December 23, 2009 ATTN: CENWO-PM-HB Contract No. …...Task Order #0001 Prepared by TIDEWATER, INC. 7161-C Columbia Gateway Drive Columbia, Maryland 21046 December 2009 E05MN001901_01.09_0003_a

8450-D Tyco Road, Vienna, VA 22182 Phone 703 288 1844 Fax 703 288 1845 www.tideh2o.net

December 23, 2009 Ms. Taunya Howe USACE Project Manager ATTN: CENWO-PM-HB Contract No. W9128F-09-D-0005 1616 Capitol Avenue Omaha, NE 68102-4901 (402) 995-2728 Contract No.: W9128F-09-D-0005 Task Order No.: 0001 – Expanded Site Inspection, Former Gopher Ordnance Works Transmittal of Final Screening Level Ecological Risk Assessment Report Dear Ms. Howe: Tidewater, Inc. (Tidewater) appreciates the opportunity to submit the enclosed nine (9) copies of the Final Screening Level Ecological Risk Assessment Report for the Former Gopher Ordnance Works. Eleven (11) electronic copies in the pdf version of the report, and eight (8) electronic copies in editable format are also included. Please call us at (703) 288-1844 if you have any questions. Sincerely, Tidewater, Inc. Gary M. Verban, P.E. Project Manager cc: Project File

E05MN001901_01.09_0003_a

UMP029066

Final Screening Level Ecological Risk Assessment

December 2009 Former Gopher Ordnance Works Rosemount, Minnesota Prepared for United States Army Corps of Engineers - Omaha District

E05MN001901_01.09_0003_a

UMP029067

FINAL SCREENING LEVEL ECOLOGICAL RISK

ASSESSMENT

FORMER GOPHER ORDNANCE WORKS ROSEMOUNT, MINNESOTA

Prepared for

U.S. Army Corps of Engineers Omaha District

1616 Capitol Avenue Omaha, Nebraska 68102-1618

USACE Environmental Remediation Services Contract W9128F-04-D-0005

Task Order #0001

Prepared by

TIDEWATER, INC. 7161-C Columbia Gateway Drive

Columbia, Maryland 21046

December 2009

E05MN001901_01.09_0003_a

UMP029068

ES-1

Executive Summary This ecological risk assessment (ERA) for the Former Gopher Ordnance Works (FGOW) located in Rosemount, Minnesota was completed in accordance with the United States Environmental Protection Agency (EPA) 1997 Ecological Risk Assessment Guidance for Superfund (ERAGS): Process for Designing and Conducting Ecological Risk Assessments. This document consists of a screening level ERA (SLERA), which includes Steps 1 and 2 of the ERAGS guidance, and Step 3a of the ERA process, which is the initial step of the Baseline ERA (BERA). If results of Step 3a indicate chemicals or exposure pathways may pose potential ecological threats, a BERA may be warranted.

Per ERAGS, a four-step process is utilized for assessing site-related ecological risks under the assumption of a reasonable maximum exposure scenario. The SLERA is composed of these four components as listed in order below:

Problem Formulation Exposure Assessment Effects Assessment Risk Characterization

The purpose of the SLERA for this site is to (1) evaluate the potential for ecological receptors to be exposed to chemicals at each area of concern (AOC) and (2) to calculate conservative estimates of risk based on maximum exposure concentrations. AOCs evaluated in the SLERA include AOC 1 Northern Section (AOC 1N), AOC 1 Middle Section (AOC 1M), AOC 1 Southern Section (AOC 1S), AOC 6, AOC 7 Northwest Quadrant (AOC 7A), and AOC 7 Southwest Quadrant (AOC 7D). The results of the SLERA are expressed primarily as quantitative risk estimates using the hazard quotient (HQ) approach where the maximum detected chemical concentration is divided by the selected ecological screening level (ESL). ESLs are conservative benchmarks that serve as thresholds for potential threats and further evaluation. HQs were calculated to estimate risks to plants and terrestrial organisms from exposure to surface soil and to estimate risks to aquatic organisms exposed to sediment and surface water. HQs equal to or greater than 1.0 indicate potential threats and are retained for further evaluation. HQs below 1 suggest little or no risk (acceptable risk level) and are not retained for further investigation. Based on the results of the SLERA, many chemicals were retained for further analyses in Step 3a. These are termed chemicals of potential concern (COPCs). The COPCs retained following the completion of the SLERA warrant further investigation in Step 3a, where the maximum detected chemical concentration is replaced by the arithmetic mean (average) detected chemical concentration. As in the SLERA, chemicals associated with mean-based HQs greater than or equal to 1.0 are identified as COPCs. At the conclusion of Step 3a of the BERA process these COPCs are termed final COPCs.

E05MN001901_01.09_0003_a

UMP029069

Executive Summary

ES-2

Several final COPCs were retained for further evaluation in each medium of concern at each AOC at the conclusion of Step 3a. These were based on HQs greater than 1.0 or the lack of available ESLs available for some chemicals. AOCs with the greatest potential to contribute to impacts to surface soil-associated receptors are AOC 1N, AOC 1M, AOC 7A, and AOC 7D. Several chemicals detected in surface soil, including PCBs, cadmium, and mercury, are known to be highly bioaccumulative and are also known to biomagnify. Thus, the results of Step 3a suggest that food web modeling may be warranted to more fully describe risks that are associated with exposure to bioaccumulative chemicals via dietary intake. Bioaccumulative chemicals are present in surface soils at AOC 1N, AOC 1M, AOC 6, AOC 7A, and AOC 7D. The Step 3a analysis of surface water and sediment results suggests that threats to aquatic receptors are likely low, but possibly important at AOC 1S. Although nitrocellulose, a site related chemical, is present in surface water and sediment, toxicity information collected to date and provided in the literature indicates that nitrocellulose is not highly toxic, and its detection in these media may not warrant additional evaluation. The findings of the SLERA and Step 3a analyses suggest that development of a BERA may be warranted for some and possibly all of the AOCs evaluated for the FGOW site. Whether these initial risks estimates (i.e., those exceeding the threshold of 1.0 from Step 3a) are sufficiently elevated to warrant further investigation is a risk management decision beyond the realm of risk assessment.

E05MN001901_01.09_0003_a

UMP029070

i

Table of Contents Executive Summary .............................................................................................. ES-1 Section 1 Introduction ............................................................................................. 1-1

1.1 Purpose of the SLERA ................................................................................. 1-1 1.2 Report Organization.................................................................................... 1-1

Section 2 Problem Formulation ............................................................................. 2-1 2.1 Environmental Setting ................................................................................ 2-1

2.1.1 AOC 1 – Waste Disposal Ditch, Primary and Secondary Settling Ponds ................................................................................................ 2-1

2.1.2 AOC 6 – 154th Street Disturbed Area ........................................... 2-5 2.1.3 AOC 7A and 7D – Steam Plant and Associated 26.7 Acres ...... 2-7 2.1.4 Background Sampling Areas ........................................................ 2-9 2.1.5 Vertebrate Species Present at or in the Vicinity of the FGOW…

......................................................................................................... 2-10 2.1.6 Threatened and Endangered Species and State Species of

Special Concern Present at or in the Vicinity of the FGOW ... 2-11 2.2 Exposure Pathway Evaluation and Site Conceptual Exposure Model…

...................................................................................................................... 2-11 2.2.1 Exposure Pathways ...................................................................... 2-11

2.2.1.1 AOC 1 – Waste Disposal Ditch, Primary and Secondary Settling Ponds .................................................................. 2-12

2.2.1.2 AOC 6 – 154th Street Disturbed Area ............................. 2-12 2.2.1.3 AOC 7A and 7D – Steam Plant and Associated 26.7 Acres

............................................................................................ 2-13 2.2.2 Site Conceptual Exposure Model ............................................... 2-13

2.3 Assessment Endpoints .............................................................................. 2-14 2.4 Measurement Endpoints .......................................................................... 2-15 2.5 Ecological Risk Questions ........................................................................ 2-16

Section 3 Exposure Assessment ............................................................................ 3-1 3.1 Media of Concern ........................................................................................ 3-1 3.2 Data Included in the SLERA ...................................................................... 3-1

3.2.1 Soil Samples .................................................................................... 3-1 3.2.2 Surface Water Samples .................................................................. 3-2 3.2.3 Sediment Samples .......................................................................... 3-2

3.3 Chemical Classes of Interest ...................................................................... 3-2 3.4 Chemical and Physical Properties of Classes of COIs ............................ 3-2

3.4.1 Mechanisms of Toxicity ................................................................. 3-2 3.4.2 Environmental Fate and Transport .............................................. 3-5

3.5 Exposure Point Concentrations ................................................................. 3-7 Section 4 Effects Assessment ................................................................................. 4-1

4.1 Ecological Screening Levels ....................................................................... 4-1 4.1.1 Soil .................................................................................................... 4-1 4.1.2 Sediment .......................................................................................... 4-2 4.1.3 Surface Water .................................................................................. 4-3

4.2 COPC Selection ............................................................................................ 4-4 4.2.1 AOC 1N ........................................................................................... 4-5

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UMP029071

Table of Contents

ii

4.2.1.1 Surface Soil .......................................................................... 4-5 4.2.2 AOC 1M ........................................................................................... 4-5

4.2.2.1 Surface Soil .......................................................................... 4-5 4.2.3 AOC 1S ............................................................................................. 4-5

4.2.3.1 Surface soil ........................................................................... 4-5 4.2.3.2 Sediment .............................................................................. 4-5 4.2.3.3 Surface Water ...................................................................... 4-5

4.2.4 AOC 6 ............................................................................................... 4-6 4.2.4.1 Surface Soil .......................................................................... 4-6

4.2.5 AOC 7A ............................................................................................ 4-6 4.2.5.1 Surface Soil .......................................................................... 4-6

4.2.6 AOC 7D ............................................................................................ 4-6 4.2.6.1 Surface Soil .......................................................................... 4-6

Section 5 Risk Characterization ............................................................................ 5-1 5.1 AOC 1N ........................................................................................................ 5-1

5.1.1 Surface Soil ...................................................................................... 5-1 5.2 AOC 1M ........................................................................................................ 5-1

5.2.1 Surface Soil ...................................................................................... 5-1 5.3 AOC 1S .......................................................................................................... 5-2

5.3.1 Surface soil ....................................................................................... 5-2 5.3.2 Sediment .......................................................................................... 5-2 5.3.3 Surface Water .................................................................................. 5-2

5.4 AOC 6 ............................................................................................................ 5-2 5.4.1 Surface Soil ...................................................................................... 5-2

5.5 AOC 7A ......................................................................................................... 5-2 5.5.1 Surface Soil ...................................................................................... 5-2

5.6 AOC 7D ......................................................................................................... 5-2 5.6.1 Surface Soil ...................................................................................... 5-2

Section 6 Uncertainty Assessment ........................................................................ 6-1 Section 7 SLERA Conclusions ............................................................................... 7-1 Section 8 Step 3a of the BERA ............................................................................... 8-1

8.1 Refinement of EPCs ..................................................................................... 8-1 8.2 Refined Hazard Quotient Calculations and Selection of Final COPCs 8-2

8.2.1 AOC 1N ........................................................................................... 8-2 8.2.1.1 Surface Soil .......................................................................... 8-2

8.2.2 AOC 1M ........................................................................................... 8-3 8.2.2.1 Surface Soil .......................................................................... 8-3

8.2.3 AOC 1S ............................................................................................. 8-3 8.2.3.1 Surface soil ........................................................................... 8-3 8.2.3.2 Sediment .............................................................................. 8-3 8.2.3.3 Surface Water ...................................................................... 8-3

8.2.4 AOC 6 ............................................................................................... 8-4 8.2.4.1 Surface Soil .......................................................................... 8-4

8.2.5 AOC 7A ............................................................................................ 8-4 8.2.5.1 Surface Soil .......................................................................... 8-4

8.2.6 AOC 7D ............................................................................................ 8-4 8.2.6.1 Surface Soil .......................................................................... 8-4

E05MN001901_01.09_0003_a

UMP029072

Table of Contents

iii

8.3 Comparison to Background ....................................................................... 8-5 8.4 Uncertainties ................................................................................................ 8-5 8.5 Conclusions .................................................................................................. 8-5

Section 9 References ................................................................................................ 9-1

List of Tables Table 2-1 Summary of Vertebrate Species Observed on the Minnesota

Department of Natural Resources at the FGOW and Vermillion Highlands

Table 3-1 Summary of Samples used for the ERA Table 3-2 Summary of Statistics of Soil Analytical Results and Ecological

Screening Results AOC 1-Northern Section Table 3-3 Summary of Statistics of Soil Analytical Results and Ecological

Screening Results AOC 1-Middle Section Table 3-4 Summary of Statistics of Soil Analytical Results and Ecological

Screening Results AOC 1-Southern Section Table 3-5 Summary of Statistics of Sediment Analytical Results and Ecological

Screening Results AOC 1-Southern Section Table 3-6 Summary of Statistics of Surface Water Analytical Results and

Ecological Screening Results AOC 1-Southern Section Table 3-7 Summary of Statistics of Soil Analytical Results and Ecological

Screening Results AOC 6 Table 3-8 Summary of Statistics of Soil Analytical Results and Ecological

Screening Results AOC 7A Table 3-9 Summary of Statistics of Soil Analytical Results and Ecological

Screening Results AOC 7D Table 4-1 Summary of SLERA Chemicals of Potential Concern Screening by AOC Table 8-1 Summary of Step 3a Chemicals of Potential Concern Refinement by

AOC Table 8-2 Site-specific Background Concentrations of Metals in Surface Soil

List of Figures Figure 2-1 Ecological Site Conceptual Exposure Model AOCs 6, 7A, 7D, 1N, and

1M Figure 2-2 Ecological Site Conceptual Exposure Model AOC 1S Figure 3-1 AOC 1, Northern Section, Focused SI and ESI Surface Soil Sample

Locations and Detected Analytes Figure 3-2 AOC 1, Middle Section, Focused SI and ESI Surface Soil Sample

Locations and Detected Analytes Figure 3-3 AOC 1, Southern Section, Focused SI and ESI Surface Soil Sample

Locations and Detected Analytes Figure 3-5 AOC 1, Southern Section, Focused SI and ESI Sediment Sample

Locations and Detected Analytes

E05MN001901_01.09_0003_a

UMP029073

Table of Contents

iv

Figure 3-6 AOC 6 Focused SI and ESI Soil Sample Locations and Detected Analytes

Figure 3-7a AOC 7A, Northwest Quadrant, Focused SI Surface Soil Sample Locations and Detected Analytes

Figure 3-7b AOC 7A, Northwest Quadrant, ESI Surface Soil Sample Locations and Detected Analytes

Figure 3-8a AOC 7D, Southwest Quadrant, Focused SI Surface Soil Sample Locations and Detected Analytes

Figure 3-8b AOC 7D, Southwest Quadrant, ESI Surface Soil Sample Locations and Detected Analytes

List of Appendices Appendix A Photo Log Appendix B Species List for Federal Threatened and Endangered Species and

Minnesota Threatened, Endangered and Special Concern Species

E05MN001901_01.09_0003_a

UMP029074

v

Acronyms and Abbreviations % percent

ACM Asbestos Containing Material AOC area of concern AOC 1N Area of Concern 1 Northern Section AOC 1M Area of Concern 1 Middle Section AOC 1S Area of Concern 1 Southern Section AOC 7A Area of Concern 7 Northwest Quadrant AOC 7D Area of Concern 7 Southwest Quadrant

BaP benzo(a)pyrene BERA baseline ecological risk assessment bgs below ground surface BOD biological oxygen demand

CCC criterion continuous concentration CDM CDM Federal Programs Corporation CCME Canadian Council of Ministers of the Environment CMC Criterion Maximum Concentration COI chemical class of interest COPCs chemicals of potential concern

DoD Department of Defense DCEM Dakota County Environmental Management DNR Minnesota Department of Natural Resources DRO diesel range organics DNT dinitrotoluene DPA diphenylamine

Eco-SSL ecological soil screening level EPC exposure point concentration EPA United States Environmental Protection Agency ERA ecological risk assessment ERAGS Ecological Risk Assessment Guidance for Superfund ER-L effects-range low ESL ecological screening level

FGOW Former Gopher Ordnance Works

gpd gallons per day

HQ hazard quotient

Kd sediment/water partition coefficient Koc organic carbon partition coefficient Kow octanol water partition coefficient

LC50 chemical concentration resulting in mortality to half (50%) of the test organisms

E05MN001901_01.09_0003_a

UMP029075

Acronyms and Abbreviations

vi

mg/kg milligram per kilogram mmHg millimeter mercury

µg/kg microgram per kilograms µg/L microgram per liter µg/m3 microgram per cubic meter MPCA Minnesota Pollution Control Agency

nm nanometer NRWQC National Recommended Water Quality Criteria NYSDEC New York State Department of Environmental

Conservation

ORNL Oak Ridge National Laboratory

PAH polycyclic aromatic hydrocarbon PAN Pesticide Action Network PCB polychlorinated biphenyl PCE tetrachloroethene PEC probable effects concentration PERC perchlorothylene POL petroleum, oil, and lubricants

RCRA Resource Conservation and Recovery Act

SCEM site conceptual exposure model SI site investigation SLERA screening level ecological risk assessment SOS scope of services SQT sediment quality target SVOC semi-volatile organic compound SSL soil screening value

TCE trichloroethylene TEC threshold effects concentration TEL threshold effects level

UMN University of Minnesota USACE United States Army Corps of Engineers

VOC volatile organic compound

WMA wildlife management area

E05MN001901_01.09_0003_a

UMP029076

1-1

Section 1 Introduction This ecological risk assessment (ERA) for the Former Gopher Ordnance Works (FGOW) located in Rosemount, Minnesota was completed in accordance with the United States Environmental Protection Agency (EPA) 1997 Ecological Risk Assessment Guidance for Superfund (ERAGS): Process for Designing and Conducting Ecological Risk Assessments. This document consists of a screening level ERA (SLERA), which includes Steps 1 and 2 of the ERAGS guidance, and Step 3a of the ERA process, which is the initial step of the Baseline ERA (BERA). A BERA may be warranted if the results of the SLERA and Step 3a indicate that chemicals or exposure pathways may pose potential threats.

Per ERAGS, a four-step process is utilized for assessing site-related ecological risks under the assumption of a reasonable maximum exposure scenario. The SLERA is composed of these four components as listed in order below:

Problem Formulation Exposure Assessment Effects Assessment Risk Characterization

1.1 Purpose of the SLERA The purpose of the SLERA for this site is to (1) evaluate the potential for ecological receptors to be exposed to chemicals at each area of concern (AOC) and (2) to calculate conservative estimates of risk based on maximum exposure concentrations. AOCs evaluated in the SLERA include AOC 1 Northern Section (AOC 1N), AOC 1 Middle Section (AOC 1M), AOC 1 Southern Section (AOC 1S), AOC 6, AOC 7 Northwest Quadrant (AOC 7A), and AOC 7 Southwest Quadrant (AOC 7D).

1.2 Report Organization This report is composed of nine sections with tables and figures presented at the end of each section of text. The organization of the report and the contents of each section are described below.

Section 1 Introduction

Section 2 Problem Formulation – provides environmental setting for each AOC, the site conceptual exposure model of the site, the assessment and measurement endpoints for each habitat type (terrestrial and aquatic), and a list of risk questions

Section 3 Exposure Assessment – summarizes and evaluates exposure data on ecological receptors or receptor groups described in Problem Formulation

E05MN001901_01.09_0003_a

UMP029077

Section 1 Introduction

1-2

Section 4 Effects Assessment – includes an evaluation of effects data sources and data types, and presents media-specific and chemical-specific ecological screening levels

Section 5 Risk Characterization – integrates exposure and effects information to derive quantitative risk estimates

Section 6 Uncertainty Assessment – describes the impacts of uncertainties associated with the database, exposure assessment, and effects assessment

Section 7 SLERA Conclusions – presents responses to the questions posed in Problem Formulations and provides conclusions for the SLERA

Section 8 Step 3a of the BERA – refines exposure point concentrations, recalculates HQs based on mean concentrations of COPCs, and presents conclusions of Step 3a

Section 9 References – lists references cited in this report

E05MN001901_01.09_0003_a

UMP029078

2-1

Section 2 Problem Formulation This section provides:

a description of the environmental setting for each AOC, including: □ a review of the historical site description and use □ descriptions of the historical contamination associated with former

Department of Defense (DoD) activities □ descriptions of the current use of each AOC □ summary of observations from the site visit conducted by CDM Federal

Programs Corporation (CDM) staff on September 16 and 17, 2009, including: • descriptions of major habitat types within each AOC • discussion of species (i.e., potential ecological receptors) observed at each

of the AOCs during the site visit conducted in September 2009 and those known to frequent the property, including threatened, endangered, and State species of special concern

the site conceptual exposure model (SCEM), which depicts relationships between primary and secondary chemical sources, chemical migration pathways, exposure routes, and receptors

the assessment endpoints for each habitat type (terrestrial and aquatic) measurement endpoints for each habitat type (terrestrial and aquatic) a list of risk questions or hypotheses.

2.1 Environmental Setting 2.1.1 AOC 1 – Waste Disposal Ditch, Primary and Secondary Settling Ponds Historical AOC 1 Description and DoD Uses This AOC, including AOC 1N, AOC 1M, and AOC 1S, begins at 160th Street with the Waste Disposal Ditch and continues south to the outfall of the Secondary Settling Pond. According to the drainage schematics provided by Dakota County, "process" water historically was collected in the Laminex Woodbox Sewer system from the nitrocellulose production areas, solvent areas, and the smokeless powder manufacturing areas. The Laminex Woodbox Sewer’s outfall was located approximately 1,000 feet north of the northern edge of AOC 1N. In addition, treated effluent from the sanitary lines also flowed through the Wastewater Treatment Plant and then into the Laminex lines less than 0.5 miles northeast of the Laminex Woodbox Sewer’s outfall. The waste disposal ditch, in general, followed the natural drainage contours of the area and was man-made in some areas, with sides up to 20 feet high in the area south of 170th Street (Tidewater 2009).

AOC 1N, AOC 1M, and AOC 1S are included in the SLERA. AOC 1N is located north of 170th Street on private property. Based on existing topography, the northern half of the waste ditch in this section appears to have been filled (Tidewater, 2009).

E05MN001901_01.09_0003_a

UMP029079

Section 2 Problem Formulation

2-2

AOC 1M begins at 170th Street (where the former Coates Dump is located), trends southward and includes the primary settling basin and drainage ditch to approximately the secondary settling basin. Solid waste deposited in the Coates Dump at the head of the drainage ditch would have made the ditch unusable as a waste water disposal ditch. Therefore, the landfill waste would likely have been disposed after DuPont/DoD operations had terminated. Additionally, the landfill may have been used by the public. The Primary Settling Basin is located approximately 600 feet down gradient of the former dump. The ditch enters the settling basin at its northeast corner. What appears to be an old weir or dam structure is located in the ditch at the outfall/toe end of the basin (Tidewater 2009). Exposure to chemicals associated with the former Coates Dump are not evaluated in the SLERA, as these chemicals would have been deposited or released after the DoD activities ceased.

AOC 1S includes the Secondary Settling Basin, a former secondary acid neutralization plant, contact mixing basin, former chemical storehouse, and a still-well. The dam/weir structure is present at the outlet of the basin. Surface water is usually only observed in AOC 1S below the former dam/weir structure (Tidewater 2009).

During DuPont/DoD activities at the FGOW, the underground Laminex Woodbox Sewer system was designed to collect 100,000,000-gallons-per-day (gpd) of process water. The process water came from the acid/oleum production areas as well as the nitrocellulose production facilities where large amounts of fresh water were used to break down cotton fibers, neutralize acid and remove impurities from the nitrated cotton. This process water was released into the Waste Disposal Ditch along the east boundary of the FGOW. The Laminex Woodbox sewers, located on property transferred to the Regents of the University of Minnesota (UMN) in 1948, are not part of this AOC. Two acid neutralization systems were installed at the FGOW: the first was located to treat the process water from the acid manufacturing area, and the second was located at the outfall of the secondary settling basin (Tidewater 2009).

The sanitary sewers were designed to collect 300,000 gpd of wastewater from laundries and personal hygiene facilities as well as shop maintenance operations and also carried sewage to the wastewater treatment facility located in the northeast part of FGOW. After chlorination and dilution to meet the state’s biological oxygen demand (BOD) standard, the treated wastewater was released into the Laminex Woodbox Sewer system and then into the waste disposal ditch (Tidewater 2009).

Contamination of AOC 1 Associated with Historical DoD Activities DuPont production operations may have potentially contributed the following substances to the Waste Disposal Ditch:

Nitrocellulose Dinitrotoluene (DNT) Diphenylamine (DPA) Industrial Solvents and Degreasers Petroleum, Oil, and Lubricants (POLs)

E05MN001901_01.09_0003_a

UMP029080


2-3

Mercury Polynuclear Aromatic Hydrocarbons (PAHs) Metals Oleum Sulfuric Acid Nitric Acid

Mercury may have been present as an impurity in the coal burned at the FGOW Steam Plant. However, documentation also exists showing that from 1974 to the present, UMN has applied wastewater biosolids, which may have contained mercury, to areas within the boundaries of FGOW (Tidewater 2009).

Dakota County Environmental Management (DCEM) and the Minnesota Pollution Control Agency (MPCA) collected soil samples in the settling basins in 2003. Mercury, chromium, 2,4-DNT, 2,6-DNT and o-nitrotoluene were detected. DCEM collected groundwater samples in 1992 in association with the Coates Dump. Metals, perchloroethylene (PERC), and trichloroethylene (TCE) were detected. Since solid waste disposal activities in the Coates Dump blocked the Waste Disposal Ditch that was used by FGOW, these activities occurred after FGOW operations ceased in late-1945, and include possible UMN and public disposal that may have contributed the following potential hazardous substances in the form of volatile organic compounds (VOCs), semi-VOCs (SVOCs), and metals (Tidewater 2009). A release of these substances could have also occurred as part of Federal Government or UMN dismantling activities, from post-DuPont/DoD activities, such as the small arms practice rounds encountered during the field work, or other activities occurring since the end of March 1961. Therefore, DNT, DPA and other substances associated with the flow of wastewater could be present in the waste disposal ditch. However, DNT detected in the Primary Settling Basin may have come from sources other than the production of smokeless powder (Tidewater, 2009) due to other historical site activities.

Current Uses of AOC 1N, AOC 1M and AOC 1S AOC 1N is located on private property. The waste disposal ditch, settling ponds and surrounding areas of AOC 1M and AOC 1S are now used for agricultural, wildlife management, and recreational purposes. Included in these portions of AOC1 are regions of mixed pine and hardwood forest and grassland. Some of the agricultural lands have been allowed to return to open field and prairie habitats. Remnants of the dam/weir structure and some of the buildings associated with the secondary settling basin, including the chemical storehouse building and still-well, can be observed in AOC 1S. The ditch in AOC 1M is vegetated and is normally dry with the exception of seasonal rain events during which it is a pathway for surface runoff. Surface water is usually only observed in AOC 1S below the former dam/weir structure (Tidewater 2009).

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UMP029081


2-4

September 16 and 17, 2009 Site Visit Observations at AOC 1M and AOC 1S Observations could not be made at AOC 1N during the site visit due to the inability to obtain access from the current property owner within the time frame required. Due to the extensive size of AOC 1, representative sections of AOC 1M and AOC 1S were viewed during the site visit conducted in September 2009. Both AOC 1M and AOC 1S were accessed by car, with subsequent walking from the access roads. A portion of the former Coates Dump, which was covered by vegetation, was observed at the northern border of AOC 1M. At the time of the site visit, the primary settling basin was an open field habitat.

In the recent history, this area was used for agricultural purposes; however, it was recently allowed to return to a natural field habitat. With time, the primary basin may return to native prairie habitat. The primary settling basin was relatively flat in elevation with a slight increase in grade approaching the stands of mature trees bordering the field. There was little exposed soil within the field of the settling basin. Cow vetch (Vicia cracca), rhubarb (Rheum sp.), common mullen (Verbascum thapsus), ragweed (Ambrosia sp.), and clover (Trifolium sp.) were among the plants observed in the field habitat, and some of these species are commonly associated with disturbed conditions. Spruce and pine trees located at the edges of the field provide suitable edge habitat.

Little bird activity was observed in the field during the site visit, probably in part because of fall migration. However, a blue jay (Cyanocitta cristata) was observed flying overhead and turkey feathers (Meleagris gallopavo) were present on the ground at several locations along the edge of the field habitat. Further, numerous hawks (species undetermined) were observed throughout FGOW property and likely frequent any of the AOCs. Additional organisms observed at AOC 1M included grasshoppers, caterpillars of the Isabella tiger moth (Pyrrharctia isabella), cicadas, and a variety of dragonflies.

The drainage ditch of AOC 1M contained no running or standing water at the time of the site visit, but the trees bordering the walking trail and along the banks of the drainage ditch included very tall, mature cottonwoods (Populus deltoides). Poison ivy (Toxicodendron radicans) was commonly observed at AOC 1M, particularly along the unpaved dirt walking trail leading to the ditch and along the banks of the ditch. Tracks of several animals were observed along the walking path leading to AOC 1M. These included raccoon (Procyon lotor), white-tailed deer (Odocoileus virginianus), and an aquatic dependent bird species, such as a great blue heron (Ardea herodias) and sandhill crane (Grus canadensis).

AOC 1S contained both open field and prairie-like habitat similar to that identified at AOC 1M, as well as wooded areas with mature trees, bushes, and shrubs along the edges of the drainage ditch. Insects observed in the field habitat included butterflies, bees, and crickets. The wooded areas along the ditch slope down towards the drainage system and several woodpeckers (species undetermined) were heard calling from the tree canopy. A former dam/weir structure was identified, which prevents

E05MN001901_01.09_0003_a

UMP029082


2-5

water movement throughout AOC 1S. Surface water was observed in a portion of the drainage ditch, although there was minimal flow and areas with water were, at times, separated by exposed sediments. Thus, the water was pooled in certain areas of AOC 1S, including the immediate vicinity of the former dam/weir structure. At this pool, white-tailed deer and raccoon tracks were observed.

No fish, amphibians, or reptiles were observed in the vicinity of the water during the site visit. However, according to accounts from previous site visits and field sampling events, normal water level and flow were likely impacted by the extremely dry conditions experienced by Dakota County in the month prior to the site visit. Historical and recent accounts indicate that flow is typical in this portion of the drainage ditch in AOC 1S. Also observed within the limits of AOC 1S was a still-well, a structure historically used to measure water level in the drainage ditch, reportedly with a mercury-based instrument. Animal scat (unknown taxa) was observed on top of the structure.

There was no observed human activity or evidence of such at AOC 1M during the site visit. However, there are unpaved dirt paths adjacent to this AOC that allow for access. AOC 1S is located in the Vermillion Highlands, which “is a 2,822-acre research, recreation and wildlife management area (WMA) adjacently south of UMore Park. The property is jointly managed by the University of Minnesota and the Minnesota Department of Natural Resources (DNR), in conjunction with Dakota County” (UMN 2009). Representative photographs of AOC 1M and AOC 1S from the site visit conducted in September 2009 are presented in Appendix A.

Legislation was signed in 2006 that set aside the Vermillion Highlands to remain a natural area for public recreational use in perpetuity. The Highlands is used simultaneously for research, wildlife management activities, and recreational activities on Lone Rock Trail. Lone Rock Trail is comprised of a series of named loop trails encompassing a total of 10.5 miles. Horseback riding is currently permitted from April 1 through October 31 and hiking is permitted from January 2 to October 1. Additionally, cross country skiing is available, conditions permitting, between December 14 and March 31. Car access to the trail system is limited to one access point and there is a daily fee to be paid for use. “Vermillion Highlands, the state's first and only modified WMA, offers a variety of hunting activities throughout the year. Permitted trapping, archery and firearms hunting provide for responsible management of turkey, deer, pheasant, goose, coyote, raccoon and other animals per the regulations provided by DNR” (UMN 2009). Thus, AOC 1S is frequented by people for a variety of recreational activities throughout the calendar year.

2.1.2 AOC 6 – 154th Street Disturbed Area Historical AOC 6 Description and DoD Uses The 154th Street Disturbed Area (AOC 6) lies between Patrol Road and 155th Street. This area is a football-field-size depression with sloped borders containing large amounts of surface and buried construction debris. AOC 6 appears to be a

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reclamation area or borrow area, an area or excavation from which soil, clay, sand, rock, or gravel has been excavated for a specific purpose or use. Although no records were found to indicate the date the debris was deposited, this area may have been in use during demolition and dismantlement activities during and immediately following the operation of FGOW. It is also possible that some debris may have been placed at AOC 6 more recently (Tidewater 2009).

