2012_DRAFT_BIA_27-Acre_SI_Report_(full_report).pdf

DRAFT

SITE INVESTIGATION REPORT

BETHEL BIA 27-ACRE PARCEL

YUKON DELTA NATIONAL WILDLIFE REFUGE

BETHEL, ALASKA

Contract No. 701818-C-850

Bethel Services, Inc. Project No. 2008105

May 2010

Prepared for:

U.S. Fish and Wildlife Service

OWNER:

US Fish & Wildlife Service - R7 Contracting & General Services 1011 East Tudor Road, Mail Stop 171 Anchorage, Alaska 99503-6199

Prepared By:

GENERAL CONTRACTOR:

Bethel Services Inc.

2605 Denali Street, Suite 100 Anchorage, Alaska 99503-2749

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Draft Site Investigation Report

Bethel BIA 27-Acre Parcel Yukon Delta National Wildlife Refuge

Bethel, Alaska

Prepared for:

U.S. Fish and Wildlife Service Contract No. 701818-C-850

May 2010

John Spielman, Program Manager

Joe Thomas, Environmental Scientist

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TABLE OF CONTENTS

1.0 INTRODUCTION

1.1 Background

1.2 Physical Setting

1.3 Scope of Work

2.0 SITE INVESTIGATION ACTIVITIES

2.1 Composite Building 413

2.1.1 Floor Drains and Drain Piping - Sediment/Residue Sampling

2.1.2 Drain Piping - Bulk ACM Sampling

2.1.3 Paint Sampling - PCBs (Potential PCB Bulk Product Waste)

2.2 Closed Sewage Lagoon

2.2.1 Cap/Fence Inspection

2.2.2 PCB Soil Sampling

2.3 General Debris Survey

2.4 Asbestos Removal

3.0 CONCEPTUAL SITE MODEL

3.1 Hazardous Materials CSM

3.2 POLs, PCBs, And Pesticides CSM

4.0 SAMPLING AND ANALYSES

4.1 Surface Soil Sampling

4.2 Composite Surface Sampling

4.3 Hand Auger Soil Sampling

4.4 Sample Identification

4.5 Surveying

4.6 Quality Assurance/Quality Control

5.0 ANALYTICAL RESULTS

5.1 Composite Building 413

5.1.1 Floor Drains and Drain Piping - Sediment/Residue Sampling

5.1.2 Drain Piping - Bulk ACM Sampling

5.1.3 Paint Sampling - PCBs (Potential PCB Bulk Product Waste)

5.2 Closed Sewage Lagoon

6.0 CONCLUSIONS AND RECOMMENDATIONS

6.1 Composite Building 413

6.1.1 Floor Drains/Trenches

6.1.2 Sewage Pipe

6.1.3 ACM Pipe Insulation

6.1.4 Paint Sampling

6.2 Closed Sewage Lagoon

6.3 Other Concerns

6.3.1 Petroleum Contaminated Soil Beneath Building 413 Footprint

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TABLE OF CONTENTS (Continued)

6.3.2 Monitoring Wells

6.3.3 106,000-Gallon Diesel Spill (Bethel BIA Spill - White Alice Tank)

7.0 REFERENCES

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LIST OF FIGURES

Figure 1 Site Vicinity Map Figure 2 18-Acre and 27-Acre Parcel Boundaries Figure 3 Composite Building Sampling Locations Figure 4 Closed Sewage Lagoon Area Figure 5 General Debris Survey

LIST OF TABLES

Table 3-1 Conceptual Site Model for Bethel BIA 27-Acre Parcel for Areas Containing

Hazardous Materials Table 3-2 Conceptual Site Model for Bethel BIA 27-Acre Parcel for Areas Containing

POLs, PCBs, Pesticides and Solvents Table 5-1 Composite Building PCB and Pesticide Results (µg/kg) Table 5-2 Composite Building Bulk Sample Asbestos Results Table 5-3 Composite Building PCBs in Paint Results (µg/kg) Table 5-4 Northwest Corner of Closed Sewage Lagoon PCB Results (µg/kg)

LIST OF APPENDICES

Appendix A Field Notes Appendix B Photographic Log Appendix C Asbestos Abatement Documents Appendix D GPS Data Appendix E Data Validation Report and ADEC Laboratory Data Review Checklist Appendix F Analytical Reports

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ACRONYMS AND ABREVIATIONS

11 CEOS ........Civil Engineering Operations Squadron Operating Engineers AAC ...............Alaska Administrative Code ACMs .............asbestos-containing materials ADEC .............Alaska Department of Environmental Conservation AST ................Aboveground Storage Tank BIA .................Bureau of Indian Affairs BNC ...............Bethel Native Corporation BSI .................Bethel Services, Inc.

bgs ..................below ground surface BTEX .............benzene, toluene, ethylbenzene, and xylenes COC ...............contaminants of concern CFR ................Code of Federal Regulations CSM ...............Conceptual Site Model DDD ...............Dichlorodiphenyldichloroethane DDE ...............Dichlorodiphenyldichloroethylene DDT ...............Dichlorodiphenyltrichloroethane DQO ...............Data Quality Objectives DVR ...............Data validation report DRO ...............diesel-range organics EPA ................Environmental Protection Agency ESA ................Equitable Servitude Agreement FUDS .............Formerly Used Defense Sites GRO ...............gasoline-range organics GPS ................Global Positioning System HEPA .............High efficiency particulate absorbing ICs ..................Institutional Controls ID ...................Identification J ......................Estimated concentration LBP ................Lead-based paint mg/kg .............milligrams per kilogram mg/l ................milligrams per liter NAPL .............Non-Aqueous Phase Liquid ND ..................Non-detect NFRAR ..........No Further Remedial Action Required O&M ..............Operations and Maintenance PA ..................Preliminary Assessment PCBs ..............polychlorinated biphenyls POL ................petroleum, oil, and lubricant PPE .................Personal protective equipment PQL ................Practical Quantitation Limit QA ..................Quality assurance QC ..................Quality control RBCL .............Risk-based cleanup level

