent elevation units and projection.

HYDROLOGIC INFORMATION

Flood Zone Data: This data, available in select counties across the country, was obtained by EDR in 2003 & 2011 from the Federal Emergency Management Agency (FEMA). Data depicts 100-year and 500-year flood zones as defined by FEMA.

NWI: National Wetlands Inventory. This data, available in select counties across the country, was obtained by EDR in 2002, 2005 and 2010 from the U.S. Fish and Wildlife Service.

State Wetlands Data: Wetlands, Swamps, or Marshes Source: Center for Advanced Spatial Technologies, University of Arkansas Telephone: 605-594-6933

HYDROGEOLOGIC INFORMATION

AQUIFLOW R Information System Source: EDR proprietary database of groundwater flow information EDR has developed the AQUIFLOW Information System (AIS) to provide data on the general direction of groundwater flow at specific points. EDR has reviewed reports submitted to regulatory authorities at select sites and has extracted the date of the report, hydrogeologically determined groundwater flow direction and depth to water table information.

GEOLOGIC INFORMATION

Geologic Age and Rock Stratigraphic Unit Source: P.G. Schruben, R.E. Arndt and W.J. Bawiec, Geology of the Conterminous U.S. at 1:2,500,000 Scale - A digital representation of the 1974 P.B. King and H.M. Beikman Map, USGS Digital Data Series DDS - 11 (1994).

STATSGO: State Soil Geographic Database Source: Department of Agriculture, Natural Resources Conservation Services The U.S. Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS) leads the national Conservation Soil Survey (NCSS) and is responsible for collecting, storing, maintaining and distributing soil survey information for privately owned lands in the United States. A soil map in a soil survey is a representation of soil patterns in a landscape. Soil maps for STATSGO are compiled by generalizing more detailed (SSURGO) soil survey maps.

SSURGO: Soil Survey Geographic Database Source: Department of Agriculture, Natural Resources Conservation Services (NRCS) Telephone: 800-672-5559 SSURGO is the most detailed level of mapping done by the Natural Resources Conservation Services, mapping scales generally range from 1:12,000 to 1:63,360. Field mapping methods using national standards are used to construct the soil maps in the Soil Survey Geographic (SSURGO) database. SSURGO digitizing duplicates the original soil survey maps. This level of mapping is designed for use by landowners, townships and county natural resource planning and management.

TC4284895.1s Page PSGR-1 PHYSICAL SETTING SOURCE RECORDS SEARCHED

LOCAL / REGIONAL WATER AGENCY RECORDS

FEDERAL WATER WELLS

PWS: Public Water Systems Source: EPA/Office of Drinking Water Telephone: 202-564-3750 Public Water System data from the Federal Reporting Data System. A PWS is any water system which provides water to at least 25 people for at least 60 days annually. PWSs provide water from wells, rivers and other sources.

PWS ENF: Public Water Systems Violation and Enforcement Data Source: EPA/Office of Drinking Water Telephone: 202-564-3750 Violation and Enforcement data for Public Water Systems from the Safe Drinking Water Information System (SDWIS) after August 1995. Prior to August 1995, the data came from the Federal Reporting Data System (FRDS).

USGS Water Wells: USGS National Water Inventory System (NWIS) This database contains descriptive information on sites where the USGS collects or has collected data on surface water and/or groundwater. The groundwater data includes information on wells, springs, and other sources of groundwater.

OTHER STATE DATABASE INFORMATION

RADON

State Database: AR Radon Source: Department of Health Telephone: 501-661-2301 Radon Test Results

Area Radon Information Source: USGS Telephone: 703-356-4020 The National Radon Database has been developed by the U.S. Environmental Protection Agency (USEPA) and is a compilation of the EPA/State Residential Radon Survey and the National Residential Radon Survey. The study covers the years 1986 - 1992. Where necessary data has been supplemented by information collected at private sources such as universities and research institutions.

EPA Radon Zones Source: EPA Telephone: 703-356-4020 Sections 307 & 309 of IRAA directed EPA to list and identify areas of U.S. with the potential for elevated indoor radon levels.

OTHER

Airport Landing Facilities: Private and public use landing facilities Source: Federal Aviation Administration, 800-457-6656

Epicenters: World earthquake epicenters, Richter 5 or greater Source: Department of Commerce, National Oceanic and Atmospheric Administration

Earthquake Fault Lines: The fault lines displayed on EDR’s Topographic map are digitized quaternary faultlines, prepared in 1975 by the United State Geological Survey

TC4284895.1s Page PSGR-2 PHYSICAL SETTING SOURCE RECORDS SEARCHED

STREET AND ADDRESS INFORMATION

© 2010 Tele Atlas North America, Inc. All rights reserved. This material is proprietary and the subject of copyright protection and other intellectual property rights owned by or licensed to Tele Atlas North America, Inc. The use of this material is subject to the terms of a license agreement. You will be held liable for any unauthorized copying or disclosure of this material.

TC4284895.1s Page PSGR-3

APPENDIX F

Historical Aerial Photographs

Ü

( Cattle Head

0 260 520 1,040 1,560 2,080 Coordinate System: GCS WGS 1984 Cattle Head Datum: WGS 1984 Feet Units: Degree

Cattle Head Legend Site Map (December 31, 1936) ( Cattle Head Site ID 3PP657 Big Piney Ranger District, Ozark National Forest Ü

( Cattle Head

0 260 520 1,040 1,560 2,080 Coordinate System: GCS WGS 1984 Cattle Head Datum: WGS 1984 Feet Units: Degree

Cattle Head Legend Site Map (October 11, 1941) ( Cattle Head Site ID 3PP657 Big Piney Ranger District, Ozark National Forest

APPENDIX G

Analytical Results Summary

Attachment G-1 Arsenic Data Summary Cattle Head Site (3PP657) Ozark National Forest

Arsenic XRF Result Fixed Laboratory Boring ID Depth (mg/kg) Analytical Results pH % Field Capacity % Moisture Result Error (mg/kg) 0-6" 154.0 (+/-) 2.0 220.0 SB01 6.9 25.0% 11.3% 6-12" 142.0 (+/-) 2.0 na 0-6" 144.0 (+/-) 2.0 na SB02 6.8 5.0% 2.3% 6-12" 112.2 (+/-) 1.8 na 0-6" 14.1 (+/-) 1.0 na SB03 6.95 5.0% 2.3% 6-12" 10.2 (+/-) 1.0 11.0 0-6" 22.6 (+/-) 1.1 na SB04 6.95 15.0% 6.8% 6-12" 12.7 (+/-) 1.1 na 0-6" 16.2 (+/-) 1.0 na SB05 6.95 15.0% 6.8% 6-12" 13.2 (+/-) 1.0 na 0-6" 68.7 (+/-) 1.8 na SB06 6.95 20.0% 9.0% 6-12" 61.7 (+/-) 1.4 na 0-6" 23.1 (+/-) 1.1 na SB07 6.9 20.0% 9.0% 6-12" 14.8 (+/-) 1.1 na 0-6" 45.4 (+/-) 1.1 na SB08 6.95 15.0% 6.8% 6-12" 77.2 (+/-) 1.6 na 0-6" 29.3 (+/-) 1.2 na SB09 6.95 20.0% 9.0% 6-12" 18.3 (+/-) 1.1 na SB01 0-4' 53.0 (+/-) 1.4 49.0 na na na SB01 DUP 0-4' 53.0 (+/-) 1.4 81.0 na na na

Notes: CDMVP-specific low-level threat waste screening criterion exceedances in bold. Soil moisture and pH measured using Kelway soil pH and moisture meter. na = not analyzed

Page 1 of 1

APPENDIX H

Complete Laboratory Analytical Results

Attachment H-1 Cattle Head Site (3PP657) Ozark National Forest Soil Metals and OC Pesticides Analytical Results *EPA Region **CDVMP Parameter Units 3PP657-SB01-0-4' 3PP657-SB01-0-4' DUP 3PP657-SB01-0-6" 3PP657-SB03-6-12" IV RML Screening Level METALS ARSENIC NA 456 mg/kg 49 81 220 11 ARSENIC SPLP NA NA mg/L 0.17 0.19 0.1 na IRON 55,000 NA mg/kg 37,000-D 41,000-D 38,000-D 19,000 LEAD 400 NA mg/kg 14-D 13-D 23-D 11 OC PESTICIDES 4,4'-DDD 230,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U 4,4'-DDE 200,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U 4,4'-DDT 37,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U-UJ ALDRIN 2,300 NA µg/kg 220U-D 220U-D 2400U-D 1.1U ALPHA-BHC 8,600 NA µg/kg 220U-D 220U-D 2400U-D 1.1U ALPHA-CHLORDANE 34,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U BETA-BHC 30,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U DELTA-BHC NA NA µg/kg 220U-D 220U-D 2400U-D 1.1U DIELDRIN 3,200 NA µg/kg 220U-D 220U-D 2400U-D 1.1U ENDOSULFAN I 470,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U ENDOSULFAN II NA NA µg/kg 220U-D 220U-D 2400U-D 1.1U ENDOSULFAN SULFATE 470,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U ENDRIN 19,000 NA µg/kg 270U-D 270U-D 2900U-D 1.3U ENDRIN ALDEHYDE 19,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U ENDRIN KETONE NA NA µg/kg 220U-D 220U-D 2400U-D 1.1U GAMMA-BHC (LINDANE) 21,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U GAMMA-CHLORDANE 34,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U HEPTACHLOR 13,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U HEPTACHLOR EPOXIDE 1,000 NA µg/kg 220U-D 220U-D 2400U-D 1.1U METHOXYCHLOR 320,000 NA µg/kg 890U-D 890U-D 9500U-D 4.4U-UJ TOXAPHENE 49,000 NA µg/kg 61,000-D 69,000-D 2,400,000-D 410