Contamination of AOC 6 Associated with Historical DoD Activities Historical DuPont/DoD activities at FGOW may have potentially contributed polycyclic aromatic hydrocarbons (PAHs) and metals at AOC 6 (Tidewater 2009).

Current Uses of AOC 6 This area does not appear to be currently managed by the UMN for any agricultural or wildlife activities. AOC 6 is currently inactive and is surrounded by agriculture fields.

September 16 and 17, 2009 Site Visit Observations at AOC 6 AOC 6 was accessed by Patrol Road, which leads to an unnamed dirt haul road immediately adjacent to the AOC. AOC 6 was bordered to the east and north by corn fields, to the south by the dirt haul road used for access, and to the west by Patrol Road. The corn plants at the edges of the crop field adjacent to AOC 6 appeared stressed; however, stressed corn was present at the perimeter of several fields observed throughout the property and may have been due to the extremely dry conditions. Signs of stress included yellow and brown discoloration of leaves. Piles of small rocks spanning several feet along the dirt haul road at the top of the sloped sides of AOC 6 created potential habitat for smaller vertebrates such as toads or snakes, neither of which were observed during the site visit.

AOC 6 was primarily covered with dense knee-high grasses (presumptive Poa sp.) with little exposed soil. Sparse mature stands of trees, dominated by Chinese elms (Ulmus parvifolia), were present along the sloped sides and base of the AOC 6 depression. Additional plants observed at AOC 6 included common mullen (Verbascum thapsus) and grape vines. Debris including rebar, concrete, and asphalt were visible on the ground surface. Much of the debris was partially covered by the ground, with pieces of the debris protruding from beneath the surface. The debris created numerous holes and depressions, with tripping hazards for both human and animal visitors. The debris also created burrowing and denning habitats, which were actively being used by wildlife. Butterflies, spiders, grasshoppers, beetles, cicadas, and evidence of termites were observed at AOC 6.

Coyote (Canis latrans) scat was observed adjacent to AOC 6 on the haul road. Eastern bluebirds (Sialia sialis), red-bellied woodpeckers (Melanerpes carolinus), and downy woodpeckers (Picoides pubescens) were observed during the site visit within or immediately adjacent to AOC 6. Turkey feathers and possible evidence of deer bedding was also observed at AOC 6. There was no evidence of recent active use by human receptors; however, it is possible that personnel working in the adjacent corn

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fields may sit on the slopes of AOC 6 during breaks. Due to the numerous debris and associated tripping hazards, it is expected that AOC 6 would be infrequently used by human receptors. Representative photographs of AOC 6 from the site visit conducted in September 2009 are presented in Appendix A.

2.1.3 AOC 7A and 7D – Steam Plant and Associated 26.7 Acres Historical AOC 7A and 7D Description and DoD Uses AOC 7 is located in the northeast corner of FGOW, east of Blaine Avenue. In addition to the Steam Plant Building 401A, other FGOW-facility support structures were located on the 26.7-acres. Construction of the FGOW facility began in 1942. Records indicate that the Steam Plant became operational in mid-1943. Production operations finally began in January 1945, but production only occurred on lines A, B, and C with final operations ending in September 1945. Lines D, E, and F were never completed or made operational. Dismantlement and decontamination of FGOW facilities were conducted in 1945 and 1946 (Tidewater 2009). Only AOC 7A and AOC 7D are evaluated in this SLERA, based on the results of previous investigations (Tidewater 2009).

AOC 7A is located in the northwest quadrant of AOC 7. The main historical features and/or buildings in this area included the following (Tidewater 2009):

402-A Water Reservoir including:

412-A Pump House (attached to the south side of Building 402-A) Transformer Pads, south of Building 412-A Water Inlet House (attached to the north side of Building 402-A) 53-TC47 Boiler House

AOC 7D is located in the southwest quadrant of AOC 7. The main historical features and/or buildings in this area were the following (Tidewater 2009):

401-A Steam Plant A (also referred to as Power House) 401-AA Flash Mixer 401-AA1 Precipitators Drainage Ditch 405-A Electrical Substation (Transformer pads) Fuel Oil Tanks 410-A Ash Disposal Pit and Sump Secondary Containment Reservoir Soft Water Tank (Water Tower)

Contamination of AOC 7A and AOC 7D Associated with Historical DoD Activities Historical DoD operations at FGOW may have potentially contributed polychlorinated biphenyls (PCBs), industrial solvents and degreasers, POLs, and heavy metals at AOC 7A. Operations at FGOW may have potentially contributed the following substances at AOC 7D: nitrocellulose, DNT, DPA, industrial solvents and

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degreasers, POLs, mercury, SVOCs, heavy metals, oleum, sulfuric and nitric acids, and PCBs. Current Uses of AOC 7A and AOC 7D The majority of AOC 7A contains remnants of the collapsed buildings (water reservoir, pump house, and water inlet house). The Boiler House is no longer present. Features currently remaining at AOC 7D include remnants of foundations and towers with the exception of the secondary containment reservoir and water tower. AOC 7A and AOC 7D do not appear to be currently managed by the UMN for any agricultural or wildlife activities (Tidewater 2009).

September 16 and 17, 2009 Site Visit Observations at AOC 7A and AOC 7D AOC 7 was accessed by car using Blaine Avenue during the September 2009 site visit. AOC 7A, most of which is currently surrounded by a chain-link fence, is dominated by the presence of the building remnants. Open land with grasses (likely Poa sp.), few trees (Chinese elms), and grape vines were present at AOC 7A. A small stand of maple trees (Acer sp.) is present at the edge of AOC 7A along the access road. This area is a relatively flat disturbed habitat with a slight rise in elevation of approximately two feet to the former water reservoir building. Although the AOC is surrounded by a fence, it is easily accessed through an unlocked gate. Evidence of recent human use, including the presence of multiple candles and graffiti, was observed in the building. Once inside the fence, access to the building is not restricted. Animal scat was observed adjacent to AOC 7A on the dirt access road. A bird nest and wasp nest were observed in the building and a house wren (Troglodytes aedon) was observed at AOC 7A.

In addition to the building remnants, AOC 7D currently contains wooded areas, open land with grasses and exposed soil, and remnants of building towers and foundations. Rows of pre-cast concrete structures several feet in diameter are placed in an area immediately east of the power house. The wooded area consists of cottonwood trees (Populus deltoides), few aspens (Populus tremuloides), wild grape, and invasive spotted knapweed (Centaurea maculosa). Herbaceous herbs and creeping vines dominated the understory of the forested area, including Virginia creeper (Parthenocissus quinquefolia). The open areas of AOC 7A were disturbed vegetated areas dominated by grasses, some invasive plant species, and very dry, exposed soil. Plants observed in the disturbed field habitat included ragweed, clover, alfalfa (Medicago sativa), and spotted knapweed.

Evidence of use by white-tailed deer was observed in the disturbed field, including the presence of a large number of tracks. Elm trees were present throughout AOC 7D, particularly in the disturbed area immediately east of the foundation and stack remnants. The remains of the buildings, including the stacks, provide potential habitat for raptors and bats, although the openings of the stacks may allow too much daytime light infiltration for suitable bat habitat. Rock doves (Columba livia) were observed perching on the stacks and a red-tailed hawk (Buteo jamaicensis) feather was observed on the ground adjacent to one of the stacks. Bird nests were present in the

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light fixtures on the walls of the stacks. Crickets, grasshoppers, and cicadas were present at AOC 7D.

Adjacent to one of the stacks was the remains of a vertical structure manufactured by “Carbon Air Services”. The top was open to the elements allowing for rain water to collect in the bottom of the structure. There was a hole in the bottom of the structure allowing for access by small animals. This created a small aquatic habitat with standing water and vegetation, including mosses, on the rocks inside. Standing water is also present within a concrete lined depression in the Power House building.

Although some of the building remains are surrounded by fencing, they are easily accessed through openings. There was evidence of human activities, including the presence of graffiti inside the stacks, several of the pre-cast concrete structures near the stacks, and within the Power House building. The graffiti within the Power House building consisted of extensive drawing on the walls, likely done over a lengthy period of time by one or more individuals. Additional evidence of human activity at AOC 7D included cans and bottles from alcohol consumption and paintball residue. Representative photographs of AOC 7A and AOC 7D from the site visit conducted in September 2009 are presented in Appendix A.

2.1.4 Background Sampling Areas Several potential background locations were identified and visited in preparation for sample collection. The criteria for selection of background samples in order of priority included:

the potential background locations were to be within areas of the property not utilized for historical DoD activities

habitats of these background areas would be similar to those of the AOCs Due to the extensive use of much of the property for DoD-related activities, current use and habitats of background areas may not be consistent with the habitat types found within the majority of the AOCs. It should be noted that the background areas may have been used for other activities following DoD use of the property and, therefore, are likely not impacted.

The first area selected for proposed background sample collection was a farm located north of AOC 6. As this area was not utilized by DoD, samples were to be collected from atop a small hill currently used as a pasture. The pasture consists of grassed covered areas and some exposed soil. No drainage or water features were present, although it is likely that water may collect at the base of the hill during rain or melting events. It appears that some of the grasses present in the pasture may be consistent with grasses present throughout the AOCs. At the time of the site visit, a hawk was observed in the distance, landing in the trees bordering the fields selected as a background location. This location was selected primarily based on the first criterion.

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The second area selected for background sample collection was east of AOC 7 and covered with grasses, trees, and a corn field. This area is in the vicinity of a former railroad bed, although the exact location of the railroad was not clearly identified in the field. The corn plants at the edges of the crop field were stressed; however, stressed corn was also observed throughout the property and may have been affected by the extremely dry conditions. Signs of stress included yellow and brown discoloration. Samples were not proposed to be collected from beneath the stressed corn plants. White-tailed deer tracks were observed immediately adjacent to the proposed sample locations. Thus, this location was selected primarily based on the first criterion as it was not impacted by DoD activities but is probably not impacted.

Two areas were selected for proposed background sample collection within the Vermillion Highlands. Specifically, one of the locations, which is likely not impacted by any anthropogenic source, is located within a sandstone outcrop. This area was not utilized for DoD activities and was not subsequently developed or used as farm land. It includes a wooded trail and displayed a gradual elevation up to the top of the sandstone formation. Several large sandstone boulders were identified. Mature trees, including oaks (Quercus sp.), dominated the area observed and acorns were present on the ground. Blackberry (Rubus sp.) was identified in the understory and woodpeckers could be heard in the canopy. Thus, this location met both criteria for selection. The second area within the Vermillion Highlands was on Lone Rock Trail. This area had mature trees and an understory with blackberry vines and common buckthorn (Rhamnus cathartica), among other vegetation. Blue jays (Cyanocitta cristata) could be heard in the trees. This area was also believed to be undeveloped both by DoD and by subsequent users of the land and, thus, met both criteria for selection.

The final area selected for proposed background sample collection was located along the edge of a soybean crop field to the west of the northern section of AOC 1M. White-tailed deer tracks, turkey feathers, and grasshoppers were observed between the field and the proposed sampling location. The sampling location was within a mature tree line adjacent to the cropland. Grasses similar to those identified within the boundaries of AOC 6 were present beneath the stand of trees.

2.1.5 Vertebrate Species Present at or in the Vicinity of the FGOW A site visit, not a survey, was conducted in September 2009, to record observations regarding habitats and species present at the site. Although the DNR has not completed a formal, complete survey of species present for all or part of their life cycle at the FGOW and the Vermillion Highlands, the agency provided a list of the common vertebrate species observed (personal communication). The list should not be considered necessarily complete for the above stated reasons and is amended by DNR as new species are observed. Thus, the list of vertebrate species observed by DNR is provided in Table 2-1 (personal communication).

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2.1.6 Threatened and Endangered Species and State Species of Special Concern Present at or in the Vicinity of the FGOW As stated previously, DNR provided a list of the Federal and State Listed Threatened and Endangered Species and State Species of Special Concern observed on the property (personal communication, Tim Pharis, DNR, 10/12/09). They include the following:

Trumpeter Swan (Cygnus buccinator) – State Threatened Bald Eagle (Haliaeetus leucocephalus) – State Species of Special Concern Loggerhead Shrike (Lanius ludovicianus) – State Threatened Blanding’s Turtle (Emydoidea blandingii) -- State Threatened

Additionally, DNR recently published an on-line Rare Species Guide database of threatened, endangered, and special concern species confirmed in the State of Minnesota (DNR 2009). It should be noted that surveys are completed only on State lands and are completed on private lands if DNR receives information about a sighting. The lists may not be complete, since surveys are updated as new information is received and surveys on private lands typically only include confirmation regarding the particular species about which DNR receives information. This database can be sorted by group (e.g., mammal or reptile), status (e.g., federally threatened), and by county. This database was queried for: all groups; federal and state threatened and endangered species and state species of special concern; and Dakota County, within which FGOW and the adjacent Vermillion Highlands are located. Thus, the list of species (79 in total) meeting these criteria is presented in Appendix B.

2.2 Exposure Pathway Evaluation and Site Conceptual Exposure Model 2.2.1 Exposure Pathways Exposure pathways indicate how ecological receptors can come in contact with hazardous chemicals or contaminated media. Incorporated into the exposure pathway evaluation are fate and transport mechanisms from a source in one medium or area to another and exposure routes to receptors. The fate and transport mechanisms are ways by which chemicals in contaminated media may be released to other media or other locations. Exposure routes are ways chemicals enter ecological receptors and include direct exposures, such as ingestion, dermal contact or inhalation, and indirect exposures, such as food web exposures via consumption of contaminated food items. The exposure pathway evaluation is presented below for each AOC. This approach facilitates future decision making with regard to remediation or closure on an AOC-specific basis. If potential ecological threats are identified in this SLERA then a BERA may be warranted, AOCs adjacent to each other and with similar habitat types may be evaluated as a single exposure unit for certain wide ranging receptors in a BERA.

Exposure pathways are described with regard to completeness, significance, and ability to evaluate based on data availability. The SCEM for each AOC illustrates

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complete and incomplete ecological exposure pathways. Complete and significant exposure pathways are evaluated in the SLERA. However, some of the exposure pathways identified as complete are not quantitatively evaluated in this SLERA because these pathways are either insignificant, data are lacking to quantify such exposures, or they are sufficiently represented by other pathways. Pathways, such as these, are qualitatively discussed. The SCEM for AOC 1N, AOC 1M, AOC 6, AOC 7A, and AOC 7D is presented as Figure 2-1. The SCEM for AOC 1S is presented as Figure 2-2.

2.2.1.1 AOC 1 – Waste Disposal Ditch, Primary and Secondary Settling Ponds Surface soil, surface water, and sediments in the AOC 1 drainage system may have been contaminated by the waste water released to the drainage ditch and by waste deposited in the former Coates Dump, the latter of which is not evaluated in the SLERA. Additionally, surface water and sediments present at AOC 1S may have received chemicals from historical site activities during surface runoff from surface soils during rain events.

Chemicals in surface soil (AOC 1N, AOC 1M, and AOC 1S) may be taken up by terrestrial plants through their root systems and terrestrial invertebrates, such as earthworms, may be exposed via direct dermal contact with and ingestion of soil. Terrestrial vertebrates, including those that burrow, may be exposed to chemicals in soil via direct contact, ingestion, inhalation, or ingestion of contaminated food items (e.g., plants and invertebrates). Omnivorous vertebrates may be exposed to chemicals in surface soil via direct contact, incidental soil ingestion or ingestion of contaminated food items (e.g., plants and invertebrates). Carnivorous vertebrates may be exposed to chemicals in surface soil via direct contact, ingestion, or ingestion of contaminated food items (e.g., invertebrates and small mammals). The SCEM for AOC 1N and AOC 1M is provided as Figure 2-1.

Chemicals released to surface water (AOC 1S) in the drainage ditch could either remain suspended in the water column or settle onto the sediments. Aquatic invertebrates present in the drainage ditch could be exposed to chemicals via ingestion of contaminated sediments or direct exposure to chemicals in the water column or in sediment pore water. Fish and larval amphibians could be exposed through direct contact with chemicals in surface water or sediment or through ingestion of contaminated food or prey items (e.g., invertebrates and algae). Water-dependent/piscivorous birds and mammals could be exposed to chemicals in sediment and surface water via direct dermal contact with and ingestion of those media or indirectly via ingestion of contaminated aquatic prey items that have taken in chemicals from those media. The SCEM for AOC 1S is provided as Figure 2-2.

2.2.1.2 AOC 6 – 154th Street Disturbed Area Chemicals may have been directly deposited on the ground surface with the demolition debris. Thus, surface soil may have been contaminated and chemicals may potentially migrate across the ground surface within the AOC via over-land flow

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during rain events. Subsurface soil and groundwater may have been contaminated via the leaching pathway.

Chemicals in surface soil may be taken up by terrestrial plants through their root systems and terrestrial invertebrates, such as earthworms, may be exposed via direct dermal contact with and ingestion of soil. Terrestrial vertebrates, including those that burrow, may be exposed to chemicals in soil via direct contact, ingestion, inhalation, or ingestion of contaminated food items (e.g., plants and invertebrates). Omnivorous vertebrates may be exposed to chemicals in surface soil via direct contact, incidental soil ingestion, or ingestion of contaminated food items (e.g., plants and invertebrates). Carnivorous vertebrates may be exposed to chemicals in surface soil via direct contact, incidental ingestion, ingestion of contaminated food items (e.g., worms and small mammals). Since no surface water is present at or in the vicinity of this AOC, no complete exposure pathway for aquatic or water-dependent receptors exists. The SCEM for AOC 6 is provided as Figure 2-1.

2.2.1.3 AOC 7A and 7D – Steam Plant and Associated 26.7 Acres Former operations at the steam plant, including leaks or spills at the plant, may have contaminated the surface soil at both of these AOCs. The chemical migration and exposure pathway analysis described above for surface soil at AOC 6 is applicable for AOC 7A and AOC 7D. Since no surface water is present at or in the vicinity of these AOCs, no complete exposure pathway for aquatic or water-dependent receptors exists. The SCEM applicable to both AOC 7A and AOC 7D is provided as Figure 2-1.

2.2.2 Site Conceptual Exposure Model One major outcome of problem formulation is the preliminary SCEM, which describes potential exposure pathways and reveals the potential or likely relationships between stressors (e.g., chemicals), receptors, assessment endpoints, and measurement endpoints for each medium of concern at each AOC. The SCEM graphically depicts relationships between primary and secondary chemical sources, chemical migration pathways, exposure routes, and receptors. Receptors are depicted as general categories (e.g., aquatic invertebrates, terrestrial plants, etc.).

Pathways considered complete but not quantitatively evaluated include inhalation of volatile organics for burrowing mammals, direct contact with and ingestion of sediment pore water, and dermal absorption for terrestrial vertebrates due to lack of data.

Terrestrial vertebrates are assessed primarily using birds and mammals as representative receptor groups. This approach is based on the sparse toxicity data for other vertebrate groups (i.e., reptiles and amphibians). Therefore, this SLERA focused on potential threats associated with the uptake (by plants), direct contact (animals), and ingestion (animals) of chemicals associated with historical use of each AOC in multiple media (soil, sediment, and surface water), when applicable, via various pathways (e.g., ingestion of soil, plants, or prey).

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Risks to upper trophic level receptors, like insectivorous birds, carnivorous birds, and omnivorous or carnivorous mammals, are relevant only if the COPCs identified at this site are bioaccumulative. Most of these types of receptors would receive their highest chemical doses via ingestion of contaminated food items (plants or prey). Risks to upper trophic level receptors based on food web exposures are typically not quantitatively evaluated in Steps 1, 2 or 3a of the ERA process. Thus, chemicals in soil are compared to soil ecological screening levels (ESLs) that consider bioaccumulation and risks to upper trophic level receptors.

Eco-SSLs (EPA 2008) and other similar ESLs are used in this SLERA to identify chemicals that warrant further or more in-depth evaluation. Exceedences of these ESLs indicate that further evaluation is needed. If the results of the SLERA and Step 3a suggest that detected chemicals have potential to bioaccumulate and adversely affect upper trophic level receptors based on a direct comparison to ESLs at these steps of the ERA process, the SLERA recommends that they be quantitatively evaluated in subsequent steps of the ERA process.

2.3 Assessment Endpoints Assessment endpoints are those parts of the environment that should be protected from adverse effects associated with exposure to site contamination. The definition of an assessment endpoint includes an entity (such as soil invertebrates) and a measurable property of the entity, (such as reproduction, growth, or survival). For ERAs, EPA defines an assessment endpoint as “an explicit expression of the environmental value that is to be protected” (EPA 1997). Valuable ecological resources include those without which ecosystem function would be significantly impaired (e.g., mortality of a prey base), those providing critical resources (e.g., habitat), and those perceived as valuable by humans (e.g., endangered species and commercial or game species).

Selected assessment endpoints consider key ecosystem, community, or ecological functions, chemicals present, the extent and magnitude of contamination, mechanisms of toxicity, susceptibility to the toxicity of the COPCs, and potential exposure pathways. Adverse effects typically include impairment to growth, reproduction, or survival. ERAs generally consider effects at the population or community level, but may also consider effects at the individual organism level for special status (e.g., Threatened and endangered) species. Since the SLERA is a conservative assessment, assessment endpoints are provided as general statements at this stage of the process. The assessment endpoints listed below are focused on protection of populations and communities, but it is implied that similar endpoints would be applicable to individuals of special status taxa. The terrestrial and aquatic assessment endpoints for this SLERA and Step 3a are listed below. If assessment endpoints are modified in Step 3a, they are discussed in that section.

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Terrestrial Assessment Endpoints:

Protection of growth, survival, and reproduction of terrestrial plant communities exposed to chemicals in surface soil

Protection of growth, survival, and reproduction of terrestrial invertebrate communities exposed to chemicals in surface soil

Protection of amphibians and reptiles to ensure that direct contact with and ingestion of chemicals in water, sediment, soil, and prey do not have an adverse impact on survival, reproduction, or growth.

Protection of herbivorous birds and mammals to ensure that ingestion of chemicals in soil and plants does not have negative impacts on growth, survival, and reproduction

Protection of growth, survival, and reproduction of small terrestrial omnivorous mammal communities exposed to chemicals in surface soil via direct contact, incidental soil ingestion, or ingestion of contaminated food items (e.g., plants and invertebrates)

Protection of insectivorous birds to ensure that ingestion of chemicals in surface soil and prey does not have negative impacts on growth, survival, and reproduction

Protection of carnivorous birds and mammals to ensure that ingestion of chemicals in prey does not have negative impacts on growth, survival, and reproduction

Aquatic Assessment Endpoints:

Protection of aquatic invertebrate, larval amphibian, and fish communities from the toxic effects (on survival and growth) of site-related chemicals in sediment or surface water

Protection of water-dependent piscivorous bird and mammal communities to ensure that ingestion of chemicals in surface water, sediment, and prey does not have negative impacts on growth, survival, and reproduction

2.4 Measurement Endpoints Measurement endpoints are chosen to link existing site conditions and data to the goals established by the assessment endpoints. Measurement endpoints are quantitative expressions of observed or measured biological responses to contamination relevant to selected assessment endpoints. For a SLERA, ESLs are commonly used as measurement endpoints. For this SLERA, measurement endpoints are based on the most conservative ESLs for each medium from the sources discussed in Section 4. The measurement endpoints are used to calculate hazard quotients

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(HQs), thus providing a quantitative expression of risk. These HQs are used in the following manner for estimating risks:

For terrestrial organisms (all AOCs): comparison of exposure (site-related) HQs to a HQ of 1. Exposure HQs are calculated for individual chemicals by dividing the soil concentrations by terrestrial-based ESLs.

For aquatic organisms (AOC 1S): comparison of exposure HQs to a HQ of 1. Exposure HQs are calculated for individual chemicals by dividing the surface water and sediment concentrations by aquatic-based surface water or sediment ESLs.

2.5 Ecological Risk Questions Ecological risk questions, or testable hypotheses, are questions about the relationships between assessment endpoints and the predicted responses of receptors when exposed to chemicals. Risk questions summarize important components of the problem formulation phase of the SLERA. Risk hypotheses are developed from assessment endpoints, representative receptors, and potentially complete exposure pathways, and provide a basis for identifying needed studies and evaluating study results. Risk questions are directly related to testable hypotheses that can be accepted or rejected using the results of the SLERA. Selected risk questions to be answered in this SLERA are as follows:

Are site-related chemicals present in surface soil, sediment, or surface water at one or more AOC where ecological receptors may be exposed?

□ This question is addressed in the Exposure Assessment phase of the

SLERA.

Where present, are the concentrations of chemicals from historical DoD activities sufficiently elevated to impair the survival, growth, or reproduction of sensitive ecological receptors?

□ This question is addressed in the Effects Assessment and Risk

Characterization phases of the SLERA. .

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Section 3 Exposure Assessment The Exposure Assessment component of the SLERA summarizes and evaluates available exposure data on ecological receptors or receptor groups described in Problem Formulation. The purpose of this section is to evaluate the potential for receptor exposure to potentially hazardous chemical constituents at the site. The primary output of Exposure Assessment is an exposure profile that presents the magnitude and distribution of chemicals to which ecological receptors may be exposed. Exposure profiles for chemical stressors serve as input into the final stage of the SLERA, Risk Characterization. Exposure profiles describe the (1) chemical properties related to exposure potential for the site COPCs including chemical fate and transport, (2) the magnitude and distribution (i.e., concentrations and geographic distribution) of COPCs identified in the Problem Formulation phase, and (3) exposure information relevant to representative ecological receptors or receptor categories.

3.1 Media of Concern The medium of concern for AOC 1N, AOC 1M, AOC 6, AOC 7A, and AOC 7D is surface soil, since no aquatic resources are present in these AOCs. The media of concern for AOC 1S include surface soil, sediment, and surface water.

3.2 Data Included in the SLERA In accordance with the United States Army Corps of Engineers (USACE) June 10, 2009 Scope of Services (SOS), the goal of the Expanded Site Investigation (SI) is to obtain and analyze environmental samples, to investigate potential human and environmental exposure to hazardous substances, and to perform a risk screen for human health and ecological risk (combining data obtained under this SOS with data from the Focused SI) (Tidewater, 2009). Therefore, this SLERA includes data collected from AOC 1N, AOC 1M, AOC 1S, AOC 6, AOC 7A, and AOC 7D during field sampling programs conducted as part of the Focused SI and the Expanded SI. The data collected from these environmental investigations are combined into one data set for each AOC. Sample locations and detected analytes per medium for each AOC are presented in Figures 3-1 to 3-8b. A summary of samples used in the SLERA, including the number of samples per medium for each AOC and the laboratory analytical methods, is provided in Table 3-1.

Although background locations were identified from which samples were collected, the results are not included in this SLERA for purposes of selecting COPCs for each AOC, since chemicals are not eliminated as COPCs based on a comparison to background concentrations or low frequency of detection. A summary of the data collection efforts and analytical results for each site investigation are provided below.

3.2.1 Soil Samples In the Focused SI, surface soil samples were collected from 0-6 inches below ground surface (bgs). All volatile organic compounds (VOCs), semi-volatile organic

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compounds (SVOCs), polycyclic aromatic hydrocarbons (PAHs), diesel range organics (DRO) and nitrocellulose samples were collected as discrete aliquots from the middle of the interval without homogenization. All remaining samples were collected from homogenized soil over the depth interval. In the Expanded SI, surface soil samples also were collected from 0 to 6 inches bgs. Although subsurface soil samples were collected as part of these site investigations, this SLERA only includes soil samples collected from 0 to 6 inches bgs to evaluate ecological receptors’ direct contact with and ingestion of surface soil.

3.2.2 Surface Water Samples Two surface water samples were collected at AOC 1S during the Focused SI and three additional surface water samples were collected during the Expanded SI. Surface water samples were collected just below the water surface. Surface water samples were analyzed for VOCs, SVOCs, Resource Conservation and Recovery Act (RCRA) metals, dinitrotoluene (DNT), and nitrocellulose. Surface water samples were not collected from any AOC other than AOC 1S. 3.2.3 Sediment Samples Sediment samples were collected from 0 to 4 inches bgs. Two sediment samples were collected at AOC 1S during the Focused SI and analyzed for VOCs, PAHs, RCRA metals, DNT, and nitrocellulose. Three additional samples were collected at AOC 1S during the Expanded SI and analyzed for PAHs, RCRA metals and DNT. Sediment samples were not collected from any AOC other than AOC 1S. 3.3 Chemical Classes of Interest Historical site information and the results of sample collection from the AOCs of interest during the Focused SI and Expanded SI field investigations indicate that several chemical classes are present at concentrations in media of concern at each AOC that require evaluation. The chemical classes of interest (COIs) include PCBs, metals, VOCs, SVOCs, and explosives. In addition, nitrocellulose has been detected as part of chemical analysis during field investigations conducted to date, particularly in each medium of concern at AOC 1, and soil at AOC 7D. The chemical and physical properties of each of these chemical classes are summarized below.

3.4 Chemical and Physical Properties of Classes of COIs Information about classes of chemicals is necessary to effectively evaluate risks associated with COPCs. This information includes an understanding of the mechanism of toxicity, environmental fate and transport, and bioaccumulation potential for each class of COPCs.

3.4.1 Mechanisms of Toxicity Inorganic Constituents Inorganic constituents have been detected in surface soil in each medium of concern at one or more AOC. Many inorganic chemicals, including metals, are relatively

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nontoxic to ecological receptors, and some are essential for life. These include, for example, calcium, magnesium, sodium, potassium, copper, and zinc. Some of the essential elements can be toxic at elevated concentrations or in certain forms. For example, elevated levels of dissolved copper and zinc can be quite toxic to fish and other aquatic life even though low concentrations are biologically essential. Other metals, such as cadmium, mercury, and arsenic are not essential and, in fact, can be highly toxic at very low exposure concentrations.

Some of the most toxic metals like mercury and cadmium also accumulate in biological tissues (i.e., are considered bioaccumulative). Mercury is known to biomagnify, resulting in adverse effects in upper trophic level receptors. The bioavailability and toxicity of metals can be affected by the chemical form of the metal. For example, dissolved metals are frequently implicated in toxic effects while metals bound to particulate matter are generally less bioavailable and exhibit lower toxicity to aquatic life. The aquatic toxicity of other metals, such as aluminum, is most influenced by water pH. In soils, increased acidity (lower pH) often increases the bioavailability of metals. The variable toxicity of metals can be revealed by comparing accepted criteria, benchmark concentrations, or screening levels for individual metals.

PCBs PCBs are a group of toxic and bioaccumulative compounds that can cause adverse effects in lower and especially in upper trophic level biota. One or more PCB Aroclors have been detected in abiotic media samples collected at one or more AOC. PCBs include many individual congeners, some of which are highly toxic while others are less so. PCB concentrations can be reported as concentrations of individual congeners, as total PCBs, or as Aroclors. Aroclors such as 1242, 1248, 1254, and 1260 are industry-derived mixtures of various congeners. PCBs are readily accumulated in aquatic biota and, therefore, predators linked to aquatic environments such as mink, raccoons, and piscivorous birds can be at significant risk. Some fish can accumulate high levels of PCBs without suffering observable effects while posing substantial risks to piscivorous wildlife.

PCBs are persistent in the environment and degradation by biological and other means is minimal. Most of these compounds are lipophilic, with a tendency to accumulate in the liver and other fatty tissues of biota. Levels of PCBs assumed to be safe for exposed biota are often very low due to bioaccumulation-related risks. Safe levels of total PCBs in soil are generally considered to be at or below about 1 part per million (mg/kg), depending on the receptor warranting protection. For water exposures, concentrations of total PCBs below 1 microgram per liter (µg/L) can cause adverse effects in exposed aquatic biota.

VOCs VOCs are rarely implicated as major contributors to adverse ecological effects, primarily because they are not often persistent in surface media. In some cases, however, VOCs can cause adverse effects where a continuing source occurs, such as a groundwater discharge to surface waters. VOCs are not persistent in sediments or

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surface soils, but may persist in groundwater and deeper soils. Exposure to VOCs can, therefore, be a concern for burrowing mammals and other wildlife that may contact deeper contaminated soils.

Some VOCs can be quite toxic to exposed aquatic biota, such as fish and larval amphibians. For example, PCE has been shown to cause adverse chronic effects in daphnids at 750 µg/L (Suter and Tsao 1996). Other VOCs can be substantially less toxic to aquatic life. For example, daphnids exposed to 1,1,2-trichloroethane in water begin to suffer adverse chronic effects at 18,400 µg/L (Suter and Tsao 1996). The likelihood of VOCs contributing significantly to adverse ecological effects increases where highly contaminated sources continue to release VOCs to surface media, especially surface water.