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ACRONYMS AND ABREVIATIONS (Continued)

RRO ...............residual-range organics RRS ................Radio Relay Station SI ....................Site Investigation TSCA .............Toxic Substance Control Act µg/kg ..............micrograms per kilogram USAF .............U.S. Air Force USFWS ..........U.S. Fish and Wildlife Service UST ................Underground Storage Tank VOC ...............Volatile organic compound WACS ............White Alice Communication System WGS ...............World Geodetic System YDNWR ........Yukon Delta National Wildlife Refuge YKHC ............Yukon-Kuskokwim Health Corporation

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1.0 INTRODUCTION

The purpose of this Site Investigation Report is to describe field activities that were conducted to characterize the extent and nature of human health and environmental concerns and address known data gaps for the 27-Acre parcel at the former Bethel Bureau of Indian Affairs (BIA) Site in Bethel, Alaska. These data gaps and concerns are identified in the May 2009 Final Preliminary Assessment Report Contaminant Investigation Bethel BIA Site Yukon Delta National Wildlife Refuge prepared for the U.S. Fish and Wildlife Service (USFWS) by Bethel Services, Inc. (BSI) (BSI, 2009a). This report describes current and past work performed at a 27-Acre parcel, which along with a separate 18-Acre parcel, have been split off of a larger former U.S.

Air Force (USAF) site managed under the Formerly Used Defense Site (FUDS) program and conveyed to the USFWS. The legal description of the 27-Acre parcel is Tract QCD of Sections 14 and 15, Township 8 North, Range 72 West, Seward Meridian, Alaska. Figure 1 shows the vicinity of the Bethel BIA site and Figure 2 shows the boundaries of the 27-Acre and 18-Acre parcels superimposed onto a 2007 aerial photograph.

The 27-Acre and 18-Acre parcels were independently investigated as part of a September 2009 field effort, and findings are presented and discussed in this report and a report for the 18-Acre parcel under a separate cover. Analytical samples for both parcels were submitted under a single work order, and hence quality assurance/quality control (QA/QC) requirements are jointly evaluated.

The objectives of this investigation were to identify and characterize human health and environmental concerns so that any required remedial actions can be planned and implemented.

The USFWS requires this information so that lands under their management may be managed properly, cleaned up to acceptable levels, and eventually transferred to other parties. The USFWS plans to transfer ownership of the 27-acre parcel to the Yukon-Kuskokwim Health Corporation (YKHC) after cleanup, as mandated by Public Law 102-497 enacted in 1992.

1.1 BACKGROUND

The Bethel BIA site, also known as the Bethel BIA Administrative Site, is a FUDS with principle cleanup responsibility resting with the U.S. Army Corps of Engineers FUDS program.

The site is listed on the FUDS inventory with FUDS ID: F10AK0510 and Federal Facility ID:

AK09799F699900. The Bethel BIA Site currently consists of two parcels of land, referred to as the 27-Acre parcel and the 18-Acre parcel (18.42 acres actual), which were pared down from a 125-acre BIA parcel over the years. Both parcels are managed by the USFWS as part of the Yukon Delta National Wildlife Refuge (YDNWR) and have differing environmental issues, responsible parties for cleanup, and future land status plans. Figure 2 shows the approximate boundaries of the 27- and 18-Acre parcels as well as previous parcels pared down from the initial 1,467.31 acre USAF parcel which is shown in Figure 1.

The USAF first developed the site in 1957 and constructed facilities as part of the White Alice Communication System (WACS). The WACS facilities included a 60,000-square foot Composite Building (Building 413), numerous support structures, and a Radio Relay Station (RRS) located about 2,500 feet southwest of the Composite Building. The Composite Building was later used by the BIA from the early 1960s to the mid 1980s as their Bethel Administrative

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Headquarters. Use of the site by the BIA ended in 1990 and the site has remained vacant since.

The condition of the abandoned facilities has continued to deteriorate over the years. The central portion of the Composite Building was destroyed by fire in August 2001. Un-burnt portions of the structure, now exposed to the elements have deteriorated significantly and, along with other derelict structures on the property, pose a physical hazard.

A number of environmental investigations, assessments, and cleanup actions have been conducted at the BIA Administrative Site and adjacent areas over the years. A thorough review of these can be found in the Preliminary Assessment (PA) report dated May 2009 and prepared by BSI for the USFWS (BSI, 2009a). Environmental contaminants and concerns have included:

Petroleum, oil, and lubricants (POLs) - Spilled/leaked fuels related to above ground storage tanks (ASTs), bulk above ground tanks and associated piping and fuels, oils, and other POLs related to drum storage and handling. Specific POL-related contaminants include diesel-range organics (DRO); residual-range organics (RRO); gasoline-range organics (GRO); and benzene, ethylbenzene, toluene, and xylenes (BTEX).

Asbestos - Primarily within building materials used in the interior and exterior of buildings, now mainly related to the Composite Building.

Polychlorinated biphenyls (PCBs) - In and near the Composite Building, former Sewage Lagoon, and other areas.