Notes Detections are shown in bold font. Screening Level Exceedances are shaded *EPA Region IV RML: EPA Region IV Excel Spreadsheet for a 10E-4 risk level for carcinogens and Hazard Quotient of 1 for non-carcinogens. July 2015. Residential Soil Screening Level used. **CDVMP Screening Level: Forest Service Cattle Dip Vat Management Program screening criterion for low-level threat waste ARSENIC SPLP: Synthetic Precipitaiton Leaching Procedure, EPA SW-846 Method 1312 NA = Not Applicable na - not analyzed

Laboratory Data Qualifiers (stand to the left of dash, or alone. e.g. "U-D" or "N") U. Parameter not detected above method detection limit.

Data Validation Qualifiers (stand to the right of dash. e.g., "N-J" or "-B") D. Result detected in sample with laboratory dilution. N. The analysis indicates the presence of an analyte for which there is presumptive evidence to make a “tentative identification" (Not applicable to inorganics). UJ. Not detected; quantitation limit is estimated.

Page 1 of 6 Attachment H-2 Cattle Head Site (3PP657) Ozark National Forest Soil SVOCs Analytical Results

Sampled Collected 08/29/2015 Sample Collected 11/18/2015 Parameter EPA Region IV RML Units 3PP657-SB01-0-6" 3PP657-SB01-0-6" 1,2,4-TRICHLOROBENZENE 58,000 µg/kg 120U 130U 1,2-DICHLOROBENZENE 1,800,000 µg/kg 120U-R 130U 1,3-DICHLOROBENZENE NA µg/kg 120U-R 130U 1,4-DICHLOROBENZENE 260,000 µg/kg 120U 130U 1-METHYLNAPHTHALENE 1,800,000 µg/kg 120U-R 130U 2,3,4,6-TETRACHLOROPHENOL 1,900,000 µg/kg 160U-R 170U 2,4,5-TRICHLOROPHENOL 6,300,000 µg/kg 120U-R 130U 2,4,6-TRICHLOROPHENOL 63,000 µg/kg 120U-R 130U 2,4-DICHLOROPHENOL 190,000 µg/kg 120U-R 130U 2,4-DIMETHYLPHENOL 1,300,000 µg/kg 120U-R 130U 2,4-DINITROPHENOL 130,000 µg/kg 180U-R 200U-UJ 2,4-DINITROTOLUENE 130,000 µg/kg 120U 130U 2,6-DINITROTOLUENE 19,000 µg/kg 120U-R 130U 2-CHLORONAPHTHALENE 4,800,000 µg/kg 120U-R 130U 2-CHLOROPHENOL 390,000 µg/kg 120U 130U 2-METHYLNAPHTHALENE 240,000 µg/kg 120U-R 130U 2-METHYLPHENOL NA µg/kg 120U-R 130U 2-NITROANILINE 630,000 µg/kg 120U-R 130U 2-NITROPHENOL NA µg/kg 120U-R 130U 3,3'-DICHLOROBENZIDINE 120,000 µg/kg 120U-R 130U 3+4-METHYLPHENOL 3,200,000 µg/kg 120U-R 130U 3-NITROANILINE NA µg/kg 120U-R 130U 4,6-DINITRO-2-METHYLPHENOL 5,100 µg/kg 290U-R 310U-UJ 4-BROMOPHENYL PHENYL ETHER NA µg/kg 120U-R 130U 4-CHLORO-3-METHYLPHENOL 6,300,000 µg/kg 120U 130U 4-CHLOROANILINE 250,000 µg/kg 120U-R 130U 4-CHLOROPHENYL PHENYL ETHER NA µg/kg 120U-R 130U 4-NITROANILINE 250,000 µg/kg 120U-R 130U 4-NITROPHENOL NA µg/kg 160U 170U ACENAPHTHENE 3,600,000 µg/kg 120U 130U ACENAPHTHYLENE NA µg/kg 120U-R 130U ANILINE 440,000 µg/kg 120U-R 130U ANTHRACENE 18,000,000 µg/kg 120U-R 130U AZOBENZENE 560,000 µg/kg 120U-R 130U BENZO(A)ANTHRACENE 16,000 µg/kg 120U-R 130U BENZO(A)PYRENE 1,600 µg/kg 120U-R 130U BENZO(B)FLUORANTHENE 16,000 µg/kg 120U-R 130U BENZO(G,H,I)PERYLENE NA µg/kg 120U-R 130U BENZO(K)FLUORANTHENE 160,000 µg/kg 120U-R 130U BENZOIC ACID 250,000,000 µg/kg 800U-R 870U-R BENZYL ALCOHOL 6,300,000 µg/kg 120U-R 130U BIS(2-CHLOROETHOXY)METHANE 190,000 µg/kg 120U-R 130U BIS(2-CHLOROETHYL)ETHER 23,000 µg/kg 120U-R 130U BIS(2-CHLOROISOPROPYL)ETHER 490,000 µg/kg 120U-R 130U BIS(2-ETHYLHEXYL)PHTHALATE 1,300,000 µg/kg 120U-R 130U BUTYL BENZYL PHTHALATE 1,300,000 µg/kg 120U-R 130U CARBAZOLE NA µg/kg 120U-R 130U CHRYSENE 1,600,000 µg/kg 120U-R 130U DIBENZO(A,H)ANTHRACENE 1,600 µg/kg 120U-R 130U DIBENZOFURAN 73,000 µg/kg 120U-R 130U DIETHYL PHTHALATE 51,000,000 µg/kg 120U-R 130U DIMETHYL PHTHALATE 7,800,000 µg/kg 120U-R 130U DI-N-BUTYL PHTHALATE 6,300,000 µg/kg 120U-R 130U DI-N-OCTYL PHTHALATE 630,000 µg/kg 120U-R 130U FLUORANTHENE 2,400,000 µg/kg 120U-R 130U FLUORENE 2,400,000 µg/kg 120U-R 130U HEXACHLOROBENZENE 21,000 µg/kg 120U-R 130U HEXACHLOROBUTADIENE 78,000 µg/kg 120U-R 130U HEXACHLOROCYCLOPENTADIENE 1,800 µg/kg 180U-R 200U HEXACHLOROETHANE 45,000 µg/kg 120U-R 130U INDENO(1,2,3-CD)PYRENE 16,000 µg/kg 120U-R 130U ISOPHORONE 13,000,000 µg/kg 120U-R 130U NAPHTHALENE 130,000 µg/kg 120U-R 130U NITROBENZENE 130,000 µg/kg 120U-R 130U-UJ N-NITROSODIMETHYLAMINE 200 µg/kg 120U-R 130U N-NITROSO-DI-N-PROPYLAMINE 7,800 µg/kg 120U 130U N-NITROSODIPHENYLAMINE 11,000,000 µg/kg 120U-R 130U PENTACHLOROPHENOL 100,000 µg/kg 240U 260U PHENANTHRENE NA µg/kg 120U-R 130U PHENOL 19,000,000 µg/kg 120U 130U PYRENE 1,800,000 µg/kg 120U 130U PYRIDINE 78,000 µg/kg 200U-R 220U

Notes Detections are shown in bold font. EPA Region IV RML: EPA Region IV Excel Spreadsheet for a 10E-4 risk level for carcinogens and Hazard Quotient of 1 for non-carcinogens. July 2015. Residential Soil Screening Level Used NA = Not Applicable

Laboratory Data Qualifiers (stand to the left of dash, or alone. e.g. "U-D" or "N") U. Parameter not detected above method detection limit.