SVOCs SVOCs include a wide variety of potential chemicals, most importantly PAHs. PAHs include both low and high molecular weight compounds consisting of hydrogen and carbon arranged in the form of two or more fused benzene rings. Of most concern are PAHs with molecular weights ranging from about 128 (naphthalene) to about 300 (coronene) (Eisler 1987). Within this range are many potentially toxic compounds commonly found in environmental media. Many of the lower molecular weight compounds are acutely toxic but not carcinogenic. In contrast, some of the higher molecular weight compounds exhibit low toxicity but are carcinogenic, mutagenic, or teratogenic to fish, amphibians, birds, and mammals.

Benzo(a)pyrene (BaP) is an example of one of the most potent and ubiquitous of the carcinogenic PAHs. BaP toxicity data for plants are inconclusive, and concentrations in soil as high as 48,000 milligrams per kilogram (mg/kg) resulted in no adverse effects in exposed earthworms (Canadian Council of Ministers of the Environment [CCME] 2002). These data support the assumption of low acute toxicity for the higher molecular weight PAHs. In water, BaP caused chronic toxicity in daphnids at 0.30 µg/L (Suter and Tsao 1996).

Naphthalene is an example of a more mobile and often acutely toxic PAH. Naphthalene concentrations of 54 mg/kg resulted in 25% mortality in exposed earthworms (Environment Canada 1995 in CCME 2002). Daphnids and aquatic plants exposed to naphthalene in water suffered chronic effects at 1,163 µg/kg and 33,000 µg/L, respectively (Suter and Tsao 1996). In spite of the high lipid solubility of some PAHs, they have low bioaccumulation potential in vertebrates because these compounds are rapidly metabolized. PAHs can accumulate in invertebrates that cannot metabolize these compounds. PAHs have low potential for biomagnification and food web effects.

Nitrocellulose Available ecotoxicity data are limited and summarized in PAN, 2009. The few toxicity studies completed indicate that nitrocellulose is not highly toxic. The toxicity results for a single crustacean, a single insect, and four fish species provide a mean toxic dose

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of 1,000,000 µg/L for each of the test species with endpoints of observed stress (crustacean and insect) and mortality (fish). Acute toxicity studies were conducted for several species of phytoplankton (three algae species and a diatom species). The results provided a range of toxic doses from 10,000 µg/L to 1,000,000 µg/L. Finally, two studies evaluating the toxic effects of nitrocellulose on zooplankton provided a mean toxic dose of 1,000,000 µg/L. Collectively, the data indicate that nitrocellulose is not highly toxic to aquatic organisms. Data evaluating the toxic effects on terrestrial organisms were not identified (PAN 2009). Explosives (2,4-Dinitrotoluene and 2,6-Dinitrotoluene) The ecotoxicity data for 2,4-DNT and 2,6-DNT are extremely limited. Toxicity studies located from the literature (PAN 2009) identified an average 2,4-DNT concentration resulting in mortality to half the test organisms (LC50) for the fathead minnow of 29,600 µg/L, which suggested that this chemical may not be highly toxic to aquatic receptors. Specific toxicity studies were not identified for 2,6-DNT.

3.4.2 Environmental Fate and Transport Fate and transport information describes how chemicals degrade and where they travel in the environment, whether naturally occurring or released. Chemicals in the environment are analyzed in terms of a modeling system that indicates not only how the chemicals move through air, water, and soil (transport), but also how the chemicals change in the presence of other chemicals and particles (fate).

Physical processes influencing chemical fate and transport include diffusion (e.g., random movement of molecules) and advection (e.g., flow of groundwater to surface water). Soil erosion, sedimentation, and sediment resuspension describe the sequestering or transport of soil and sediment particles to which chemicals may be sorbed.

Chemical processes that can affect chemical fate and transport include various chemical reactions. Acid-base reactions affect the chemical form of the chemical; precipitation reactions can result in sequestering of chemicals with carbonates, hydrous oxides, and sulfides; and oxidation-reduction reactions can alter the chemical form or speciation of a chemical. Sorption reactions are dependent on the hydrophobic properties of chemicals and the likelihood of sorption of chemicals to soil and sediment particles. These reactions affect bioavailability and toxicity. Volatilization, hydrolysis, photolysis, and ligand complexation can also affect the persistence and properties of chemicals.

Biological processes may also affect chemical fate and transport. Biotransformation is a chemical reaction occurring within an organism that alters the chemical form of a chemical. Chemicals may transfer from the atmosphere, water, soil, and sediment to biota via bioaccumulation. Further, ingestion of contaminated prey or other food items can contribute to chemical exposures to upper trophic level receptors.

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Inorganic Constituents Metals vary widely in chemical form and properties; however, metals differ from organic compounds because none degrade in the environment, many exist naturally in soil and sediment, and a few (e.g., copper and zinc) are essential nutrients for living organisms. The fate of metals in the environment is primarily dependent on sorption, chemical speciation, complexation, biotransformation, and bioaccumulation.

Metals occurring in soil may be sorbed to particles (silt- and clay-size), bound in a complex molecule, bound in a precipitate (e.g., sulfides), or may exist in a free ionic state. The dissolved forms of metals in water represent the most bioavailable and, therefore, potentially most toxic forms to aquatic life. Total analysis, which includes both dissolved and particulate material, may be more important for evaluating ingestion (i.e., drinking) by upper trophic level organisms. Organisms can easily bioaccumulate most dissolved and other highly bioavailable forms of metals.

PCBs PCBs are a group of synthetic organic chemicals that contain many individual congeners with varying harmful effects. There are no known natural sources of PCBs in the environment. Before 1977, PCBs entered the air, water, and soil during their manufacture and use. PCBs also entered the environment from accidental spills and leaks during the transport of the chemicals, or from leaks or fires in transformers, capacitors, or other products containing PCBs. In water, a small amount of PCBs may remain dissolved but most tend to adhere to particles and sediments. PCBs in water concentrate in fish and can reach levels several times greater than the levels in water.

PCBs bind strongly to soil and sediments and may remain there for several years. PCBs partially evaporate from soil surfaces to air. In general, the breakdown of PCBs in the water and soil occurs over several years, or even decades. Sediments containing PCBs at the bottom of a large body of water such as a lake, river, or ocean generally act as a reservoir from which PCBs may be released in small amounts to the water (Eco-USA 2008). PCBs are likely tightly bound to soil particles and will not migrate significantly.

VOCs VOCs do not sorb strongly to soils making them relatively mobile in water. VOCs rapidly volatilize from surface water into the atmosphere. Rates of degradation in the atmosphere are compound-specific, ranging from slow to rapid depending on rates of photooxidation. Bioconcentration of VOCs is not a significant process for aquatic or terrestrial organisms.

SVOCs SVOCs include a wide variety of chemicals that are ubiquitous in the environment. Included in this category are low and high molecular weight PAHs, which differ substantially in environmental persistence and toxicity to ecological receptors. In spite of the high lipid solubility of some PAHs, they have low bioaccumulation potential in vertebrates because these compounds are rapidly metabolized. PAHs can accumulate

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in invertebrates that cannot metabolize these compounds. PAHs often accumulate to high levels in aquatic invertebrates, but vertebrate consumers of such invertebrates are at low risk because of generally rapid and efficient elimination. PAHs have low potential for biomagnification and food web effects are not significant.

Nitrocellulose The USACE published a document regarding the fate and transport of propellant compounds (USACE 2006), including nitrocellulose. The document concludes that transport and fate processes of propellant-associated compounds in the environment require further definition and refinement due, in part, to the lack of a suitable method to quantify nitrocellulose fiber residues in soils. However, the document indicates that conventional propellants used in artillery ammunition are composite materials that consist primarily of energetic compounds and stabilizers within a nitrocellulose matrix.

Nitrocellulose is a non-volatile, white fibrous material that is insoluble in water when in its fibrous form. Nitrocellulose will not dissolve or hydrolyze in aqueous solutions except with strong base and high temperatures. Nitrocellulose fines will flocculate from aqueous suspension when the pH is raised to 11.6 through the addition of lime. Nitrocellulose, as well as other energetic plasticizers and binders, reacts in sunlight to produce transformation products that may impart color to aqueous solutions. Nitrocellulose fibers show color change from white to yellow to brown after exposure to ultraviolet radiation (USACE 2006).

Explosives (2,4-Dinitrotoluene and 2,6-Dinitrotoluene) The USACE published document regarding the fate and transport of propellant compounds reference above (USACE 2006) included 2,4-DNT. The report documented that 2,4-DNT is an energetic binder in some propellant and high explosives formulations. Although 2,4-DNT has moderate aqueous solubility, hydrolysis is not an important transformation reaction under environmental conditions because the molecule lacks readily hydrolysable substituent groups.

Experimental data interpret sorption behavior of 2,4-DNT are limited. Estimated log octanol-water partition coefficient (Kow) and organic carbon partition coefficient (Koc) values suggest moderately hydrophilic behavior and limited sorption, respectively. Batch sorption experiments yielded low study-specific sediment/water partition coefficient (Kd) values, suggesting limited partitioning of 2,4-DNT into sediment. 2,4-DNT reacts rapidly by photolysis (wavelengths greater than 290 nanometers [nm]), particularly in alkaline pH solutions. Photolysis rates of 2,4-DNT are enhanced in natural waters with humic acids and aqueous solutions with surfactants (USACE 2006). Data regarding the fate and transport of 2,6-DNT were not identified.

3.5 Exposure Point Concentrations Data collected during the Focused SI and the Expanded SI, as described above, were used to describe the magnitude and distribution of chemicals in relevant media for each AOC at the site. Although no single concentration value can truly represent the

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variability of chemical concentrations measured in each medium of concern, EPA guidance (1997) for conducting SLERAs recommends using the maximum detected value of each chemical to initially assess risk. Therefore, for this SLERA, the maximum detected concentration for each detected chemical within each medium of concern at each of the AOCs was compared to conservative ESLs to select COPCs for that medium in the AOC.

Maximum detected chemical concentrations for each medium of concern at each AOC are presented in Tables 3-2 through 3-9. Following EPA guidance, if the maximum detected concentration of a chemical exceeds the selected ecological screening level concentration, then a potential for adverse ecological effects may exist. Tables 3-2 through 3-9 also reveal the locations where the maximum concentration of each chemical was measured and the frequency of detection for each chemical detected.

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Section 4 Effects Assessment Effects assessment includes an evaluation of effects data sources and data types, and presents media-specific and chemical-specific ESLs that serve as effects concentrations for the SLERA. This section of the SLERA describes and provides support for the sources and types of effects data selected for use in the SLERA. As appropriate for a SLERA, effects data for each medium are limited to conservative ESLs. Other less conservative benchmark concentrations (e.g., toxicity values from laboratory studies) are more appropriate for estimating risks if screening levels are exceeded by the maximum detected concentrations of COPCs, a step performed in the BERA. The ESLs selected for each medium are described below in the order of preference. If chemical-specific values are not available, ESLs for surrogate chemicals are considered, based on similar chemical structure

4.1 Ecological Screening Levels The ESLs were selected for each medium in the hierarchy described below and each ESL source is also described. Multiple sources of ESLs are provided for each medium because no single source provides ESLs for all chemicals of interest. If an ESL was not available from the primary source, one was selected from the secondary or tertiary sources described below.

4.1.1 Soil Ecological Soil Screening Values (EPA 2008) EPA derived Eco-SSLs to be employed in the process of identifying COPCs and impacted geographical areas that need to be evaluated further in the risk assessment process. Eco-SSLs are intended to be protective of ecological receptors that are exposed to soil either by direct contact (Eco-SSLs for plants and invertebrates) or by ingesting organisms that live in or on the soil (Eco-SSLs for birds and mammals). These values may be employed to determine if there are ecological risks associated with on-site soil; which chemicals are associated with the risk and need to be included in the risk characterization; and which receptors are at greatest risk. Following a four step peer-reviewed process, EPA’s working groups derived plant and invertebrate screening values after an evaluation of chronic toxicity data.

The avian and mammalian values were back-calculated from a Hazard Index of 1, assuming food web transfer; therefore, these values consider bioaccumulation and are appropriate for screening potential hazards to upper trophic level receptors. Eco-SSLs are applicable for sites where soil parameters such as pH and organic matter content fall within specific (generally observed) ranges and where ecological receptors are exposed to contaminated site surface soil either directly or indirectly via ingestion. EPA Eco-SSLs were selected to be the primary source of ESLs for soil.

EPA Region 5 ESLs (EPA 2003) Region 5 has developed ESLs for various media, including soil. ESLs are initial screening levels to which site chemical concentrations can be compared. ESLs are not

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meant to be used as cleanup values. The website where this information was obtained does not explain in detail the derivation of these values, but footnotes provide some supporting information. In some cases, the ESLs are based on other studies or other recommended values. In other cases, the ESLs are based on protection of a single, sensitive species (e.g., many soil ESLs are based on protection of vermivorous small mammals [shrew], and as such consider bioaccumulation potential). In a few cases, the ESLs are based on the lowest detection limit that can commonly be attained. Region 5 ESLs were selected as a secondary source of screening levels for soil.

Oak Ridge National Laboratory (ORNL) Toxicological Benchmarks for Screening Chemicals of Potential Concern for Effects on Terrestrial Plants: 1997 Revision (ORNL 1997a) This document, published by the ORNL, presents plant toxicity data from multiple studies and derives from these studies a single benchmark concentration to be used as an ESL. Also, the confidence in the derived benchmark values is described, which helps interpret screening results based on these benchmarks. This document also describes the method for deriving benchmarks, the data concerning effects of chemicals in soil on plants, and provides phytotoxicity benchmarks for 38 chemicals. ORNL benchmarks were selected as a secondary source of screening levels for soil.

Oak Ridge National Laboratory (ORNL) Toxicological Benchmarks for Screening Chemicals of Potential Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process: 1997 Revision (ORNL 1997b) This document, published by the ORNL, presents a review of the literature and provides a standard method for deriving benchmarks for assessing chemicals in soil with respect to their toxicity to earthworms, heterotrophic bacteria and fungi and their processes, and other invertebrates (soil and litter-dwelling invertebrates). The values are intended for use in chemical screening during the hazard identification (problem formulation) phase of ERAs (Step 1). ORNL benchmarks were selected to be a secondary source of screening levels for soil.

ESL based on ESL for Surrogate Chemical (same chemical class and similar chemical structure) These were used for COPCs where screening levels have not been developed for the above-mentioned sources. Surrogate ESLs, if available, were selected as a tertiary source of screening levels for soil.

4.1.2 Sediment MacDonald, D.D., C.G. Ingersoll, and T.A. Berger (2000) Consensus-based threshold effects concentrations (TECs) consider sediment quality guidelines and toxicity tests from a variety of sources to select a consensus value among the approaches (Swartz 1999, MacDonald et al. 2000). Information incorporated into TECs includes threshold effects levels (TELs), effects-range low (ER-Ls), lowest effect levels (LELs), minimal effect threshold, equilibrium partitioning values, and sediment quality advisory levels. Consensus-based values were applied first to compounds known to exist as mixtures, such as PAHs (Swartz 1999), and then

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to total PCBs, metals, and other PAHs. MacDonald et al. derived both TECs and probable effects concentrations (PECs). TECs represent concentrations at which adverse effects may begin to be observed, while PECs represent concentrations where adverse effects are almost always observed. TECs are better suited as screening levels because of the greater conservatism associated with these values. TECs were selected as the primary source of screening levels for sediment.

EPA Region 5 ESLs (EPA 2003) The sediment ESLs established by EPA Region 5 were selected as a secondary source for sediment screening levels. A requirement of the Resource Conservation and Recovery Act (RCRA) Corrective Action and Permit programs within Region 5 is that adverse risk to the environment be evaluated and controlled. This risk is determined through an ERA and the Region 5 RCRA ESLs are one of the accepted initial tools employed. The ESLs represent protective levels for chemicals in freshwater sediments, as well as other environmental media. ESLs were revised in 2003 using more current information and were based on a variety of sources. Of the 99 revised sediment ESLs, forty are lower than the previously published values.

ESL based on ESL for Surrogate Chemical (same chemical class and similar chemical structure) These were used for COPCs where screening levels have not been developed for the above-mentioned sources. Surrogate ESLs, if available, were selected as a tertiary source of screening levels for sediment.

Sediment Quality Targets (SQTs) for Minnesota Pollution Control Agency (MPCA 2007) These State values were provided for reference and were not used independently for quantitative purposes in this SLERA, although some of the values for specific chemicals may correspond to those selected above from original sources. The sources for these values include the freshwater consensus-based sediment quality guidelines (MacDonald et al., 2000), the New York State Department of Environmental Conservation (NYSDEC) sediment guidance (NYSDEC 1999), and Canadian environmental quality guidelines (CCME 2002).

4.1.3 Surface Water CCC for Freshwater Aquatic Life in National Recommended Water Quality Criteria (EPA 2009) Analytical results of surface water sampling were compared to the National Recommended Water Quality Criteria (NRWQC), which were most recently updated in 2009 by the EPA. The NRWQC were developed for both acute and chronic effects for use in screening surface water for risk to aquatic organisms. NRWQC, Criterion Maximum Concentration (CMC) and Criterion Continuous Concentration (CCC), respectively, are based on lethal (both CMC and CCC) and sublethal effects (i.e., effects on survival, growth, and reproduction; CCC only), respectively, for a diverse aquatic community consisting of freshwater fish, benthic and water column invertebrates, and in some cases aquatic plants and larval amphibians. Toxicity data

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used in development of NRWQC are derived from laboratory experiments conducted over longer duration exposures compared to acute toxicity data. NRWQC are intended to protect 95 percent of aquatic species most of the time. Therefore, maintaining exposure concentrations of chemicals in surface water below NRWQC CCC should protect most species most of the time from sublethal effects. Freshwater CCC values were selected as the primary source of screening levels for surface water.

EPA Region 5 Ecological Screening Values for Freshwater (EPA 2003) If screening levels could not be obtained from the above source, the freshwater ecological screening values established by EPA Region 5 were selected as a secondary source for surface water screening levels. A requirement of the RCRA Corrective Action and Permit programs within Region 5 is that adverse risk to the environment be evaluated and controlled. This risk is determined through an ERA and the Region 5 RCRA ESLs are one of the initial tools employed. The ESLs represent protective levels for chemicals in freshwater, as well as other environmental media. ESLs were revised in 2003 using more current information and were based on a variety of sources.

MPCA Tier I Screening Benchmarks for Surface Water (MPCA 2006) These State values were provided for reference and were not independently used for quantitative purposes in this SLERA. The screening benchmarks are developed for each state designated water body based on the state’s beneficial use classification. The values for surface water bodies designated as Class 2C waters are provided for reference. Class 2C waters are to permit propagation and maintenance of indigenous fish and aquatic life and their habitats.

4.2 COPC Selection An important preliminary step in the evaluation of ecological risk is the identification of chemicals related to a site release or historical site use that may pose a threat to ecological receptors. For the FGOW site, COPCs were selected separately for each medium of concern within a particular AOC. Surface soil was identified as a medium of concern for each AOC subject to this Expanded SI. Additionally, sediment and surface water were identified as media of concern for AOC 1S.

COPCs are usually determined using a multi-step process. In the first step of the COPC selection process, a chemical detected at a concentration greater than the reporting limit in one or more samples collected from a medium within an AOC was retained as a chemical of interest for that medium at that AOC. In the second step, the maximum detected chemical concentration was compared to the selected conservative media- and chemical-specific ESL. If the maximum detected concentration was greater than the ESL, that chemical was retained as a COPC for that medium at that AOC. In addition, if screening criterion was not available for a detected chemical in this step, that chemical was retained as a COPC. Frequency of detection and a comparison to background concentrations were not criteria employed for the selection of COPCs in this SLERA, but may be considered when interpreting the results of risk characterization.

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COPCs for each medium of concern within each AOC are selected below and a summary of the COPCs selected for each AOC is provided in Table 4-1.

4.2.1 AOC 1N 4.2.1.1 Surface Soil As presented in Table 3-2 (Step 2), a total of seven chemicals were selected as COPCs, including one explosive, two metals, one SVOC, two VOCs, and nitrocellulose. The two VOCs and nitrocellulose were selected as COPCs since ESLs were unavailable. The remaining chemicals were selected as COPCs, since their maximum detected concentrations were above the ESLs. 4.2.2 AOC 1M 4.2.2.1 Surface Soil As presented in Table 3-3 (Step 2), a total of seven chemicals were selected as COPCs, including three metals, two SVOCs, one VOC, and nitrocellulose. One SVOC (benzoic acid), the VOC, and nitrocellulose were selected as COPCs, due to lack of ESLs. The remaining chemicals were selected as COPCs, since their maximum detected concentrations were above the ESLs.

4.2.3 AOC 1S 4.2.3.1 Surface soil As presented in Table 3-4 (Step 2), ten chemicals were selected as surface soil COPCs at AOC 1S, including three metals, five SVOCs, one VOC, and nitrocellulose. Two of the SVOCs, the VOC, and nitrocellulose were selected as COPCs, since ESLs were unavailable. The remaining chemicals were selected as COPCs, since their maximum detected concentrations were above the ESLs.

4.2.3.2 Sediment As presented in Table 3-5 (Step 2), nine chemicals were selected as sediment COPCs at AOC 1S, including three metals, two PAHs, three VOCs, and nitrocellulose. Two metals, one VOC, and nitrocellulose were selected as COPCs, due to lack of ESLs.The remaining chemicals were selected as COPCs, since their maximum detected concentrations were above the ESLs.

4.2.3.3 Surface Water As presented in Table 3-6 (Step 2), two chemicals were selected as surface water COPCs at AOC 1S, including lead and nitrocellulose. Nitrocellulose was selected as a COPC, since an ESL was not available. Lead was selected as a COPC, since the maximum detected concentration was above the ESL.

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4.2.4 AOC 6 4.2.4.1 Surface Soil As presented in Table 3-7 (Step 2), eight chemicals were selected as COPCs, including four metals and four PAHs. Each chemical was selected as a COPC, since its maximum detected concentration was above its respective ESL.

4.2.5 AOC 7A 4.2.5.1 Surface Soil As presented in Table 3-8 (Step 2), a total of 18 chemicals were selected as COPCs, including total PCBs, 4 metals, 11 SVOCs, and 2 VOCs. Two SVOCs and two VOCs were selected as COPCs, since ESLs were unavailable. The remaining chemicals were selected as COPCs, since their maximum detected concentrations were above the ESLs. Total PCBs was selected as a COPC based on the sum of the detected concentrations of Aroclors 1254 and 1260 in surface soil at this AOC.

4.2.6 AOC 7D 4.2.6.1 Surface Soil As presented in Table 3-9 (Step 2), a total of 17 chemicals were selected as COPCs, including DRO, total PCBs, 6 metals, 7 SVOCs, 1VOC, and nitrocellulose. DRO, two SVOCs, one VOC, and nitrocellulose were selected as COPCs, since ESLs were unavailable. The remaining chemicals were selected as COPCs, since their maximum detected concentrations were above the ESLs. Total PCBs was selected as a COPC based on the sum of the detected concentrations of Aroclors 1254 and 1260 in surface soil at this AOC.

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Section 5 Risk Characterization Risk characterization integrates exposure and effects information to derive quantitative risk estimates. Risk estimates for this ERA are based on the HQ approach and are obtained by dividing the exposure concentration (in this case the maximum detected concentration) by the conservative chemical-specific ESL selected for each medium from the hierarchy listed above.

HQ = EPC / ESL

where

HQ = hazard quotient EPC = exposure point concentration (maximum detected

concentration) for that COPC ESL = ecological screening level

HQs were calculated to estimate risks to plants and terrestrial invertebrates from exposure to surface soil and to estimate risks to aquatic organisms exposed to sediment and surface water. HQs equal to or greater than 1.0 indicate potential threats and are retained for further evaluation. HQs below 1 suggest little or no risk (acceptable risk level) and are not retained for further investigation. Higher HQs are not necessarily indicative of more severe adverse effects but instead suggest greater likelihood of adverse effects. The results of chemical screening based on maximum detected chemical concentrations are summarized below for each medium of concern at each AOC. Since ESLs were not available for all selected COPCs, these chemicals were retained as COPCs but risks associated with exposure were not quantitatively evaluated. A summary of the rationale for selection of COPCs and the associated HQs for each AOC completed as part of the SLERA is provided in Table 4-1. The screening tables that include the calculation of HQs are provided for each AOC, as referenced below.

5.1 AOC 1N 5.1.1 Surface Soil HQs were equal to or greater than 1.0 for one explosive, two metals, and one SVOC. As presented in Table 3-2 (Step 2), HQs equal to or greater than 1.0 ranged from 3.1 (di-n-butyl phthalate) to 110 (mercury). These chemicals are evaluated further in Step 3a. In addition, those retained as COPCs due to lack of ESLs are also retained as COPCs in Step 3a.

5.2 AOC 1M 5.2.1 Surface Soil HQs were equal to or greater than 1.0 for three metals and one SVOC. As presented in Table 3-3 (Step 2), HQs equal to or greater than 1.0 ranged from 1.1 (chromium) to 49

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(mercury). These chemicals are evaluated further in Step 3a. In addition, those retained as COPCs due to lack of ESLs are also retained as COPCs in Step 3a.

5.3 AOC 1S 5.3.1 Surface soil HQs were equal to or greater than 1.0 for three metals and three SVOCs. As presented in Table 3-4 (Step 2), HQs equal to or greater than 1.0 ranged from 1.0 (chromium) to 29 (lead). These chemicals are evaluated further in Step 3a. In addition, those retained as COPCs due to lack of ESLs are also retained as COPCs in Step 3a.

5.3.2 Sediment HQs were equal to or greater than 1.0 for one metal, two PAHs, and two VOCs. As presented in Table 3-5 (Step 2), HQs equal to or greater than 1.0 ranged from 1.1 (arsenic) to 11 (acetone). These chemicals are evaluated further in Step 3a. In addition, those retained as COPCs due to lack of ESLs are also retained as COPCs in Step 3a.

5.3.3 Surface Water HQs were equal to or greater than 1.0 for lead, with a resulting HQ of 6.0, as shown in Table 3-6 (Step 2). Lead and nitrocellulose, which did not have an available ESL, are also retained in Step 3a.

5.4 AOC 6 5.4.1 Surface Soil HQs were equal to or greater than 1.0 for four metals and four PAHs. As presented in Table 3-7 (Step 2), HQs equal to or greater than 1.0 ranged from 1.7 (benzo(a)anthracene and chromium) to 15 (lead). These chemicals are evaluated further in Step 3a.

5.5 AOC 7A 5.5.1 Surface Soil HQs were equal to or greater than 1.0 for total PCBs, four metals, and nine SVOCs. As presented in Table 3-8 (Step 2), the HQ for PCBs was 77,771. The remaining HQs ranged from 1.2 (2-methylnaphthalene) to 84 (naphthalene). These chemicals are evaluated further in Step 3a. In addition, those retained as COPCs due to lack of ESLs are also retained as COPCs in Step 3a.

5.6 AOC 7D 5.6.1 Surface Soil HQs were equal to or greater than 1.0 for total PCBs, six metals, and five SVOCs. As presented in Table 3-9 (Step 2), the HQ for PCBs was 4,819. The remaining HQs ranged from 1.0 (barium) to 66 (lead). These chemicals are evaluated further in Step

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3a. In addition, those retained as COPCs due to lack of ESLs are also retained as COPCs in Step 3a.

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Section 6 Uncertainty Assessment Uncertainties are inherent in the risk assessment process, including those resulting from limitations of the studies upon which the assessment is based. It is important to identify the sources and effects of uncertainty in the risk assessment to provide defensible risk estimations and to minimize subjective interpretation of the nature and degree of potential risks posed by COPCs. Most assumptions in the ERA process, particularly in this SLERA, are intentionally conservative, so that the risk assessment more likely overestimates than underestimates the potential risks to ecological receptors. Assumptions must be made in assessments of exposure, effects, and risks when values are unknown or when multiple values are possible. The qualitative effects of the major assumptions in this risk assessment are discussed below.

This SLERA evaluated risks to terrestrial receptors using data collected from surface soil, zero to six inches bgs. Exposure to subsurface soil was not evaluated since the majority of wildlife, including terrestrial plants and invertebrates, would likely be exposed to surface soil (defined here to include the root zone of most terrestrial plants and the zone most utilized by soil-associated invertebrates). If concentrations of chemicals are greater in subsurface soil, risks to burrowing animals from exposure to these soils may be greater than those estimated using surface soil alone, so risks may be underestimated. However, the most significant exposure pathway is ingestion, which is evaluated through the use of ESLs, which were developed primarily based on the ingestion pathway using maximum detected concentrations in surface soil.

This SLERA evaluated soil exposure pathways assumed to be complete and significant. It did not quantitatively evaluate risks to burrowing mammals via the inhalation pathway, considered potentially complete but not significant. It is possible that exposures to volatile COPCs at the site are, therefore, underestimated for the selected receptors; however, the ingestion exposure route is the significant exposure pathway, and likely the most significant source of risk.

Uncertainty is associated with the selection of representative receptors appropriate for the FGOW site because it is not feasible to evaluate all species and communities potentially at risk. The ecological receptors selected as assessment endpoints for the evaluation of risks represent a range of trophic levels that are present at the FGOW during part or all of their life cycle. The measurement endpoints (conservative ESLs) were selected to evaluate risk to receptors of multiple trophic levels exposed to one or more contaminated media. Not all potential receptors can be quantitatively evaluated (such as threatened and endangered species or amphibians), because toxicity data are sparse or lacking for some taxa and some chemicals.

The exposure estimation step of the SLERA assumed that a receptor would be exposed to each soil, sediment, or surface water COPC at its maximum concentration consistently throughout the terrestrial or aquatic areas and for sufficient duration to elicit adverse effects. Ecological receptors are unlikely to be exposed to the maximum detected concentration of each chemical in each medium of concern across each AOC.

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Therefore, it is unlikely that risks to ecological receptors are underestimated for exposure to the maximum detected concentration of chemicals in surface soil, sediment, or surface water for which screening values are available. Use of the maximum detected concentration likely would overestimate the exposure across the AOC medium and the resultant risk, but is appropriate in the SLERA, since conservative exposure assumptions are employed.

The selection of ESLs contributes to the uncertainty in the ERA results for several reasons. First, there is considerable uncertainty in the retention of a chemical as a COPC simply because toxicity data or ESLs are lacking. In many cases those chemicals that are not well-studied are not considered highly toxic—the most toxic chemicals are often the most studied. Also, some ESLs are more specific to receptor type than others. The use of the more general (less preferred) ESLs increases uncertainty in the risk estimates for a particular species or receptor type. Additionally, all ESLs are biased toward overprotection. For example, the soil ESLs used to estimate risks to directly exposed biota are limited in their applicability. These benchmarks are generally based on a few plant species, earthworms, and a limited microbial community. It is unknown if these benchmarks are protective of, or overestimate toxicity to, other non-tested soil dwelling biota. The benchmarks selected, however, are widely used and assumed to be useful for screening purposes.

ESLs are unavailable for several chemicals or compounds detected in abiotic media. One chemical included in this list, nitrocellulose, is common to all three media types. The lack of suitable ESLs for these chemicals contributes to uncertainties in the overall estimate of risks. The following discussion provides a general interpretation, based on available data, regarding the potential for these chemicals to contribute to adverse ecological effects.

Nitrocellulose (surface soil, sediment, and surface water): Available toxicity data for nitrocellulose is discussed in Section 3.4.1, and these data suggest low potential for adverse ecological effects.

Barium (sediment): Barium is a commonly detected inorganic chemical in

sediment and soil; yet, ecotoxicity data for barium is sparse. The limited data available for evaluating the toxicity of barium in surface water and soil suggest that barium often combines with other metals to form compounds with reduced bioavailability, is not highly toxic, and that adverse effects linked to barium are uncommon.

Selenium (sediment): Selenium is an essential nutrient that can be quite toxic

to ecological receptors depending on the form and exposure concentration. Soil and surface water data suggest that selenium can adversely affect sensitive ecological receptors (including invertebrates, birds, and mammals) at low concentrations, and bioaccumulation has been demonstrated. However, data are lacking for assessing selenium in sediment. It is reasonable to expect that elevated concentrations of selenium in sediments have potential to

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contribute to adverse effects in exposed biota, such as benthic macroinvertebrates.

