1992-USAF_Preliminary_Assessment_Bethel_BIA(1).pdf

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File: 17G S.H.

BETHEL CREEK RRS

ALASKA

ADMINISTRATIVE RECORD

' ' ' 'COVER SHEET

AR File Number ._

PRELIMINARY ASSESSMENT

BUREAU OF INDIAN AFFAIRS

BETHEL, ALASKA

Prepared by llth Civil Engineering Operations Squadron Operating Engineers

21885 2nd Street Elmendorf AFB AK 99506-4420

Interagency Agreement No. AG2E0000060

Final Report March 1992

Prepared for

Bureau of Indian Affairs

Facilities Management and Construction Center

Albuquerque, New Mexico 87103

000001

1 File: BET

! Category #: 1.30

Document Date: 3/01/92/

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PRELIMINARY ASSESSMENT

BUREAU OF INDIAN AFFAIRS

BETHEL, ALASKA

Prepared by llth Civil Engineering Operations Squadron

Operating Engineers 21885 2nd Street

EImendorf AFB AK 99506-4420

Interagency Agreement No. AG2E0000060

Final Report

March 1992

Prepared for

Bureau of Indian Affairs

Facilities Management and Construction Center

Albuquerque, New Mexico 87103

NOTICE

This report has been prepared for the Bureau of Indian Affairs by the USAF 11 Civil

Engineering Operations Squadron for the purpose of aiding in the evaluation of the site under the Environmental Protection Agency Hazardous Ranking System (HRS). The limited objectives of this report along with the evolving knowledge of site conditions and chemical effects on the environment and health, must be considered when evaluating this report. Facts learned subsequent to this report may become known that make it premature or inaccurate.

Acceptance of this report in performance of the contract under which it was prepared does not mean that the Bureau of Indian Affairs adopts the conclusions, recommendations, or other views expressed herein, which are those of the contractor only and do not necessarily reflect the official position of the Bureau of Indian Affairs.

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TABLE OF CONTENTS

INTRODUCTION

BACKGROUND

AUTHORITY

I

SCOPE

PURPOSE OF THE PRELIMINARY ASSESSMENT

PRELIMINARY ASSESSMENT

SH_ INVESTIGATION

METHODOLOGY

ENVIRONMENTAL SETTING

LOCATION

POPULATION

SITE DESCPdPrION

OPERATIONAL HISTORY AND WASTE CHARACTERISTICS

CLIMATE

DRAINAGE

SURFACE WATER

GEOLOGY

SOILS

PERMAFROST

GROUND WATER

CRITICAL HABITATS/ENDANGERED

OR THREATENED SPECIES

FOOD CHAIN

PAST REMEDIAL ACTIONS

PAGE

5 ",0

FIELD INVESTIGATION

WALK THROUGH SURVEY

SITE I

SITE 2

SITE 3

TERRAIN CONDUCTIVITY SURVEY

TEST BORINGS

SOILS FIELD SAMPLING PROCEDURE

MONITOR WELLS

MONITOR WELL CONSTRUCTION

MONITOR WELL SAMPLING

FINDINGS

CHEMICALS

CONSOLIDATING CHEMICALS

PETROLEUM RELATED CONTAMINATION

MIGRATION PATHWAYS

LANDFILL

SEWAGE LAGOON

CHEMICAL ANALYSIS

FIELD TESTING

EPA METHOD 3810; HEADSPACE GAS

SUMMARY OF LABORATORY ANALYSIS

S1TE 1 AND 2

EPA METHOD 8240

EPA METHOD ,418.1

EPA METHOD 8080

ii

__3' 60

EPA METHOD 8020

TCLP METALS, EPA METHOD 1311/7000

EPA METHOD 8015 (MODIFIED)

SITE 3

EPA METHOD 8240

EPA METHOD 418.1

EPA METHOD 8080

TCLP METALS, EPA METHOD 1311/7000

EPA METHOD 8015 (MODII,'IED)