Data Validation Qualifiers (stand to the right of dash. e.g., "N-J" or "-B") J. The analyte was positively identified, but the asociated numerical value is an estimated concentration. R. The samples results are rejected due to a laboratory quality control infraction. Rejected analytes were not included in the laboratory control sample, MS, or MSD. As a result, the results could not be evaluated for overall method bias or precision. UJ. Not detected; quantitation limit is estimated.

Page 2 of 6 Attachment H-3 Cattle Head Site (3PP657) Ozark National Forest Vat Water Arsenic and OC Pesticides Analytical Results

Parameter EPA Region IV RML Units 3PP657-VW01 METALS DISSOLVED ARSENIC 5.2 µg/L 370 OC PESTICIDES 4,4'-DDD 3.1 µg/L 0.16-UJ 4,4'-DDE 4.6 µg/L 0.061-UJ 4,4'-DDT 10 µg/L 0.19-N ALDRIN 0.092 µg/L 0.096-UJ ALPHA-BHC 0.71 µg/L 0.14-J ALPHA-CHLORDANE 1.3 µg/L 0.088-UJ BETA-BHC 2.5 µg/L 0.13-N DELTA-BHC NA µg/L 0.098-UJ DIELDRIN 0.17 µg/L 0.33-UJ ENDOSULFAN I 100 µg/L 0.031U-UJ ENDOSULFAN II 100 µg/L 0.31-J ENDOSULFAN SULFATE NA µg/L 0.031U-UJ ENDRIN 2.3 µg/L 0.21-J ENDRIN ALDEHYDE NA µg/L 0.13-N ENDRIN KETONE NA µg/L 0.031U-UJ GAMMA-BHC (LINDANE) 3.6 µg/L 0.21-J GAMMA-CHLORDANE 1.3 µg/L 0.031U-UJ HEPTACHLOR 0.14 µg/L 0.053-UJ HEPTACHLOR EPOXIDE 0.12 µg/L 0.031U-UJ METHOXYCHLOR 37 µg/L 0.031U-UJ TOXAPHENE 1.5 µg/L 0.77U-UJ

Notes EPA Region IV RML for Residential Tapwater, July 2015

NA = Not Applicable. No established EPA Region IV RML Value

Laboratory Data Qualifiers (stand to the left of dash, or alone. e.g. "U-D", or "N") J. Estimated concentration. U. Parameter not detected above method detection limit.

Data Validation Qualifiers (stand to the right of dash. e.g., "N-J" or "-B") J. Estimated concentration. N. The analysis indicates the presence of an analyte for which there is presumptive evidence to make a “tentative identification" (Not applicable to inorganics) UJ. Not detected; quantitation limit may be inaccurate or imprecise.

Page 3 of 6 Attachment H-4 Cattle Head Site (3PP657) Ozark National Forest Follow-on Soil Sampling Analytical Results

EPA Region IV Parameter Units 3PP657-SB11-0-12" 3PP657-SB12"-0-12"" 3PP657-SB13-0-12" RML 4,4'D µg/kg 5,700 1.1U 1.1U 6.6U 4,4'E µg/kg 70,000 1.1U 1.1U 6.6U 4,4'T µg/kg 110,000 1.1U-UJ 1.1U 6.6U ALDRIN µg/kg 3,900 1.1U 1.1U 6.6U ALPHA-BHC µg/kg 8,600 1.1U 1.1U 6.6U ALPHA-CHLORDANE µg/kg 100,000 1.1U 1.1U 6.6U BETA-BHC µg/kg 30,000 1.1U 1.1U 6.6U DELTA-BHC µg/kg 30,000 1.1U 1.1U 6.6U DIELDRIN µg/kg 3,400 1.1U 1.1U 6.6U ENDOSULFAN I µg/kg 1,400,000 1.1U 1.1U 6.6U ENDOSULFAN II µg/kg 1,400,000 1.8J 1.1U 6.6U ENDOSULFAN SULFATE µg/kg 1,400,000 1.1U 1.1U 6.6U ENDRIN µg/kg 57,000 1.1U 1.1U 6.6U ENDRIN ALDEHYDE µg/kg NA 1.1U 1.1U 6.6U ENDRIN KETONE µg/kg NA 1.1U 1.1U 6.6U GAMMA-BHC (LINDANE) µg/kg 57,000 1.1U 1.1U 41 GAMMA-CHLORDANE µg/kg 100,000 1.1U 1.1U 6.6U HEPTACHLOR µg/kg 13,000 1.1U 1.1U 6.6U HEPTACHLOR EPOXIDE µg/kg 3,100 1.1U 1.1U 6.6U METHOXYCHLOR µg/kg 950,000 8.6U-UJ 8.6U 50U TOXAPHENE µg/kg 49,000 28U 200 7,300

EPA Region IV Parameter Units 3PP657-SB13-12-24" 3PP657-SB14-0-12" 3PP657-SB14-12-24" RML 4,4'D µg/kg 5,700 3.3U 220U-UJ 76U-UJ 4,4'E µg/kg 70,000 3.3U 220U 76U-UJ 4,4'T µg/kg 110,000 3.3U 220U-UJ 76U-UJ ALDRIN µg/kg 3,900 3.3U 220U 76U-UJ ALPHA-BHC µg/kg 8,600 3.3U-UJ 220U 76U-UJ ALPHA-CHLORDANE µg/kg 100,000 3.3U-UJ 220U 76U-UJ BETA-BHC µg/kg 30,000 3.3U 220U 76U-UJ DELTA-BHC µg/kg 30,000 3.3U-UJ 220U 76U-UJ DIELDRIN µg/kg 3,400 3.3U-UJ 220U 76U-UJ ENDOSULFAN I µg/kg 1,400,000 3.3U-UJ 220U 76U-UJ ENDOSULFAN II µg/kg 1,400,000 3.3U-UJ 220U 76U-UJ ENDOSULFAN SULFATE µg/kg 1,400,000 3.3U-UJ 220U 76U-UJ ENDRIN µg/kg 57,000 3.3U 220U 76U-UJ ENDRIN ALDEHYDE µg/kg NA 3.3U-UJ 220U 76U-UJ ENDRIN KETONE µg/kg NA 3.3U-UJ 220U 76U-UJ GAMMA-BHC (LINDANE) µg/kg 57,000 21-J 220U 76U-UJ GAMMA-CHLORDANE µg/kg 100,000 3.3U-UJ 220U 76U-UJ HEPTACHLOR µg/kg 13,000 3.3U-UJ 220U 76U-UJ HEPTACHLOR EPOXIDE µg/kg 3,100 3.3U-UJ 220U 76U-UJ METHOXYCHLOR µg/kg 950,000 25U-UJ 1700U-UJ 580U-UJ TOXAPHENE µg/kg 49,000 5,200-J 100,000 96,000-J

Notes Detections are shown in bold font. Screening Level Exceedances are shaded *EPA Region IV RML: EPA Region IV Excel Spreadsheet for a 10E-4 risk level for carcinogens and Hazard Quotient of 1 for non-carcinogens. November 2017. Residential Soil Screening Level used.

Laboratory Data Qualifiers (stand to the left of dash, or alone. e.g., "U-D" or "N") J. Analyte present. Reported value may or may not be precise U. Parameter not detected above method detection limit.

Data Validation Qualifiers (stand to the right of dash. e.g., "N-J" or "-B") J. Analyte present. Reported value may or may not be precise UJ. Not detected; quantitation limit is estimated.

Page 4 of 6 Attachment H-4 Cattle Head Site (3PP657) Ozark National Forest Follow-on Soil Sampling Analytical Results

EPA Region IV Parameter Units 3PP657-SB15-0-12" 3PP657-SB15-0-12" DUP 3PP657-SB16-0-12" RML 4,4'D µg/kg 5,700 1.1U 1.1U 1.1U 4,4'E µg/kg 70,000 1.1U 1.1U 1.1U 4,4'T µg/kg 110,000 1.1U-UJ 1.1U-UJ 1.1U-UJ ALDRIN µg/kg 3,900 1.1U 1.1U 1.1U ALPHA-BHC µg/kg 8,600 1.1U 1.1U 1.1U ALPHA-CHLORDANE µg/kg 100,000 1.1U 1.1U 1.1U BETA-BHC µg/kg 30,000 1.1U 1.1U 1.1U DELTA-BHC µg/kg 30,000 1.1U 1.1U 1.1U DIELDRIN µg/kg 3,400 1.1U 1.1U 1.1U ENDOSULFAN I µg/kg 1,400,000 1.1U 1.1U 1.1U ENDOSULFAN II µg/kg 1,400,000 1.1U 1.1U 1.1U ENDOSULFAN SULFATE µg/kg 1,400,000 1.1U 1.1U 1.1U ENDRIN µg/kg 57,000 1.1U 1.1U 1.1U ENDRIN ALDEHYDE µg/kg NA 1.1U 1.1U 1.1U ENDRIN KETONE µg/kg NA 1.1U 1.1U 1.1U GAMMA-BHC (LINDANE) µg/kg 57,000 1.1U 1.1U 1.1U GAMMA-CHLORDANE µg/kg 100,000 1.1U 1.1U 1.1U HEPTACHLOR µg/kg 13,000 1.1U 1.1U 1.1U HEPTACHLOR EPOXIDE µg/kg 3,100 1.1U 1.1U 1.1U METHOXYCHLOR µg/kg 950,000 8.4U-UJ 8.3U-UJ 8.6U-UJ TOXAPHENE µg/kg 49,000 28U 27U 360-J