1,3,5-Trimethylbenzene (sediment): Ecotoxicity data are lacking for assessing

1,3,5-trimethylbenzene in sediment. Data for 1,2,4-trichlorobenzene in sediment suggest relatively low toxicity (i.e., the EPA Region 5 ESL for this chemical exceeds 5,000 µg/kg). Whether or not this surrogate chemical is toxicologically sufficiently similar to 1,3,5-trimethylbenzene cannot be determined.

1,2,4-Trimethylbenzene (surface soil): The information presented above for

1,3,5-trimethylbenzene applies to this chemical as well, since none of the trimethylbenzenes are well-studied with regard to ecotoxicity.

p-Isopropylbenzene (surface soil): Isopropylbenzene in soil is not well-studied

with regard to ecotoxicity and data are lacking for this and potential surrogate chemicals.

Benzoic acid (surface soil): Benzoic acid in soil is not well-studied with regard

to ecotoxicity and data are lacking for this and potential surrogate chemicals.

Carbazole (surface soil): Carbozole in soil is not well-studied with regard to ecotoxicity and data are lacking for this chemical. The EPA Region 5 ESL for the relatively similar diphenylamine is 1,010 µg/kg, but application of this ESL to carbazole is highly uncertain.

Dibenzofuran (surface soil): The ecotoxicity of dibenzofuran in soil is not well-

studied. EPA Region 5 ESLs for this chemical in sediment (449 µg/kg) suggests low to moderate toxicity in that medium. Toxicity to soil-associated organisms exposed to surface soil is unknown.

DRO (surface soil): Fuels in soil are not well-studied with regard to

ecotoxicity. Most chemicals comprising fuels and similar compounds including DRO are relatively easily degraded (not persistent) and associated with low toxicity. Studies conducted by Washington State Department of Ecology and CDM on the ecotoxicity of Bunker-C oil revealed very low toxicity to rye grass (representative terrestrial plant) and earthworms (representative soil invertebrate). The resulting earthworm No Effect Level was 6,700 mg/kg and the Low Effect Level was 18,000 mg/kg (Peterson et al., 2009, in press). Based on these studies, DRO in soil is not expected to contribute significantly to adverse ecological effects.

Ecological receptors are often exposed to multiple chemicals concurrently within a medium; however, ESLs were established to estimate risk due to exposure to individual chemicals. Some chemicals may act synergistically or antagonistically, so single chemical evaluations may overestimate or underestimate risks.

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The risk estimation method used, based on HQs, probably overly simplifies the relationship between exposure and effects. HQs can be used to estimate risks in a general fashion, and are particularly useful for comparison across receptors and COPCs. However, consideration should be given to other factors not included in the HQ derivation. These include parameters related to habitat quality (e.g., presence and quality of cover, prey availability, soil moisture, etc.) and life history. Additionally, the HQ method is associated with inherent uncertainties in the exposure (EPC) and effects (ESL) values. The HQ method itself can contribute uncertainty to the risk calculations and conclusions as the threshold level of 1.0 is not a “bright line” and risks may, in fact, be acceptable where HQ exceeds one or unacceptable where HQ is less than one.

Total PCBs were selected as a COPC for surface soil at AOC 7A and AOC 7D based on the detections of individual Aroclors. Detected concentrations of Aroclor 1254 and 1260 were summed to provide a calculated total PCB concentration for use in the screening as ESLs have been developed for total PCBs as opposed to individual Aroclors. The sum of the Aroclors for risk estimation is likely conservative as the two detected Aroclors may include one or more of the same PCB congeners, leading to an overestimation of the total concentration and resulting risk estimate. Additionally, the ESL for total PCBs is an extremely conservative value as it is based on dietary exposures for shrews. This ESL, therefore, considers uptake and bioaccumulation potential but may substantially overestimate risks to other receptors for which direct contact exposures are most important (e.g., soil invertebrates such as earthworms). The use of this very conservative ESL is appropriate at this stage of the ERA process, but more receptor-specific toxicity data (in the form of toxicity reference values or TRVs) will be used if it is determined that a BERA is warranted for this site. Total PCBs is evaluated further in Step 3a with other chemicals retained as COPCs.

In summary, sufficient conservatism is applied to each step of the ERA process direct contact exposures to ensure that the uncertainties (known and unknown) bias the assessment towards over protection rather than under protection of ecological resources.

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Section 7 SLERA Conclusions This section provides responses to the questions posed in Problem Formulation and provides conclusions for the SLERA.

Risk Questions:

Are site-related chemicals present in surface soil, sediment, or surface water at one or more AOC where ecological receptors may be exposed?

□ Yes, chemicals associated with former DoD activities were detected in each medium of concern at each AOC.

Where present, are the concentrations of chemicals from historical DoD activities

sufficiently elevated to impair the survival, growth, or reproduction of sensitive ecological receptors?

□ Yes, several chemicals are present at concentrations above the ESLs,

resulting in HQs greater than or equal to 1.0. HQs equal to or greater than 1.0 were calculated for several COPCs in surface soil at each AOC and in surface water and sediment at AOC 1S. Additionally, several chemicals were selected as COPCs in surface soil at each AOC, with the exception of AOC 6, and in surface water and sediment at AOC 1S, since ESLs were not available. Elevated HQs indicate that threats to terrestrial receptors could exist at each AOC and for aquatic life exposed to surface water and sediment at AOC 1S. These risk estimates are based on the conservative assumption that surface soil, surface water, and sediment COPC concentrations (maximum detected concentrations) represent reasonable exposures for terrestrial and aquatic receptors.

This SLERA documents elevated threats associated with exposure to COPCs in surface soil at each AOC, and with exposure to sediment and surface water at AOC 1S. To provide additional evaluation into the possible risks associated with exposure to each medium, the following section presents the first step of the BERA, Step 3a, which uses refined, less conservative exposure estimates (the arithmetic mean) to refine the list of COPCs and evaluate associated risks. Step 3a of the BERA only evaluates chemicals that had a direct exposure risk estimate (HQ) equal to or greater than 1.0 at the conclusion of the risk characterization step of the SLERA and those chemicals for which ESLs were not available.

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Section 8 Step 3a of the BERA At the conclusion of the SLERA, several COPCs were retained for further evaluation. In Step 3a, potential threats associated with those COPCs are re-evaluated using less conservative EPCs. This streamlined Step 3a evaluation includes the following steps:

Refinement of EPCs, which entails substituting the maximum detected concentration with the mean (arithmetic average) concentration as the EPC for each chemical retained for further evaluation at the conclusion of the SLERA in the applicable media at each AOC.

Recalculation of HQs by dividing the mean concentration by the previously selected ESL

Identification of those COPCs with HQs < 1.0 and elimination of them from further evaluation at the conclusion of Step 3a

A low frequency of detection (<5%) and a comparison to background were not criteria for elimination of COPCs from further evaluation in the BERA process. However, the range of detected background concentrations for metals is presented for each AOC to provide a frame of reference for data interpretation

Presenting information from Step 3a allows more focused conclusions concerning site contamination and associated risks to ecological receptors. The sections below describe the refined EPCs (mean concentrations) as well as a summary of the resulting refined COPC lists and risk estimates (HQs) for each AOC. The surface soil, sediment, and surface water data and corresponding ESLs for each AOC included in the Step 3a remain unchanged from the SLERA. Exposure assumptions, including the assessment and measurement endpoints, are not discussed below as they remain unchanged from the SLERA. Items not discussed below remain unchanged from the SLERA process.

8.1 Refinement of EPCs Data collected during the Focused SI and the Expanded SI, as described in the SLERA, were used to describe the magnitude and distribution of chemicals in relevant media for each AOC at the site. EPCs for evaluation of risks associated with exposure to impacted media at each AOC were refined and based on the mean concentration.

EPC for Direct Contact Exposure at each AOC = Mean concentration Mean chemical concentrations for COPCs identified in Step 2 as a COPC for each medium of concern at each AOC are presented in Tables 3-2 through 3-9.

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8.2 Refined Hazard Quotient Calculations and Selection of Final COPCs HQs were recalculated using mean exposure point concentrations and the resulting HQs were used to refine the final COPC list for each medium of concern at each AOC. Refined HQs were only calculated in this Step 3a for chemicals that had a direct exposure risk estimate (HQ) equal to or greater than 1.0 at the conclusion of the risk characterization step of the SLERA.

HQs are obtained by dividing the mean concentration by the conservative chemical-specific ESL selected for each medium in the SLERA.

HQ = EPC / ESL

Where

HQ = hazard quotient EPC = exposure point concentration (arithmetic mean

concentration) for that COPC ESL = ecological screening level

The results of chemical screening based on mean chemical concentrations are summarized below for each medium of concern at each AOC. Since ESLs were not available for all COPCs retained at the conclusion of the SLERA, these chemicals were again retained as final COPCs for this Step 3a but risks associated with exposure were not quantitatively evaluated. A summary of the HQs and the rationale for selection of final COPCs for each AOC completed as part of Step 3a is provided in Table 8-1. The screening tables that include the calculation of HQs are provided for each AOC, as referenced below. Chemicals with HQs equal to or greater than 1.0 at the conclusion of Step 3a or those chemicals without ESLs were retained as final COPCs for each medium of concern in each AOC. These chemicals may warrant further evaluation in a BERA.

8.2.1 AOC 1N 8.2.1.1 Surface Soil At the conclusion of the SLERA, seven chemicals were retained as COPCs for further evaluation in Step 3a. For the four COPCs with ESLs, the HQs equal to or greater than 1.0 ranged from 3.1 (di-n-butyl phthalate) to 110 (mercury). As a result of the refinement in Step 3a, refined HQs for the four chemicals with ESLs ranged from 4.3 (lead) to 918 (di-n-butyl phthalate) as presented in Table 3-2. The refined HQ for di-n-butyl phthalate was much higher than the HQ calculated using the maximum concentration (460 µg/kg) due to one non-detected value with an extremely high reporting limit (550,000 µg/kg). One half of the reporting limit was used in the calculation of the mean; therefore, the mean-based HQ for this chemical is biased high. Although this chemical is retained as a COPC, it is unlikely to contribute to

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adverse effects due to relatively low toxicity and because it is not environmentally persistent (i.e., it is relatively readily degraded).

Each of the seven COPCs retained at the conclusion of the SLERA were retained as final surface soil COPCs for AOC 1N at the conclusion of Step 3a.

8.2.2 AOC 1M 8.2.2.1 Surface Soil At the conclusion of the SLERA, seven chemicals were retained as COPCs for further evaluation in Step 3a. For the four COPCs with ESLs, the HQs equal to or greater than 1.0 ranged from 1.1 (chromium) to 49 (mercury). As a result of the refinement in Step 3a, refined HQs for the four chemicals with ESLs ranged from less than 1.0 (chromium) to 9.0 (mercury) as presented in Table 3-3. Of the seven COPCs retained at the conclusion of the SLERA, six were retained as final surface soil COPCs for AOC 1M at the conclusion of Step 3a. Chromium was not retained, since the refined HQ was less than 1.0.

8.2.3 AOC 1S 8.2.3.1 Surface soil At the conclusion of the SLERA, ten chemicals were retained as COPCs for further evaluation in Step 3a. For the six COPCs with ESLs, the HQs equal to or greater than 1.0 ranged from 1.0 (chromium) to 29 (lead). As a result of the refinement in Step 3a, refined HQs for the six chemicals with ESLs ranged from less than 1.0 (chromium, mercury, benzo(a)anthracene, benzo(a)pyrene and chrysene) to 4.4 (lead) as presented in Table 3-4. Of the ten COPCs retained at the conclusion of the SLERA, five were retained as final surface soil COPCs for AOC 1S at the conclusion of Step 3a. Only lead was retained due to an HQ greater than 1.0; the remaining four chemicals were retained as final COPCs as ESLs were unavailable. 8.2.3.2 Sediment At the conclusion of the SLERA, nine chemicals were retained as COPCs for further evaluation in Step 3a. For the five COPCs with ESLs, the HQs equal to or greater than 1.0 ranged from 1.1 (arsenic) to 11 (acetone). As a result of the refinement in Step 3a, refined HQs for the five chemicals with ESLs ranged from less than 1.0 (arsenic and dibenzo(a,h)anthracene) to 9.2 (acetone) as presented in Table 3-5. Of the nine COPCs retained at the conclusion of the SLERA, seven were retained as final sediment COPCs for AOC 1S at the conclusion of Step 3a.

Acenaphthene, acetone, and methyl ethyl ketone were retained due to an HQ equal to or greater than 1.0; the remaining four chemicals were retained as final COPCs as ESLs were unavailable.

8.2.3.3 Surface Water At the conclusion of the SLERA, two chemicals (lead and nitrocellulose) were retained as COPCs for further evaluation in Step 3a. The HQ for lead was 6.0. An ESL was not

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available for nitrocellulose. As a result of the refinement in Step 3a, the refined HQ for lead was 1.6, as presented in Table 3-6. Both of these chemicals were retained as final surface water COPCs for AOC 1S at the conclusion of Step 3a, with lead retained due to an HQ greater than 1.0 and nitrocellulose retained since an ESL was unavailable.

8.2.4 AOC 6 8.2.4.1 Surface Soil At the conclusion of the SLERA, eight chemicals were retained as COPCs for further evaluation in Step 3a. ESLs were available for each COPC. The HQs equal to or greater than 1.0 ranged from 1.7 (chromium and benzo(a)anthracene) to 15 (lead). As a result of the refinement in Step 3a, refined HQs ranged from less than 1.0 (cadmium, chromium, benzo(a)anthracene, benzo(a)pyrene, and chrysene) to 3.5 (naphthalene) as presented in Table 3-7. Of the eight COPCs retained at the conclusion of the SLERA, three were retained as final surface soil COPCs for AOC 6 at the conclusion of Step 3a.

8.2.5 AOC 7A 8.2.5.1 Surface Soil At the conclusion of the SLERA, 18 chemicals were retained as COPCs for further evaluation in Step 3a. For the 14 COPCs with ESLs, HQs equal to or greater than 1.0 ranged from 1.2 (2-methylnaphthalene) to 84 (naphthalene) and the HQ for PCBs was 77,771. As a result of the refinement in Step 3a, refined HQs for the 14 chemicals with ESLs ranged from less than 1.0 (chromium, mercury, 2-methylnaphthalene, benzo(b)fluoranthene, flouranthene, phenanthrene, and pyrene) to 15 (naphthalene) as presented in Table 3-8. The HQ for PCBs was reduced to 9,801. Of the 18 COPCs retained at the conclusion of the SLERA, 11 were retained as final surface soil COPCs for AOC 7A at the conclusion of Step 3a. Seven final COPCs were retained due to an HQ greater than 1.0; the remaining four chemicals were retained as final COPCs as ESLs were unavailable.

8.2.6 AOC 7D 8.2.6.1 Surface Soil At the conclusion of the SLERA, 17 chemicals were retained as COPCs for further evaluation in Step 3a. For the 12 COPCs with ESLs, HQs equal to or greater than 1.0 ranged from 1.0 (barium) to 66 (lead) and the HQ for PCBs was 4819. As a result of the refinement in Step 3a, refined HQs for the 12 chemicals with ESLs ranged from less than 1.0 (barium, cadmium, chromium, benzo(a)anthracene, benzo(a)pyrene, and chrysene) to 6.3 (naphthalene) as presented in Table 3-9. The HQ for PCBs was reduced to 469. Of the 17 COPCs retained at the conclusion of the SLERA, 11 were retained as final surface soil COPCs for AOC 7D at the conclusion of Step 3a. Six final COPCs were retained due to an HQ greater than 1.0; the remaining five chemicals were retained as final COPCs as ESLs were unavailable.

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8.3 Comparison to Background As part of the Expanded SI field investigation, soil samples were collected from background areas described in Section 2.1.4. Samples were submitted for laboratory analysis of metals. The range of background results is presented in Table 8-2 and provides a frame of reference for chemical concentrations detected in surface soils from AOCs impacted by former DoD activities.

The range of background concentrations suggests that maximum detected concentrations of arsenic in AOC 1N, AOC 1S and AOC 7D are above background. Maximum concentrations of barium are outside the range of background concentrations in surface soils at AOC 1N, AOC 1M, AOC 1S, and AOC 7D. Maximum detected concentrations of lead were above the range of background concentrations in surface soil samples collected from each AOC. The range of background concentrations suggests that detected concentrations of chromium are also above background in surface soils at AOC 6 and AOC 7A, and that maximum concentrations of mercury are above the range of background concentrations in surface soils at AOC 1N, AOC 1M, AOC 6, and AOC 7D. Detected concentrations of selenium and silver were above the range of background in surface soil samples collected from AOC 7D and AOC 6, respectively.

Cadmium concentrations detected in surface soil samples collected from each AOC were within the range of background.

Overall, the data suggest that surface soil at each AOC contains elevated concentrations of one or more metals compared to concentrations detected from background areas.

8.4 Uncertainties Less conservative exposure estimates (EPCs) were used for the calculation of Step 3a risk estimates. The EPCs were estimated by the mean concentrations. The refined EPCs represent more reasonable exposure concentrations, and are less likely to overestimate exposure and risk than use of the maximum concentrations. The risk estimates based on arithmetic mean COPC concentrations can be viewed in combination with the initial risk estimates based on the maximums from the SLERA to reveal a range of risk estimates to which ecological receptors might be exposed.

8.5 Conclusions Final COPCs were identified for further evaluation in each medium of concern at each AOC at the conclusion of Step 3a. These COPCs were based either on HQs greater than 1.0 or on the lack of available ESLs available for select chemicals. AOCs with the greatest potential to contribute to impacts to surface soil-associated receptors are AOC 1N, AOC 1M, AOC 7A, and AOC 7D.

Several chemicals detected in surface soil, including PCBs, cadmium, and mercury, are known to be highly bioaccumulative and are also known to biomagnify. Thus, the

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results of Step 3a suggest that food web modeling may be warranted to further and more fully describe risks associated with exposure to bioaccumulative chemicals via dietary intake. Bioaccumulative chemicals are present in surface soils at AOC 1N, AOC 1M, AOC 6, AOC 7A and AOC 7D.

The Step 3a analysis of the surface water and sediment results suggests that threats to aquatic receptors are likely low, but possibly important at AOC 1S. Although nitrocellulose, a site related chemical, is present in surface water and sediment, toxicity information collected to date and provided in the literature indicate that nitrocellulose is not highly toxic, and its detection in these media may not warrant additional evaluation.

These findings of the SLERA and Step 3a analyses suggest that conducting a BERA may be warranted for some and possibly all of the AOCs evaluated for the FGOW site. Whether these initial risks estimates (i.e., those exceeding the threshold of 1.0 from Step 3a) are sufficiently elevated to warrant further investigation is a risk management decision beyond the realm of risk assessment.

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Section 9 References Canadian Council of Ministers of the Environment (CCME) 2002. Canadian Environmental Quality Criteria for Contaminated Sites. Environmental Quality Guidelines Division, Water Quality Branch, Environment Canada, Ottawa, Canada.

Minnesota Department of Natural Resources (DNR). 2009. Rare Species Guide. Accessed at: http://www.dnr.state.mn.us/rsg/index.html Eco-USA. 2008. (http://www.eco-usa.net/toxics/pcbs.shtml#fate). Eisler, R. 1987. “Polycyclic Aromatic Hydrocarbon Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review.” U.S. Fish and Wildlife Service Biological Report 85(1.11). United States Environmental Protection Agency (EPA). 1997. Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessments, Interim Final. EPA/540/R-97/006. OSWER 9285.7-25. June. EPA. 2003. Ecological Screening Levels. U.S. Environmental Protection Agency. Region 5. August. http://www.epa.gov/reg5rcra/ca/ESL.pdf

EPA. 2008. Ecological Soil Screening Levels (Eco-SSLs). Last updated December 9. http://www.epa.gov/ecotox/ecossl/ EPA. 2009. National Recommended Water Quality Criteria. U.S. Environmental Protection Agency. Office of Water. Office of Science and Technology. http://www.epa.gov/waterscience/criteria/wqctable/nrwqc-2009.pdf

MacDonald, D.D., C.G. Ingersoll, and T.A. Berger. 2000a. Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Arch Environ Contam Toxicol. 39: 20-31. Minnesota Pollution Control Agency (MPCA). 2006. Minnesota Pollution Control Agency Remediation Programs. Working Draft Surface Water Pathway Evaluation User's Guide. January 30. Accessed at: http://www.pca.state.mn.us/publications/c-s4-01.pdf The screening values are provided in table 11 accessed at: http://www.pca.state.mn.us/cleanup/riskbasedoc.html#surfacewaterpathway MPCA. 2007. Guidance for the Use and Application of Sediment Quality Targets for the Protection of Sediment-Dwelling Organisms in Minnesota. MPCA Document Number: tdr-gl-04. Accessed at: http://www.pca.state.mn.us/publications/tdr-gl-04.pdf

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New York State Department of Environmental Conservation (NYSDEC). 1999. Technical guidance for screening contaminated sediments. Division of Fish, Wildlife and Marine Resources, New York State Department of Environmental Conservation, Albany, NY. 39 pp. Oak Ridge National Laboratory (ORNL). 1997a. Toxicological Benchmarks for Screening Contaminants of Potential Concern for Effects on Terrestrial Plants: 1997 Revision. November. Accessed at: http://www.hsrd.ornl.gov/ecorisk/tm85r3.pdf

ORNL. 1997b. Toxicological Benchmarks for Screening Contaminants of Potential Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process: 1997 Revision. November. Accessed at: http://www.esd.ornl.gov/programs/ecorisk/documents/tm126r21.pdf

PAN. 2009. Pesticide Action Network Pesticides Database. Accessed at: http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC37277 Personal communication, Tim Pharis, DNR, October 12, 2009. Peterson, L.E., T.C. Gendusa, K.L. Tobiason, L. Auster, and D.C. Sternberg. 2008. Derivation of a Bioassay Based Site-Specific Cleanup Value for Weathered Bunker C-Contaminated Soils. Presented at the Society of Environmental Toxicology and Chemistry national conference. Tampa, FL. November.

Suter, G.W. II, and C.K, Tsao. 1996. Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Aquatic Biota: 1996 Revision. ES/ER/TM-96/R2. Health Sciences Research Division, Oak Ridge National Laboratory. Oak Ridge, TN.

Swartz, R.C. 1999. Consensus sediment quality guidelines for PAH mixtures. Environ Toxicol Chem 18:780-787. Tidewater. 2009. Final Sampling and Analysis Plan. Expanded Site Inspection. Former Gopher Ordnance Works, Rousemount, Minnesota. Prepared for the U.S. Army Corps of Engineers Omaha District. September. UMN, 2009. UMore Park University of Minnesota Outreach, Education and Outreach Park. Vermillion Highlands: A Research, Recreation and Wildlife Management Area. Update 12/1/2009. Accessed at: http://www.umorepark.umn.edu/Vermillion_Highlands.html USACE. 2006. Environmental Transport and Fate Process Descriptors for Propellant Compounds. Environmental Quality and Technology Program. June E. Mirecki, Beth Porter, and Charles A. Weiss, Jr. ERDC/EL TR-06-7. June. Accessed at: http://el.erdc.usace.army.mil/elpubs/pdf/trel06-7.pdf.

E05MN001901_01.09_0003_a

UMP029126

Tables

E05MN001901_01.09_0003_a

UMP029127

Scientific Name Common NameHerpsAmbystoma tigrinum Tiger SalamanderBufo americanus American Toad Rana pipiens Northern Leopard FrogThamnophis sirtalis Common Gartersnake Chelydra serpentina Snapping Turtle Chrysemys picta Painted Turtle

MammalsDidelphis virginiana Virginia OpossumSciurus carolinensis Eastern Gray SquirrelTamiasciurus hudsonicus Red SquirrelSpermophilus tridecemlineatus Thirteen-lined Ground SquirrelMarmota monax WoodchuckTamias striatus Eastern ChipmunkCastor canadensis American BeaverZapus hudsonius Meadow Jumping MouseGeomys bursarius Plains Pocket GopherMicrotus pennsylvanicus Meadow VoleOndatra zibethicus Common MuskratPeromyscus spp. DeermouseMus musculus House MouseSylvilagus floridanus Eastern CottontailSorex cinereus Cinereus ShrewBlarina brevicauda Northern Short-tailed ShrewScalopus aquaticus Eastern MoleEptesicus fuscus Big Brown BatMyotis lucifugus Little Brown MyotisUrocyon cinereoargenteus Gray FoxMephitis mephitis Striped SkunkProcyon lotor RaccoonCanis latrans CoyoteOdocoileus virginianus White-tailed Deer

Birds

Branta canadensis Canada Goose Aix sponsa Wood Duck Anas strepera Gadwall Anas americana American Wigeon Anas rubripes American Black Duck Anas platyrhynchos Mallard Anas discors Blue-winged Teal Anas clypeata Northern Shoveler Anas acuta Northern Pintail Anas crecca Green-winged Teal Aythya valisineria Canvasback Aythya americana Redhead Aythya collaris Ring-necked Duck Aythya marila Greater ScaupAythya affinis Lesser Scaup Bucephala albeola Bufflehead Bucephala clangula Common Goldeneye Oxyura jamaicensis Ruddy Duck Phasianus colchicus Ring-necked PheasantBonasa umbellus Ruffed Grouse

**many of these species do not breed in the area but do come through during migration

Table 2-1Summary of Vertebrate Species Observed on the Minnesota


Former Gopher Ordnance Works, Rosemount, Minnesota

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Scientific Name Common Name




Birds continuedMeleagris gallopavo Wild Turkey Podilymbus podiceps Pied-billed Grebe Ardea herodias Great Blue Heron Ardea alba Great Egret Butorides virescens Green Heron Cathartes aura Turkey Vulture Haliaeetus leucocephalus Bald EagleCircus cyaneus Northern Harrier Accipiter striatus Sharp-shinned Hawk Accipiter cooperii Cooper's Hawk Buteo platypterus Broad-winged Hawk Buteo swainsoni Swainson's Hawk Buteo jamaicensis Red-tailed Hawk Buteo lagopus Rough-legged HawkFalco sparverius American Kestrel Porzana carolina Sora Rallus limicola Virginia Rail Grus canadensis Sandhill CraneCharadrius vociferus Killdeer Tringa melanoleuca Greater YellowlegsTringa flavipes Lesser YellowlegsBartramia longicauda Upland SandpiperScolopax minor American Woodcock Larus delawarensis Ring-billed Gull Columba livia Rock PigeonZenaida macroura Mourning Dove Bubo virginianus Great Horned OwlStrix varia Barred Owl Chordeiles minor Common Nighthawk Caprimulgus vociferus Whip-poor-will Chaetura pelagica Chimney Swift Archilochus colubris Ruby-throated Hummingbird Ceryle alcyon Belted Kingfisher Melanerpes erythrocephalus Red-headed Woodpecker Melanerpes carolinus Red-bellied Woodpecker Sphyrapicus varius Yellow-bellied Sapsucker Picoides pubescens Downy Woodpecker Picoides villosus Hairy Woodpecker Colaptes auratus Northern Flicker Dryocopus pileatus Pileated Woodpecker Contopus cooperi Olive-sided Flycatcher Contopus virens Eastern Wood-Pewee Empidonax flaviventris Yellow-bellied Flycatcher Empidonax alnorum Alder Flycatcher Empidonax traillii Willow Flycatcher Empidonax minimus Least Flycatcher Sayornis phoebe Eastern Phoebe Myiarchus crinitus Great Crested FlycatcherTyrannus tyrannus Eastern Kingbird Vireo flavifrons Yellow-throated Vireo Vireo gilvus Warbling Vireo Vireo philadelphicus Philadelphia Vireo Vireo olivaceus Red-eyed Vireo Cyanocitta cristata Blue Jay Corvus brachyrhynchos American Crow Eremophila alpestris Horned Lark

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Birds continuedProgne subis Purple Martin Tachycineta bicolor Tree Swallow Stelgidopteryx serripennis Northern Rough-winged Swallow Riparia riparia Bank Swallow Petrochelidon pyrrhonata Cliff Swallow Hirundo rustica Barn Swallow Poecile atricapillus Black-capped Chickadee Sitta canadensis Red-breasted Nuthatch Sitta carolinensis White-breasted Nuthatch Certhia americana Brown Creeper Troglodytes aedon House Wren Troglodytes troglodytes Winter Wren Cistothorus platensis Sedge Wren Cistothorus palustris Marsh Wren Regulus satrapa Golden-crowned Kinglet Regulus calendula Ruby-crowned Kinglet Polioptila caerulea Blue-gray Gnatcatcher Sialia sialis Eastern Bluebird Catharus fuscescens Veery Catharus minimus Gray-cheeked ThrushCatharus ustulatus Swainson's Thrush Catharus guttatus Hermit Thrush Hylocichla mustelina Wood Thrush Turdus migratorius American Robin Dumetella carolinensis Gray Catbird Mimus polyglottos Northern MockingbirdToxostoma rufum Brown Thrasher Bombycilla cedrorum Cedar Waxwing Vermivora pinus Blue-winged Warbler Vermivora chrysoptera Golden-winged Warbler Vermivora peregrina Tennessee WarblerVermivora celata Orange-crowned WarblerVermivora ruficapilla Nashville Warbler Parula americana Northern Parula Dendroica petechia Yellow Warbler Dendroica pensylvanica Chestnut-sided Warbler Dendroica magnolia Magnolia Warbler Dendroica tigrina Cape May Warbler Dendroica coronata Yellow-rumped Warbler Dendroica virens Black-throated Green Warbler Dendroica fusca Blackburnian Warbler Dendroica pinus Pine Warbler Dendroica palmarum Palm Warbler Dendroica castanea Bay-breasted Warbler Dendroica striata Blackpoll WarblerMniotilta varia Black-and-white Warbler Setophaga ruticilla American Redstart Seiurus aurocapilla Ovenbird Seiurus noveboracensis Northern Waterthrush Seiurus motacilla Louisiana WaterthrushOporornis formosus Kentucky WarblerOporornis agilis Connecticut Warbler Oporornis philadelphicus Mourning Warbler Geothlypis trichas Common Yellowthroat Wilsonia citrina Hooded WarblerWilsonia pusilla Wilson's Warbler

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Birds continuedWilsonia canadensis Canada Warbler Piranga olivacea Scarlet Tanager Pipilo erythrophthalmus Eastern Towhee Spizella arborea American Tree SparrowSpizella passerina Chipping Sparrow Spizella pusilla Field Sparrow Pooecetes gramineus Vesper Sparrow Chondestes grammacus Lark Sparrow Passerella iliaca Fox SparrowMelospiza melodia Song Sparrow Melospiza lincolnii Lincoln's Sparrow Melospiza georgiana Swamp Sparrow Zonotrichia albicollis White-throated Sparrow Zonotrichia querula Harris's SparrowZonotrichia leucophrys White-crowned SparrowJunco hyemalis Dark-eyed Junco Plectrophenax nivalis Snow BuntingCardinalis cardinalis Northern Cardinal Pheucticus ludovicianus Rose-breasted Grosbeak Passerina cyanea Indigo Bunting Spiza americana Dickcissel Dolichonyx oryzivorus Bobolink Agelaius phoeniceus Red-winged Blackbird Sturnella magna Eastern Meadowlark Quiscalus quiscula Common Grackle Molothrus ater Brown-headed Cowbird Icterus spurius Orchard Oriole Icterus galbula Baltimore Oriole Carpodacus purpureus Purple Finch Carpodacus mexicanus House FinchCarduelis flammea Common RedpollCarduelis hornemanni Hoary RedpollCarduelis pinus Pine Siskin Carduelis tristis American Goldfinch Passer domesticus House Sparrow

Notes:FGOW - Former Gopher Ordnance WorksInformation provided from the Minnesota Department of Natural Resources

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UMP029131

Analytical Parameter Performed in Each AOC Medium No of Samples Field Duplicate

VOCs, SVOCs, RCRA Metals, DNT, Nitrocellulose Surface Soil 2 1

PAHs, RCRA Metals, DNT Surface Soil 2 1AOC1M

VOCs, SVOCs, RCRA Metals, DNT, Nitrocellulose Surface Soil 5 1

PAHs, RCRA Metals, DNT Surface Soil 7 1

VOCs, SVOCs, RCRA Metals, DNT, Nitrocellulose Surface Soil 5 1VOCs, PAHs, RCRA Metals, DNT, Nitrocellulose Sediment 2 0VOCs, SVOCs, RCRA Metals, DNT, Nitrocellulose Surface Water 2 0

PAHs, RCRA Metals, DNT Surface Soil 11 1PAHs, RCRA Metals, DNT Sediment 3 1RCRA Metals, VOCs, SVOCs Surface Water 3 1