EPA METHOD 3810, FIELD TESTING GC

SUMMARY OF PROCEDURES

AND PROCEDURAL RESULTS

RECOMMENDATIONS

SUMMARY OF LABORATORY RESULTS

REFERENCES

37-50

51-52 iii

J j

P

LIST OF FIGURES

METHODOLOGY FLOW CHART

VICINITY MAP

SITE MAP

DRAINAGE MAP

PERMAFROST MAP OF ALASKA

1989 SITE CONTAMINATION SKETCH

MAP SHOWING SITES INVESTIGATED

TEST BORING/MONITORING WELL LOCATION MAP

SITES 1 AND 2

TEST BORING/MONITORING WELL LOCATION MAP

SITE 3

PAGE

iv

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TABLE 1

TABLE2

TABLE3

TABLE 4

TABLE5

TABLE6

TABLE7

TABLE8

TABLE9

, LIST OF TABLES

POPULATION DISTANCE RINGS

STREAMFLOW DATA

WATER WELL DISTANCE RINGS

COMMERCIAL FISHING STATISTICS

SUBSIb-rENCE FISHING STATISTICS

ADEC MATRIX SCORES

SITE 1 & 2 SAMPLES ABOVE MCL

SITE 3 SAMPLES ABOVE MCL

SUMMARY OF ANALYTICAL DATA

26-28

37-50

LIST OF APPENDICES

APPENDIX A

APPENDIX B

APPENDIX C

APPENDIX D

APPENDIX E

APPENDIX F

APPENDIX G

APPENDIX H

TEST BORING/MONITORING WELL LOGS

AREA WATER WELL DATA

ANALYTICAL DATA

CHAIN-OF-CUSTODY FORMS

CLIMATIC DATA

CHEMICAL INVENTORY DATA

WELL DEVELOPMENT DATA

TERRAIN CONDUCTIVITY SURVEY

vi

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INTRODUCTION

The USAF llth Civil Engineering Operations Squadron under contract with the Bureau of Indian Affairs (BIA) conducted a Preliminary Site

Assessment at the abandoned BIA Operations Support and Maintenance

Facility located in Bethel, Alaska. The objective of the Preliminary

Assessment (PA) was to determine if past waste management practices at the site posed a significant threat to health and the environment.

The findings indicate the health and environmental risk at the BIA site are low. Areas of petroleum, insecticide, and polychlorinated biphenyls (PCB's) contamination were found, however most were quite small and limited in extent. This document presents the data collected to support these findings.

BACKGROUND: In September of 1990, the llth civil Engineering

Operations Squadron conducted a Remedial Investigation and Feasibility

Study (RI/FS) of the Radio Relay Station located about 2,500 feet south west of building 413. At the end of the RI/FS field program, the Air Force agreed to conduct a limited subsurface investigation at the BIA site in an attempt to document and provide analytical evidence of site contamination. Consequently, the scope of the investigation was increased to include a partial Site Investigation (SI) along with a PA.

AUTHORITY: The llth Civil Engineering Operations Squadron was issued a "Notice to Proceed" through the Interagency Agreement No.

AG2E0000060, dated September 16, 1991.

SCOPE: The scope of the PA, involved the following major task:

a. The acquisition of available geological, hydrological, meteorological, land use, and critical habitat data from various

Federal, State and local agencies

b. The acquisition of pertinent information related to installation boundaries, history, materials use and hazardous waste generation and disposal practices at the installation

c. The acquisition of maps, aerial photos, available topography, drainage patterns, potable well locations, population counts, and other PA data requirements

d. An on site visit to visually locate possible hazards and contaminated sites

e. Collect representative samples of the soils and/or water from the targeted sites for analysis in order to verify the presence or absence of hazardous materials

f. Review and analyze all information obtained

e. Th_ preparation of a report to include recommendations for further actions, if warranted

PURPOSE OF THE PRELIMINARY ASSESSMENT: The Environmental Protection

Agency (EPA) uses a structured program to determine appropriate response for Superfund sites. The site assessment phase identifies sites for the National Priority Listing (NPL). The remedial phase determines the extent of contamination and implements cleanup remedies. The primary objective of the site assessment is to obtain the data necessary to identify the highest priority sites posing threats to human health and the environment.

The site assessment phase begins with site discovery, or by notification to EPA of possible releases of hazardous substances.

Sites are discovered by Regional EPA offices, State agencies, and citizens who file a PA petition. Section 105(d) of the Superfund

Amendment and Reauthorization Act (SARA) of 1986 established the PA petition as a formal mechanism for citizens to report potential hazardous waste sites. Publication 9200.5-301FS, "Preliminary

Assessment Petition," published by EPA's Office of Emergency and

Remedial Response describes the process. Once discovered, sites are entered into the Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS). EPA's computerized inventory of potential hazardous waste sites. EPA then evaluates the potential for a release of hazardous substance from a site during two investigative steps.

PRELIMINARY ASSESSMENT: A PA is a limited-scope investigation preformed by states or EPA on every CERCLIS site. Investigators collect readily available information and conduct a site and environs reconnaissance. Information includes local geological, hydrological, and meteorological conditions that may effect migration of contaminants, and local land use that could effect the potential for exposure to contaminants, and the ecological settings that indicate environmentally sensitive habits or evidence of environmental stress.

The PA is designed to distinguish between sites that pose little or no threat to human health and the environment and sites that require further investigation. The PA also identifies sites requiring assessment for possible emergency response action.

SITE INVESTIGATION: Site investigators typically collect waste and environmental samples to determine the substance present at a site and whether they are being released to the environment. The objective of the SI is to identify which sites have a high probability of qualifying for the NPL. A second objective is to identify sites posing immediate health or environmental threats which require emergency response.