EPA Region IV Parameter Units 3PP657-SB17-0-12" 3PP657-SB18-0-12" 3PP657-SB18-12-24" RML 4,4'D µg/kg 5,700 1.1U 3.3U-UJ 3.5U-UJ 4,4'E µg/kg 70,000 1.1U 3.3U 3.5U-UJ 4,4'T µg/kg 110,000 1.1U-UJ 3.3U-UJ 3.5U-UJ ALDRIN µg/kg 3,900 1.1U 3.3U 3.5U-UJ ALPHA-BHC µg/kg 8,600 1.1U 3.3U 3.5U-UJ ALPHA-CHLORDANE µg/kg 100,000 1.1U 3.3U 3.5U-UJ BETA-BHC µg/kg 30,000 1.1U 3.3U 3.5U-UJ DELTA-BHC µg/kg 30,000 1.1U 3.3U 3.5U-UJ DIELDRIN µg/kg 3,400 1.1U 3.3U 3.5U-UJ ENDOSULFAN I µg/kg 1,400,000 1.1U 3.3U 3.5U-UJ ENDOSULFAN II µg/kg 1,400,000 1.1U 3.3U 3.5U-UJ ENDOSULFAN SULFATE µg/kg 1,400,000 1.1U 3.3U 3.5U-UJ ENDRIN µg/kg 57,000 1.1U 3.3U 3.5U-UJ ENDRIN ALDEHYDE µg/kg NA 1.1U 3.3U 3.5U-UJ ENDRIN KETONE µg/kg NA 1.1U 3.3U 3.5U-UJ GAMMA-BHC (LINDANE) µg/kg 57,000 1.1U 3.3U 3.5U-UJ GAMMA-CHLORDANE µg/kg 100,000 1.1U 3.3U 3.5U-UJ HEPTACHLOR µg/kg 13,000 1.1U 3.3U 3.5U-UJ HEPTACHLOR EPOXIDE µg/kg 3,100 1.1U 3.3U 3.5U-UJ METHOXYCHLOR µg/kg 950,000 8.4U-UJ 25U-UJ 26U-UJ TOXAPHENE µg/kg 49,000 130-J 2,500 3,400

Notes Detections are shown in bold font. Screening Level Exceedances are shaded *EPA Region IV RML: EPA Region IV Excel Spreadsheet for a 10E-4 risk level for carcinogens and Hazard Quotient of 1 for non-carcinogens. November 2017. Residential Soil Screening Level used.

Laboratory Data Qualifiers (stand to the left of dash, or alone. e.g., "U-D" or "N") J. Analyte present. Reported value may or may not be precise U. Parameter not detected above method detection limit.

Data Validation Qualifiers (stand to the right of dash. e.g., "N-J" or "-B") J. Analyte present. Reported value may or may not be precise UJ. Not detected; quantitation limit is estimated.

Page 5 of 6 Attachment H-4 Cattle Head Site (3PP657) Ozark National Forest Follow-on Soil Sampling Analytical Results

EPA Region IV Parameter Units 3PP657-SB19-0-12" RML 4,4'D µg/kg 5,700 1.1U 4,4'E µg/kg 70,000 1.1U 4,4'T µg/kg 110,000 1.1U-UJ ALDRIN µg/kg 3,900 1.1U ALPHA-BHC µg/kg 8,600 1.1U ALPHA-CHLORDANE µg/kg 100,000 1.1U BETA-BHC µg/kg 30,000 1.1U DELTA-BHC µg/kg 30,000 1.1U DIELDRIN µg/kg 3,400 1.1U ENDOSULFAN I µg/kg 1,400,000 1.1U ENDOSULFAN II µg/kg 1,400,000 1.1U ENDOSULFAN SULFATE µg/kg 1,400,000 1.1U ENDRIN µg/kg 57,000 1.1U ENDRIN ALDEHYDE µg/kg NA 1.1U ENDRIN KETONE µg/kg NA 1.1U GAMMA-BHC (LINDANE) µg/kg 57,000 1.1U GAMMA-CHLORDANE µg/kg 100,000 1.1U HEPTACHLOR µg/kg 13,000 1.1U HEPTACHLOR EPOXIDE µg/kg 3,100 1.1U METHOXYCHLOR µg/kg 950,000 8.6U-UJ TOXAPHENE µg/kg 49,000 1,500

Notes Detections are shown in bold font. Screening Level Exceedances are shaded *EPA Region IV RML: EPA Region IV Excel Spreadsheet for a 10E-4 risk level for carcinogens and Hazard Quotient of 1 for non-carcinogens. November 2017. Residential Soil Screening Level used.

Laboratory Data Qualifiers (stand to the left of dash, or alone. e.g., "U-D" or "N") J. Analyte present. Reported value may or may not be precise U. Parameter not detected above method detection limit.

Data Validation Qualifiers (stand to the right of dash. e.g., "N-J" or "-B") J. Analyte present. Reported value may or may not be precise UJ. Not detected; quantitation limit is estimated.

Page 6 of 6

APPENDIX I

Soil Boring Logs

APA - SUBSURFACE SOIL BORING LOG Site Name: Cattle Head Boring ID: SB01 Site Identification No.: 3PP657 Coordinates: 35.475671165, -93.056635362 National Forest: Ozark National Forest Date: 8/29/2015 Total Depth: 4' Drill Method: Direct Push Boring Diameter: 2.25" Drill Rig: Track-Mounted GeoProbe® 54DT Driller: David Schanzle Inspector: Doug Kmiotek Comments: Groundwater was not encountered before refusal. Two boring attempts were made at this location, one hit refusal at approximately 3' and the second hit refusal at 4'. Soil sample 3PP657-SB01-0-4' was collected at 14:55.

Depth Description ('bgs) (%) (ppm) USCS Lithology Recovery XRF Result 0-1.0': Dark brown silty medium to coarse sand with some medium to coarse shale gravel. Some rust colored fines with weathered shale. Roots and other organics. Dry.

2' SM 53±1.4 1.0-3.0': Light brown silty fine to medium sand with coarse shale gravel. Dry. 100%

3.0-3.5': Brown silty fine to medium sand with coarse shale gravel. Dry. 4' NA 3.5-4.0': Weathered shale. Dry Refusal at 4'

Soil Boring Litholgy (USCS):

GW SP OL

GP SM MH

GM SC CH

GC ML OH

SW CL Pt

Notes: 'bgs - feet below ground surface NA - Weathered bedrock SB - Soil Boring SM - Silty Sand USCS - Unified Soil Classification System XRF - X-Ray Fluorescence

Cattle Head - Ozark National Forest Page 1 of 1 CDVMP Site Investigation

APPENDIX J

XRF and Fixed Laboratory Analytical Results Correlation and Regression Analysis Summary

Attachment J XRF and Fixed Laboratory Analytical Results Correlation and Regression Analysis Summary Road 1815 Vat, Ozark National Forest, Arkansas

Table J-1 XRF and Fixed Laboratory Analysis Results and Correlation Analysis for the Cattle Head Site

Fixed Lab XRF Arsenic Sample Identification Arsenic Result Result (ppm) (ppm) 3PP657-SB01-0-4' 49 53 ± 1.4 3PP657-SB01-0-4' DUP 81 53 ± 1.4 3PP657-SB01-0-6" 220 154 ± 2 3PP657-SB03-6-12" 11 10.2 ± 1 Correlation Coefficient (R) 0.988

Table J-2 XRF and Fixed Laboratory Analysis Results and Correlation Analysis for All Site Data