Lead-based paint (LBP) and potentially PCBs in paint - Related to the Composite Building and possibly other structures.

Pesticides - Dichloro-diphenyl-trichloroethane (DDT), dichloro-diphenyl-dichloro-ethylene (DDE), and dichloro-diphenyl-dichloroethane (DDD) identified near the Composite Building 413, closed Sewage Lagoon, and other areas.

Other non-contaminant hazards include physical hazards associated with abandoned and damaged buildings, structures, and general site debris.

The 27-Acre parcel contains most of the infrastructure constructed by the USAF and later used by the BIA during their occupancy of the site, including several abandoned buildings, a closed sewage lagoon, and an undeveloped area impacted by a 106,000-gallon diesel fuel spill that occurred in 1993. Several contaminant issues have been identified and addressed by past investigations and remedial efforts. The site was granted a No Further Remedial Action Required (NFRAR) decision by the Alaska Department of Environmental Conservation (ADEC) in 2000 (ADEC, 2000) but the required intuitional controls (ICs) have yet to be implemented. A fire that partially destroyed the 60,000-square-foot Composite Building has raised new human health and environmental concerns that were unanticipated at the time of the NFRAR decision.

Changes in environmental regulations and changes in planned land use and ownership also generate new data gaps. The relevant site history and data gaps to be addressed by this site investigation are described in detail in Section 2.

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1.2 PHYSICAL SETTING

The Bethel BIA Site is located approximately 4 miles west of the City of Bethel, Alaska and the Kuskokwim River, as shown in Figure 1. Bethel is located near the mouth of the Kuskokwim River and 340 miles west of Anchorage and serves a major air and water transportation hub in the region with an estimated population of about 6,356 residents, as of 2006. According to a 1992 PA by the USAF 11th Civil Engineer Operations Squadron Operating Engineers (11 CEOS), 23% of the residents live within 1 to 2 miles of the BIA site, and the remainder of residents live more than 2 miles from the site (11 CEOS, 1992). The site is accessible year-round by a gravel road that ends approximately 0.5 miles to the south of the site. Access to the site is currently restricted by an un-manned locked gate; however, snowmobile, 4-wheeler, and foot traffic can easily bypass the gate. Other off-road trails in the area also allow unrestricted access to site.

Average precipitation for the Bethel area is 16 inches a year including 50 inches of snow.

Summer temperatures range from 42° to 62° Fahrenheit (F); winter temperatures average -2° to 19° F.

1.3 SCOPE OF WORK

This project involved the completion of the following site investigative activities performed at the locations identified below.

Inspection of cap and fencing at closed sewage lagoon containing sediments with PCBs to evaluate their integrity

Sampling of near surface and subsurface soil/sediment for PCBs downgradient of the closed sewage lagoon where a sediment sample from 1995 contained 7.2 milligram per kilogram (mg/kg) PCBs; to reevaluate the location and extent of off-site migration of PCBs prior to sewage lagoon closure

Sampling of sediment/residue in floor drains, utility trenches, and crawlspace sewage pipes for possible PCBs and pesticides.

Sampling of crawlspace and above-ground sewage pipes at Composite Building for asbestos-containing materials (ACM)

Sampling of painted surfaces at Composite Building for PCBs (i.e. PCBs in paint).

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2.0 SITE INVESTIGATION ACTIVITIES

Site investigation activities were conducted according to the work plan (BSI, 2009c) which implemented the recommendations presented in the PA report prepared by BSI (BSI, 2009a).

This work plan also incorporated additional sampling of paint requested by the ADEC to address some additional issues identified after their review of the draft workplan. Sewage lagoon, residue/sediment and paint samples were submitted to SGS Environmental Services, Inc. of Anchorage, Alaska. Asbestos bulk samples were analyzed by White Environmental Consultants, Inc. of Anchorage Alaska. A copy of the Field note books is included in Appendix A.

2.1 COMPOSITE BUILDING 413

A lack of maintenance, fire, and vandalism has lead to an ever increasing state of deterioration of Composite Building 413 and has raised a number of human health and environmental concerns.

The investigation activities described below address building materials sampling conducted to assess their risk to site visitors and future demolition workers, and to characterize future waste materials for disposal. Figure 3 is a 2007 aerial photograph showing the partially burned Composite Building and the approximate sample locations that were collected as described below. Photos 1 and 2 in Appendix B also show the current condition of the Composite Building.

2.1.1 Floor Drains and Drain Piping - Sediment/Residue Sampling Up to 4.9 mg/kg PCBs (Aroclor 1260) and detectable concentrations of the pesticides DDD and DDT have been identified in sediments from the closed sewage lagoon. In addition, PCBs and pesticides were found in gravel floors within and outside the garage area of the Composite Building, and PCBs were found on concrete floor surfaces within generator and transformer areas of the building (Figure 3). Because of this distribution, it was reasonable to suspect that these compounds may have entered floor drains within the Composite Building and were then subsequently pumped into the sewage lagoon. Floor drains and grate-covered floor utility trenches within the generator room and shop area of the Composite Building, as well as sewage piping beneath the crawlspace were considered suspect for PCB and pesticide contamination, as well as the contents of the elevated sewage line that leads to the lagoon. Samples of sediments remaining in these locations were collected and analyzed to assess possible exposure hazards to future demolition workers and properly characterize these components for disposal.