RCRA Metals, PAHs Surface Soil 6 1

RCRA Metals, PAHs Surface Soil 6 1

VOCs, SVOCs, PCBs, RCRA Metals Surface Soil 11 (6 PCBs) 1

PAHs, PCBs, RCRA Metals Surface Soil 5 1

VOCs, SVOCs, RCRA Metals, PCBs, DNT, TPH, Nitrocellulose

Surface Soil 9(4 for PCBs)

(6 for DNT, Nitrocellulose)(5 for TPH)

2

PAHs, PCBs, RCRA Metals Surface Soil 14 1Expanded SI

AOC1S Focused SI

AOC7D Focused SI

Expanded SI

Table 3-1Summary of Samples Used for the SLERA


AOC 6

Expanded SI

AOC7A

Focused SI

Focused SI

AOC1N Focused SI

Focused SI

Expanded SI

Expanded SI

Expanded SI

Page 1 of 2 E05MN001901_01.09_0003_a

UMP029132

Analytical Parameter Performed in Each AOC Medium No of Samples Field Duplicate

Table 3-1Summary of Samples Used for the SLERA


RCRA Metals Surface Soil 14 2

RCRA Metals Surface Soil 10 3

Notes:AOC - area of concernSI - site investigationSLERA - screening level ecological risk assessmentVOCs - volatile organic compoundsSVOCs - semi-volatile organic compoundsRCRA Metals - Resource Conservation and Recovery Act metals (arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver)DNT – dinitrotoluenePAH – polynuclear aromatic hydrocarbonsPCB – polychlorinated biphenylsTPH - total petroleum hydrocarbon

Analytical Methods:VOCs - EPA 8260B (Soil, Sediment, Surface Water) SVOCs and PAHs - EPA 8270C (Soil, Sediment, Surface Water)Metals - EPA 6010B/7471A (Soil, Sediment), EPA 6020 (Surface Water)DNT - EPA 8330 (Soil, Sediment, Surface Water)Nitrocellulose - EPA 353.2 (Soil, Sediment, Surface Water)PCBs - EPA 8082 (Soil)TPH - EPA 8015B (Soil)

Background Samples

Expanded SI

Focused SI

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UMP029133

ESL ESL Source

Selected as a COPC (Yes/No)

RationaleMax

Hazard Quotient

Mean Hazard

Quotient

Selected as Final COPC

(Yes/No)

Rationale

Volatile Organic Compounds1,2,3-Trichlorobenzene 87-61-6 µg/kg 3.2 J J^ J --- 3.2 J J^ J 1 / 2 FGOW-AOC1N-SS-SS1(0-6INCHES) 20000 (3a) No BSL 0.00016 --- --- ---1,2,4-Trichlorobenzene 120-82-1 µg/kg 2.4 J J^ J --- 2.4 J J^ J 1 / 2 FGOW-AOC1N-SS-SS1(0-6INCHES) 11100 (2) No BSL 0.00022 --- --- ---1,2,4-Trimethylbenzene 95-63-6 µg/kg 1.1 J J^ J 1.2 1.3 J 2 / 2 FGOW-AOC1N-SS-GP1(0-6INCHES) NA --- Yes NSL --- --- Yes NSL1,2-Dichlorobenzene 95-50-1 µg/kg 0.82 J J^ J 2.6 0.82 J J^ J 1 / 2 FGOW-AOC1N-SS-SS1(0-6INCHES) 2960 (2) No BSL 0.00028 --- --- ---Methyl ethyl ketone 78-93-3 µg/kg 4.4 J J^ J --- 4.4 J J^ J 1 / 2 FGOW-AOC1N-SS-SS1(0-6INCHES) 89600 (2) No BSL 4.9E-05 --- --- ---Acetone 67-64-1 µg/kg 9.1 J J^ J --- 9.1 J J^ J 1 / 2 FGOW-AOC1N-SS-SS1(0-6INCHES) 2500 (2) No BSL 0.0036 --- --- ---Methylene chloride 75-09-2 µg/kg 1.6 J B --- 1.7 J J^ J 2 / 2 FGOW-AOC1N-SS-SS1(0-6INCHES) 4050 (2) No BSL 0.0004198 --- --- ---p-Isopropyltoluene 99-87-6 µg/kg 3.2 J 3.4 3.2 J 1 / 2 FGOW-AOC1N-SS-GP1(0-6INCHES) NA --- Yes NSL --- --- Yes NSLToluene 108-88-3 µg/kg 1 J J^ J --- 1 J J^ J 1 / 2 FGOW-AOC1N-SS-SS1(0-6INCHES) 5450 (2) No BSL 0.00018 --- --- ---Semi-volatile Organic Compoundsbis(2-Ethylhexyl) phthalate 117-81-7 µg/kg 94 J --- 94 J 1 / 2 FGOW-AOC1N-SS-GP1(0-6INCHES) 925 (2) No BSL 0.10 --- --- ---Di-n-butyl phthalate 84-74-2 µg/kg 460 137730 460 1 / 2 FGOW-AOC1N-SS-GP1(0-6INCHES) 150 (2) Yes ASL 3.1 918 Yes HQ>1Explosives2,4-Dinitrotoluene 121-14-2 mg/kg 0.55 --- 0.67 2 / 4 FGOW-AOC1N-SS-GP102(0-6IN) 1.28 (2) No BSL 0.52 --- --- ---2,6-Dinitrotoluene 606-20-2 mg/kg 0.12 JJ 0.16 0.16 J 2 / 4 FGOW-AOC1N-SS-GP102(0-6IN) 0.0328 (2) Yes ASL 4.9 5.0 Yes HQ>1MetalsArsenic 7440-38-2 mg/kg 2 J --- 8.3 4 / 4 FGOW-AOC1N-SS-GP1(0-6INCHES) 18 (1a) No BSL 0.46 --- --- ---Barium 7440-39-3 mg/kg 25 --- 190 4 / 4 FGOW-AOC1N-SS-GP1(0-6INCHES) 330 (1b) No BSL 0.58 --- --- ---Cadmium 7440-43-9 mg/kg 0.11 --- 0.14 J 2 / 4 FGOW-AOC1N-SS-SS1(0-6INCHES) 0.36 (1d) No BSL 0.39 --- --- ---Chromium 7440-47-3 mg/kg 7.6 --- 25 4 / 4 FGOW-AOC1N-SS-GP1(0-6INCHES) 26 (1c) No BSL 0.96 --- --- ---Lead 7439-92-1 mg/kg 2.3 47 80 4 / 4 FGOW-AOC1N-SS-GP102(0-6IN) 11 (1c) Yes ASL 7.3 4.3 Yes HQ>1Mercury 7439-97-6 mg/kg 0.52 4.7 11 J 3 / 4 FGOW-AOC1N-SS-SS1(0-6INCHES) 0.1 (2) Yes ASL 110 47 Yes HQ>1OtherNitrocellulose 9004-70-0 mg/kg 2500 10250 18000 2 / 2 FGOW-AOC1N-SS-SS1(0-6INCHES) NA --- Yes NSL --- --- Yes NSL

Note: Qualifier:mg/kg - milligram per kilogram J - estimated valueµg/kg - microgram per kilogram B - indicates there was blank contamination above the method detection limit for that particular analyteNA - not available K - the value may consist of both benzo(b)fluoranthene and benzo(k)fluorantheneESL - ecological screening level J^ - estimated value due to low internal standard recovery, and sample value detected below reporting limitCOPC - chemical of potential concernSLERA - screening level ecological risk assessmentMaximum detected concentration used for COPC selection for the SLERA.Mean concentrations are used to refine COPC selection in Step 3a.Hazard Quotients greater than 1.0 are boldMax hazard quotients (HQs) calculated by dividing the maximum detected concentration by the selected ESL to select COPCs in the SLERA. Those selected are to be evaluated in Step 3a. Mean HQs calculated in Step 3a for chemicals retained as COPCs in the SLERA. The mean concentration is divided by the selected ESL.Chemicals selected as Final COPCs in Step 3a based on the mean HQ are those that warrant further evaluation.

Sources: Selection Rationale: (1) EPA. 2008. Ecological Soil Screening Levels (Eco-SSLs) ASL - Above Screening Level a - plant BSL - Below Screening Level b - invertebrate NSL - No Screening Level Available c - avian HQ>1 - Hazard quotient greater than 1 d - mammalian HQ<1 - Hazard quotient less than 1(2) EPA. 2003. EPA Region 5, RCRA Ecological Screening Levels. August.(3) ORNL. 1997. Toxicological Benchmarks for Contaminants of Potential Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process: 1997 Revision a - earthworm b - soil microorganism and microbial processes (4) ORNL. 1997. Toxicological Benchmarks for Contaminants of Potential Concern for Effects on Terrestrial Plants: 1997 Revision

Table 3-2Summary Statistics of Soil Analytical Results and Ecological Screening Results

AOC1-Northern Section Former Gopher Ordnance Works, Rosemount, Minnesota

Chemicals CAS No. UnitMinimum Detected

Concentration

Mean Concentration

Maximum Detected

Concentration

Step 3a Step 2

Location of Maximum ConcentrationDetection Frequency

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029134

ESL ESL Source


RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale

Volatile Organic CompoundsMethylene chloride 75-09-2 µg/kg 1.3 J B --- 1.8 J B J^ J 5 / 5 FGOW-AOC1M-SS-GP1(0-6INCHES) 4050 (2) No BSL 0.00044 --- --- ---p-Isopropyltoluene 99-87-6 µg/kg 2.2 J J^ J 3.0 2.2 J J^ J 1 / 5 FGOW-AOC1N-SS-GP102(0-6IN) NA --- Yes NSL --- --- Yes NSLSemi-volatile Organic Compounds2,4-Dinitrotoluene 121-14-2 µg/kg 190 J --- 190 J 1 / 5 FGOW-AOC1N-SS-GP102(0-6IN) 1280 (2) No BSL 0.15 --- --- ---Benzo(b)fluoranthene 205-99-2 µg/kg 87 J J --- 87 J J 1 / 12 FGOW-AOC1M-SS-GP1(0-6INCHES) 59800 (2) No BSL 0.0015 --- --- ---Benzo(k)fluoranthene 207-08-9 µg/kg 230 J J --- 260 J 2 / 12 FGOW-AOC1M-SS-GP2(0-6INCHES) 148000 (2) No BSL 0.0018 --- --- ---Benzoic acid 65-85-0 µg/kg 460 J 1304 560 J J 4 / 5 FGOW-AOC1M-SS-SS1(0-6INCHES) NA --- Yes NSL --- --- Yes NSLbis(2-Ethylhexyl) phthalate 117-81-7 µg/kg 85 J J --- 440 J J 5 / 5 FGOW-AOC1M-SS-GP1(0-6INCHES) 925 (2) No BSL 0.48 --- --- ---Di-n-butyl phthalate 84-74-2 µg/kg 110 J 761 2900 4 / 5 FGOW-AOC1N-SS-GP102(0-6IN) 150 (2) Yes ASL 19 5.1 Yes HQ>1Phenanthrene 85-01-8 µg/kg 97 J --- 430 J 5 / 12 FGOW-AOC1N-SS-GP102(0-6IN) 45700 (2) No BSL 0.0094 --- --- ---Explosives2,4-Dinitrotoluene 121-14-2 mg/kg 0.067 J --- 0.46 4 / 12 FGOW-AOC1N-SS-GP102(0-6IN) 1.28 (2) No BSL 0.36 --- --- ---MetalsArsenic 7440-38-2 mg/kg 2.4 J --- 7.8 12 / 12 FGOW-AOC1M-SS-GP103(0-6IN) 18 (1a) No BSL 0.43 --- --- ---Barium 7440-39-3 mg/kg 28 B --- 190 B 12 / 12 FGOW-AOC1M-SS-GP101(0-6IN) 330 (1b) No BSL 0.58 --- --- ---Cadmium 7440-43-9 mg/kg 0.048 J --- 0.19 J 11 / 12 FGOW-AOC1M-SS-GP2(0-6INCHES) 0.36 (1d) No BSL 0.53 --- --- ---Chromium 7440-47-3 mg/kg 9.6 17 29 12 / 12 FGOW-AOC1M-SS-GP1(0-6INCHES) 26 (1c) Yes ASL 1.1 0.66 No HQ<1Lead 7439-92-1 mg/kg 7.6 J 21 44 12 / 12 FGOW-AOC1M-SS-GP101(0-6IN) 11 (1c) Yes ASL 4.0 1.9 Yes HQ>1Mercury 7439-97-6 mg/kg 0.02 J 0.90 4.9 12 / 12 FGOW-AOC1M-SS-SS2(0-6INCHES) 0.1 (2) Yes ASL 49 9.0 Yes HQ>1OtherNitrocellulose 9004-70-0 mg/kg 6.3 J 3277 11000 J j^ 5 / 5 FGOW-AOC1M-SS-GP1(0-6INCHES) NA --- Yes NSL --- --- Yes NSL

Note: Qualifier:mg/kg - milligram per kilogram J - estimated valueµg/kg - microgram per kilogram B - indicates there was blank contamination above the method detection limit for that particular analyteNA - not available K - the value may consist of both benzo(b)fluoranthene and benzo(k)fluorantheneESL - ecological screening level J^ - estimated value due to low internal standard recovery, and sample value detected below reporting limitCOPC - chemical of potential concernSLERA - screening level ecological risk assessmentMaximum detected concentration used for COPC selection for the SLERAMean concentrations are used to refine COPC selection in Step 3aHazard Quotients greater than 1.0 are boldMax hazard quotients (HQs) calculated by dividing the maximum detected concentration by the selected ESL to select COPCs in the SLERA. Those selected are to be evaluated in Step 3a. Mean HQs calculated in Step 3a for chemicals retained as COPCs in the SLERA. The mean concentration is divided by the selected ESL.Chemicals selected as Final COPCs in Step 3a based on the mean HQ are those that warrant further evaluation.



AOC1-Middle Section Former Gopher Ordnance Works, Rosemount, Minnesota

Maximum Detected

Concentration

Detection Frequency Location of Maximum Concentration

Step 2 Step 3a


Concentration

Mean Concentration

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029135

ESL ESL Source

Selected as a

COPC (Yes/No)

RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale

Volatile Organic Compounds1,2,4-Trimethylbenzene 95-63-6 µg/kg 0.88 J J^ J 2.3 1.1 J J^ J 3 / 5 FGOW-AOC1S-SS-SS3(0-6INCHES) NA --- Yes NSL --- --- Yes NSLMethyl ethyl ketone 78-93-3 µg/kg 13 J J^ J --- 17 J 2 / 5 FGOW-AOC1S-SS-SS1(0-6INCHES) 89600 (2) No BSL 0.00019 --- --- ---Acetone 67-64-1 µg/kg 60 J^ J --- 170 2 / 5 FGOW-AOC1S-SS-SS1(0-6INCHES) 2500 (2) No BSL 0.068 --- --- ---Methylene chloride 75-09-2 µg/kg 1.3 J B J^ J --- 2.1 J B J^ J 5 / 5 FGOW-AOC1S-SS-GP1(0-6INCHES) 4050 (2) No BSL 0.00052 --- --- ---Toluene 108-88-3 µg/kg 1.2 J --- 1.2 J 1 / 5 FGOW-AOC1S-SS-SS1(0-6INCHES) 5450 (2) No BSL 0.00022 --- --- ---Semi-volatile Organic CompoundsAcenaphthene 83-32-9 µg/kg 34 J --- 580 J 2 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 682000 (2) No BSL 0.00085 --- --- ---Anthracene 120-12-7 µg/kg 20 J --- 2000 J 3 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 1480000 (2) No BSL 0.0014 --- --- ---Benzo(a)anthracene 56-55-3 µg/kg 37 J 1072 14000 5 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 5210 (2) Yes ASL 2.7 0.21 No HQ<1Benzo(a)pyrene 50-32-8 µg/kg 48 J 1146 15000 4 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 1520 (2) Yes ASL 9.9 0.75 No HQ<1Benzo(b)fluoranthene 205-99-2 µg/kg 81 J K --- 31000 K 4 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 59800 (2) No BSL 0.52 --- --- ---Benzo(ghi)perylene 191-24-2 µg/kg 140 J --- 11000 3 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 119000 (2) No BSL 0.092 --- --- ---Benzo(k)fluoranthene 207-08-9 µg/kg 260 J --- 260 J 1 / 16 FGOW-AOC1S-SS-GP2(0-6INCHES) 148000 (2) No BSL 0.0018 --- --- ---Benzoic acid 65-85-0 µg/kg 520 J 3150 2300 J^ 4 / 5 FGOW-AOC1S-SS-SS3(0-6INCHES) NA --- Yes NSL --- --- Yes NSLbis(2-Ethylhexyl) phthalate 117-81-7 µg/kg 64 J --- 110 J J 3 / 5 FGOW-AOC1S-SS-GP1(0-6INCHES) 925 (2) No BSL 0.12 --- --- ---Carbazole 86-74-8 µg/kg 2000 J 604 2000 J 1 / 5 FGOW-AOC1S-SS-SS2(0-6INCHES) NA --- Yes NSL --- --- Yes NSLChrysene 218-01-9 µg/kg 40 J 1315 18000 6 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 4730 (2) Yes ASL 3.8 0.28 No HQ<1Dibenz(a,h)anthracene 53-70-3 µg/kg 2300 J --- 2300 J 1 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 18400 (2) No BSL 0.13 --- --- ---Fluoranthene 206-44-0 µg/kg 69 J --- 32000 4 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 122000 (2) No BSL 0.26 --- --- ---Fluorene 86-73-7 µg/kg 28 J --- 580 J 2 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 122000 (2) No BSL 0.0048 --- --- ---Indeno(1,2,3-cd)pyrene 193-39-5 µg/kg 110 J --- 9800 3 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 109000 (2) No BSL 0.090 --- --- ---Phenanthrene 85-01-8 µg/kg 99 J --- 12000 5 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 45700 (2) No BSL 0.26 --- --- ---Pyrene 129-00-0 µg/kg 18 J --- 26000 6 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 78400 (2) No BSL 0.33 --- --- ---MetalsArsenic 7440-38-2 mg/kg 1.1 J --- 9.3 16 / 16 FGOW-AOC1S-SS-GP2(0-6INCHES) 18 (1a) No BSL 0.52 --- --- ---Barium 7440-39-3 mg/kg 23 B --- 280 B 16 / 16 FGOW-AOC1S-SS-GP102(0-6IN) 330 (1b) No BSL 0.85 --- --- ---Cadmium 7440-43-9 mg/kg 0.085 J --- 0.31 J 6 / 16 FGOW-AOC1S-SS-GP102(0-6IN) 0.36 (1d) No BSL 0.86 --- --- ---Chromium 7440-47-3 mg/kg 8.9 17 27 16 / 16 FGOW-AOC1S-SS-GP1(0-6INCHES) 26 (1c) Yes ASL 1.0 0.66 No HQ<1Lead 7439-92-1 mg/kg 6.4 48 320 16 / 16 FGOW-AOC1S-SS-SS2(0-6INCHES) 11 (1c) Yes ASL 29 4.4 Yes HQ>1Mercury 7439-97-6 mg/kg 0.0072 0.079 0.38 16 / 16 FGOW-AOC1S-SS-GP1(0-6INCHES) 0.1 (2) Yes ASL 3.8 0.79 No HQ<1OtherNitrocellulose 9004-70-0 mg/kg 1.7 B J u 21 74 J 5 / 5 FGOW-AOC1S-SS-GP1(0-6INCHES) NA --- Yes NSL --- --- Yes NSL


Sources: Selection Rationale: (1) EPA. 2008. Ecological Soil Screening Levels (Eco-SSLs) ASL - Above Screening Level a - plant BSL - Below Screening Level b - invertebrate NSL - No Screening Level Available c - avian HQ>1 - Hazard quotient greater than 1 d - mammalian HQ<1 - Hazard quotient less than 1(2) EPA. 2003. U.S. EPA Region 5, RCRA Ecological Screening Levels. August.(3) ORNL. 1997. Toxicological Benchmarks for Contaminants of Potential Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process: 1997 Revision a - earthworm b - soil microorganism and microbial processes (4) ORNL. 1997. Toxicological Benchmarks for Contaminants of Potential Concern for Effects on Terrestrial Plants: 1997 Revision


AOC1-Southern Section Former Gopher Ordnance Works, Rosemount, Minnesota

Maximum Detected

Concentration

Detection Frequency

Location of Maximum Concentration

Step 2 Step 3a


Concentration

Mean Concentration

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029136

ESL ESL Source

MPCA Level I Sediment

Quality Targets


RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale

Volatile Organic Compounds1,3,5-Trimethylbenzene 108-67-8 µg/kg 1.5 J J 3.3 1.5 J J 1 / 2 FGOW-AOC1S-SED-SED1(0-4INCHES) NA --- NA Yes NSL --- --- Yes NSLMethyl ethyl ketone 78-93-3 µg/kg 36 B J 45 53 B J 2 / 2 FGOW-AOC1S-SED-SED2(0-4INCHES) 42.4 (2) NA Yes ASL 1.3 1.0 Yes HQ>1Acetone 67-64-1 µg/kg 72 J 91 110 J 2 / 2 FGOW-AOC1S-SED-SED2(0-4INCHES) 9.9 (2) NA Yes ASL 11 9.2 Yes HQ>1Carbon disulfide 75-15-0 µg/kg 0.87 J J --- 0.87 J J 1 / 2 FGOW-AOC1S-SED-SED1(0-4INCHES) 23.9 (2) NA No BSL 0.036 --- --- ---Toluene 108-88-3 µg/kg 1.1 J J --- 1.1 J J 1 / 2 FGOW-AOC1S-SED-SED1(0-4INCHES) 1220 (2) NA No BSL 0.00090 --- --- ---Semi-volatile Organic Compounds2-Methylnaphthalene 91-57-6 µg/kg 2.8 J --- 2.8 J 1 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 20.2 (2) 20 No BSL 0.14 --- --- ---Acenaphthene 83-32-9 µg/kg 0.46 8.9 11 2 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 6.71 (2) 6.7 Yes ASL 1.6 1.3 Yes HQ>1Acenaphthylene 208-96-8 µg/kg 0.68 --- 3.6 2 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 5.87 (2) 5.9 No BSL 0.61 --- --- ---Anthracene 120-12-7 µg/kg 0.62 --- 19 4 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 57.2 (1) 57 No BSL 0.33 --- --- ---Benzo(a)anthracene 56-55-3 µg/kg 0.57 --- 62 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 108 (1) 110 No BSL 0.57 --- --- ---Benzo(a)pyrene 50-32-8 µg/kg 0.68 --- 120 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 150 (1) 150 No BSL 0.80 --- --- ---Benzo(b)fluoranthene 205-99-2 µg/kg 2 --- 210 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 10400 (2) NA No BSL 0.02 --- --- ---Benzo(ghi)perylene 191-24-2 µg/kg 0.97 --- 140 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 170 (2) NA No BSL 0.82 --- --- ---Chrysene 218-01-9 µg/kg 1.3 --- 84 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 166 (1) 170 No BSL 0.51 --- --- ---Dibenzo(a,h)anthracene 53-70-3 µg/kg 1.1 11 42 4 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 33.0 (1) 33 Yes ASL 1.3 0.33 No HQ<1Fluoranthene 206-44-0 µg/kg 1.7 --- 110 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 423 (1) 420 No BSL 0.26 --- --- ---Fluorene 86-73-7 µg/kg 3.1 --- 12 3 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 77.4 (1) 77 No BSL 0.16 --- --- ---Indeno(1,2,3-cd)pyrene 193-39-5 µg/kg 0.74 --- 120 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 200 (2) NA No BSL 0.60 --- --- ---Naphthalene 91-20-3 µg/kg 0.47 --- 5.7 4 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 176 (1) 180 No BSL 0.032 --- --- ---Phenanthrene 85-01-8 µg/kg 0.93 --- 38 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 204 (1) 200 No BSL 0.19 --- --- ---Pyrene 129-00-0 µg/kg 1.3 --- 98 5 / 5 FGOW-AOC1S-SED-SED1(0-4INCHES) 195 (1) 200 No BSL 0.50 --- --- ---MetalsArsenic 7440-38-2 mg/kg 3 7.0 11 5 / 5 FGOW-AOC1S-SED-SED107(0-4IN) 9.79 (1) 9.8 Yes ASL 1.1 0.71 No HQ<1Barium 7440-39-3 mg/kg 74 B 140 220 B 5 / 5 FGOW-AOC1S-SED-SED107(0-4IN) NA --- NA Yes NSL --- --- Yes NSLCadmium 7440-43-9 mg/kg 0.17 --- 0.39 3 / 5 FGOW-AOC1S-SED-SED2(0-4INCHES) 0.99 (1) 0.99 No BSL 0.39 --- --- ---Chromium 7440-47-3 mg/kg 10 J --- 17 5 / 5 FGOW-AOC1S-SED-SED107(0-4IN)/

FGOW-AOC1S-SED-SED107(0-4IN)43.4 (1) 43 No BSL 0.39 --- --- ---

Lead 7439-92-1 mg/kg 5.9 --- 27 5 / 5 FGOW-AOC1S-SED-SED107(0-4IN) 35.8 (1) 36 No BSL 0.75 --- --- ---Mercury 7439-97-6 mg/kg 0.007 J --- 0.054 J 5 / 5 FGOW-AOC1S-SED-SED107(0-4IN) 0.18 (1) 0.18 No BSL 0.30 --- --- ---Selenium 7782-49-2 mg/kg 0.54 J 1.8 2.5 4 / 5 FGOW-AOC1S-SED-SED2(0-4INCHES) NA --- NA Yes NSL --- --- Yes NSLSilver 7440-22-4 mg/kg 0.038 J J --- 0.065 J 2 / 5 FGOW-AOC1S-SED-SED2(0-4INCHES) 0.5 (2) NA No BSL 0.13 --- --- ---OtherNitrocellulose 9004-70-0 mg/kg 5.1 B J u 8.6 12 J 2 / 2 FGOW-AOC1S-SED-SED1(0-4INCH) NA --- NA Yes NSL --- --- Yes NSL

Note: Qualifier:mg/kg - milligram per kilogram J - estimated valueµg/kg - microgram per kilogram B - indicates there was blank contamination above the method detection limit for that particular analyteNA - not available K - the value may consist of both benzo(b)fluoranthene and benzo(k)fluorantheneESL - ecological screening level J^ - estimated value due to low internal standard recovery, and sample value detected below reporting limitCOPC - chemical of potential concernSLERA - screening level ecological risk assessmentMaximum detected concentration used for COPC selection for the SLERA Selection Rationale: Mean concentrations are used to refine COPC selection in Step 3a ASL - Above Screening LevelHazard Quotients greater than 1.0 are bold BSL - Below Screening LevelMax hazard quotients (HQs) calculated by dividing the maximum detected concentration by the selected ESL to select NSL - No Screening Level Available COPCs in the SLERA. Those selected are to be evaluated in Step 3a. HQ>1 - Hazard quotient greater than 1Mean HQs calculated in Step 3a for chemicals retained as COPCs in the SLERA. The mean concentration HQ<1 - Hazard quotient less than 1 is divided by the selected ESL.Chemicals selected as Final COPCs in Step 3a based on the mean HQ are those that warrant further evaluation.

Sources:(1) MacDonald, et al. 2000. Development and Evaluation of Consensus-Based Sediment Quality Guidelines for Freshwater Ecosystems. Arch. Environ. Contam. Toxicol. 39, 20-31 (2000). Consensus-Based Threshold Effect Concentrations (TECs).(2) EPA. 2003. EPA Region 5, RCRA Ecological Screening Levels. August.

Table 3-5Summary Statistics of Sediment Analytical Results and Ecological Screening Results


Maximum Detected

Concentration


Step 2 Step 3a


Concentration

Mean Concentration

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029137

ESL ESL Source

MPCA Screening

Benchmarks (3)

Selected as a

COPC (Yes/No)

RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale

Volatile Organic CompoundsAcetone 67-64-1 µg/L 3.8 J --- 4.4 J 2 / 5 FGOW-AOC1S-W-S107 1700 (2) NA No BSL 0.0026 --- --- ---Semi-volatile Organic Compounds2-Methylnaphthalene 91-57-6 µg/L 0.033 J --- 0.033 J 1 / 5 FGOW-AOC1S-W-S1 330 (2) NA No BSL 0.0001 --- --- ---Acenaphthene 83-32-9 µg/L 0.14 --- 0.14 1 / 5 FGOW-AOC1S-W-S1 38 (2) 20 No BSL 0.0037 --- --- ---Acenaphthylene 208-96-8 µg/L 0.0056 J --- 0.0056 J 1 / 5 FGOW-AOC1S-W-S1 4840 (2) NA No BSL 1.2E-06 --- --- ---Anthracene 120-12-7 µg/L 0.019 J --- 0.019 J 1 / 5 FGOW-AOC1S-W-S1 0.035 (2) 0.035 No BSL 0.54 --- --- ---Benzo(a)anthracene 56-55-3 µg/L 0.0057 J --- 0.0057 J 1 / 5 FGOW-AOC1S-W-S1 0.025 (2) NA No BSL 0.23 --- --- ---Benzyl alcohol 100-51-6 µg/L 0.6 J --- 0.6 J 1 / 3 FGOW-AOC1S-W-S110 8.6 (2) NA No BSL 0.070 --- --- ---Fluoranthene 206-44-0 µg/L 0.0052 J --- 0.033 J 2 / 5 FGOW-AOC1S-W-S1 1.9 (2) 1.9 No BSL 0.017 --- --- ---Fluorene 86-73-7 µg/L 0.081 J --- 0.081 J 1 / 5 FGOW-AOC1S-W-S1 19 (2) NA No BSL 0.004 --- --- ---Naphthalene 91-20-3 µg/L 0.41 --- 0.41 1 / 5 FGOW-AOC1S-W-S1 13 (2) 81 No BSL 0.032 --- --- ---Phenanthrene 85-01-8 µg/L 0.048 J --- 0.048 J 1 / 5 FGOW-AOC1S-W-S1 3.6 (2) 3.6 No BSL 0.013 --- --- ---Pyrene 129-00-0 µg/L 0.019 J --- 0.019 J 1 / 5 FGOW-AOC1S-W-S1 0.3 (2) NA No BSL 0.063 --- --- ---MetalsArsenic 7440-38-2 µg/L 1 --- 8 5 / 5 FGOW-AOC1S-W-S1 150 (1) 53 No BSL 0.053 --- --- ---Barium 7440-39-3 µg/L 56 --- 200 5 / 5 FGOW-AOC1S-W-S110 220 (2) NA No BSL 0.91 --- --- ---Cadmium 7440-43-9 µg/L 0.055 J --- 0.22 J 2 / 5 FGOW-AOC1S-W-S110 0.25 (1) NA No BSL 0.88 --- --- ---Chromium 7440-47-3 µg/L 0.57 J --- 7.7 J 4 / 5 FGOW-AOC1S-W-S110 74 (1) NA No BSL 0.10 --- --- ---Lead 7439-92-1 µg/L 0.19 J 3.9 15 4 / 5 FGOW-AOC1S-W-S110 2.5 (1) NA Yes ASL 6.0 1.6 Yes HQ>1Mercury 7439-97-6 µg/L 0.031 J --- 0.031 J 1 / 5 FGOW-AOC1S-W-S110 0.77 (1) 0.0069 No BSL 0.040 --- --- ---Selenium 7782-49-2 µg/L 1.8 J --- 2.3 J 2 / 5 FGOW-AOC1S-W-S110 5.0 (1) 5.0 No BSL 0.46 --- --- ---Silver 7440-22-4 µg/L 0.016 J --- 0.04 J 2 / 5 FGOW-AOC1S-W-S110 0.12 (2) 1 No BSL 0.33 --- --- ---OtherNitrocellulose 9004-70-0 mg/L 0.19 B 0.21 0.23 B 2 / 2 FGOW-AOC1S-W-S2 NA --- NA Yes NSL --- --- Yes NSL

Note: Qualifier:mg/L - milligram per liter J - estimated valueµg/L - microgram per liter B - indicates there was blank contamination above the method detection limit for that particular analyteNA - not available K - the value may consist of both benzo(b)fluoranthene and benzo(k)fluorantheneESL - ecological screening level J^ - estimated value due to low internal standard recovery, and sample value detected below reporting limitCOPC - chemical of potential concernSLERA - screening level ecological risk assessmentMaximum detected concentration used for COPC selection for the SLERAMean concentrations are used to refine COPC selection in Step 3aHazard Quotients greater than 1.0 are boldMax hazard quotients (HQs) calculated by dividing the maximum detected concentration by the selected ESL to select COPCs in the SLERA. Those selected are to be evaluated in Step 3a.Mean HQs calculated in Step 3a for chemicals retained as COPCs in the SLERA. The mean concentration is divided by the selected ESLChemicals selected as Final COPCs in Step 3a based on the mean HQ are those that warrant further evaluation.