Fixed Lab XRF Arsenic Sample Identification Arsenic Result Result (ppm) (ppm) 3JO460-SB01-0-4' 120 79.6 ± 1.6 3JO460-SB01-0-6" 220 195 ± 2 3JO460-SB01-0-6" DUP 210 195 ± 2 3JO460-SB05-0-6" 9.2 9.4 ± 1 3NW1181-SB02-6-12" 270 163 ± 2 3NW1181-SB06-0-6" 11 12.4 ± 1 3NW1181-SB09-0-4' 25 25.3 ± 1 3PP318-SB03-6-12" 85 91.5 ± 1.7 3PP318-SB05-0-6" 17 16.9 ± 1.2 3PP505-SB05-0-6" 89 69.3 ± 1.8 3PP505-SB06-6-12" 10 10.5 ± 1.3 3PP522-SB03-0-6" 110 96 ± 1.8 3PP522-SB08-0-6" 6.2 8.5 ± 0.9 3PP618-COMPOSITE-0-6" 220 256 ± 3 3PP618-COMPOSITE-6-12" 220 177 ± 2 3PP618-SB06-6-12" 1,100 843 ± 5 3PP618-SB06-6-12" DUP 1,100 843 ± 5 3PP618-SB08-0-6" 23 19.6 ± 1.2 3PP618-SB15-0-4' 52 53.2 ± 1.5 3PP657-SB01-0-4' 49 53 ± 1.4 3PP657-SB01-0-4' DUP 81 53 ± 1.4 3PP657-SB01-0-6" 220 154 ± 2 3PP657-SB03-6-12" 11 10.2 ± 1 Correlation Coefficient (R) 0.995

Page 1 of 3 Cattle Head (3PP657) Arsenic XRF vs. Fixed Laboratory Data - Linear Regression Analysis 180

160 y = 0.6624x + 7.7645 R² = 0.9769

140

120

100

80

60

40 Arsenic Concentration (ppm) via (ppm) via XRF Arsenic Concentration Analysis

20

0 0 50 100 150 200 250 Arsenic Concentration (ppm) via Fixed Laboratory Analysis

Cattle Head Linear (Cattle Head)

Page 2 of 3 Seven CDVMP Sites in the Ozark National Forest Arsenic XRF vs. Fixed Laboratory Data - Linear Regression Analysis 900 y = 0.7616x + 8.3043 R² = 0.9898 800

700

600

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200 Arsenic Concentration (ppm) via (ppm) via XRF Arsenic Concentration Analysis

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0 0 200 400 600 800 1,000 1,200 Arsenic Concentration (ppm) via Fixed Laboratory Analysis

All Site Data Linear (All Site Data)

Page 3 of 3

APPENDIX K

Field Change Request Forms

FIELD CHANGE REQUEST FORM: Reduction in the number of confirmation samples at the Indian Creek Site Contract No.: AG-43ZP-D-13-0020 Project Number: 3362 Page 1 of 1

Project Name: DIRPP/Cattle Di~ Vat Management Program Demonstration National Forest: Ozark National Forest Cattle Dip Vat Site: Indian Creek

Change Request Description of Change: The SAP specifies that a minimum of four (4) confirmation soil samples will be collected from each site. The field change is to collect confirmation samples at a frequency of 10%. The number of samples collected will be rounded up to the nearest whole number (e.g., if 16 XRF measurements are collected, 2 confirmation samples will be collected). If the number of confirmation samples is 2, one will be collected from each of the lower and upper range of concentrations measured; if only 1 confirmation sample is collected it will be taken from the highest concentration measured by XRF. Additional confirmation samples (up to 4) can be selected at the discretion of the field manager.

Reason for Change: The FS On-Site Coordinator and BMT Field Operations manager agreed that the minimum number of confirmation samples required for each site (4) was too great for the number of XRF measurements at the Indian Creek Site.

Impact on Present and Completed Work: The reduction in the number of confirmation samples does not affect the data quality at this site or other sites to be sampled as part of this program. Confirmation samples must be collected at minimum-) a freq~fi 10%/ to comply with the provisions of the QAPP. Requested by: . )!_// _u/ ..J,

On Site Coordinator Recommendation Recommended Disposition: Lisa Alcorn via email on 8/26/15- "I agree basically with your (field change) forms although there's a bit more needed on the sample reduction. I suggested, and Margueritte agrees, that 10% confirmation samples per site, is adequate. If this is 2, one each from lower and upper range of concentrations measured; if 1, taken from the highest concentration measured by XRF. Additional confirmation samples (up to 4) can be selected in the field at the discretion of the field manager. " Recommended by: ~7tt4&~ Date: 9/15/2015 (On Site Coordinator) Project Manager Approval Final Disposition: I agree with the field change described herein and do not anticipate that the change will adversely affect data quality.

Appro~IID'•ppro"" by ~ -r;~ Date: ,1/J;k- (Project Manager) FIELD CHANGE REQUEST FORM: Simplification of soil sample homogenization procedures

Contract No.: AG-43ZP-D-13-0020 Project Number: 3362 Page 1 of 1

Project Name: DIRPP/Cattle Di~ Vat Management Program Demonstration National Forest: Ozark National Forest Cattle Dip Vat Site: Indian Creek

Change Request Description of Change: The field cone and quartering procedure for the homogenization of soil samples prior to XRF analysis was simplified to: 1. Place the sample in the plastic bag 2. Flatten the samples and mix while rotating the bag 3. Break up clumps and remove rocks 4. Mix while rotating the bag

Reason for Change: The field cone and quartering procedure for the homogenization of soil samples prior to XRF analysis was determined to be Ineffective in homogenizing the sample prior to analysis. Additionally, it was observed to be very time consuming. The field change was implemented because of the ineffectiveness of the homogenization procedure and the potential for it resulting in project delays.

Impact on Present and Completed Work: The ineffectiveness of the planned homogenization may result in greater subsample heterogeneity and XRF results that are potentially less representative of actual arsenic concentrations in soil. The effects of sample and subsample heterogeneity are expected for the discrete sampling program being employed and this change will not significantly affect the data quality of XRF measurements. The reduced homogenization method was tested in the field and It was found that XRF measurements from different portions of tzmple (e.~ .• top and bottom) were similar. < . _ .

Requested by: ~.,., / D."" ,, t( Date: CJ 7/u AO/J (Field Personnel) On Site Coordinator Recommendation Recommended Disposition: Lia Alcorn via email on 8/26/15 -"Based on my experience yesterday and on discussions with Deana who is involved In the new revisions to 6200, I don't think our new method will be less effective (if visual inspection verifies appropriate dis-aggregation) than the cone and quarter method. It will be less effective than sieving etc ... but that is acceptable for our field screening context."

Recommended by: LUa. 71i A h14t- Date: 9/15/2015 (On Site Coordinator) Project Manager Approval Final Disposition: I agree with the field change described herein and do not anticipate that the change will adversely affect data quality. Approval/Disapproved by: ~ -(~ Date: (Project Ma ager) ~/s;ltr

APPENDIX L

HHRA RAGS D Tables

RAGS PART D TABLE 1 SELECTION OF HUMAN HEALTH EXPOSURE PATHWAYS CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Exposure Receptor Receptor On-Site/ Type of Medium Exposure Point Exposure Route Rationale for Selection or Exclusion of Exposure Pathway Timeframe Medium Population Age Off-Site Analysis

Outdoor Dermal Absorption On-site Quant Current/Future Surface Soil Surface Soil Surface Soil Adult Excavation of the land by current or possible future outdoor site workers. Worker Ingestion On-site Quant

Dermal Absorption On-site Quant This is the most conservative exposure scenario and is typically an EPA Adult Ingestion On-site Quant requirement for all human health risk assessments. The nearest residence from Future Surface Soil Surface Soil Surface Soil Resident the Cattle Head CDV Site is 0.5 miles and the Site is on Forest Service land. The Dermal Absorption On-site Quant land is unlikely to be used for future residential use. However, the pathway is Child Ingestion On-site Quant evaluated as a worst case. RAGS PART D TABLE 2 OCCURRENCE, DISTRIBUTION AND SELECTION OF CHEMICALS OF POTENTIAL CONCERN SURFACE SOILS CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timetable: Current/Future Medium: Surface Soils Exposure Medium: Surface Soils

Screening Value Location of Maximum Detected CAS RN Maximum Detected Frequency of Maximum > Parameter Units Concentration Comments COPC No. Concentration Detection Screening Value Conc1 C/N2

ORGANOCHLORINE PESTICIDES TOXAPHENE 8001-35-2 2.40E+03 mg/kg 3PP657-SB01-0-6" 12 of 14 4.9E-01 C yes TOXAPHENE

Notes 1 Screening Value for noncarcinogens (N) = U.S. EPA Regional Screening Level for Residential Soil multiplied by 0.10. Screening Value for carcinogens (C) = RSL for Residential Soil equal to 1E-06 risk. Units are mg/kg. United States Environmental Protection Agency (EPA). Regional Screening Levels for Chemical Contaminants at Superfund Sites. (November 2018). https://www.epa.gov/risk/regional‐screening‐levels‐rsls 2C = Carcinogen; N = Noncarcinogen COPC = Chemicals of Potential Concern kg = killograms mg = milligrams NA = Not Applicable Surface Soils are defined as 0 to 24 inches. RAGS PART D TABLE 3 EXPOSURE POINT CONCENTRATION (EPC) SUMMARY REASONABLE MAXIMUM EXPOSURE (RME) CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Medium: Surface Soils Exposure Medium: Surface Soils