As part of this site investigation, BSI collected samples from residue/sediment remaining in the garage area floor drains, generator and transformer room grated utility trenches; and a drain manifold pipe in the crawlspace and elevated sewage pipe leading to the sewage lagoon. The samples were analyzed for PCBs and pesticides by Environmental Protection Agency (EPA) methods 8082/8081A. Samples were collected from the following areas: two of the five garage floor drain intakes, the sewage manifold pipe beneath the building downgradient of the garage floor drains, fuel pipe trench around generators, and sewage outfall pipe exiting the north side of the building. To collect in-pipe residue/sediment samples, a portion of the pipe was abated for asbestos (ACM sampling described below), encapsulated, and a portable band saw was used to remove a section of pipe. The approximate location of these samples is indicated on Figure 3.

Photographs of drain pipes and sample locations are shown in Photos 3 through 11 of Appendix B.

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2.1.2 Drain Piping - Bulk ACM Sampling

Sewage piping in the crawlspace was also suspect for possible ACM. A post-fire assessments by Phukan Inc. performed in 2001 and 2002 (Phukan, 2002) identified ACM on a pipe elbow from the crawl space, but determined that a section of straight pipe insulation to be non-ACM. As a precaution prior to cutting the pipe to perform the PCB/pesticide sampling described in the previous section, four insulation samples from the crawlspace sewer pipe were collected for bulk asbestos analysis to protect workers from exposure. Two samples were collected from beneath the garage (designated Samples G-1 and G-2) and two samples were collected from sewage line insulation in the northern portion of the building (designated Samples S-1 and S-2).

Approximate sample locations are shown on Figure 3. A disconnected insulation-free segment of pipe was identified outside the north end of the building for sampling pipe residue, thereby eliminating the need for cutting the pipe at this location. Bulk asbestos samples S-1 and S-2 were collected to test the pipe insulation in the northern portion of the structure to further characterize these materials for planned demolition.

2.1.3 Paint Sampling - PCBs (Potential PCB Bulk Product Waste) The ADEC expressed concerns regarding possible PCBs in paint at the Composite Building, and possible dioxin/furans in ash (i.e. burned building debris). Some military buildings of similar vintage in Alaska have been found to have been painted with PCB-containing paint. The rationale for sampling the paint for PCBs is that dioxins/furans can be generated by the combustion of PCB-containing materials, and therefore they could potentially be present in the building’s ash/burn debris. Because of the high cost for dioxins/furans laboratory analysis and because of the hit or miss nature of attempting to identify and sample ash generated from combusted painted material, testing for PCBs was conducted to potentially rule-out the need for dioxins/furans testing. It should be noted that very little painted combustible material (e.g.

wood, fiberboard, and paneling) remains in the Composite Building since the ACM was abated.

Personnel first visually evaluated the painted surfaces in the building, especially those intact exterior areas bordering the burned areas, and selected six appropriate sites to represent major painted surfaces such as trim and moldings, walls, etc. Identifying appropriate sample locations was difficult since little paint remained at the site because the building had been stripped of sheetrock and paneling during previous abatement activities. The sampler obtained the laboratory-recommended 5 grams of paint for each sample using a calibrated digital scale. Paint samples were tested for PCBs by method 8082. Photographs of painted surfaces sampled for PCBs are shown in Photos 12 through 15.

2.2 CLOSED SEWAGE LAGOON

The closed sewage lagoon contains sediments with the PCB Aroclor 1260 at concentrations above the ADEC cleanup level as well as detectable pesticide concentrations. The lagoon has been dewatered, capped, and fenced off and the site has been granted a status of “Cleanup Complete – Institutional Controls” by the ADEC. ICs in the form of deed restrictions have yet to be implemented. In addition, a sediment sample (SS11) collected during a 1995 site investigation (EMCON, 1996a) from near the northwest corner of the subsequently fenced and closed lagoon, had a PCB concentration of 7.2 mg/kg. This concentration met the 10 mg/kg PCB cleanup level in affect at that time, but exceeds the current 1 mg/kg cleanup level specified

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 7 in 18 Alaska Administrative Code (AAC) 75 and therefore required confirmation and further investigation.

Fieldwork associated with the closed lagoon included visually inspecting the lagoon’s earthen cap and surrounding fence for damage or compromised integrity, and soil/sediment sampling outside the boundaries of the lagoon . Soil/sediment samples were collected at and in the vicinity of sediment sample SS11, and downgradient of the sample and northwest corner of the lagoon.

Figure 4 shows the closed sewage lagoon and sample locations collected near its northwest corner.

2.2.1 Cap/Fence Inspection

BSI personnel walked around the perimeter of the closed sewage lagoon and inspected the cap and fence for damage and signs of breaches, and surveyed the corners of the fence using a hand held Global Positioning System (GPS) unit. Digital photographs were taken to document the current conditions and field observations and were recorded in the field notebook. A copy of the field notebook is included in Appendix A and photographs of the cap and fence are included in the Photographic log in Appendix B.

The fence was found to be completely intact, however frost jacking of some fence posts was noted near the gate along its eastern side. The bottom of the fence and gate has risen enough so that an adult could conceivably slide under and enter the restricted area (Photograph 16). The frost jacking has also caused the lower gate hinge to come unfastened (Photograph 17). The area around the gate is heavily overgrown with thick brush and there was no sign of human traffic in the area, and no signs of entry under the raised portion of the fence. Repair to the frost-jacked area of the fence would be required to ensure that entry was not physically possible, however given to location of the gate in dense brush, unauthorized entry is not likely.

The liner appeared to be completely covered, and the capping soil has become very heavily overgrown with brush precluding the likelihood of erosion.