Sources:(1) EPA. 2009. National Recommended Water Quality Criteria. Office of Water. Office of Science and Technology. Freshwater Criterion Continuous Concentration values. ESLs for hardness-dependent metals based on hardness = 100 mg/L CaCO3.(2) EPA. 2003. EPA Region 5, RCRA Ecological Screening Levels. August.(3) MPCA. 2006. Minnesota Pollution Control Agency Remediation Programs Working Draft Surface Water Pathway Evaluation User's Guide. January. Values are Tier 2 chronic values for Class 2C waters

Selection Rationale: ASL - Above Screening Level BSL - Below Screening Level NSL - No Screening Level Available HQ>1 - Hazard quotient greater than 1 HQ<1 - Hazard quotient less than 1

Table 3-6Summary Statistics of Surface Water Analytical Results and Ecological Screening Results


Maximum Detected

Concentration

Detection Frequency


Step 2 Step 3a


Concentration

Mean Concentration

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029138

ESL ESL Source

Selected as a

COPC (Yes/No)

RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale

Semi-volatile Organic CompoundsAcenaphthene 83-32-9 µg/kg 33 J --- 1400 J 4 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 682000 (2) No BSL 0.0021 --- --- ---Anthracene 120-12-7 µg/kg 62 J --- 4500 7 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 1480000 (2) No BSL 0.0030 --- --- ---Benzo(a)anthracene 56-55-3 µg/kg 25 J 1375 9100 10 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 5210 (2) Yes ASL 1.7 0.26 No HQ<1Benzo(a)pyrene 50-32-8 µg/kg 38 J 1256 7300 9 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 1520 (2) Yes ASL 4.8 0.83 No HQ<1Benzo(b)fluoranthene 205-99-2 µg/kg 70 J K --- 12000 K 9 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 59800 (2) No BSL 0.20 --- --- ---Benzo(ghi)perylene 191-24-2 µg/kg 26 J --- 3700 9 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 119000 (2) No BSL 0.031 --- --- ---Chrysene 218-01-9 µg/kg 33 J 1365 8800 11 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 4730 (2) Yes ASL 1.9 0.29 No HQ<1Dibenz(a,h)anthracene 53-70-3 µg/kg 39 J --- 680 5 / 12 FGOW-AOC6-SS-TP6(0-.5FT) 18400 (2) No BSL 0.037 --- --- ---Fluoranthene 206-44-0 µg/kg 76 J --- 18000 9 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 122000 (2) No BSL 0.15 --- --- ---Fluorene 86-73-7 µg/kg 22 J --- 1500 J 5 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 122000 (2) No BSL 0.012 --- --- ---Indeno(1,2,3-cd)pyrene 193-39-5 µg/kg 29 J --- 3600 8 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 109000 (2) No BSL 0.033 --- --- ---Naphthalene 91-20-3 µg/kg 370 J 348 370 J 1 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 99.4 (2) Yes ASL 3.7 3.5 Yes HQ>1Phenanthrene 85-01-8 µg/kg 45 J --- 15000 9 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 45700 (2) No BSL 0.33 --- --- ---Pyrene 129-00-0 µg/kg 27 J --- 16000 10 / 12 FGOW-AOC6-SS-TP4(0-.5FT) 78400 (2) No BSL 0.20 --- --- ---MetalsArsenic 7440-38-2 mg/kg 2.4 J --- 8 12 / 12 FGOW-A0C6-SS-GP101(0-6IN) 18 (1a) No BSL 0.44 --- --- ---Barium 7440-39-3 mg/kg 24 B --- 170 12 / 12 FGOW-AOC6-SS-TP6(0-.5FT) 330 (1b) No BSL 0.52 --- --- ---Cadmium 7440-43-9 mg/kg 0.049 J 0.36 1.3 8 / 12 FGOW-A0C6-SS-GP103(0-6IN) 0.36 (1d) Yes ASL 3.6 0.99 No HQ<1Chromium 7440-47-3 mg/kg 8.9 19 43 12 / 12 FGOW-AOC6-SS-TP6(0-.5FT) 26 (1c) Yes ASL 1.7 0.73 No HQ<1Lead 7439-92-1 mg/kg 3.4 34 170 12 / 12 FGOW-AOC6-SS-TP6(0-.5FT) 11 (1c) Yes ASL 15 3.1 Yes HQ>1Mercury 7439-97-6 mg/kg 0.013 J 0.19 0.74 12 / 12 FGOW-AOC6-SS-TP3(0-.5FT) 0.1 (2) Yes ASL 7.4 1.9 Yes HQ>1Silver 7440-22-4 mg/kg 0.22 J --- 1.1 J 4 / 12 FGOW-AOC6-SS-TP6(0-.5FT) 4.2 (1c) No BSL 0.26 --- --- ---




AOC6Former Gopher Ordnance Works, Rosemount, Minnesota

Maximum Detected

Concentration

Detection Frequency


Step 2 Step 3a


Concentration

Mean Concentration

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029139

ESL ESL Source

Selected as a

COPC (Yes/No)

RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale

Volatile Organic Compounds1,2,4-Trimethylbenzene 95-63-6 µg/kg 0.68 J J 2.9 4.6 J J 5 / 11 FGOW-AOC7A-SS-SS1(0-6INCHES) NA --- Yes NSL --- --- Yes NSLMethyl ethyl ketone 78-93-3 µg/kg 17 J B J --- 150 B J 11 / 11 FGOW-AOC7A-SS-SS1(0-6INCHES) 89600 (2) No BSL 0.0017 --- --- ---Acetone 67-64-1 µg/kg 73 J --- 1500 J 11 / 11 FGOW-AOC7A-SS-SS1(0-6INCHES) 2500 (2) No BSL 0.60 --- --- ---

Benzene 71-43-2 µg/kg 0.54 J J --- 2.9 J J 10 / 11FGOW-AOC7A-SS-SS3(0-6INCHES)/ FGOW-AOC7A-SS-SS4(0-6INCHES) 255 (2) No BSL 0.011 --- --- ---

Carbon disulfide 75-15-0 µg/kg 0.92 J J --- 7.1 J 8 / 11 FGOW-AOC7A-SS-GP4(0-6INCHES) 94.1 (2) No BSL 0.075 --- --- ---Ethylbenzene 100-41-4 µg/kg 0.89 J J --- 1.4 J J 4 / 11 FGOW-AOC7A-SS-SS2(0-6INCHES) 5160 (2) No BSL 0.00027 --- --- ---Methylene chloride 75-09-2 µg/kg 0.9 J J --- 0.9 J J 1 / 11 FGOW-AOC7A-SS-GP7(0-6INCHES) 4050 (2) No BSL 0.00022 --- --- ---Naphthalene 91-20-3 µg/kg 0.98 J J --- 17 J 6 / 11 FGOW-AOC7A-SS-SS1(0-6INCHES) 99.4 (2) No BSL 0.17 --- --- ---p-Isopropyltoluene 99-87-6 µg/kg 2.2 J J 3.6 3.9 J J 2 / 11 FGOW-AOC7A-SS-GP2(0-6INCHES) NA --- Yes NSL --- --- Yes NSLToluene 108-88-3 µg/kg 1 J J --- 5.1 J J 11 / 11 FGOW-AOC7A-SS-SS1(0-6INCHES) 5450 (2) No BSL 0.00094 --- --- ---Semi-volatile Organic Compounds2-Methylnaphthalene 91-57-6 µg/kg 31 J 752 3800 J 8 / 16 FGOW-AOC7A-SS-SS1(0-6INCHES)/

FGOW-AOC7A-SS-SS3(0-6INCHES)3240 (2) Yes ASL 1.2 0.23 No HQ<1

Acenaphthene 83-32-9 µg/kg 28 J --- 22000 13 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 682000 (2) No BSL 0.032 --- --- ---Acenaphthylene 208-96-8 µg/kg 56 J --- 56 J 1 / 16 FGOW-AOC7A-SS107(0-6IN) 682000 (2) No BSL 0.00008 --- --- ---Anthracene 120-12-7 µg/kg 71 J --- 43000 13 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 1480000 (2) No BSL 0.029 --- --- ---Benzo(a)anthracene 56-55-3 µg/kg 49 J 12983 110000 15 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 5210 (2) Yes ASL 21 2.5 Yes HQ>1Benzo(a)pyrene 50-32-8 µg/kg 39 J 10418 85000 15 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 1520 (2) Yes ASL 56 6.9 Yes HQ>1Benzo(b)fluoranthene 205-99-2 µg/kg 65 J K 19024 160000 K 15 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 59800 (2) Yes ASL 2.7 0.32 No HQ<1Benzo(ghi)perylene 191-24-2 µg/kg 19 J --- 44000 15 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 119000 (2) No BSL 0.37 --- --- ---bis(2-Ethylhexyl) phthalate 117-81-7 µg/kg 79 J --- 79 J 1 / 11 FGOW-AOC7A-SS-GP4(0-6INCHES) 925 (2) No BSL 0.085 --- --- ---Carbazole 86-74-8 µg/kg 59 J 5877 31000 9 / 11 FGOW-AOC7A-SS-SS3(0-6INCHES) NA --- Yes NSL --- --- Yes NSLChrysene 218-01-9 µg/kg 60 J 13327 110000 15 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 4730 (2) Yes ASL 23 2.8 Yes HQ>1Dibenz(a,h)anthracene 53-70-3 µg/kg 59 J --- 14000 J 5 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 18400 (2) No BSL 0.76 --- --- ---Dibenzofuran 132-64-9 µg/kg 140 J 2925 12000 J 7 / 11 FGOW-AOC7A-SS-SS3(0-6INCHES) NA --- Yes NSL --- --- Yes NSLFluoranthene 206-44-0 µg/kg 92 J 35875 300000 15 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 122000 (2) Yes ASL 2.5 0.29 No HQ<1Fluorene 86-73-7 µg/kg 26 J --- 23000 13 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 122000 (2) No BSL 0.19 --- --- ---Indeno(1,2,3-cd)pyrene 193-39-5 µg/kg 54 J --- 42000 14 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 109000 (2) No BSL 0.39 --- --- ---Naphthalene 91-20-3 µg/kg 59 J 1468 8300 J 8 / 16 FGOW-AOC7A-SS-SS1(0-6INCHES) 99.4 (2) Yes ASL 84 15 Yes HQ>1Phenanthrene 85-01-8 µg/kg 67 J 31921 240000 15 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 45700 (2) Yes ASL 5.3 0.70 No HQ<1Pyrene 129-00-0 µg/kg 77 J 27517 230000 15 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 78400 (2) Yes ASL 2.9 0.35 No HQ<1Polychlorinated Biphenyls (PCB)Total PCB µg/kg 39 J 3254 25800 7 / 11 FGOW-AOC7A-SS-SS1(0-6INCHES) 0.332 (2) Yes ASL 77711 9801 Yes HQ>1


AOC7AFormer Gopher Ordnance Works, Rosemount, Minnesota

Maximum Detected

Concentration


Step 2 Step 3a


Concentration

Mean Concentration

Page 1 of 2 E05MN001901_01.09_0003_a

UMP029140

ESL ESL Source

Selected as a

COPC (Yes/No)

RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale


AOC7AFormer Gopher Ordnance Works, Rosemount, Minnesota

Maximum Detected

Concentration


Step 2 Step 3a


Concentration

Mean Concentration

MetalsArsenic 7440-38-2 mg/kg 2.3 J --- 6 16 / 16 FGOW-AOC7A-SS-GP101(0-6IN) 18 (1a) No BSL 0.33 --- --- ---Barium 7440-39-3 mg/kg 28 --- 120 16 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 330 (1b) No BSL 0.36 --- --- ---Cadmium 7440-43-9 mg/kg 0.05 J 0.47 1.5 16 / 16 FGOW-AOC7A-SS-SS4(0-6INCHES) 0.36 (1d) Yes ASL 4.2 1.3 Yes HQ>1Chromium 7440-47-3 mg/kg 8.6 15 40 16 / 16 FGOW-AOC7A-SS-SS2(0-6INCHES) 26 (1c) Yes ASL 1.5 0.57 No HQ<1Lead 7439-92-1 mg/kg 4.2 J 95 520 16 / 16 FGOW-AOC7A-SS-SS3(0-6INCHES) 11 (1c) Yes ASL 47 8.6 Yes HQ>1Mercury 7439-97-6 mg/kg 0.0077 J 0.054 0.19 16 / 16 FGOW-AOC7A-SS-SS1(0-6INCHES) 0.1 (2) Yes ASL 1.9 0.54 No HQ<1Silver 7440-22-4 mg/kg 0.22 J --- 0.22 1 / 16 FGOW-AOC7A-SS-SS1(0-6INCHES) 4.2 (1c) No BSL 0.052 --- --- ---

Note: Qualifier:mg/kg - milligram per kilogram J - estimated valueµg/kg - microgram per kilogram B - indicates there was blank contamination above the method detection limit for that particular analyteNA - not available K - the value may consist of both benzo(b)fluoranthene and benzo(k)fluorantheneESL - ecological screening level J^ - estimated value due to low internal standard recovery, and sample value detected below reporting limiCOPC - chemical of potential concernSLERA - screening level ecological risk assessmentMaximum detected concentration used for COPC selection for the SLERAMean concentrations are used to refine COPC selection in Step 3aHazard Quotients greater than 1.0 are boldMax hazard quotients (HQs) calculated by dividing the maximum detected concentration by the selected ESL to select COPCs in the SLERA. Those selected are to be evaluated in Step 3a. Mean HQs calculated in Step 3a for chemicals retained as COPCs in the SLERA. The mean concentration is divided by the selected ESL.Chemicals selected as Final COPCs in Step 3a based on the mean HQ are those that warrant further evaluation.Total PCBs calculated from sum of detected values for detected Aroclors (1254 and 1260)


Page 2 of 2 E05MN001901_01.09_0003_a

UMP029141

ESL ESL Source


RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale

Volatile Organic Compounds1,2,4-Trimethylbenzene 95-63-6 µg/kg 0.92 J 2.8 2.8 J 3 / 9 FGOW-AOC7D-SS-GP1(0-6INCHES) NA --- Yes NSL --- --- Yes NSLAcetone 67-64-1 µg/kg 9.6 J J J^ --- 14 J J 2 / 9 FGOW-AOC7D-SS-GP4(0-6INCHES) 2500 (2) No BSL 0.0056 --- No ---Ethylbenzene 100-41-4 µg/kg 1.9 J --- 1.9 J 1 / 9 FGOW-AOC7D-SS-GP1(0-6INCHES) 5160 (2) No BSL 0.00037 --- No ---m-Xylene & p-Xylene 136777-61-2 µg/kg 1.3 J --- 3.6 J 2 / 9 FGOW-AOC7D-SS-GP1(0-6INCHES) 10000 (2) No BSL 0.00036 --- No ---Methylene chloride 75-09-2 µg/kg 1.2 J --- 2 J B u 2 / 9 FGOW-AOC7D-SS-GP8(0-6INCHES) 4050 (2) No BSL 0.00049 --- No ---Naphthalene 91-20-3 µg/kg 0.95 J --- 12 8 / 9 FGOW-AOC7D-SS-GP3(0-6INCHES) 99.4 (2) No BSL 0.12 --- No ---Toluene 108-88-3 µg/kg 0.81 J --- 1.8 J 3 / 9 FGOW-AOC7D-SS-GP1(0-6INCHES) 5450 (2) No BSL 0.00033 --- No ---Semi-volatile Organic Compounds2-Methylnaphthalene 91-57-6 µg/kg 23 J --- 480 8 / 23 FGOW-AOC7D-SS-GP5(0-6INCHES) 3240 (2) No BSL 0.15 --- --- ---Acenaphthene 83-32-9 µg/kg 14 J --- 1600 12 / 23 FGOW-AOC7D-SS109(0-6IN) 682000 (2) No BSL 0.0023 --- --- ---Acenaphthylene 208-96-8 µg/kg 45 J --- 45 J 1 / 23 FGOW-AOC7D-SS109(0-6IN) 682000 (2) No BSL 6.6E-05 --- --- ---Anthracene 120-12-7 µg/kg 34 J --- 4200 12 / 23 FGOW-AOC7D-SS109(0-6IN) 1480000 (2) No BSL 0.0028 --- --- ---Benzo(a)anthracene 56-55-3 µg/kg 27 J 1708 10000 19 / 23 FGOW-AOC7D-SS109(0-6IN) 5210 (2) Yes ASL 1.9 0.33 No HQ<1Benzo(a)pyrene 50-32-8 µg/kg 22 J 1473 7100 17 / 23 FGOW-AOC7D-SS109(0-6IN) 1520 (2) Yes ASL 4.7 0.97 No HQ<1Benzo(b)fluoranthene 205-99-2 µg/kg 37 J K --- 13000 K 18 / 23 FGOW-AOC7D-SS109(0-6IN) 59800 (2) No BSL 0.22 --- --- ---Benzo(ghi)perylene 191-24-2 µg/kg 20 J --- 3800 15 / 23 FGOW-AOC7D-SS109(0-6IN) 119000 (2) No BSL 0.032 --- --- ---Benzo(k)fluoranthene 207-08-9 µg/kg 3900 --- 3900 1 / 23 FGOW-AOC7D-SS-GP3(0-6INCHES) 148000 (2) No BSL 0.026 --- --- ---bis(2-Ethylhexyl) phthalate 117-81-7 µg/kg 69 J 1345 10000 3 / 9 FGOW-AOC7D-SS-GP2(0-6INCHES) 925 (2) Yes ASL 11 1.5 Yes HQ>1Carbazole 86-74-8 µg/kg 110 J 332 1200 3 / 9 FGOW-AOC7D-SS-GP3(0-6INCHES) NA --- Yes NSL --- --- Yes NSLChrysene 218-01-9 µg/kg 43 J 1344 9500 20 / 23 FGOW-AOC7D-SS109(0-6IN) 4730 (2) Yes ASL 2.0 0.28 No HQ<1Di-n-octyl phthalate 117-84-0 µg/kg 190 J --- 190 J 1 / 9 FGOW-AOC7D-SS-GP2(0-6INCHES) 709000 (2) No BSL 0.00027 --- --- ---Dibenz(a,h)anthracene 53-70-3 µg/kg 57 J --- 790 5 / 23 FGOW-AOC7D-SS-GP3(0-6INCHES) 18400 (2) No BSL 0.043 --- --- ---Dibenzofuran 132-64-9 µg/kg 350 J 290 710 2 / 9 FGOW-AOC7D-SS-GP3(0-6INCHES) NA --- Yes NSL --- --- Yes NSLFluoranthene 206-44-0 µg/kg 57 J --- 22000 18 / 23 FGOW-AOC7D-SS109(0-6IN) 122000 (2) No BSL 0.18 --- --- ---Fluorene 86-73-7 µg/kg 23 J --- 1800 10 / 23 FGOW-AOC7D-SS109(0-6IN) 122000 (2) No BSL 0.015 --- --- ---Indeno(1,2,3-cd)pyrene 193-39-5 µg/kg 47 J --- 4100 12 / 23 FGOW-AOC7D-SS109(0-6IN) 109000 (2) No BSL 0.038 --- --- ---Naphthalene 91-20-3 µg/kg 46 J 625 480 6 / 23 FGOW-AOC7D-SS109(0-6IN) 99.4 (2) Yes ASL 4.8 6.3 Yes HQ>1Pentachlorophenol 87-86-5 µg/kg 310 J --- 310 J 1 / 9 FGOW-AOC7D-SS-GP3(0-6INCHES) 2100 (1c) No BSL 0.15 --- --- ---Phenanthrene 85-01-8 µg/kg 40 J --- 15000 21 / 23 FGOW-AOC7D-SS109(0-6IN) 45700 (2) No BSL 0.33 --- --- ---Pyrene 129-00-0 µg/kg 34 J --- 17000 20 / 23 FGOW-AOC7D-SS109(0-6IN) 78400 (2) No BSL 0.22 --- --- ---Total Petroleum HydrocarbonDiesel Range Organics mg/kg 4.8 J 176 690 5 / 5 FGOW-AOC7D-SS-GP3(0-6INCHES) NA --- Yes NSL --- --- Yes NSLPolychlorinated Biphenyls (PCB)Total PCB µg/kg 14 J 156 1600 9 / 18 FGOW-AOC7D-SS109(0-6IN) 0.332 (2) Yes ASL 4819 469 Yes HQ>1


AOC7DFormer Gopher Ordnance Works, Rosemount, Minnesota

Maximum Detected

Concentration


Step 2 Step 3a


Concentration

Mean Concentration

Page 1 of 2 E05MN001901_01.09_0003_a

UMP029142

ESL ESL Source


RationaleMax

Hazard Quotient

Mean Hazard

Quotient


(Yes/No)

Rationale


AOC7DFormer Gopher Ordnance Works, Rosemount, Minnesota

Maximum Detected

Concentration


Step 2 Step 3a


Concentration

Mean Concentration

MetalsArsenic 7440-38-2 mg/kg 1.4 J --- 11 23 / 23 FGOW-AOC7D-SS-GP9(0-6INCHES) 18 (1a) No BSL 0.61 --- --- ---Barium 7440-39-3 mg/kg 17 86 340 23 / 23 FGOW-AOC7D-SS-GP5(0-6INCHES) 330 (1b) Yes ASL 1.0 0.26 No HQ<1Cadmium 7440-43-9 mg/kg 0.069 J 0.32 2 13 / 23 FGOW-AOC7D-SS-GP5(0-6INCHES) 0.36 (1d) Yes ASL 5.6 0.89 No HQ<1Chromium 7440-47-3 mg/kg 7.4 14 28 23 / 23 FGOW-AOC7D-SS-GP9(0-6INCHES) 26 (1c) Yes ASL 1.1 0.52 No HQ<1Lead 7439-92-1 mg/kg 5.2 J 67 730 23 / 23 FGOW-AOC7D-SS-GP5(0-6INCHES) 11 (1c) Yes ASL 66 6.1 Yes HQ>1Mercury 7439-97-6 mg/kg 0.011 J 0.17 1.2 J 23 / 23 FGOW-AOC7D-SS113(0-6IN) 0.1 (2) Yes ASL 12 1.7 Yes HQ>1Selenium 7782-49-2 mg/kg 0.99 J 1.7 2.8 J 2 / 23 FGOW-AOC7D-SS-GP5(0-6INCHES) 0.52 (1a) Yes ASL 5.4 3.2 Yes HQ>1OtherNitrocellulose 9004-70-0 mg/kg 1.1 B 2.5 5 B 6 / 6 FGOW-AOC7D-SS-SS2 NA --- Yes NSL --- --- Yes NSL

Note: Qualifier:mg/kg - milligram per kilogram J - estimated valueµg/kg - microgram per kilogram B - indicates there was blank contamination above the method detection limit for that particular analyteNA - not available K - the value may consist of both benzo(b)fluoranthene and benzo(k)fluorantheneESL - ecological screening level J^ - estimated value due to low internal standard recovery, and sample value detected below reporting limitCOPC - chemical of potential concernSLERA - screening level ecological risk assessmentMaximum detected concentration used for COPC selection for the SLERAMean concentrations are used to refine COPC selection in Step 3aHazard Quotients greater than 1.0 are boldMax hazard quotients (HQs) calculated by dividing the maximum detected concentration by the selected ESL to select COPCs in the SLERA. Those selected are to be evaluated in Step 3a. Mean HQs calculated in Step 3a for chemicals retained as COPCs in the SLERA. The mean concentration is divided by the selected ESL.Chemicals selected as Final COPCs in Step 3a based on the mean HQ are those that warrant further evaluation.Total PCBs calculated from sum of detected values for detected Aroclors (1254 and 1260)


Page 2 of 2 E05MN001901_01.09_0003_a

UMP029143

Surface Soil COPC Rationale Max HQ Surface Soil COPC Rationale Max HQMercury ASL 110 Lead ASL 15Lead ASL 7.3 Mercury ASL 7.42,6-Dinitrotoluene ASL 4.9 Benzo(a)pyrene ASL 4.8Di-n-butyl phthalate ASL 3.1 Naphthalene ASL 3.71,2,4-Trimethylbenzene NSL --- Cadmium ASL 3.6p-Isopropyltoluene NSL --- Chrysene ASL 1.9Nitrocellulose NSL --- Benzo(a)anthracene ASL 1.7

Chromium ASL 1.7

Surface Soil COPC Rationale Max HQMercury ASL 49 Surface Soil COPC Rationale Max HQDi-n-butyl phthalate ASL 19 PCBs, total ASL 77,711Lead ASL 4.0 Naphthalene ASL 84Chromium ASL 1.1 Benzo(a)pyrene ASL 56Benzoic acid NSL --- Lead ASL 47p-Isopropyltoluene NSL --- Chrysene ASL 23Nitrocellulose NSL --- Benzo(a)anthracene ASL 21

Phenanthrene ASL 5.3Cadmium ASL 4.2

Surface Soil COPC Rationale Max HQ Pyrene ASL 2.9Lead ASL 29 Benzo(b)fluoranthene ASL 2.7Benzo(a)pyrene ASL 9.9 Fluoranthene ASL 2.5Chrysene ASL 3.8 Mercury ASL 1.9Mercury ASL 3.8 Chromium ASL 1.5Benzo(a)anthracene ASL 2.7 2-Methylnaphthalene ASL 1.2Chromium ASL 1.0 1,2,4-Trimethylbenzene NSL ---Benzoic acid NSL --- Carbazole NSL ---Carbazole NSL --- Dibenzofuran NSL ---1,2,4-Trimethylbenzene NSL --- p-Isopropyltoluene NSL ---Nitrocellulose NSL ---

Surface Water COPC Rationale Max HQLead ASL 6.0 Surface Soil COPC Rationale Max HQNitrocellulose NSL --- PCBs, total ASL 4,819

Sediment COPC Rationale Max HQ Lead ASL 66Acetone ASL 11 Mercury ASL 12Acenaphthene ASL 1.6 bis(2-Ethylhexyl) phthalate ASL 11Dibenzo(a,h)anthracene ASL 1.3 Cadmium ASL 5.6Methyl ethyl ketone ASL 1.3 Selenium ASL 5.4Arsenic ASL 1.1 Naphthalene ASL 4.8Barium NSL --- Benzo(a)pyrene ASL 4.7Selenium NSL --- Chrysene ASL 2.01,3,5-Trimethylbenzene NSL --- Benzo(a)anthracene ASL 1.9Nitrocellulose NSL --- Chromium ASL 1.1

Barium ASL 1.0Diesel Range Organics NSL ---Carbazole NSL ---Dibenzofuran NSL ---1,2,4-Trimethylbenzene NSL ---Nitrocellulose NSL ---

Note:SLERA - screening level ecological risk assessmentAOC - area of concernCOPC - chemical of potential concernMax hazard quotients (HQs) calculated by dividing the maximum detected concentration by the selected ESL to select COPCs in the SLERA. Those selected are to be evaluated in Step 3a. Selection Rationale: ASL = Above Screening Level NSL = No Screening Level Available

AOC 6

AOC 7A

AOC 7D

AOC1-Southern Section

Table 4-1Summary of SLERA Chemicals of Potential Concern Screening by AOC


AOC1-Northern Section

AOC1-Middle Section

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029144

Surface Soil COPC Rationale Mean HQ Surface Soil COPC Rationale Mean HQDi-n-butyl phthalate HQ>1 918 Naphthalene HQ>1 3.5Mercury HQ>1 47 Lead HQ>1 3.12,6-Dinitrotoluene HQ>1 5.0 Mercury HQ>1 1.9Lead HQ>1 4.31,2,4-Trimethylbenzene NSL ---p-Isopropyltoluene NSL --- Surface Soil COPC Rationale Mean HQNitrocellulose NSL --- PCBs, total HQ>1 9,801

Naphthalene HQ>1 15Lead HQ>1 8.6

Surface Soil COPC Rationale Mean HQ Benzo(a)pyrene HQ>1 6.9Mercury HQ>1 9.0 Chrysene HQ>1 2.8Di-n-butyl phthalate HQ>1 5.1 Benzo(a)anthracene HQ>1 2.5Lead HQ>1 1.9 Cadmium HQ>1 1.3Benzoic acid NSL --- 1,2,4-Trimethylbenzene NSL ---p-Isopropyltoluene NSL --- Carbazole NSL ---Nitrocellulose NSL --- Dibenzofuran NSL ---

p-Isopropyltoluene NSL ---

Surface Soil COPC Rationale Mean HQLead HQ>1 4.4 Surface Soil COPC Rationale Mean HQBenzoic acid NSL --- PCBs, total HQ>1 469Carbazole NSL --- Naphthalene HQ>1 6.31,2,4-Trimethylbenzene NSL --- Lead HQ>1 6.1Nitrocellulose NSL --- Selenium HQ>1 3.2

Surface Water COPC Rationale Mean HQ Mercury HQ>1 1.7Lead HQ>1 1.6 bis(2-Ethylhexyl) phthalate HQ>1 1.5Nitrocellulose NSL --- Diesel Range Organics NSL ---

Sediment COPC Rationale Mean HQ Carbazole NSL ---Acetone HQ>1 9.2 Dibenzofuran NSL ---Acenaphthene HQ>1 1.3 1,2,4-Trimethylbenzene NSL ---MEK HQ>1 1.0 Nitrocellulose NSL ---Barium NSL ---Selenium NSL ---1,3,5-Trimethylbenzene NSL ---Nitrocellulose NSL ---

Note:AOC - area of concernMean hazard quotients (HQs) are calculated in Step 3A for chemicals retained as chemicals of potential concern (COPCs) in the screening level ecological risk assessment. The mean concentration is divided by the selected ESL.Chemicals selected as Final COPCs in Step 3a based on the mean HQ are those that warrant further evaluation.Selection Rationale: NSL = No Screening Level Available HQ>1 = Hazard quotient greater than 1

AOC1-Middle Section

AOC1-Southern Section AOC 7D

Table 8-1Summary of Step 3a Chemical of Potential Concern Refinement by AOC


AOC 6

AOC 7A

AOC1-Northern Section

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029145

Min Mean1 Max AOC 1N AOC 1M AOC 1S AOC 6 AOC 7A AOC 7DArsenic mg/kg 0.80 4.9 8.2 8.3 7.8 9.3 8 6 11Barium mg/kg 2.9 99.1 170 190 190 B 280 B 170 120 340Cadmium mg/kg 0.052 0.20 1.4 0.14 J 0.19 J 0.31 J 1.3 1.5 2Chromium mg/kg 1.0 14.8 28 25 29 27 43 40 28Lead mg/kg 1.9 11.8 32 80 44 320 170 520 730Mercury mg/kg 0.0056 0.05 0.46 11 J 4.9 0.38 0.74 0.19 1.2 JSelenium mg/kg ND - ND ND ND ND ND ND 2.8 JSilver mg/kg 0.49 0.84 0.49 ND ND ND 1.1 J 0.22 ND

Notes:AOC - area of concernmg/kg - milligram per kilogramND - not detectedvalues shown in bold considered elevated relative to background (values with maximum detected concentration greater than maximum background concentration)values not bolded considered similar to or within background range1 Mean concentration are calculated using 1/2 reporting limit for non-detect valuesQualifier:J - estimated valueB - indicates there was blank contamination above the method detection limit for that particular analyte

Background Concentration Maximum Detected Concentration, Site, by AOC

Table 8-2Site-specific Background Concentrations of Metals in Surface Soil


UnitAnalyte

Page 1 of 1 E05MN001901_01.09_0003_a

UMP029146

Figures

E05MN001901_01.09_0003_a

UMP029147

Primary Source

Secondary Source

Tertiary Source

Primary Receptors

Secondary Release

Mechanism

Secondary Receptors

Tertiary Receptors

Terrestrial Plants Surface Soil Terrestrial Plants

Direct Contact / Uptake

Carnivorous Vertebrates

Terrestrial Invertebrates

Multiple Sources (AOCs 6, 7A, 7D, and 1M)

Omnivorous Vertebrates


Direct Contact / Accumulation

Uptake

Subsurface Soil

Drainage Ditch Soils

Direct Contact & Inhalation

Erosion to Ditch

Groundwater Groundwater Flow

Assumed incomplete and/or insignificant exposure pathway

Confirmed or assumed complete and significant exposure pathway

Figure 2-1Ecological Site Conceptual Exposure Model

AOCs 6, 7A, 7D, 1N, and 1MFormer Gopher Ordnance Works, Rosemount, Minnesota

E05MN001901_01.09_0003_a

UMP029148

Primary Source

Secondary Source

Tertiary Source

Primary Receptors

Secondary Release

Mechanism

Secondary Receptors

Tertiary Receptors

Terrestrial Plants Surface Soil Terrestrial Plants

Direct Contact / Uptake

Carnivorous Vertebrates


Multiple Sources (AOC1S)