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METHODOLOGY: A flow chart of the Preliminary Assessment Methodology is presented in Figure 1. This Preliminary Assessment methodology ensures a comprehensive collection and review of pertinent site specific information, and is used in the identification and assessment of potentially contaminated hazardous waste spill/disposal sites.

Sites that showed signs of contamination and sites that were suspected of contamination were investigated, however, other areas of subsurface contamination could exist.

ENVIRONMENTAL SETTING

LOCATION: The Bethel BIA site is located in southwestern Alaska approximately 3 miles west of the village of Bethel, Alaska, and the

Kuskokwim River, (Figure 2). Access to the BIA is by a road leading west from the village. The site's geographic coordinates were determined using the linear interpolation method described in the

USEPA publication, Guidance Document for Performinu Preliminary

Assessments Under CERCLA. For convenience, the northwest corner of the composite building (Bldg 413) was selected as the site reference point. The base map for the calculations was the USGS 1:25,000

Topographic Map of Bethel, Alaska. The coordinates were calculated to be:

LONGITUDE i_i O 52' 45.8"

LATITUDE 60 v 40' 16.1"

The legal description of the 125 acre tract is.

Sl/2 NWl/4 NWl/4, SWl/4 El/2 SEI/4 NEI/4 NEI/4, El/2 SEI/4 SEI/4 NEI/4, El/2 SEI/4 NEI/4 SEI/4, NWI/4, NWI/4 SWI/4, Section 14, El/2 NEI/4 SEI/4 NEI/4, El/2 NEI/4 NEI/4 SEI/4, Section 15, Township 8 North, Range 72 West, Seward Meridian, Alaska.

Containing an easement right-of-way 50 feet wide beginning at the

Northeast corner and bearing North 57 degrees 46 minutes and 23 seconds East, a distance of 1,500 feet.

POPULATION: The city of Bethel is located approximately 3.6 miles by road from the BIA site and has a population of 4,674. Seventy-seven percent of the residents live greater than 2 miles from the site. The remaining 23 percent are within 1-2 miles from the site boundary. The population within 4 miles of the site was calculated using 1:100 scale aerial photographs to count houses. The method assumes an average of

3.45 persons per dwelling unit (Darbyshire, 1980). The population in

EPA distance ring formats were calculated as follows:

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PRELIMINARY ASSESSMENT METHODOLOGY FLOW CHART

BUREAU OF INDIAN AFFAIRS - BETHEL, ALASKA

DELETEsiT_s I

COMPLETE LIST OF

SITES / LOCATIONS

I

EVALUATION OF PAST

OPERATIONS AT LISTED

SITES

POTENTIAL FOR

CONTAMINATION

POTENTIAL FOR lMIGRATION

POTENTIAL FOR OTHER

ENVIRONMENTAL

CONCERNS

REFER TO BIA I

IENVIRONMENTAL

PROGRAM

LIST OF SITES ]TO BE RATED

CONSOLIDATE

SPECIFIC SITE

DATA

BIA REVIEW OF

REPORT

RECOMMENDATIONS

NO I I INITIATE

FURTHER SI/RI/FS

ACTION

FIGURE 1

3 14

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,i • ]

I-

4_ t',, I.U I,-

I.U

It.

--- CO

3 15

TABLE 1

POPULATION DISTANCE RINGS

RADIUS FROM BIA SITE NUMBER OF PEOPLE

0 - 1/4 mile: 0

1/4 - 1/2 mile:

1/2 - 1 mile:

1 - 2 miles: 1,076

2 - 3 miles: 2,939

3 - 4 miles: 659

TOTAL 4,674

SITE DESCRIPTION: The site is approximately 180 feet above mean sea level and is slightly elevated from the surrounding terrain. The site slopes 2 percent to the south and 2 percent to the east. Slopes on the north and west sides average 1 percent. Road access to the site is restricted by a locked gate, otherwise, access is unrestricted to foot traffic, off-road, and all-terrain vehicles. The 125 acre parcel is rectangular in shape and consists of several concrete and steel buildings, (Figure 3). Associated with these buildings are three large 400,000 gallon above ground fuel storage tanks (AGFT) which are half full of fuel, one medium i0,000 AGFT, eleven small 300 to 500 gallon AGFTs with various amounts of fuel, a sewage lagoon, three pit areas used as a borrow source and drum storage area.

OPERATIONAL HISTORY AND WASTE CHARACTERISTICS: In 1957 the military constructed the installation as part of the White Alice Communication

System (WACS). The WACS consisted of the Aircraft Control and Warning

(AC&W) System and the Distant Early Warning (DEW-line) System. The system was activated in 1958 and deactivated in 1979. In 1963 the BIA acquired a 125 acre parcel from the Air Force which included the old

Air Force barracks, several outlying buildings, fuel tanks, water treatment plant, and sewage lagoon. In 1964 the BIA remodeled the barracks to serve as family living quarters, and a staging and operations support and maintenance facility. The BIA operated the site until 1990, when the last personnel left the site.