2.2.2 PCB Soil Sampling

EMCON Alaska collected sediment sample SS11 from near the northwest corner of the fenced closed lagoon in 1995, which had a PCB (Aroclor 1260) concentration of 7.2 mg/kg (EMCON, 1996a). This sample represents soil/sediment that was dispersed downgradient of the sewage lagoon prior to its capping and closure. A lath marking this sample location was found still intact during the 2009 sampling effort. The goal of the 2009 sampling was to confirm the historic PCB detection, document current levels, and attempt to delineate the northern and southern extent of impacted area.

The workplan (BSI, 2009c) stated that four composite surface soil/sediment samples and one discrete subsurface soil/sediment sample from just above the permafrost interface would be collected for PCB analysis by EPA Method SW8082 to evaluate this area. The intention of the planned composite sampling was to test a broad target area with less chance of missing a small zone of contamination than grab (i.e. discrete) sampling. For variable contaminant distributions across a given area, composite sampling also provides more representative data than discrete grab samples. Upon observing the area, however, it was evident that surface sediments from the

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 8 lagoon were restricted to a narrow bog, and field personnel decided that collecting one composite sample near historic sample SS11 and three near-surface discrete samples north and south of Sample SS11 would be more appropriate. It was believed that composite sampling over a wider area would have diluted PCBs compared to the actual discharge channel, and the channel was too narrow to collect composite samples in the manner proposed in the workplan.

One composite and three discrete samples were collected from 0.3 feet below ground surface (bgs), in mineral soil (silty sand) underlying a vegetated mat, or from small non-vegetated patches. Samples were collected along a north-south-oriented drainage swale covered by sedges typical to Alaskan wetlands. In addition, one sample was collected from approximately 5.5 feet bgs, approximately 2 feet east of historical Sample SS11. The purpose of the deeper samples was to evaluate PCB and pesticide concentrations closer to the permafrost interface at the request of the ADEC. Closed sewage lagoon samples were tested for PCBs by method 8082.

Photographs 19 through 23 were taken during sampling activities at the closed sewage lagoon and are included in Appendix B.

In addition to the sampling, BSI personnel attempted to locate the historic discharge point (channel) along the west side of the lagoon, but it was not discernable as the margin of lagoon is now uniformly bermed. However, parallel sets of northwest-trending rivulets leading from the sewage outfall pipe area to the vicinity of SS11 are clearly visible on a 1963 aerial photograph that is included as Figure 5 in BSI's 2009 PA report (BS1, 2009a).

2.3 GENERAL DEBRIS SURVEY

A debris survey was not specifically planned for the 27-Acre parcel site investigation, however during the course of the debris survey on the adjacent 18-Acre parcel, BSI personnel did identify some significant debris that fell within the 27-Acre parcel. The majority if the debris is located in the southeast corner of parcel along the perimeter of a prominent clearing on the northeast side of the road, approximately 100 to 150 feet south of Building 414. The location of the debris is depicted on Figure 5; the debris includes:

1. refrigerated van (Photograph 24)

2. truck motor

3. wood platform (Photograph 24)

4. abandoned snowmobile

5. large electric (water) pump and concrete tank cradle (Photograph 25)

6. burn barrel, 55-gal steel drum with burned contents (Photograph 26)

Materials or footprint soil sampling was not conducted for the 27-Acre debris. Photographs of debris are provided in the Photographic Log, included in Appendix B.

2.4 ASBESTOS REMOVAL

Approximately one linear foot of non-friable ACM insulation (cellular glass insulation with ACM mastic) was removed from a section of sewage pipe in the crawlspace of the Composite Building. Because of the small amount of ACM removed, and the purpose of obtaining samples rather than abatement, this work falls under Class III Operations and Maintenance (O&M) activities [40 Code of Federal Regulations (CFR) Part 763]. The work was performed using a

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 9 glovebag by BSI’s on-site Asbestos Competent Person in Level C Personal Protective Equipment (PPE) following the appropriate prescribed procedures. Asbestos workers certification and Asbestos Regulated Area Sign In/Out Sheet is included in Appendix C.

The exposed cut ends of the insulation (Photograph 5) were wrapped (encapsulated). The glovebag with ACM was placed into an ACM disposal bag. The material was shipped to Anchorage and disposed of as ACM debris at the Anchorage Municipal Landfill. The volume of ACM was estimated to be approximately one cubic foot and the weight of the containerized material was 7.27 kilograms (16 pounds). A copy of the Air Waybill, Shipper's Declaration of Dangerous Goods, Waste Shipment Record, and disposal receipt are included in Appendix C.

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3.0 CONCEPTUAL SITE MODEL

The Conceptual site model (CSM) was previously developed for 27-Acre and 18-Acre parcels by BSI as a standalone document titled Final Conceptual Site Model, Bethel BIA Site, Yukon Delta National Wildlife Refuge, and dated May 2009 (BSI, 2009b). Some details of the CSM remain to be finalized pending discussions between the USFWS and ADEC regarding future land use.

Minor changes to the final CSM document included here at the request of the ADEC, include now indicating the migration to groundwater pathway as complete for POLs, and showing residential potential human receptor exposure as a "Potential Future Pathway". Anticipated land use for preparation of this CSM is industrial since ICs must be implemented to meet the conditional closure requirements already enacted for the 27-acre parcel.