Omnivorous Vertebrates


Direct Contact / Accumulation

Uptake

Aquatic Invertebrates

Subsurface Soil

Ditch Sediment

Direct Contact & Inhalation

Erosion to Ditch

Water-dependent / Piscivorous Vertebrates

Ditch Surface Water

Aquatic Vertebrates

Aquatic Plants

Groundwater Groundwater Flow

Assumed incomplete and/or insignificant exposure pathway

Confirmed or assumed complete and significant exposure pathway

‘Ditch’ refers to all locations that intermittently convey or retain surface water

Figure 2-2Ecological Site Conceptual Exposure Model

AOC 1S Former Gopher Ordnance Works, Rosemount, Minnesota

E05MN001901_01.09_0003_a

UMP029149

FGOW-AOC1N-GP101 SS-GP101Sample Date 9/25/2009

Depth (ft) 0-0.5 UnitsArsenic 2 J mg/kgBarium 25 mg/kgCadmium <0.47 mg/kgChromium 7.6 mg/kgLead 2.3 mg/kgMercury <0.033 mg/kg2,4-Dinitrotoluene <0.25 mg/kg2,6-Dinitrotoluene <0.5 mg/kg

FGOW-AOC1N-GP102 SS-GP102Sample Date 9/28/2009

Depth (ft) 0-0.5 UnitsArsenic 2.7 mg/kgBarium 35 j mg/kgCadmium 0.11 J mg/kgChromium 14 j mg/kgLead 80 mg/kgMercury 7.3 mg/kg2,4-Dinitrotoluene 0.67 mg/kg2,6-Dinitrotoluene 0.16 J mg/kg

FGOW-AOC1N-SS-SS1 0-6 INCHES 0-6 IN (DUP)Sample Date 9/27/2007 9/27/20072,4‐Dinitrotoluene 0.55 0.4 mg/kg2,6‐Dinitrotoluene 0.12 J J <0.25 mg/kgArsenic 3.7 2.7 J mg/kgLead 78 67 mg/kgBenzo(a)pyrene <550000 <460000 ug/kgbis(2‐Ethylhexyl) phthalate <550000 <460000 ug/kgDibenz(a,h)anthracene <550000 <460000 ug/kgNitrocellulose 18000 J j^ 16000 J j^ mg/kg

Units

FGOW-AOC1N- SS-GP1Depth 0-6 INCHES

Sample Date 9/18/20072,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 8.3 mg/kgLead 27 mg/kgBenzo(a)pyrene <440 ug/kgbis(2‐Ethylhexyl) phthalate 94 J ug/kgDibenz(a,h)anthracene <440 ug/kgNitrocellulose 2500 j^ mg/kg

Units

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogram(D),(Dup) ‐ DuplicateQualifiers: J,j ‐ estimated; j^ ‐ estimated due to low internal standard recovery and sample detected below reporting limit

E05MN001901_01.09_0003_a

UMP029150

Sample Date 9/27/2007 Units

2,4‐Dinitrotoluene 0.46 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 4.7 mg/kgLead 39 mg/kgBenzo(a)pyrene <1800 ug/kgbis(2‐Ethylhexyl) phthalate 360 J ug/kgDibenz(a,h)anthracene <1800 ug/kgNitrocellulose 4600 J j^ mg/kg

FGOW-AOC1M-SS-SS2(0-6INCHES)

FGOW-AOC1M-SS-SS1 0-6 INCHES 0-6 IN (DUP)Sample Date 9/27/2007 9/27/20072,4‐Dinitrotoluene <0.25 <0.25 mg/kg2,6‐Dinitrotoluene <0.25 <0.25 mg/kgArsenic 3.8 4.5 mg/kgLead 6.9 J 7.6 J mg/kgBenzo(a)pyrene <390 <410 ug/kgbis(2‐Ethylhexyl) phthalate <390 85 J J ug/kgDibenz(a,h)anthracene <390 <410 ug/kgNitrocellulose 6.3 J 5.2 B J u mg/kg

Units

FGOW-AOC1M- SS-GP3Depth 0-6 INCHES

Sample Date 9/27/20072,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 5.4 mg/kgLead 22 mg/kgBenzo(a)pyrene <420 ug/kgbis(2‐Ethylhexyl) phthalate 90 J ug/kgDibenz(a,h)anthracene <420 ug/kgNitrocellulose 430 J j^ mg/kg

Units


Sample Date 9/27/20082,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 5 mg/kgLead 13 mg/kgBenzo(a)pyrene <470 ug/kgbis(2‐Ethylhexyl) phthalate 100 J ug/kgDibenz(a,h)anthracene <470 ug/kgNitrocellulose 350 J j^ mg/kg

Units


Sample Date 9/27/20082,4‐Dinitrotoluene 0.16 J mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 7.6 mg/kgLead 38 mg/kgBenzo(a)pyrene <450 ug/kgbis(2‐Ethylhexyl) phthalate 440 J J ug/kgDibenz(a,h)anthracene <450 ug/kgNitrocellulose 11000 J j^ mg/kg

Units

FGOW-AOC1M-SS107 SS107Sample Date 10/1/2009

Depth (ft) 0-0.5 UnitsArsenic 6 mg/kgBarium 170 mg/kgChromium 16 mg/kgLead 14 mg/kgMercury 0.14 mg/kg2,4-Dinitrotoluene <0.25 mg/kg


Depth (ft) 0-0.5 UnitsArsenic 3.9 mg/kgBarium 79 mg/kgChromium 10 mg/kgLead 7.7 mg/kgMercury 0.02 J mg/kg2,4-Dinitrotoluene <0.25 mg/kg


Depth (ft) 0-0.5 UnitsArsenic 3.6 mg/kgBarium 56 mg/kgChromium 9.6 mg/kgLead 15 mg/kgMercury 0.26 mg/kg2,4-Dinitrotoluene <0.25 mg/kg

FGOW-AOC1M-SS104 SS104 SS104(D)Sample Date 10/1/2009 10/1/2009

Depth (ft) 0-0.5 0-0.5 UnitsArsenic 2.4 J 2.4 mg/kgBarium 28 26 mg/kgChromium 7.2 9.7 mg/kgLead 15 14 mg/kgMercury 0.2 0.16 mg/kg2,4-Dinitrotoluene <0.25 <0.25 mg/kg

FGOW-AOC1M-GP103 SS-GP103Sample Date 9/24/2009

Depth (ft) 0-0.5Arsenic 7.8 mg/kgBarium 160 mg/kgChromium 22 mg/kgLead 20 mg/kgMercury 0.46 mg/kg2,4-Dinitrotoluene 0.12 J mg/kg

Units

FGOW-AOC1M-GP102 SS-GP102Sample Date 9/24/2009

Depth (ft) 0-0.5Arsenic 6 mg/kgBarium 130 mg/kgChromium 17 mg/kgLead 14 mg/kgMercury 0.18 mg/kg2,4-Dinitrotoluene <0.25 mg/kg

Units

FGOW-AOC1M-GP101 SS-GP101(RE) SS-GP101Sample Date 9/24/2009 9/24/2009

Depth (ft) 0-0.5 0-0.5Arsenic 7.5 7.3 mg/kgBarium 190 160 mg/kgChromium 26 25 mg/kgLead 44 43 mg/kgMercury 1.4 1.5 mg/kg2,4-Dinitrotoluene 0.067 J 0.067 J mg/kg

Units

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogram(D), (Dup) ‐ Duplicate, (RE) ‐ Re‐extraction and analysisQualifiers: J,j ‐ estimated; B ‐ blank contamination above the MDL, j ̂‐ estimated due to low internal standard recovery and sample detected below reporting limit, u ‐ validated non‐detect

E05MN001901_01.09_0003_a

UMP029151

Sample Date 10/4/20072,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 1.1 J mg/kgLead 14 mg/kgBenzo(a)pyrene 48 J ug/kgbis(2‐Ethylhexyl) phthalate 64 J ug/kgDibenz(a,h)anthracene <440 ug/kgNitrocellulose 3.7 B J u mg/kg

FGOW-AOC1S-SS-SS3(0-6INCHES)

Units

Sample Date 10/4/20072,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 2.6 J mg/kgLead 320 mg/kgBenzo(a)pyrene 15000 ug/kgbis(2‐Ethylhexyl) phthalate <4200 ug/kgDibenz(a,h)anthracene 2300 J ug/kgNitrocellulose 1.7 B J u mg/kg


Units

Sample Date 10/4/20072,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 4.7 mg/kgLead 14 mg/kgBenzo(a)pyrene <450 ug/kgbis(2‐Ethylhexyl) phthalate <450 ug/kgDibenz(a,h)anthracene <450 ug/kgNitrocellulose 12 J mg/kg

Units


FGOW-AOC1S - SS114SS114

Sample Date 10/1/2009Depth (ft) 0-0.5

Arsenic 5.1 mg/kgBarium 180 mg/kgCadmium <0.25 u mg/kgChromium 20 mg/kgLead 18 mg/kgMercury 0.14 mg/kgAcenaphthene <480 ug/kgAnthracene <480 ug/kgBenzo(a)anthracene <480 ug/kgBenzo(a)pyrene <480 ug/kgBenzo(b)fluoranthene <480 ug/kgBenzo(ghi)perylene <480 ug/kgChrysene 40 J ug/kgFluoranthene <480 ug/kgFluorene <480 ug/kgIndeno(1,2,3-cd)pyrene <480 ug/kgPhenanthrene <480 ug/kgPyrene <580 ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units

FGOW-AOC1S-SS113SS113


Arsenic 6.8 mg/kgBarium 190 mg/kgCadmium <0.23 u mg/kgChromium 16 mg/kgLead 15 mg/kgMercury 0.091 mg/kgAcenaphthene <450 ug/kgAnthracene <450 ug/kgBenzo(a)anthracene <450 ug/kgBenzo(a)pyrene <450 ug/kgBenzo(b)fluoranthene <450 ug/kgBenzo(ghi)perylene <450 ug/kgChrysene <450 ug/kgFluoranthene <450 ug/kgFluorene <450 ug/kgIndeno(1,2,3-cd)pyrene <450 ug/kgPhenanthrene <450 ug/kgPyrene <550 ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units



Arsenic 6.7 mg/kgBarium 200 mg/kgCadmium <0.21 u mg/kgChromium 17 mg/kgLead 15 mg/kgMercury 0.077 mg/kgAcenaphthene <480 ug/kgAnthracene <480 ug/kgBenzo(a)anthracene 37 J ug/kgBenzo(a)pyrene <480 ug/kgBenzo(b)fluoranthene <480 ug/kgBenzo(ghi)perylene <480 ug/kgChrysene <480 ug/kgFluoranthene <480 ug/kgFluorene <480 ug/kgIndeno(1,2,3-cd)pyrene <480 ug/kgPhenanthrene <480 ug/kgPyrene 22 J ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units



Arsenic 5.1 mg/kgBarium 130 mg/kgCadmium <0.094 u mg/kgChromium 15 mg/kgLead 10 mg/kgMercury 0.05 mg/kgAcenaphthene <460 ug/kgAnthracene <460 ug/kgBenzo(a)anthracene <460 ug/kgBenzo(a)pyrene <460 ug/kgBenzo(b)fluoranthene <460 ug/kgBenzo(ghi)perylene <460 ug/kgChrysene <460 ug/kgFluoranthene <460 ug/kgFluorene <460 ug/kgIndeno(1,2,3-cd)pyrene <460 ug/kgPhenanthrene <460 ug/kgPyrene <560 ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units



Arsenic 2.8 J mg/kgBarium 87 mg/kgCadmium <0.12 u mg/kgChromium 12 mg/kgLead 12 mg/kgMercury 0.018 J mg/kgAcenaphthene <420 ug/kgAnthracene <420 ug/kgBenzo(a)anthracene <420 ug/kgBenzo(a)pyrene <420 ug/kgBenzo(b)fluoranthene <420 ug/kgBenzo(ghi)perylene <420 ug/kgChrysene 43 J ug/kgFluoranthene <420 ug/kgFluorene <420 ug/kgIndeno(1,2,3-cd)pyrene <420 ug/kgPhenanthrene <420 ug/kgPyrene 18 J ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units



Arsenic 2.7 mg/kgBarium 34 mg/kgCadmium <0.11 u mg/kgChromium 8.9 mg/kgLead 8.8 mg/kgMercury 0.0072 J mg/kgAcenaphthene 34 J ug/kgAnthracene 78 J ug/kgBenzo(a)anthracene 300 J ug/kgBenzo(a)pyrene 260 J ug/kgBenzo(b)fluoranthene 480 K ug/kgBenzo(ghi)perylene 210 J ug/kgChrysene 320 J ug/kgFluoranthene 740 ug/kgFluorene 28 J ug/kgIndeno(1,2,3-cd)pyrene 170 J ug/kgPhenanthrene 430 ug/kgPyrene 550 ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units

FGOW-AOC1S-GP105SS-GP105 Units


Arsenic 6.9 mg/kgBarium 190 mg/kgCadmium 0.25 J mg/kgChromium 20 mg/kgLead 17 mg/kgMercury 0.016 J mg/kgAcenaphthene <450 ug/kgAnthracene <450 ug/kgBenzo(a)anthracene <450 ug/kgBenzo(a)pyrene <450 ug/kgBenzo(b)fluoranthene <450 ug/kgBenzo(ghi)perylene <450 ug/kgChrysene <450 ug/kgFluoranthene <450 ug/kgFluorene <450 ug/kgIndeno(1,2,3-cd)pyrene <450 ug/kgPhenanthrene <450 ug/kgPyrene <550 ug/kg2,6-Dinitrotoluene <0.5 mg/kg

FGOW-AOC1S-GP104SS-GP104


Arsenic 8.1 mg/kgBarium 210 mg/kgCadmium 0.24 J mg/kgChromium 20 mg/kgLead 17 mg/kgMercury 0.17 mg/kgAcenaphthene <460 ug/kgAnthracene <460 ug/kgBenzo(a)anthracene <460 ug/kgBenzo(a)pyrene <460 ug/kgBenzo(b)fluoranthene <460 ug/kgBenzo(ghi)perylene <460 ug/kgChrysene <460 ug/kgFluoranthene <460 ug/kgFluorene <460 ug/kgIndeno(1,2,3-cd)pyrene <460 ug/kgPhenanthrene <460 ug/kgPyrene <560 ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units

FGOW-AOC1S-GP102SS-GP102 SS-GP102(RE)

Sample Date 9/28/2009 9/28/2009Depth (ft) 0-0.5 0-0.5

Arsenic 6.5 7.5 mg/kgBarium 280 j 270 j mg/kgCadmium 0.31 J 0.27 J mg/kgChromium 16 j 22 j mg/kgLead 11 30 mg/kgMercury 0.031 J 0.062 mg/kgAcenaphthene <530 <530 ug/kgAnthracene <530 <530 ug/kgBenzo(a)anthracene <530 <530 ug/kgBenzo(a)pyrene <530 <530 ug/kgBenzo(b)fluoranthene <530 <530 ug/kgBenzo(ghi)perylene <530 <530 ug/kgChrysene <530 <530 ug/kgFluoranthene <530 <530 ug/kgFluorene <530 <530 ug/kgIndeno(1,2,3-cd)pyrene <530 <530 ug/kgPhenanthrene <530 <530 ug/kgPyrene <640 <530 ug/kg2,6-Dinitrotoluene <0.5 0.16 j mg/kg

Units



Arsenic 2.9 mg/kgBarium 23 j mg/kgCadmium 0.085 J mg/kgChromium 10 j mg/kgLead 230 mg/kgMercury 0.014 J mg/kgAcenaphthene <340 ug/kgAnthracene 20 J ug/kgBenzo(a)anthracene 150 J ug/kgBenzo(a)pyrene 170 J ug/kgBenzo(b)fluoranthene 310 j ug/kgBenzo(ghi)perylene 140 J ug/kgChrysene 190 J ug/kgFluoranthene 280 J ug/kgFluorene <340 ug/kgIndeno(1,2,3-cd)pyrene 110 J ug/kgPhenanthrene 99 J ug/kgPyrene 230 J ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units

Depth 0‐6 INCHESSample Date 9/28/20072,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 9.3 mg/kgLead 24 mg/kgBenzo(a)pyrene <490 ug/kgbis(2‐Ethylhexyl) phthalate 100 J ug/kgDibenz(a,h)anthracene <490 ug/kgNitrocellulose 13 J mg/kg

FGOW-AOC1S-S-GP2

Units

Depth 0‐6 INCHES 0‐6 IN (DUP)Sample Date 9/28/2007 9/28/20072,4‐Dinitrotoluene <0.25 <0.25 mg/kg2,6‐Dinitrotoluene <0.25 <0.25 mg/kgArsenic 6.5 9 mg/kgLead 18 21 mg/kgBenzo(a)pyrene <520 <660 ug/kgbis(2‐Ethylhexyl) phthalate 110 J J <660 ug/kgDibenz(a,h)anthracene <520 <660 ug/kgNitrocellulose 51 J 74 J mg/kg

Units

FGOW-AOC1S-S-GP1



Arsenic 3.8 mg/kgBarium 84 mg/kgCadmium <0.49 mg/kgChromium 13 mg/kgLead 6.4 mg/kgMercury 0.015 J mg/kgAcenaphthene <370 ug/kgAnthracene <370 ug/kgBenzo(a)anthracene <370 ug/kgBenzo(a)pyrene <370 ug/kgBenzo(b)fluoranthene <370 ug/kgBenzo(ghi)perylene <370 ug/kgChrysene <370 ug/kgFluoranthene <370 ug/kgFluorene <370 ug/kgIndeno(1,2,3-cd)pyrene <370 ug/kgPhenanthrene <370 ug/kgPyrene <450 ug/kg2,6-Dinitrotoluene <0.5 mg/kg

Units

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogram(D), (Dup) ‐ Duplicate(RE) ‐ Re‐extraction and analysisQualifiers: J,j ‐ estimated; u ‐ validated non‐detect; B ‐ blank contamination above the MDL, K ‐ Reported benzo(b)fluoranthene may consist of benzo(b) and benzo(k)fluoranthene, B ‐ blank contamination above the MDL

E05MN001901_01.09_0003_a

UMP029152

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogram(D) ‐ DuplicateQualifiers: J ‐ estimate; U ‐ non‐detect; B ‐ blank contamination above the MDL

FGOW-AOC1SW-S110 W-S110(D)

Sample Date 9/30/2009 9/30/2009Arsenic 6.4 4.6 J ug/LBarium 200 150 ug/LCadmium 0.22 J 0.17 J ug/LChromium 7.7 J 5.5 J ug/LLead 15 10 ug/LMercury 0.028 J 0.031 J ug/LSelenium 2.3 J 1.5 J ug/LSilver 0.04 J 0.021 J ug/LBenzyl alcohol 0.6 J 0.33 J ug/LAcetone 3.8 J ND ug/L

Units

FGOW-AOC1SW-S107

Sample Date 9/30/2009Arsenic 3 J ug/LBarium 79 ug/LCadmium 0.055 J ug/LChromium 1.7 J ug/LLead 2.4 J ug/LMercury <0.20 ug/LSelenium <5.0 ug/LSilver <5.0 ug/LBenzyl alcohol <24 ug/LAcetone 4.4 J ug/L

Units

FGOW-AOC1SW-S106

Sample Date 9/30/2009Arsenic 2.8 J ug/LBarium 65 ug/LCadmium <1.0 ug/LChromium 0.65 J ug/LLead 0.39 J ug/LMercury <0.20 ug/LSelenium <5.0 ug/LSilver 0.016 J ug/LBenzyl alcohol <24 ug/LAcetone <10 UJ ug/L

Units

Sample Date 8/24/2007 8/8/20072,4‐Dinitrotoluene <0.40 ug/L2,6‐Dinitrotoluene <0.40 ug/LArsenic 1 J ug/LLead <3.0 ug/LBenzo(a)pyrene <0.10 ug/LDibenz(a,h)anthracene <0.10 ug/LNitrocellulose 0.23 B mg/L

FGOW-AOC1S-W-S2

UnitsSample Date 8/24/2007 8/8/20072,4‐Dinitrotoluene <0.40 ug/L2,6‐Dinitrotoluene <0.40 ug/LArsenic 8 ug/LLead 0.19 J ug/LBenzo(a)pyrene <0.10 ug/LDibenz(a,h)anthracene <0.10 ug/LNitrocellulose 0.19 B mg/L

FGOW-AOC1S-W-S1Units

E05MN001901_01.09_0003_a

UMP029153

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogram(D) ‐ DuplicateQualifiers: J,j ‐ estimate; j ̂‐ estimated due to low internal standard recovery and sample detected below reporting limit; u ‐ validated non‐detect; K ‐ reported benzo(b)fluoranthene may consist of benzo(b) and benzo(k)fluoranthene

FGOW-AOC1S-SEDSED110 SED110(D)

Sample Date 10/1/2009 10/1/2009Depth (ft) 0-0.33 0-0.33

Arsenic 11 8.9 mg/kgBarium 160 j 130 j mg/kgCadmium <0.3 u <0.3 u mg/kgChromium 17 j 13 j mg/kgLead 27 26 mg/kgMercury 0.054 J 0.049 J mg/kgSelenium 2.2 J <3.3 mg/kgAcenaphthene 0.46 J <12 ug/kgAcenaphthylene 0.68 J <12 ug/kgAnthracene 1.6 J 0.32 J ug/kgBenzo(a)anthracene 7.6 J 1.7 J ug/kgBenzo(a)pyrene 14 2.7 J ug/kgBenzo(b)fluoranthene 25 K 5.1 J K ug/kgBenzo(ghi)perylene 21 3.5 J ug/kgChrysene 11 j 3 j ug/kgDibenzo(a,h)anthracene 4.5 J 0.63 J ug/kgFluoranthene 10 J 3.3 J ug/kgFluorene 3.1 J 0.61 J ug/kgIndeno(1,2,3-cd)pyrene 14 2.5 J ug/kgNaphthalene 1.2 J 0.74 J ug/kgPhenanthrene 5.6 J 1.5 J ug/kgPyrene 11 J 2.9 J ug/kg

Units

FGOW-AOC1S-SEDSED107


Arsenic 10 mg/kgBarium 220 mg/kgCadmium 0.38 J mg/kgChromium 17 mg/kgLead 18 mg/kgMercury 0.046 J mg/kgSelenium 2.2 J mg/kgAcenaphthene <14 ug/kgAcenaphthylene <14 ug/kgAnthracene 0.62 J ug/kgBenzo(a)anthracene 2.1 J ug/kgBenzo(a)pyrene 3.4 J ug/kgBenzo(b)fluoranthene 7.3 j ug/kgBenzo(ghi)perylene 7.6 J ug/kgChrysene 4.3 j ug/kgDibenzo(a,h)anthracene 1.1 J ug/kgFluoranthene 5.6 J ug/kgFluorene <14 ug/kgIndeno(1,2,3-cd)pyrene 4.2 J ug/kgNaphthalene 1.1 J ug/kgPhenanthrene 3 J ug/kgPyrene 4.4 J ug/kg

Units

FGOW-AOC1S-SEDSED106


Arsenic 3 mg/kgBarium 74 j mg/kgCadmium <0.073 u mg/kgChromium 12 mg/kgLead 5.9 mg/kgMercury 0.007 J mg/kgSelenium <3.3 mg/kgAcenaphthene <5.7 ug/kgAcenaphthylene <5.7 ug/kgAnthracene <5.7 ug/kgBenzo(a)anthracene 0.57 J ug/kgBenzo(a)pyrene 0.68 J ug/kgBenzo(b)fluoranthene 2 j ug/kgBenzo(ghi)perylene 0.97 J ug/kgChrysene <5.7 ug/kgDibenzo(a,h)anthracene <5.7 ug/kgFluoranthene 1.7 J ug/kgFluorene <5.7 ug/kgIndeno(1,2,3-cd)pyrene 0.74 J ug/kgNaphthalene 0.47 J ug/kgPhenanthrene 0.93 J ug/kgPyrene 1.3 J ug/kg

Units

FGOW-AOC1S-SED-SED2 0‐4 INCHES 0‐4 IN (RE2) 0‐4 INCHESSample Date 8/24/2007 8/24/2007 8/8/20072,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 6.5 mg/kgLead 19 mg/kgBenzo(a)pyrene 17 J j^ 13 ug/kgDibenz(a,h)anthracene 4.8 J 3.5 J ug/kgNitrocellulose 5.1 B J u mg/kg

Units

FGOW-AOC1S-SED-SED1 0‐4 INCHES 0‐4 IN (RE2) 0‐4 INCHESSample Date 8/24/2007 8/24/2007 8/8/20072,4‐Dinitrotoluene <0.25 mg/kg2,6‐Dinitrotoluene <0.25 mg/kgArsenic 4.4 J mg/kgLead 9 J mg/kgBenzo(a)pyrene 120 J j^ 120 ug/kgDibenz(a,h)anthracene 42 J 35 ug/kgNitrocellulose 12 J mg/kg

Units

E05MN001901_01.09_0003_a

UMP029154

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogram(D) ‐ DuplicateQualifiers: J,j ‐ estimate; K ‐ reported benzo(b)fluoranthene may consist of benzo(b) and benzo(k)fluoranthene

FGOW-AOC6- SS-TP6Depth 0‐.5 FEETSample Date 8/7/2007Arsenic 5.7 mg/kgAcenaphthene 150 J ug/kgBenzo(a)pyrene 3200 ug/kgFluoranthene 3800 ug/kgFluorene 190 J ug/kgNaphthalene <390 ug/kgPyrene 3700 ug/kg

Units

FGOW-AOC6- SS-TP5Depth 0‐.5 FEETSample Date 8/7/2007Arsenic 3.2 mg/kgAcenaphthene <4000 ug/kgBenzo(a)pyrene 1700 J ug/kgFluoranthene 2900 J ug/kgFluorene <4000 ug/kgNaphthalene <4000 ug/kgPyrene 2600 J ug/kg

Units

FGOW-AOC6- SS-TP4Depth 0‐.5 FEETSample Date 8/7/2007Arsenic 3.3 mg/kgAcenaphthene 1400 J ug/kgBenzo(a)pyrene 7300 ug/kgFluoranthene 18000 ug/kgFluorene 1500 J ug/kgNaphthalene 370 J ug/kgPyrene 16000 ug/kg

Units

FGOW-AOC6- SS-TP3Depth 0‐.5 FEETSample Date 8/7/2007Arsenic 4.4 mg/kgAcenaphthene 50 J ug/kgBenzo(a)pyrene 350 ug/kgFluoranthene 800 ug/kgFluorene 52 J ug/kgNaphthalene <350 ug/kgPyrene 680 ug/kg

Units

FGOW-AOC6- SS-TP2Depth 0‐.5 FEETSample Date 8/7/2007Arsenic 5.6 mg/kgAcenaphthene <350 ug/kgBenzo(a)pyrene 220 J ug/kgFluoranthene 400 ug/kgFluorene <350 ug/kgNaphthalene <350 ug/kgPyrene 360 J ug/kg

Units

FGOW-AOC6- SS-TP1 S-TP1Depth 0‐.5 FEET 0‐.5 FT (DUP)Sample Date 8/7/2007 8/7/2007Arsenic 2.5 J 1.9 J mg/kgAcenaphthene <350 <340 ug/kgBenzo(a)pyrene 230 J j 1400 j ug/kgFluoranthene 430 J j 2400 j ug/kgFluorene <350 43 J ug/kgNaphthalene <350 <340 ug/kgPyrene 400 J j 2200 j ug/kg

Units

FGOW-AOC6-GP106 SS-GP106Sample Date 9/23/2009

Depth (ft) 0-0.5 UnitsArsenic 6.7 mg/kgBarium 110 mg/kgCadmium <0.55 mg/kgChromium 17 mg/kgLead 11 mg/kgMercury 0.041 mg/kgSilver <1.7 mg/kg2-Methylnaphthalene <370 ug/kgAcenaphthene <370 ug/kgAcenaphthylene <370 ug/kgAnthracene <370 ug/kgBenzo(a)anthracene <370 ug/kgBenzo(a)pyrene <370 ug/kgBenzo(b)fluoranthene <370 ug/kgBenzo(ghi)perylene <370 ug/kgChrysene 33 J ug/kgDibenz(a,h)anthracene <370 ug/kgFluoranthene <370 ug/kgFluorene <370 ug/kgIndeno(1,2,3-cd)pyrene <370 ug/kgNaphthalene <370 ug/kgPhenanthrene <370 ug/kgPyrene <450 ug/kg


Depth (ft) 0-0.5Arsenic 5.7 mg/kgBarium 99 mg/kgCadmium 0.049 J mg/kgChromium 17 mg/kgLead 9.5 mg/kgMercury 0.035 J mg/kgSilver <1.6 mg/kg2-Methylnaphthalene <390 ug/kgAcenaphthene <390 ug/kgAcenaphthylene <390 ug/kgAnthracene <390 ug/kgBenzo(a)anthracene 25 J ug/kgBenzo(a)pyrene <390 ug/kgBenzo(b)fluoranthene <390 ug/kgBenzo(ghi)perylene <390 ug/kgChrysene 38 J ug/kgDibenz(a,h)anthracene <390 ug/kgFluoranthene <390 ug/kgFluorene <390 ug/kgIndeno(1,2,3-cd)pyrene <390 ug/kgNaphthalene <390 ug/kgPhenanthrene <390 ug/kgPyrene 27 J ug/kg

Units


Depth (ft) 0-0.5 UnitsArsenic 2.4 J mg/kgBarium 24 mg/kgCadmium 0.066 J mg/kgChromium 12 mg/kgLead 3.4 mg/kgMercury 0.013 J mg/kgSilver <1.5 mg/kg2-Methylnaphthalene <360 ug/kgAcenaphthene <360 ug/kgAcenaphthylene <360 ug/kgAnthracene <360 ug/kgBenzo(a)anthracene <360 ug/kgBenzo(a)pyrene <360 ug/kgBenzo(b)fluoranthene <360 ug/kgBenzo(ghi)perylene <360 ug/kgChrysene <360 ug/kgDibenz(a,h)anthracene <360 ug/kgFluoranthene <360 ug/kgFluorene <360 ug/kgIndeno(1,2,3-cd)pyrene <360 ug/kgNaphthalene <360 ug/kgPhenanthrene <360 ug/kgPyrene <430 ug/kg


Depth (ft) 0-0.5Arsenic 6.5 mg/kgBarium 120 mg/kgCadmium 1.3 mg/kgChromium 35 mg/kgLead 19 mg/kgMercury 0.14 mg/kgSilver 0.87 J mg/kg2-Methylnaphthalene <350 ug/kgAcenaphthene <350 ug/kgAcenaphthylene <350 ug/kgAnthracene <350 ug/kgBenzo(a)anthracene 45 J ug/kgBenzo(a)pyrene 42 J ug/kgBenzo(b)fluoranthene 72 J ug/kgBenzo(ghi)perylene 32 J ug/kgChrysene 63 J ug/kgDibenz(a,h)anthracene <350 ug/kgFluoranthene 80 J ug/kgFluorene <350 ug/kgIndeno(1,2,3-cd)pyrene 29 J ug/kgNaphthalene <350 ug/kgPhenanthrene 45 J ug/kgPyrene 72 J ug/kg

Units


Depth (ft) 0-0.5Arsenic 7.5 mg/kgBarium 110 mg/kgCadmium <0.32 mg/kgChromium 23 mg/kgLead 16 mg/kgMercury 0.066 mg/kgSilver <1.6 mg/kg2-Methylnaphthalene <360 ug/kgAcenaphthene <360 ug/kgAcenaphthylene <360 ug/kgAnthracene <360 ug/kgBenzo(a)anthracene 45 J ug/kgBenzo(a)pyrene 38 J ug/kgBenzo(b)fluoranthene 70 J ug/kgBenzo(ghi)perylene 26 J ug/kgChrysene 58 J ug/kgDibenz(a,h)anthracene <360 ug/kgFluoranthene 76 J ug/kgFluorene <360 ug/kgIndeno(1,2,3-cd)pyrene <360 ug/kgNaphthalene <360 ug/kgPhenanthrene 51 J ug/kgPyrene 72 J ug/kg