Exposure Point Concentration (EPC) (ProUCL) Arithmetic Chemical of Potential Frequency of Mean of Maximum Detected Exposure Point Units Concern Detection Detected Concentration Recommended UCLa Distribution Statistic Values

Organochloride Pesticides Cattle Dip Vat Site Surface Soils Toxaphene mg/kg 12 of 14 2.18E+02 2.40E+03 1.89E+03 Lognormal 99% KM (Chebyshev) UCL

UCL = Upper 95% Confidence Limit of the arithmatic mean equals the EPC. EPCs are identified using ProUCL 5.1.00 Statistical Software.(https://www.epa.gov/land-research/proucl-software.) NA = Not applicable Surface soils are defined as 0 to 24 inches below ground surface. TABLE 4 VALUES USED FOR DAILY INTAKE CALCULATIONS REASONABLE MAXIMUM EXPOSURE CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Medium: Surface Soils Exposure Medium: Surface Soils

Exposure Route Receptor Population Receptor Age Exposure Point Parameter Parameter Definition Value Units Rationale/ Intake Equation/ Code Reference Model Name

Dermal Absorption Resident Adult Surface Soils Csoil Chemical Concentration in Surface Soils See Table 3 mg/kg Table 3 Dermally Absorbed Dose (DAD) (mg/kg-day) = EV Event Frequency 1 Events/day EPA, 2001 DA-event x EV x ED x EF x SA x 1/BW x 1/AT ED Exposure Duration 20 years EPA, 2014 where DA-Event (mg/cm2-event) = EF Exposure Frequency 350 days/year EPA, 2014 2 SA Skin Surface Area 6,032 cm EPA, 2014 DA-event = Csoil x CF x AF x ABSd BW Body Weight 80 kg EPA, 2014 AF Adherence factor of soil to skin 0.07 mg/cm2-event EPA, 2014 AT-C = 365 days per year X 70 year lifetime CF Conversion Factor 10-6 kg/mg - - AT-N = 365 days per year X ED (years) LF Lifetime 70 years EPA, 2014 AT-C Averaging Time - Cancer 25,550 days EPA, 2014 AT-N Averaging Time - Non-Cancer 7,300 days EPA, 2014

Child Surface Soils Csoil Chemical Concentration in Surface Soils See Table 3 mg/kg See Table 3 Dermally Absorbed Dose (DAD) (mg/kg-day) = EV Event Frequency 1 Events/day EPA, 2001 DA-event x EV x ED x EF x SA x 1/BW x 1/AT ED Exposure Duration 6 years EPA, 2014 where DA-Event (mg/cm2-event) = EF Exposure Frequency 350 days/year EPA, 2014 2 SA Skin Surface Area 2,373 cm EPA, 2014 DA-event = Csoil x CF x AF x ABSd BW Body Weight 15 kg EPA, 2014 AF Adherence factor of soil to skin 0.20 mg/cm2-event EPA, 2014 AT-C = 365 days per year X 70 year lifetime CF Conversion Factor 10-6 kg/mg EPA, 2014 AT-N = 365 days per year X ED (years) LF Lifetime 15 years EPA, 2014 AT-C Averaging Time - Cancer 25,550 days EPA, 2014 AT-N Averaging Time - Non-Cancer 2,190 days EPA, 2014

Ingestion Resident Adult Surface Soils Csoil Chemical Concentration in Surface Soils See Table 3 mg/kg See Table 3

IRsoil Ingestion Rate of Soil 100 mg/day EPA, 2014 Chronic Daily Intake (CDI) (mg/kg-day)=

EF Exposure Frequency 350 days/year EPA, 1991 Csoil x IRsoil x EF x ED x 1/BW x 1/AT ED Exposure Duration 20 years EPA, 2014 BW Body Weight 80 kg EPA, 2014 AT-C = 365 days per year X 70 year lifetime AT-C Averaging Time - Cancer 25,550 days EPA, 2014 AT-N = 365 days per year X ED (years) AT-N Averaging Time - Non-Cancer 7,300 days EPA, 2014

Child Surface Soils Csoil Chemical Concentration in Surface Soils See Table 3 mg/kg Table 3 Chronic Daily Intake (CDI) (mg/kg-day)= IR soil Ingestion Rate of Soil 200 mg/day EPA, 2014 Csoil x IRsoil x EF x CF x ED x 1/BW x 1/AT EF Exposure Frequency 350 days/year EPA, 2014

CF Conversion Factor 0.001 kgsoil/mgsoil EPA, 1989 ED Exposure Duration 6 years EPA, 1991 AT-C = 365 days per year X 70 year lifetime BW Body Weight 15 kg EPA, 1991 AT-N = 365 days per year X ED (years) AT-C Averaging Time - Cancer 25,550 days EPA, 2014 AT-N Averaging Time - Non-Cancer 2,190 days EPA, 2014 TABLE 4 VALUES USED FOR DAILY INTAKE CALCULATIONS REASONABLE MAXIMUM EXPOSURE CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Medium: Surface Soils Exposure Medium: Surface Soils

Exposure Route Receptor Population Receptor Age Exposure Point Parameter Parameter Definition Value Units Rationale/ Intake Equation/ Code Reference Model Name

Ingestion Outdoor Site Worker Adult Surface Soils Csoil Chemical Concentration in Surface Soils See Table 3 mg/kg See Table 3

IRsoil Ingestion Rate of Soil 100 mg/day EPA, 2014 Chronic Daily Intake (CDI) (mg/kg-day)=

EF Exposure Frequency 225 days/year EPA, 1991 Csoil x IRsoil x EF x CF x ED x 1/BW x 1/AT ED Exposure Duration 25 years EPA, 2014

CF Conversion Factor 0.001 kgsoil/mgsoil EPA, 1989 BW Body Weight 80 kg EPA, 2014 AT-C = 365 days per year X 70 year lifetime AT-C Averaging Time - Cancer 25,550 days EPA, 2014 AT-N = 365 days per year X ED (years) AT-N Averaging Time - Non-Cancer 7,300 days EPA, 2014

Dermal Absorption Outdoor Site Worker Adult Surface Soils Csoil Chemical Concentration in Surface Soils See Table 3 mg/kg Table 3 Dermally Absorbed Dose (DAD) (mg/kg-day) = ABS Dermal Absorption Factor 0.1 unitless EPA, 2018 EV Event Frequency 1 Events/day EPA, 2001 DA-event x EV x ED x EF x SA x 1/BW x 1/AT ED Exposure Duration 25 years EPA, 2014 where DA-Event (mg/cm2-event) = EF Exposure Frequency 225 days/year EPA, 2014 2 SA Skin Surface Area 3,527 cm EPA, 2014 DA-event = Csoil x CF x AF x ABSd BW Body Weight 80 kg EPA, 2014 AF Adherence factor of soil to skin 0.12 mg/cm2-event EPA, 2014 AT-C = 365 days per year X 70 year lifetime CF Conversion Factor 10-6 kg/mg - - AT-N = 365 days per year X ED (years) LF Lifetime 70 years EPA, 2014 AT-C Averaging Time - Cancer 25,550 days EPA, 2014 AT-N Averaging Time - Non-Cancer 9,125 days EPA, 2014 Sources: EPA, 1989: Risk Assessment Guidance for Superfund. Vol 1: Human Health Evaluation Manual, Part A. OERR. EPA/540/1-89/002. EPA, 1991: Risk Assessment Guidance for Superfund. Vol 1: Human Health Evaluation Manual - Supplemental Guidance, Standard Default Exposure Factors. Interim Final. OSWER Directive 9285.6-03. EPA 2001: Risk Assessment Guidance for Superfund. Volume1: Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment) Interim. EPA 2003: Region III Techniclal Guidance Manual, Risk Assessment. Updated Dermal Exposure Assessment Guidance. June. EPA 2014. Human Health Evaluation Manual, Supplemental Guidance: Update of Standard Default Exposure Factors. OSWER Directive 9200.1-120. EPA 2018. Regional Screening Levels (RSLs) Chemical Specific Supporting Parameters (November 2018) RAGS PART D TABLE 5.1 NON-CANCER TOXICITY DATA -- ORAL/DERMAL CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Medium: Surface Soils Exposure Medium: Surface Soils

Oral (Reference Dose Oral Absorption Chemical of Potential Absorbed RfD for Dermal Primary Combined RfD:Target Organ(s) CAS RN Number Chronic/Subchronic (RfDo) Efficiency for Concern (COPC) Dermal Target Uncertainty/Modifying Value Units Value Units Organ(s) Factors Source(s) Date(s)