BSI believes a very strong argument can be made that "potable" groundwater is not impacted, and will not be impacted by the known contamination at the 27-Acre site. A groundwater investigation that was part of the 1995 site characterization effort at the Bethel BIA site by EMCON (EMCON, 1996b) determined that the shallow groundwater (above the permafrost layer) at the site occurred in a seasonal unconfined aquifer. According to the report, "This unconfined aquifer is present seasonally above the permafrost and is not considered to be a potable water source". The report also states that the sites former drinking water well encountered permafrost from the near surface to a depth of 603 feet and that a likelihood of a hydraulic connection between the deep potable water aquifer and the near-surface aquifer is minimal at the site. Given the great depth to potable drinking water at the site (~600 feet), and the extensive barrier to downward contaminant migration posed by over 550 feet of permafrost, in our opinion the Migration to groundwater pathway should be considered incomplete for the site.

Two contaminant-specific graphical CSMs for the Bethel BIA site were developed based on the contaminants of concern (COCs) that were identified in the PA report. Table 3-1 depicts the CSM for areas containing hazardous materials, Table 3-2 depicts the CSM for areas containing (or suspected to contain) POLs, PCBs, and pesticides. The conceptual site models are intended to show the potential present and future routes or pathways that site contaminants may take as they move from a release location to a potential receptor. If an exposure pathway is incomplete, then it can be concluded that no current human exposure occurred. Consequently, adverse effects to human health would not be expected under current conditions. However, changes in land use in the future may result in completion of potential exposure pathways.

3.1 HAZARDOUS MATERIALS CSM

The hazardous materials associated with the Bethel BIA site include friable ACM, LBP and arsenic associated with paint and possibly treated lumber or other as yet unidentified sources.

The sources of these hazardous materials are the existing structures, debris and potentially abandoned equipment remaining at the site. Initial deposition/direct discharge of the hazardous materials to surface soil occurred due to the 2001 fire and natural weathering. The hazardous materials would continue to be transported to surrounding surface soils via air dispersion.

Subsurface soils and groundwater are not considered impacted media as the hazardous constituents are not expected to significantly leach from the paint chips or building materials deposited on the surface soils.

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The CSM shows that precipitation runoff and sheetwash are not interpreted to be significant sediment transport routes. This is because the developed portion of the Bethel BIA site (where the hazardous materials would be concentrated) is relatively flat, limiting runoff and sheet wash.

The wild plant ingestion route is interpreted to not be complete for ACM, as plants do not take up asbestos fibers into their tissues. Plant uptake of lead is potentially complete, although not anticipated to be significant. Although ptarmigan, rabbits and waterfowl may be harvested from the Bethel BIA site, the wild meat ingestion route is interpreted to not be complete for ACM because animals feeding on wild plants at the site would not be exposed via plant ingestion.

Because of the bioaccumulative properties of lead, the wild meat ingestion route is potentially complete. Animals could potentially ingest lead paint chips while feeding on plants at the site.

In addition, small soil dwelling animals (worms, voles, etc.) could be eaten by larger animals.

Although the wild meat ingestion pathway is complete, the risk to humans is believed to be small because the animals potentially affected are not a significant portion of the diet of animals used as human food and because the animals used as human food typically have a very large range relative to the portion of the Bethel BIA site where LBP has been found.

The potential receptors, exposure routes and exposure media are shown on the right side of Table 3-1. The Bethel BIA site is currently unoccupied; past use has been primarily industrial with limited residential use at one point in time. Industrial land use status would be also be required to implement the ICs required for closure, which USFWS plans to do when the land is transferred, therefore industrial exposures are portrayed as potential current and future exposure routes. Subsistence users have also been included as human receptors as berries and small game or waterfowl are harvested from the site. Current recreational site visitors (subsistence users) and potential industrial or site workers may come into contact with site-related contaminants through incidental ingestion, dermal contact, and inhalation of particulates derived from contaminated soil or suspended in the outdoor air (asbestos only). For the current site conditions, direct contact with subsurface soil by current human receptors does not represent a complete exposure pathway at the Bethel BIA site because subsurface soil is not considered impacted by the hazardous materials and is also not available for contact.

3.2 POLS, PCBS, AND PESTICIDES CSM

POLs, pesticides (DDT, DDE and DDD) and potentially chlorinated solvents in soils at the Bethel BIA site have been attributed to above ground releases or spills from tanks or drums (Table 3-2). Direct discharge of POLs to subsurface soil from floor drains and utility trenches may have also occurred, although this has not been previously investigated and confirmed.

Following a spill or leak, fugitive fuel would tend to infiltrate through the soil column toward the water table. If a sufficient quantity of fuel was spilled, the fuel would reach the seasonal (supra-permafrost) water table (not the deep potable aquifer) where it would tend to spread laterally and be immobilized (trapped) in the zone of seasonal water table fluctuation. Note that the non-aqueous phase liquid (NAPL) was likely mobile at the site for only a short time after the primary hydrocarbon source was removed (i.e. the leak or spill was stopped).

While the fuel was moving through the soil as a separate phase and after the NAPL was immobilized the individual constituents making up the fuel would tend to partition from the NAPL into the vapor, dissolved and adsorbed phases according to the phase partitioning

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 13 relationships, and then would tend to be transported away from the NAPL contaminated source area as shown in the center portion of the Table 3-2. The transport mechanisms vary according to the media. Vapors would tend to migrate away from the source area by the processes of diffusion and advection. Dissolved constituents in the soil moisture in the vadose zone would tend to be carried to the water table by infiltrating precipitation and dissolved phase constituents in the saturated zone would be advected downgradient by the flowing groundwater. Both vapor and dissolved-phase constituents would tend to be attenuated during transport by sorption and biodegradation. In the case of PCBs, these compounds are non-volatile indicating the risk associated with vapor inhalation of PCBs is negligible. PCBs have very low solubilities and are recalcitrant therefore PCBs are not readily dissolved in water and are resistant to chemical and biological degradation. PCBs dissolved in hydrocarbon NAPL may be mobilized locally with movement of the hydrocarbon plume.