Units


Depth (ft) 0-0.5Arsenic 8 mg/kgBarium 120 mg/kgCadmium <0.3 mg/kgChromium 22 mg/kgLead 30 mg/kgMercury 0.068 mg/kgSilver <1.5 mg/kg2-Methylnaphthalene <350 ug/kgAcenaphthene 33 J ug/kgAcenaphthylene <350 ug/kgAnthracene 62 J ug/kgBenzo(a)anthracene 240 J ug/kgBenzo(a)pyrene 260 J ug/kgBenzo(b)fluoranthene 430 K ug/kgBenzo(ghi)perylene 210 J ug/kgChrysene 280 j ug/kgDibenz(a,h)anthracene <350 ug/kgFluoranthene 530 ug/kgFluorene 22 J ug/kgIndeno(1,2,3-cd)pyrene 160 J ug/kgNaphthalene <350 ug/kgPhenanthrene 320 J ug/kgPyrene 440 ug/kg

Units

E05MN001901_01.09_0003_a

UMP029155

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogram(D) ‐ DuplicateQualifiers: J,j ‐ estimate; U,u ‐ validated non‐detect; K ‐ reported benzo(b)fluoranthene may consist of benzo(b) and benzo(k)fluoranthene; E ‐ estimated because value is above linear calibration range

FGOW-AOC7A- SS-SS4 SS-SS4Depth 0‐6 INCHES 0‐6 IN (RE2)Sample Date 8/15/2007 8/15/2007Total PCBs 1300 ug/kgArsenic 3.9 mg/kgLead 240 mg/kg2‐Methylphenol <1900 <3700 ug/kgBenzo(a)pyrene 11000 10000 ug/kgFluoranthene 40000 E 36000 ug/kgNaphthalene 2000 1900 J ug/kgAcetone 400 J 260 J ug/kg

FGOW-AOC7A- SS-SS3 SS-SS3Depth 0‐6 INCHES 0‐6 IN (RE2)Sample Date 8/15/2007 8/15/2007Total PCBs 2100 ug/kgArsenic 4.2 mg/kgLead 520 mg/kg2‐Methylphenol <18000 ug/kgBenzo(a)pyrene 85000 ug/kgFluoranthene 300000 ug/kgNaphthalene 7500 J ug/kgAcetone 560 J 420 J ug/kg

Units

FGOW-AOC7A- SS-SS2Depth 0‐6 INCHESSample Date 8/15/2007Total PCBs 3200 ug/kgArsenic 3 J mg/kgLead 140 mg/kg2‐Methylphenol <4100 ug/kgBenzo(a)pyrene 20000 ug/kgFluoranthene 75000 ug/kgNaphthalene 3500 J ug/kgAcetone 440 J ug/kg

Units

FGOW-AOC7A- SS-SS1Depth 0‐6 INCHESSample Date 8/15/2007Total PCBs 25800 ug/kgArsenic 3.1 J mg/kgLead 440 mg/kg2‐Methylphenol <8800 ug/kgBenzo(a)pyrene 38000 ug/kgFluoranthene 130000 ug/kgNaphthalene 8300 J ug/kgAcetone 1500 J ug/kg

Units

FGOW-AOC7A- SS-GP7Depth 0‐6 INCHESSample Date 8/15/2007Arsenic 2.7 J mg/kgLead 4.2 J mg/kg2‐Methylphenol <390 ug/kgBenzo(a)pyrene <390 ug/kgFluoranthene <390 ug/kgNaphthalene <390 ug/kgAcetone 89 J ug/kg

Units

FGOW-AOC7A- SS-GP6Depth 0‐6 INCHESSample Date 8/15/2007Total PCBs 39 J ug/kgArsenic 2.6 J mg/kgLead 28 mg/kg2‐Methylphenol <350 ug/kgBenzo(a)pyrene 1800 ug/kgFluoranthene 5700 ug/kgNaphthalene 190 J ug/kgAcetone 180 J ug/kg

Units

FGOW-AOC7A- SS-GP5Depth 0‐6 INCHESSample Date 8/15/2007Total PCBs 3100 ug/kgArsenic 4.1 mg/kgLead 46 mg/kg2‐Methylphenol <450 ug/kgBenzo(a)pyrene 1200 ug/kgFluoranthene 3700 ug/kgNaphthalene 59 J ug/kgAcetone 250 J ug/kg

Units

FGOW-AOC7A- SS-GP4 SS-GP4Depth 0‐6 INCHES 0‐6 IN (RE2)Sample Date 8/15/2007 8/15/2007Arsenic 4.7 mg/kgLead 12 J mg/kg2‐Methylphenol <480 ug/kgBenzo(a)pyrene 98 J ug/kgFluoranthene 210 J ug/kgNaphthalene <480 ug/kgAcetone 91 J 87 ug/kg

Units

FGOW-AOC7A- SS-GP3 SS-GP3 SS-GP3Depth 0‐6 INCHES 0‐6 IN (DUP) 0‐6 IN (RE2)Sample Date 8/15/2007 8/15/2007 8/15/2007Arsenic 4.9 4.3 mg/kgLead 11 11 mg/kg2‐Methylphenol <390 <380 ug/kgBenzo(a)pyrene 440 210 J ug/kgFluoranthene 1500 J 680 ug/kgNaphthalene 91 J <380 ug/kgAcetone 69 73 J 75 J ug/kg

Units

FGOW-AOC7A- SS-GP2 SS-GP2Depth 0‐6 INCHES 0‐6 IN (RE2)Sample Date 8/15/2007 8/15/2007Arsenic 4.2 mg/kgLead 6.4 J mg/kg2‐Methylphenol <370 ug/kgBenzo(a)pyrene 730 ug/kgFluoranthene 1900 ug/kgNaphthalene <370 ug/kgAcetone 100 J 140 ug/kg

Units

FGOW-AOC7A- SS-GP1 SS-GP1Depth 0‐6 INCHES 0‐6 IN (RE2)Sample Date 8/15/2007 8/15/2007Arsenic 3.8 mg/kgLead 8.3 J mg/kg2‐Methylphenol <360 ug/kgBenzo(a)pyrene 280 J ug/kgFluoranthene 750 ug/kgNaphthalene <360 ug/kgAcetone 100 J 130 J ug/kg

Units

E05MN001901_01.09_0003_a

UMP029156

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogram(D) ‐ DuplicateQualifiers: J,j ‐ estimate; U,u ‐ validated non‐detect; K ‐ reported benzo(b)fluoranthene may consist of benzo(b) and benzo(k)fluoranthene; E ‐ estimated because value is above linear calibration range

AOC7A-SS107 SS107


Arsenic 2.3 J mg/kgBarium 28 mg/kgCadmium 0.24 J mg/kgChromium 8.6 mg/kgLead 25 mg/kgMercury 0.075 mg/kg2-Methylnaphthalene 180 J ug/kgAcenaphthene 950 ug/kgAcenaphthylene 56 J ug/kgAnthracene 2200 ug/kgBenzo(a)anthracene 8400 ug/kgBenzo(a)pyrene 7200 ug/kgBenzo(b)fluoranthene 13000 K ug/kgBenzo(ghi)perylene 3900 ug/kgChrysene 8600 ug/kgFluoranthene 17000 ug/kgFluorene 980 ug/kgIndeno(1,2,3-cd)pyrene 4300 ug/kgNaphthalene 330 J ug/kgPhenanthrene 9500 ug/kgPyrene 14000 ug/kgAroclor 1254 <39 U J ug/kgAroclor 1260 <39 U J ug/kg

Units

AOC7A-SS106 SS106


Arsenic 5.3 mg/kgBarium 86 mg/kgCadmium 0.16 J mg/kgChromium 14 mg/kgLead 22 J mg/kgMercury 0.043 mg/kg2-Methylnaphthalene 31 J ug/kgAcenaphthene 67 J ug/kgAcenaphthylene <400 ug/kgAnthracene 130 J ug/kgBenzo(a)anthracene 400 ug/kgBenzo(a)pyrene 390 J ug/kgBenzo(b)fluoranthene 710 K ug/kgBenzo(ghi)perylene 240 J ug/kgChrysene 480 ug/kgFluoranthene 1100 ug/kgFluorene 63 J ug/kgIndeno(1,2,3-cd)pyrene 210 J ug/kgNaphthalene <400 ug/kgPhenanthrene 650 ug/kgPyrene 840 ug/kgAroclor 1254 <40 U J ug/kgAroclor 1260 <40 U J ug/kg

Units

AOC7A-GP103 SS-GP103


Arsenic 4.6 mg/kgBarium 59 mg/kgCadmium <0.07 u mg/kgChromium 11 j mg/kgLead 5.4 mg/kgMercury 0.025 J mg/kg2-Methylnaphthalene <340 ug/kgAcenaphthene 28 J ug/kgAcenaphthylene <340 ug/kgAnthracene 71 J ug/kgBenzo(a)anthracene 190 J ug/kgBenzo(a)pyrene 150 J ug/kgBenzo(b)fluoranthene 240 j ug/kgBenzo(ghi)perylene 70 J ug/kgChrysene 190 J ug/kgFluoranthene 390 ug/kgFluorene 26 J ug/kgIndeno(1,2,3-cd)pyrene 75 J ug/kgNaphthalene <340 ug/kgPhenanthrene 270 J ug/kgPyrene 330 J ug/kgAroclor 1254 180 ug/kgAroclor 1260 <35 ug/kg

Units

FGOW-AOC7A-GP102 SS-GP102


Arsenic 3 mg/kgBarium 41 mg/kgCadmium <0.05 u mg/kgChromium 10 j mg/kgLead 4.4 mg/kgMercury 0.0077 J mg/kg2-Methylnaphthalene <330 ug/kgAcenaphthene 48 J ug/kgAcenaphthylene <330 ug/kgAnthracene 110 J ug/kgBenzo(a)anthracene 230 J ug/kgBenzo(a)pyrene 170 J ug/kgBenzo(b)fluoranthene 280 j ug/kgBenzo(ghi)perylene 92 J ug/kgChrysene 210 J ug/kgFluoranthene 470 ug/kgFluorene 43 J ug/kgIndeno(1,2,3-cd)pyrene 71 J ug/kgNaphthalene <330 ug/kgPhenanthrene 350 ug/kgPyrene 400 J ug/kgAroclor 1254 <34 ug/kgAroclor 1260 <34 ug/kg

Units

FGOW-AOC7A-GP101 SS-GP101


Arsenic 6 mg/kgBarium 92 mg/kgCadmium <0.058 u mg/kgChromium 14 j mg/kgLead 9 mg/kgMercury 0.031 J mg/kg2-Methylnaphthalene <350 ug/kgAcenaphthene <350 ug/kgAcenaphthylene <350 ug/kgAnthracene <350 ug/kgBenzo(a)anthracene 49 J ug/kgBenzo(a)pyrene 39 J ug/kgBenzo(b)fluoranthene 65 j ug/kgBenzo(ghi)perylene 19 J ug/kgChrysene 60 J ug/kgFluoranthene 92 J ug/kgFluorene <350 ug/kgIndeno(1,2,3-cd)pyrene <350 ug/kgNaphthalene <350 ug/kgPhenanthrene 67 J ug/kgPyrene 77 J ug/kgAroclor 1254 <35 ug/kgAroclor 1260 <35 ug/kg

Units

E05MN001901_01.09_0003_a

UMP029157

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogramGroundwater analyzed for Metals and VOCs(D)(Dup) ‐ Duplicate(RE2) ‐ ReanalyzedQualifiers: J,j ‐ estimate; U,u ‐ validated non‐detect; K ‐ reported benzo(b)fluoranthene may consist of benzo(b) and benzo(k)fluoranthene; B ‐ blank contamination above the method detection limit (MDL)

FGOW-AOC7D- SS-SS4 SS-SS4(RE2) SS-SS4 SS-SS4(RE2)Sample Date 8/30/2007 8/30/2007 8/30/2007 8/30/2007Total PCBs 510 J 720 270 J 760 ug/kg

Units

FGOW-AOC7D- SS-SS3 SS-SS3(RE2)Sample Date 8/30/2007 8/30/2007Total PCBs 106 J 51 J ug/kg

Units

Sample Date 8/30/2007Nitrocellulose 5 B mg/kg

FGOW-AOC7D-SS-SS2Units

Sample Date 8/30/2007Nitrocellulose 1.1 B mg/kg

UnitsFGOW-AOC7D-SS-SS1

FGOW-AOC7D- SS-GP9Depth 0-6 INCHES

Sample Date 8/30/2007Arsenic 11 mg/kg2,4,6‐Trichlorophenol <450 ug/kgBenzo(a)pyrene 58 J ug/kgPentachlorophenol <2200 ug/kgNitrocellulose 3.6 B mg/kg

Units

FGOW-AOC7D- SS-GP8 SS-GP8Depth 0-6 INCHES 0-6 IN (DUP)

Sample Date 8/29/2007 8/29/2007Total PCBs 36 60 ug/kgArsenic 2.7 3 mg/kg2,4,6‐Trichlorophenol <360 <360 ug/kgBenzo(a)pyrene 270 J 460 ug/kgPentachlorophenol <1700 <1700 ug/kg

Units


Sample Date 8/29/2007Total PCBs <34 ug/kgArsenic 1.4 J mg/kg2,4,6‐Trichlorophenol <340 ug/kgBenzo(a)pyrene <340 ug/kgPentachlorophenol <1600 ug/kg

Units


Sample Date 8/30/2007Arsenic 8.6 mg/kg2,4,6‐Trichlorophenol <450 ug/kgBenzo(a)pyrene 52 J ug/kgPentachlorophenol <2200 ug/kgNitrocellulose 1.3 B mg/kg

Units


Sample Date 8/30/2007Arsenic 9.3 mg/kg2,4,6‐Trichlorophenol <450 ug/kgBenzo(a)pyrene 1500 ug/kgPentachlorophenol <2200 ug/kgNitrocellulose 2.9 B mg/kg

Units


Sample Date 8/30/2007Arsenic 3.3 mg/kg2,4,6‐Trichlorophenol <390 ug/kgBenzo(a)pyrene <390 ug/kgPentachlorophenol <1900 ug/kg

UnitsFGOW-AOC7D- SS-GP3 SS-GP3Depth 0-6 INCHES 0-6 IN (RE2)

Sample Date 8/28/2007 8/28/2007Arsenic 4.3 mg/kg2,4,6‐Trichlorophenol <390 <2000 ug/kgBenzo(a)pyrene 5500 J 5200 ug/kgPentachlorophenol 310 J <9500 ug/kg

Units

FGOW-AOC7D- SS-GP2 SS-GP2Depth 0-6 INCHES 0-6 IN (RE2)

Sample Date 8/28/2007 8/28/2007Arsenic 3.9 mg/kg2,4,6‐Trichlorophenol <740 <370 ug/kgBenzo(a)pyrene <740 <370 ug/kgPentachlorophenol <3600 <1800 ug/kgNitrocellulose 1.1 B mg/kg

Units


Sample Date 8/27/2007Arsenic 2.5 J mg/kg2,4,6‐Trichlorophenol <370 ug/kgBenzo(a)pyrene <370 J ug/kgPentachlorophenol <1800 ug/kg

Units

E05MN001901_01.09_0003_a

UMP029158

mg/kg = milligrams per kilogramµg/kg = micrograms per kilogramGroundwater analyzed for Metals and VOCs(D)(Dup) ‐ Duplicate(RE2) ‐ ReanalyzedQualifiers: J,j ‐ estimate; U,u ‐ validated non‐detect; K ‐ reported benzo(b)fluoranthene may consist of benzo(b) and benzo(k)fluoranthene; B ‐ blank contamination above the method detection limit (MDL)

FGOW-AOC7D-GP101 SS-GP101Sample Date 9/21/2009

Depth (ft) 0-.5Arsenic 7.1 mg/kgBarium 73 mg/kgCadmium 0.25 J mg/kgChromium 15 mg/kgLead 23 j mg/kgMercury 0.12 mg/kgSelenium <3.4 mg/kg2-Methylnaphthalene <370 ug/kgAcenaphthene 25 J ug/kgAcenaphthylene <370 ug/kgAnthracene 50 J ug/kgBenzo(a)anthracene 120 J ug/kgBenzo(a)pyrene 100 J ug/kgBenzo(b)fluoranthene 190 j ug/kgBenzo(ghi)perylene 59 J ug/kgChrysene 160 J ug/kgDibenz(a,h)anthracene <370 ug/kgFluoranthene 290 j ug/kgFluorene 23 J ug/kgIndeno(1,2,3-cd)pyrene 47 J ug/kgNaphthalene <370 ug/kgPhenanthrene 230 J ug/kgPyrene 240 J ug/kgAroclor 1254 <37 ug/kgAroclor 1260 <37 ug/kg

Units


Depth (ft) 0-0.5Arsenic 2.7 mg/kgBarium 38 mg/kgCadmium 0.14 J mg/kgChromium 12 j mg/kgLead 25 mg/kgMercury 0.073 mg/kgSelenium <2.7 mg/kg2-Methylnaphthalene 34 J ug/kgAcenaphthene 330 J ug/kgAcenaphthylene <340 ug/kgAnthracene 930 ug/kgBenzo(a)anthracene 2800 ug/kgBenzo(a)pyrene 2300 ug/kgBenzo(b)fluoranthene 3900 K ug/kgBenzo(ghi)perylene 1100 ug/kgChrysene 2800 ug/kgDibenz(a,h)anthracene <340 ug/kgFluoranthene 6700 ug/kgFluorene 310 J ug/kgIndeno(1,2,3-cd)pyrene 1000 ug/kgNaphthalene 46 J ug/kgPhenanthrene 4000 ug/kgPyrene 5200 ug/kgAroclor 1254 <34 ug/kgAroclor 1260 <34 ug/kg

Units


Depth (ft) 0-0.5Arsenic 7 mg/kgBarium 92 mg/kgCadmium 0.43 J mg/kgChromium 15 j mg/kgLead 10 mg/kgMercury 0.06 mg/kgSelenium <3.0 mg/kg2-Methylnaphthalene 23 J ug/kgAcenaphthene <370 ug/kgAcenaphthylene <370 ug/kgAnthracene <370 ug/kgBenzo(a)anthracene 45 J ug/kgBenzo(a)pyrene 38 J ug/kgBenzo(b)fluoranthene 69 j ug/kgBenzo(ghi)perylene 23 J ug/kgChrysene 74 J ug/kgDibenz(a,h)anthracene <370 ug/kgFluoranthene 76 J ug/kgFluorene <370 ug/kgIndeno(1,2,3-cd)pyrene <370 ug/kgNaphthalene <370 ug/kgPhenanthrene 54 J ug/kgPyrene 65 J ug/kgAroclor 1254 <37 ug/kgAroclor 1260 <37 ug/kg

Units


Depth (ft) 0-0.5Arsenic 3.9 mg/kgBarium 59 mg/kgCadmium 0.086 J mg/kgChromium 11 j mg/kgLead 7.2 mg/kgMercury 0.012 J mg/kgSelenium <3.0 mg/kg2-Methylnaphthalene <370 ug/kgAcenaphthene <370 ug/kgAcenaphthylene <370 ug/kgAnthracene <370 ug/kgBenzo(a)anthracene 37 J ug/kgBenzo(a)pyrene <370 ug/kgBenzo(b)fluoranthene 37 j ug/kgBenzo(ghi)perylene <370 ug/kgChrysene 43 J ug/kgDibenz(a,h)anthracene <370 ug/kgFluoranthene 57 J ug/kgFluorene <370 ug/kgIndeno(1,2,3-cd)pyrene <370 ug/kgNaphthalene <370 ug/kgPhenanthrene 46 J ug/kgPyrene 48 J ug/kgAroclor 1254 <37 ug/kgAroclor 1260 <37 ug/kg

Units

FGOW-AOC7D-SS106 SS106Sample Date 9/29/2009

Depth (ft) 0-0.5Arsenic 4.4 mg/kgBarium 70 mg/kgCadmium 0.069 J mg/kgChromium 12 mg/kgLead 12 mg/kgMercury 0.036 mg/kgSelenium <3.3 mg/kg2-Methylnaphthalene <410 ug/kgAcenaphthene 41 J ug/kgAcenaphthylene <410 ug/kgAnthracene 99 J ug/kgBenzo(a)anthracene 280 J ug/kgBenzo(a)pyrene 230 J ug/kgBenzo(b)fluoranthene 400 j ug/kgBenzo(ghi)perylene 130 J ug/kgChrysene 280 J ug/kgDibenz(a,h)anthracene <410 ug/kgFluoranthene 600 ug/kgFluorene 38 J ug/kgIndeno(1,2,3-cd)pyrene 120 J ug/kgNaphthalene <410 ug/kgPhenanthrene 380 J ug/kgPyrene 480 J ug/kgAroclor 1254 <39 ug/kgAroclor 1260 <39 ug/kg

Units


Depth (ft) 0-0.5Arsenic 2.2 J mg/kgBarium 25 mg/kgCadmium 0.24 J mg/kgChromium 7.4 mg/kgLead 5.6 mg/kgMercury 0.02 J mg/kgSelenium <3.2 mg/kg2-Methylnaphthalene <340 ug/kgAcenaphthene 14 J ug/kgAcenaphthylene <340 ug/kgAnthracene 34 J ug/kgBenzo(a)anthracene 250 J ug/kgBenzo(a)pyrene 190 J ug/kgBenzo(b)fluoranthene 370 K ug/kgBenzo(ghi)perylene 110 J ug/kgChrysene 250 J ug/kgDibenz(a,h)anthracene <340 ug/kgFluoranthene 500 ug/kgFluorene <340 ug/kgIndeno(1,2,3-cd)pyrene 98 J ug/kgNaphthalene <340 ug/kgPhenanthrene 170 J ug/kgPyrene 430 ug/kgAroclor 1254 <36 ug/kgAroclor 1260 14 J ug/kg

Units


Depth (ft) 0-0.5Arsenic 6.5 mg/kgBarium 85 mg/kgCadmium 0.48 J mg/kgChromium 16 mg/kgLead 39 mg/kgMercury 0.072 mg/kgSelenium <3.1 mg/kg2-Methylnaphthalene 140 J ug/kgAcenaphthene 130 J ug/kgAcenaphthylene <400 ug/kgAnthracene 270 J ug/kgBenzo(a)anthracene 890 ug/kgBenzo(a)pyrene 760 ug/kgBenzo(b)fluoranthene 1300 K ug/kgBenzo(ghi)perylene 410 ug/kgChrysene 880 ug/kgDibenz(a,h)anthracene <400 ug/kgFluoranthene 2000 ug/kgFluorene 110 J ug/kgIndeno(1,2,3-cd)pyrene 400 ug/kgNaphthalene 76 J ug/kgPhenanthrene 1400 ug/kgPyrene 1600 ug/kgAroclor 1254 <39 ug/kgAroclor 1260 77 ug/kg

Units


Depth (ft) 0-0.5Arsenic 4.6 mg/kgBarium 55 mg/kgCadmium 0.68 mg/kgChromium 16 mg/kgLead 200 mg/kgMercury 0.41 mg/kgSelenium <3.3 mg/kg2-Methylnaphthalene 330 J ug/kgAcenaphthene 1600 ug/kgAcenaphthylene 45 J ug/kgAnthracene 4200 ug/kgBenzo(a)anthracene 10000 ug/kgBenzo(a)pyrene 7100 ug/kgBenzo(b)fluoranthene 13000 K ug/kgBenzo(ghi)perylene 3800 ug/kgChrysene 9500 ug/kgDibenz(a,h)anthracene <390 ug/kgFluoranthene 22000 ug/kgFluorene 1800 ug/kgIndeno(1,2,3-cd)pyrene 4100 ug/kgNaphthalene 480 ug/kgPhenanthrene 15000 ug/kgPyrene 17000 ug/kgAroclor 1254 1600 ug/kgAroclor 1260 <190 ug/kg

Units


Depth (ft) 0-0.5Arsenic 3.1 mg/kgBarium 62 mg/kgCadmium 0.15 J mg/kgChromium 10 mg/kgLead 15 mg/kgMercury 0.034 J mg/kgSelenium <3.3 mg/kg2-Methylnaphthalene <370 ug/kgAcenaphthene 19 J ug/kgAcenaphthylene <370 ug/kgAnthracene 44 J ug/kgBenzo(a)anthracene 140 J ug/kgBenzo(a)pyrene 120 J ug/kgBenzo(b)fluoranthene 210 j ug/kgBenzo(ghi)perylene 78 J ug/kgChrysene 160 J ug/kgDibenz(a,h)anthracene <370 ug/kgFluoranthene 310 J ug/kgFluorene <370 ug/kgIndeno(1,2,3-cd)pyrene 69 J ug/kgNaphthalene <370 ug/kgPhenanthrene 220 J ug/kgPyrene 240 J ug/kgAroclor 1254 <39 ug/kgAroclor 1260 15 j ug/kg

Units


Depth (ft) 0-0.5Arsenic 5.6 mg/kgBarium 60 mg/kgCadmium <0.27 u mg/kgChromium 8.7 mg/kgLead 22 mg/kgMercury 0.23 mg/kgSelenium 0.99 J mg/kg2-Methylnaphthalene <20000 ug/kgAcenaphthene <20000 ug/kgAcenaphthylene <20000 ug/kgAnthracene <20000 ug/kgBenzo(a)anthracene <20000 ug/kgBenzo(a)pyrene <20000 ug/kgBenzo(b)fluoranthene <20000 ug/kgBenzo(ghi)perylene <20000 ug/kgChrysene 1800 J ug/kgDibenz(a,h)anthracene <20000 ug/kgFluoranthene <20000 ug/kgFluorene <20000 ug/kgIndeno(1,2,3-cd)pyrene <20000 ug/kgNaphthalene <20000 ug/kgPhenanthrene 1300 J ug/kgPyrene 1500 J ug/kgAroclor 1254 <38 ug/kgAroclor 1260 <38 ug/kg

Units


Depth (ft) 0-0.5Arsenic 3.3 mg/kgBarium 54 mg/kgCadmium <0.094 u mg/kgChromium 9.4 mg/kgLead 6.2 mg/kgMercury 0.021 J mg/kgSelenium <3.2 mg/kg2-Methylnaphthalene 35 J ug/kgAcenaphthene <370 ug/kgAcenaphthylene <370 ug/kgAnthracene <370 ug/kgBenzo(a)anthracene 27 J ug/kgBenzo(a)pyrene 22 J ug/kgBenzo(b)fluoranthene <370 ug/kgBenzo(ghi)perylene 20 J ug/kgChrysene 52 J ug/kgDibenz(a,h)anthracene <370 ug/kgFluoranthene <370 ug/kgFluorene <370 ug/kgIndeno(1,2,3-cd)pyrene <370 ug/kgNaphthalene <370 ug/kgPhenanthrene 58 J ug/kgPyrene 34 J ug/kgAroclor 1254 <35 ug/kgAroclor 1260 66 ug/kg

Units


Depth (ft) 0-0.5Arsenic 8.6 mg/kgBarium 97 mg/kgCadmium <0.36 u mg/kgChromium 17 mg/kgLead 130 mg/kgMercury 1.2 J mg/kgSelenium <3.3 mg/kg2-Methylnaphthalene 100 J ug/kgAcenaphthene 590 ug/kgAcenaphthylene <400 ug/kgAnthracene 1600 ug/kgBenzo(a)anthracene 4400 ug/kgBenzo(a)pyrene 4000 ug/kgBenzo(b)fluoranthene 7100 ug/kgBenzo(ghi)perylene 2200 ug/kgChrysene 4700 ug/kgDibenz(a,h)anthracene 710 ug/kgFluoranthene 10000 ug/kgFluorene 630 ug/kgIndeno(1,2,3-cd)pyrene 1800 ug/kgNaphthalene 130 J ug/kgPhenanthrene 7400 ug/kgPyrene 7800 ug/kgAroclor 1254 190 j ug/kgAroclor 1260 <39 ug/kg

Units

FGOW-AOC7D-SS114 SS114 SS114(D)Sample Date 9/30/2009 9/30/2009

Depth (ft) 0-0.5 0-0.5Arsenic 3.4 3.5 mg/kgBarium 60 58 mg/kgCadmium <0.15 u <0.15 u mg/kgChromium 10 9.5 mg/kgLead 14 12 mg/kgMercury 0.036 0.033 J mg/kgSelenium <3.1 <3.1 mg/kg2-Methylnaphthalene <370 <370 ug/kgAcenaphthene 55 J <370 ug/kgAcenaphthylene <370 <370 ug/kgAnthracene 130 J <370 ug/kgBenzo(a)anthracene 440 73 J ug/kgBenzo(a)pyrene 320 J 79 J ug/kgBenzo(b)fluoranthene 600 K 140 j ug/kgBenzo(ghi)perylene 210 J 58 J ug/kgChrysene 450 110 J ug/kgDibenz(a,h)anthracene 57 J <370 ug/kgFluoranthene 1100 170 J ug/kgFluorene 60 J <370 ug/kgIndeno(1,2,3-cd)pyrene 180 J 41 J ug/kgNaphthalene <370 <370 ug/kgPhenanthrene 730 76 J ug/kgPyrene 860 140 J ug/kgAroclor 1254 <38 <38 ug/kgAroclor 1260 <38 <38 ug/kg

Units


Depth (ft) 0-0.5Arsenic 5.6 mg/kgBarium 120 j mg/kgCadmium 0.34 j mg/kgChromium 13 mg/kgLead 150 mg/kgMercury 0.04 mg/kgSelenium <3.4 mg/kg2-Methylnaphthalene <410 ug/kgAcenaphthene <410 ug/kgAcenaphthylene <410 ug/kgAnthracene <410 U J ug/kgBenzo(a)anthracene 32 J ug/kgBenzo(a)pyrene 31 J ug/kgBenzo(b)fluoranthene 53 J ug/kgBenzo(ghi)perylene 26 J ug/kgChrysene 59 J ug/kgDibenz(a,h)anthracene <410 ug/kgFluoranthene 64 j ug/kgFluorene <410 ug/kgIndeno(1,2,3-cd)pyrene <410 ug/kgNaphthalene <410 ug/kgPhenanthrene 40 J ug/kgPyrene 58 J ug/kgAroclor 1254 <39 ug/kgAroclor 1260 <39 ug/kg

Units

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UMP029159

Appendix A

Photo Log

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UMP029160

AOC 1MField habitat in AOC 1M formerly used for agricultural purposes

(Zone 15T N: 496219; E: 4949673)

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UMP029161

AOC 1SSurface water during dry conditions at weir structure in AOC 1S

(Zone 15T N: 496930; E: 4947345)

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UMP029162

AOC 1SWooded habitat adjacent to surface water at AOC 1S

(Zone 15T N: 496938; E: 4947340)

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UMP029163

AOC 1SAOC 1SField habitat in AOC 1S (Zone 15T N: 496889; E: 4947412)

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UMP029164

AOC 6Sloped side of AOC 6 depicting sparse tree cover and grasses present (Zone 15T N: 492860; E: 4952435 ) *all coordinates for AOC 6 are approximate

E05MN001901_01.09_0003_a

UMP029165

AOC 6Debris utilized as a den at AOC 6 (Zone 15T N: 492926; E: 4952482)

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UMP029166

AOC 6Debris and rebar at entrance of space used as a den at AOC 6

(Zone 15T N: 492828; E: 4952476)

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UMP029167

AOC 6Overview of grasses and tress present in the depression of AOC 6

(Zone 15T N: 492903; E: 4952461)

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UMP029168

AOC 7AInterior of former building that encompasses the majority of AOC 7A (Zone 15T N: 495739; E: 4952512)

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UMP029169

AOC 7AOpen grass covered land with few trees present surrounding the former building at AOC 7A (Zone 15T N: 495773; E: 4952503)

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UMP029170

AOC 7DView of former Power House building and surrounding habitats from access road (Zone 15T N: 495731; E: 4952465)

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UMP029171

AOC 7DGrass habitat located at AOC 7D between former power house building and other structure remnants. Wooded area of AOC 7D with mature trees and h b l t d i b k d (Z 15T N 495759 E 4952437)shrubs located in background (Zone 15T N: 495759; E: 4952437)

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UMP029172

AOC 7DWooded area within AOC 7D (Zone 15T N: 495782; E: 4952378)

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UMP029173

AOC 7DGeneral overview of AOC 7D (Zone 15T N: 495779; E: 4952397)

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UMP029174

Appendix B

Species List for Federal Threatened and Endangered Species and Minnesota Threatened, Endangered and

Special Concern Species

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UMP029175

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UMP029176

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UMP029177

E05MN001901_01.09_0003_a

UMP029178

Documents

December 23, 2009 ATTN: CENWO-PM-HB Contract No. …...Task Order #0001 Prepared by TIDEWATER, INC. 7161-C Columbia Gateway Drive Columbia, Maryland 21046 December 2009 E05MN001901_01.09_0003_a