TABLE IS NOT USED AS THERE AR NO COPCS IDENTIFIED AS NONCARCINOGENIC TABLE 5.2 NON-CANCER TOXICITY DATA -- INHALATION CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Medium: Surface Soils Exposure Medium: Surface Soils

Inhalation (Reference Chemical of Potential Primary Combined RfC:Sources CAS RN Number Chronic/Subchronic Concentration (RfCi ) Concern (COPC) Target Uncertainty/Modifying Value Units Organ(s) Factors Source(s) Date(s)

TABLE IS NOT USED AS THERE AR NO COPCS IDENTIFIED AS NONCARCINOGENIC AND THERE ARE NO INHALATION EXPOSURE PATHWAYS IDENTIFIED FOR EVALUATION TABLE 6.1 CANCER TOXICITY DATA -- ORAL/DERMAL CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Medium: Surface Soils Exposure Medium: Surface Soils

Oral Absorption Absorbed Cancer Slope (CSF) Weight of Evidence/ Chemical of Potential Oral Cancer Slope Factor (CSF) Efficiency for Oral/Dermal CSF Source CAS RN Number Factor for Dermal (2) Cancer Guideline Concern (COPC) Dermal Description Value Units (1) Value Units Source(s) Date(s) Toxaphene 8001-35-2 1.1E+00 1/mg/kg-day 1 1.1E+00 1/mg/kg-day B2 IRIS Oct-18

(1) Regional Screening Levels (RSLs) Tables November 2018 (2) Absorbed Cancer Slope Factor = Oral CSF * Oral Absorption Efficiency =GIABS value from RSLs Tables November 2018. NA = Not Available IRIS = EPA's Integrated Risk Information Sysytem Definitions: A = Human carcinogen B1 = Probable Human Carcinogen - Agents for which there is limited human data available from epidemiologic studies and/or is classified as a likely human carcinogen. B2 = Probable Human Carcinogen - Indicates sufficient evidence in animals and inadequate or no evidence in humans C = Possible human carcinogen D = Not classifiable as to human carcinogenicity/ inadequate information E = Evidence of noncarcinogenicity for humans TABLE 6.2 CANCER TOXICITY DATA -- INHALATION CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Medium: Surface Soils Exposure Medium: Surface Soils

Chemical of Potential Concern CAS RN Inhalation Cancer Slope Factor (CSF) Weight of Evidence/ Cancer Inhalation CSF Source (COPC) Number Guideline Description Value Units Source(s) Date(s)

TABLE NOT USED AS INHALATION EXPOSURES ARE NOT IDENTIFIED FOR HUMAN HEALTH EXPOSURE SCENARIOS TABLE 7.1 RME RISKS FOR ADULTS CALCULATION OF CHEMICAL CANCER RISKS AND NON-CANCER HAZARDS REASONABLE MAXIMUM EXPOSURE CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Future Receptor Population: Resident Receptor Age: Adult

Chemical of EPC Cancer Risk Calculations Non-Cancer Hazard Calculations

Medium Exposure Medium Exposure Point Exposure Route Potential Concern Value Units Intake/Exposure Concentration CSF/Unit Risk Intake Concentration RfD/RfC Hazard Cancer Risk Value Units Value Units Value Units Value Units Quotient Dermal Toxaphene 1.89E+03 mg/kg 2.7E-04 mg/kg-day 1.1E+00 1/mg/kg-day 3.0E-04 Surface Soils Surface Soils Surface Soils Dermal Exposure Route Total 3E-04 0E+00 Ingestion Toxaphene 1.89E+03 mg/kg 6.5E-01 mg/kg-day 1.1E+00 1/mg/kg-day 7.1E-01 Ingestion Exposure Route Total 7E-01 0.0E+00 Exposure Point Total 7E-01 0.0E+00 Exposure Medium Total 7E-01 0.0E+00 Surface Soil Total 7E-01 0.0E+00 TABLE 7.2 RME RISKS FOR CHILDREN CALCULATION OF CHEMICAL CANCER RISKS AND NON-CANCER HAZARDS REASONABLE MAXIMUM EXPOSURE CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Future Receptor Population: Resident Receptor Age: Child

Chemical of EPC Cancer Risk Calculations Non-Cancer Hazard Calculations

Medium Exposure Medium Exposure Point Exposure Route Potential Concern Value Units Intake/Exposure Concentration CSF/Unit Risk Intake Concentration RfD/RfC Hazard Cancer Risk Value Units Value Units Value Units Value Units Quotient Dermal Toxaphene 1.89E+03 mg/kg 4.93E-04 mg/kg-day 1.1E+00 1/mg/kg-day 5.4E-04 Surface Soils Surface Soils Surface Soils Dermal Exposure Route Total 0E+00 Ingestion Toxaphene 1.89E+03 mg/kg 2.1E+00 mg/kg-day 1.1E+00 1/mg/kg-day 2.3E+00 Ingestion Exposure Route Total 2.3E+00 0.0E+00 Exposure Point Total 2.3E+00 0.0E+00 Exposure Medium Total 2.3E+00 0.0E+00 Surface Soil Total 2.3E+00 0.0E+00 TABLE 7.3 RME RISKS FOR OUTDOOR SITE WORKER CALCULATION OF CHEMICAL CANCER RISKS AND NON-CANCER HAZARDS REASONABLE MAXIMUM EXPOSURE CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Receptor Population: Outdoor Worker Receptor Age: Adult

Chemical of EPC Cancer Risk Calculations Non-Cancer Hazard Calculations

Medium Exposure Medium Exposure Point Exposure Route Potential Concern Value Units Intake/Exposure Concentration CSF/Unit Risk Intake Concentration RfD/RfC Hazard Cancer Risk Value Units Value Units Value Units Value Units Quotient Dermal Toxaphene 1.89E+03 mg/kg 2.2E-04 mg/kg-day 1.1E+00 1/mg/kg-day 2.4E-04 Surface Soils Surface Soils Surface Soils Dermal Exposure Route Total 2.4E-04 0E+00 Ingestion Toxaphene 1.89E+03 mg/kg 5.2E-01 mg/kg-day 1.1E+00 1/mg/kg-day 5.7E-01 Ingestion Exposure Route Total 5.7E-01 0.0E+00 Exposure Point Total 5.7E-01 0.0E+00 Exposure Medium Total 5.7E-01 0.0E+00 Surface Soil Total 5.7E-01 0.0E+00 TABLE 9.1.RME FUTURE ADULT RESIDENT SUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COPCs REASONABLE MAXIMUM EXPOSURE CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Future Receptor Population: Resident Receptor Age: Adult

Medium Exposure Exposure Chemical Carcinogenic Risk Non-Carcinogenic Hazard Quotient Medium Point of Potential Concern Ingestion Inhalation Dermal External Exposure Primary Ingestion Inhalation Dermal Exposure (Radiation) Routes Total Target Organ(s) Routes Total Toxaphene 7.1E-01 -- 3.0E-04 -- 7.1E-01

Surface Soils Surface Soils Surface Soils Chemical Total 7.1E-01 -- 3.0E-04 -- 7.1E-01 0.0E+00 0.0E+00 0.0E+00 0.0E+00 Exposure Point Total 7.1E-01 0E+00 Exposure Medium Total 7.1E-01 0E+00 Receptor Total 7.1E-01 Receptor HI Total 0E+00

Total Risk Across All Media 7.1E-01 Total Hazard Across All Media 0E+00

Total Eyes/Immune/Nails HI Across All Media = 0E+00 Total CNS HI Across All Media = 0E+00 Total Liver HI Across All Media = 0E+00 Total Kidney HI Across All Media = 0E+00 Total CNS/Immune HI Across All Media = 0E+00 TABLE 9.2 RME FUTURE CHILD RESIDENT SUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COPCs REASONABLE MAXIMUM EXPOSURE CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Future Receptor Population: Resident Receptor Age: Child

Medium Exposure Exposure Chemical Carcinogenic Risk Non-Carcinogenic Hazard Quotient Medium Point of Potential Concern Ingestion Inhalation Dermal External Exposure Primary Ingestion Inhalation Dermal Exposure (Radiation) Routes Total Target Organ(s) Routes Total Toxaphene 2.3E+00 -- 5.4E-04 -- 2.3E+00

Surface Soils Surface Soils Surface Soils Chemical Total 2.3E+00 -- 5.4E-04 -- 2.3E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 Exposure Point Total 2.3E+00 0E+00 Exposure Medium Total 2.3E+00 0E+00 Receptor Total 2.3E+00 Receptor HI Total 0E+00