PCBs detected in samples from the garage floor drains of the Composite Building confirm that spills in the garage have occurred. The sources of the detected PCBs were most likely transformers or electrical equipment that was discharge to garage floor, and were transported to the subsurface and surface from the floor drain and above ground sewage discharge pipes connected to the drains. PCBs in surface sediment dispersed from the northwest side of sewage lagoon prior to closure have also been identified. PCBs were also detected in paint chip samples collected from various areas of the Composite Building, and visible paint chips were observed in at least one residue/sediment sample.

The CSM shows that precipitation runoff and sheet wash are not interpreted to be significant dissolved phase or sediment transport routes because the Bethel BIA site is relatively flat, which limits runoff and sheet wash. According to the Baseline Human Health and Ecological Risk Assessment (EMCON, 1996b) for the Bethel BIA site, groundwater transport to surface water bodies is not interpreted to be a significant exposure route because dissolved phase contaminants are expected to be attenuated below human health risk based levels and below surface water quality standards before reaching a surface water body (wetlands). The wild plant ingestion route is interpreted to not be complete, because plants do not take up fuel hydrocarbons or PCBs into their tissues. The wild meat ingestion route is interpreted to be complete at the Bethel BIA site because of the bioaccumulation of PCBs in the fatty tissue of animals. Animals could potentially ingest PCB-impacted soil and sediment while feeding on plants at the site. In addition, small soil dwelling animals (worms, voles, etc.) could be eaten by larger animals.

Although the wild meat ingestion pathway is complete, the risk to humans is believed to be very small because; the concentration of PCBs in uncapped soil/sediment is relatively low (<2,360 ug/kg); and identified animals potentially affected are not a significant portion of the diet of animals used as human food, and because the animals used as human food typically have a very large range relative to the portion of the Bethel BIA site where PCBs have been found.

The potential receptors, exposure routes and exposure media are shown on the right side of Table 3-2. As described in the CSM for hazardous materials, industrial exposures are portrayed as potential current and future exposure routes. Subsistence users have also been included as human receptors as berries and small game or waterfowl are harvested from the site. Subsistence users and future site workers may come into contact with site-related contaminants through incidental ingestion, dermal contact, and inhalation of vapors and particulates derived from

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 14 contaminated soil. For the current site conditions, direct contact with subsurface soil by current human receptors does not represent a complete exposure pathway at the Bethel BIA 27-Acre Parcel because subsurface soil is not available for contact. Future excavation activities, such as those associated with building demolition (if foundation is removed), could result in transport of contaminants from subsurface soil to the surface, where the contaminants would be available for direct contact (e.g., ingestion, dermal contact, and particulate inhalation) by site receptors. This exposure route is considered the most likely and is associated with the highest risk. Prevention of direct contact exposure to contaminated soils is the primary impetus for the institutional controls required by the ADEC for granting site closure (ADEC, 2000) for the 27-acre parcel. If this soil were brought to the surface, then contact with COCs by recreational visitors or workers would be possible through incidental ingestion, dermal contact, and inhalation of dust and vapors.

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 15

Table 3-1 Conceptual Site Model for Bethel BIA 27-Acre Parcel for Areas Containing Hazardous Materials Contaminant

Sources Release

Mechanism Impacted Media Exposure Media

Exposure Route

Residential Subsistence Industrial Site

Workers Direct discharges/ deposition due to burning and weathering

Surface Soil Surface Soil Soil Ingestion & Dermal Contact

X PC PF PF

Hazardous Materials (Friable ACM, LBP, As) Air Dispersion Outdoor Air

Outdoor Air Inhalation

X PC PF PF

X Indoor Air Indoor Air Inhalation

X X X X

Subsurface Soil X Subsurface Soil

X Migration to Groundwater

(infiltration of NAPL & leaching)

X Groundwater Groundwater

Ingestion X X X X

Groundwater Transport

Runoff / Sheet Wash Sediment Transport

X Surface Water Surface Water

Ingestion X X X X

Sediment Sediment

Ingestion & Dermal Contact

X PC PF PF

Plant Uptake

ACM (X)

LBP (PC)

Impacted Plants Wild Plant Ingestion

X PC X X

Animal Uptake

ACM (X)

LBP (PC)

Impacted Meat Wild Meat Ingestion

X PC X X

Notes:

ACM = asbestos containing material PF = Potential Future Pathway LBP = lead based paint PC = Potentially Complete Pathway As = arsenic X = Incomplete Pathway

Potential Human Receptor ScenarioTransport Mechanisms

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 16

Table 3-2 Conceptual Site Model for Bethel BIA 27-Acre Parcel for Areas Containing POLs, PCBs, Pesticides and Solvents

Contaminant Sources

Release Mechanism

Impacted Media

Exposure Media Exposure

Route

Residential Subsistence Industrial Site

Workers Above Grade

Overfills, Spills & Leaks

Surface Soil Surface Soil Soil Ingestion & Dermal Contact

PC PC PF PF

ASTs, Drums, Transformers, Pesticides (DDT) Volatilization Outdoor Air

Outdoor Air Inhalation

PC PC PF PF

X Indoor Air Indoor Air Inhalation

X X X X

Below Grade Leaks

Subsurface Soil

Subsurface Soil

Migration to Groundwater (infiltration of NAPL & leaching) Groundwater

Groundwater Ingestion

PF X X X

Groundwater Transport

Runoff / Sheet Wash Sediment Transport

X Surface Water Surface Water

Ingestion X X X X

Sediment Sediment

Ingestion & Dermal Contact

PC PC PF PF

Plant Uptake

POLs (X) PCBs (X) Pesticides

(PC)

Impacted Plants Wild Plant Ingestion

X PC X X

Animal Uptake Impacted Meat Wild Meat Ingestion

PC PC X X

Notes:

AST = above ground storage tank PF = Potential Future Pathway

PC = Potentially Complete Pathway X = Incomplete Pathway

Transport Mechanisms Potential Human Receptor Scenario

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 17

4.0 SAMPLING AND ANALYSES

This section describes the procedures that were used for the collection of analytical samples for off-site laboratory analysis. Samples were collected by an ADEC-qualified person (18 AAC 78).

Sample collection methods and procedures were performed in accordance with 18 AAC 75 and 78 (ADEC, 2008 and 2003).

4.1 SURFACE SOIL SAMPLING

Samples were collected from freshly exposed soils exposed by a hand shovel at approximately

0.3 feet bgs. The goal of this soil sampling was to investigate surface PCB contamination in sediment/soil discharged from the Sewage Lagoon prior to capping and closure; therefore the minimum 18-inch bgs collection depth specified in the Underground Storage Tank (UST) guidance document was not appropriate. The sampling depth was chosen to represent the first layer of mineral soil (with some organics) that occurred beneath the organic layer and root masses. Samples locations were determined in the field based on relation to labeled lath marking historic sample SS11 and surface topography in the vicinity of the northwest corner of the closed sewage lagoon.

A new pair of nitrile sampling gloves and a clean stainless steel spoon was used to collect each sample. Soil samples were collected in the appropriate “certified-cleaned” laboratory-provided glass sample jars with Teflon-lined lids. Sample containers were filled as required by the analytical method. The sample containers were filled to the top, taking care to prevent soil from remaining in the lid threads prior to being sealed to prevent potential contaminant migration from the sample.

Pertinent data and observations made during sampling, such as date and time collected, proper sample identification (ID) number, analyses requested, presence of odor or staining, depth bgs collected, and soil type were recorded in the field logbook. Samples were stored in a cooler as soon as possible after collection. Cooler temperatures were maintained at 4° ±2° C during storage and transportation to the laboratory. Samples were handled and transported in a manner that maintained sample integrity.

4.2 COMPOSITE SURFACE SAMPLING

One composite soil/sediment sample was collected from an area centered approximately five feet south of the historic sample SS11, from a 10-foot by 10-foot area (Photograph 20). The composite surface sample consisted of nine equal-size aliquots (~1 tablespoon each) collected from 0.3 feet bgs and placed in an 8-ounce amber jar using a new stainless steel spoon. Soil clumps were broken up with the spoon as the soil was placed in the jar. Contents of the jar were stirred and shaken until the soil was thoroughly homogenized. A full explanation of the composite sampling procedure and rational is presented in the workplan.

4.3 HAND AUGER SOIL SAMPLING

One discrete soil sample (02SL) was collected at the former sewage lagoon site from 5.5 feet bgs using a hand auger. This sample was intended to determine whether PCB concentrations increased at depth closer to the permafrost interface compared to surface concentrations. This deeper sampling was performed at the request of the ADEC. Although permafrost was not

Bethel BIA 27-Acre Parcel - Bethel, Alaska Page 18 encountered with the hand auger, samples were collected from as deep as possible given reasonable effort. The sample was collected approximately 2 feet east of where historic sample SS11 was collected (Photograph 20). The auger was decontaminated prior to use using an Alconox wash followed by two fresh-water rinses.

4.4 SAMPLE IDENTIFICATION

All analytical samples (excluding bulk asbestos) for this project contain the follow prefix "09BIA27A-" indicating they were collected in 2009, from the BIA site 27-accre parcel; followed by a two-digit consecutive number and a two-character matrix identifier (SL - soil, PT - paint, SP

- drain or sewage pipe residue/sludge). For brevity, the "09BIA27A-" prefix will be omitted from sample identifications in this report from this point forward and samples will be referenced to the last two digits followed by the matrix identifier.

Duplicate samples were submitted to the project laboratory as blind samples, indistinguishable from the primary samples. Sample identifications for each material were documented in the field notebook.

4.5 SURVEYING

Survey control was established by referencing to a variety of existing site features such as buildings, fences, and roads. The locations of closed sewage lagoon samples were marked with labeled lath and recorded in the field notebook with swing-ties reference to the northwest fence corner of the lagoon. Building material samples were identified in field sketches and markups of workplan figures during sample collection and transferred to figures provided in this report.

A hand-held Topcon GMS-2 GPS instrument was used to record the coordinates for each soil/sediment sample location and noted debris. GPS coordinates were recorded using the World Geodetic System (WGS) 84 datum, and plotted on geo-referenced aerial photographs of the site with pixel sizes of 0.5 foot. Survey accuracy, estimated by the GPS instrument while recording each waypoint, was typically on the order of 2 to 5 feet, and rarely exceeded 9 feet. GPS-measured coordinates are provided in Appendix D.

4.6 QUALITY ASSURANCE/QUALITY CONTROL

The objectives of the Quality Assurance/Quality Control (QA/QC) program are to ensure compliance with the project specifications, ensure sampling and analysis in accordance with ADEC and EPA protocols, and to provide scientifically defensible data in terms of precision, accuracy, reproducibility, and representativeness.