Total Risk Across All Media 2.3E+00 Total Hazard Across All Media 0E+00

Total Eyes/Immune/Nails HI Across All Media = 0E+00 Total CNS HI Across All Media = 0E+00 Total Liver HI Across All Media = 0E+00 Total Kidney HI Across All Media = 0E+00 Total CNS/Immune HI Across All Media = 0E+00 TABLE 9.3 RME CURRENT/FUTURE OUTDOOR WORKER SUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COPCs REASONABLE MAXIMUM EXPOSURE CATTLE HEAD (3PP657) CATTLE DIP VAT (CDV) SITE, OZARK NATIONAL FOREST, ARKANSAS

Scenario Timeframe: Current/Future Receptor Population: Outdoor Worker Receptor Age: Adult

Medium Exposure Exposure Chemical Carcinogenic Risk Non-Carcinogenic Hazard Quotient Medium Point of Potential Concern Ingestion Inhalation Dermal External Exposure Primary Ingestion Inhalation Dermal Exposure (Radiation) Routes Total Target Organ(s) Routes Total Toxaphene 5.7E-01 -- 2.4E-04 -- 5.7E-01

Surface Soils Surface Soils Surface Soils Chemical Total 5.7E-01 -- 2.4E-04 -- 5.7E-01 0.0E+00 0.0E+00 0.0E+00 0.0E+00 Exposure Point Total 5.7E-01 0.0E+00 Exposure Medium Total 5.7E-01 0.0E+00 Receptor Total 5.7E-01 Receptor HI Total 0.0E+00

Total Risk Across All Media 5.7E-01 Total Hazard Across All Media 0.0E+00

Total Eyes/Immune/Nails HI Across All Media = 0.0E+00 Total CNS HI Across All Media = 0.0E+00 Total Liver HI Across All Media = 0.0E+00 Total Kidney HI Across All Media = 0.0E+00 Total CNS/Immune HI Across All Media = 0.0E+00

APPENDIX M

Toxaphene ProUCL Output

UCL Statistics for Data Sets with Non-Detects

User Selected Options Date/Time of Computation ProUCL 5.112/4/2018 12:47:01 PM From File ProUCL toxaphene_ds.xls Full Precision OFF Confidence Coefficient 95% Number of Bootstrap Operations 2000

Toxaphene

General Statistics Total Number of Observations 14 Number of Distinct Observations 13 Number of Detects 12 Number of Non-Detects 2 Number of Distinct Detects 12 Number of Distinct Non-Detects 1 Minimum Detect 130 Minimum Non-Detect 28 Maximum Detect2400000 Maximum Non-Detect 28 Variance Detects4.735E+11 Percent Non-Detects 14.29% Mean Detects218083 SD Detects 688119 Median Detects 2950 CV Detects 3.155 Skewness Detects 3.446 Kurtosis Detects 11.91 Mean of Logged Detects 8.372 SD of Logged Detects 2.933

Normal GOF Test on Detects Only Shapiro Wilk Test Statistic 0.361 Shapiro Wilk GOF Test 5% Shapiro Wilk Critical Value 0.859 Detected Data Not Normal at 5% Significance Level Lilliefors Test Statistic 0.485 Lilliefors GOF Test 5% Lilliefors Critical Value 0.243 Detected Data Not Normal at 5% Significance Level Detected Data Not Normal at 5% Significance Level

Kaplan-Meier (KM) Statistics using Normal Critical Values and other Nonparametric UCLs KM Mean186933 KM Standard Error of Mean 171593 KM SD614707 95% KM (BCA) UCL 522410 95% KM (t) UCL490811 95% KM (Percentile Bootstrap) UCL 522729 95% KM (z) UCL469177 95% KM Bootstrap t UCL 4711350 90% KM Chebyshev UCL701710 95% KM Chebyshev UCL 934887 97.5% KM Chebyshev UCL 1258527 99% KM Chebyshev UCL 1894257

Gamma GOF Tests on Detected Observations Only A-D Test Statistic 1.468 Anderson-Darling GOF Test 5% A-D Critical Value 0.881 Detected Data Not Gamma Distributed at 5% Significance Level K-S Test Statistic 0.334 Kolmogorov-Smirnov GOF 5% K-S Critical Value 0.273 Detected Data Not Gamma Distributed at 5% Significance Level Detected Data Not Gamma Distributed at 5% Significance Level

Page 1 of 3 Gamma Statistics on Detected Data Only k hat (MLE) 0.189 k star (bias corrected MLE) 0.198 Theta hat (MLE) 1151967 Theta star (bias corrected MLE) 1103990 nu hat (MLE) 4.544nu star (bias corrected) 4.741 Mean (detects) 218083

Gamma ROS Statistics using Imputed Non-Detects GROS may not be used when data set has > 50% NDs with many tied observations at multiple DLs GROS may not be used when kstar of detects is small such as <1.0, especially when the sample size is small (e.g., <15-20) For such situations, GROS method may yield incorrect values of UCLs and BTVs This is especially true when the sample size is small. For gamma distributed detected data, BTVs and UCLs may be computed using gamma distribution on KM estimates Minimum 0.01Mean 186929 Maximum 2400000Median 2000 SD 637913CV 3.413 k hat (MLE) 0.138k star (bias corrected MLE) 0.156 Theta hat (MLE) 1351150Theta star (bias corrected MLE) 1195800 nu hat (MLE) 3.874nu star (bias corrected) 4.377 Adjusted Level of Significance (β) 0.0312 Approximate Chi Square Value (4.38, α) 0.876Adjusted Chi Square Value (4.38, β) 0.692 95% Gamma Approximate UCL (use when n>=50) 93395695% Gamma Adjusted UCL (use when n<50) 1182252

Estimates of Gamma Parameters using KM Estimates Mean (KM) 186933SD (KM) 614707 Variance (KM) 3.779E+11SE of Mean (KM) 171593 k hat (KM) 0.0925k star (KM) 0.12 nu hat (KM) 2.589nu star (KM) 3.368 theta hat (KM) 2021395theta star (KM) 1554151 80% gamma percentile (KM) 16437890% gamma percentile (KM) 529963 95% gamma percentile (KM) 106638899% gamma percentile (KM) 2702717

Gamma Kaplan-Meier (KM) Statistics Approximate Chi Square Value (3.37, α) 0.489Adjusted Chi Square Value (3.37, β) 0.371 Gamma Approximate KM-UCL (use when n>=50) 1286788 95% Gamma Adjusted KM-UCL (use when n<50) 1694800

Lognormal GOF Test on Detected Observations Only Shapiro Wilk Test Statistic 0.921 Shapiro Wilk GOF Test 5% Shapiro Wilk Critical Value 0.859 Detected Data appear Lognormal at 5% Significance Level Lilliefors Test Statistic 0.179 Lilliefors GOF Test 5% Lilliefors Critical Value 0.243 Detected Data appear Lognormal at 5% Significance Level Detected Data appear Lognormal at 5% Significance Level

Page 2 of 3 Lognormal ROS Statistics Using Imputed Non-Detects Mean in Original Scale 186929 Mean in Log Scale 7.378 SD in Original Scale 637913 SD in Log Scale 3.707 95% t UCL (assumes normality of ROS data) 488854 95% Percentile Bootstrap UCL 529244 95% BCA Bootstrap UCL 707541 95% Bootstrap t UCL 4702309 95% H-UCL (Log ROS) 7.385E+9

Statistics using KM estimates on Logged Data and Assuming Lognormal Distribution KM Mean (logged) 7.652 KM Geo Mean 2105 KM SD (logged) 3.142 95% Critical H Value (KM-Log) 7.041 KM Standard Error of Mean (logged) 0.877 95% H-UCL (KM -Log) 1.354E+8 KM SD (logged) 3.142 95% Critical H Value (KM-Log) 7.041 KM Standard Error of Mean (logged) 0.877

DL/2 Statistics DL/2 Normal DL/2 Log-Transformed Mean in Original Scale 186931 Mean in Log Scale 7.553 SD in Original Scale 637912 SD in Log Scale 3.408 95% t UCL (Assumes normality) 488856 95% H-Stat UCL 8.394E+8 DL/2 is not a recommended method, provided for comparisons and historical reasons

Nonparametric Distribution Free UCL Statistics Detected Data appear Lognormal Distributed at 5% Significance Level

Suggested UCL to Use 99% KM (Chebyshev) UCL 1894257

Note: Suggestions regarding the selection of a 95% UCL are provided to help the user to select the most appropriate 95% UCL. Recommendations are based upon data size, data distribution, and skewness. These recommendations are based upon the results of the simulation studies summarized in Singh, Maichle, and Lee (2006). However, simulations results will not cover all Real World data sets; for additional insight the user may want to consult a statistician.

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