The facility is mostly self-contained. Electricity was supplied from the City of Bethel. Backup power was supplied from 3 Detroit Diesel generators, which are still on-site. Waste water was discharged from building 413 into a sewage treatment lagoon located approximately 375 feet north of building 413. Water was supplied from wells located

-, :3 I____6__

3 17 on-site. An "old" abandoned well is located about 1,540 feet south east of building 416. The most recent "new" water well is located 50 feet south of building 416.

Solid waste was trucked to a landfill located about 4,500 feet north west of building 413. Pertoleum-Oil-Lubricants (POL) waste and asphalt products were drummed and stored at the sand pits. During the

1989-1990 field season the Air Force razed the Radar Radio Station located about 2,500 feet south west of building 413. As part of the demolition, approximately 700 drums of asphalt and oil products were retrograded to Elmendorf AFB for disposal.

Past waste management practices at the BIA site and similar military sites throughout Alaska have shown the potential to generate hazardous materials. Activities common to all WACS Stations which generate hazardous waste include the operation of communication equipment, power generation, and equipment maintenance. Materials commonly used at such installations include:

JP-4 sludge

Diesel fuel (DFA)

Gasoline

Aviation Fuel

Transmission fluid

Engine oil

Hydraulic fluid

Sky-drol (hydraulic fluid used 20 years ago containing PCBs)

Calcium hypochlorite

Mercury used in manometers (pressure gauges)

Polychlorinated biphenyls (PCBs) used in transformer, capacitors, etc.

Asbestos (piping insulation, cement asbestos board)

Runway dye marker

Waste oils

I-i-i Trichloroethane

Mercury vapor rectifier tubes

Lead base paints

Paint thinners

Radioactive tubes

Batteries

Valvolium (solvent)

Sulfuric acid

Dynamite

Cathode ray tube screens

RF interference filters (filters containing small amounts of

PCBs)

All of the contamination found at the facility is believed to be a result of spills and leaks which may have been caused by overfills and equipment failures. There is no evidence of subsurface contamination associated with controlled waste management practices.

CLIMATE: Bethel is characterized by a cold maritime climate. High humidity, considerable cloudiness, frequent fog, and multiple periods of light rain and snow showers are typical. The wettest season is generally middle and late summer. Summer temperature during June, July, and August average 52.8 degrees F. Winter temperatures during

December, January, and February average 6.6 degrees F. The mean annual precipitation is 18.4 inches (Appendix E). This figure is based on a thirty-eight year average between 1931 - 1969.

DRAINAGE: Runoff originating from the BIA site is directed either to the southeast eventually reaching the large bog, or north into a small stream (Figure 4). The BIA site is not susceptible to flooding and is beyond the floodplain of the Kuskokwim River and it's tributaries. Shallow seasonal groundwater in the active layer may flow southeast toward the sand pits, or north toward the streams, depending on the location with respect to the top of the hill.

Recharge to the active zone is limited by low average annual precipitation. Flow is relatively slow because of the low hydraulic conductivity of the fine-grained soils, and the seasonal soil freezing.

SURFACE WATER: The dominate surface water feature in the Bethel area is the Kuskokwim River. The river flows in a broad meandering pattern that has created and intricate network of sloughs, cutoffs, and ponds.

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A/G

PUMP

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HOUSE NO I

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ALICE SITE

DRAINAGE MAP

BIA SITE

BETHEL ALASKA

,3 20

Surface water resources at the site include ponds, streams, wetlands, and bogs. The pond water is a year round brown color, referred to as "tundra tea." The brown color is reportedly due to naturally occurring tanni_in the water draining the tundra. Two small streams flow northwest from the site. One stream with its headwaters in section 15 flows in a clearly defined channel for approximately one mile and into a enclosed depression containing a small pond. Outflow from the pond is by subterranean drainage through a thawed zone (taliks) in the permafrost. The second stream, originating as a small lake, in section 14 follows a circuitous route from the site to just east of the town where it empties into the Kuskokwim River. The stream is connected to many lakes and ponds through a maze of sluggish waterways and channels. All surface water bodies within 2 miles of the BIA site are shown on Figure 2. Streamflow estimates for the two streams are shown below.

Drainage Basin

TABLE 2

STREAMFLOW DATA

Precipitation Drainage Area

(INIYR) (MI-)I(ACRES)

Mean Annual

Streamflow ofs

SECTION 15 CRK.

Entire length

SECTION 14 CRK.

From headwaters 1.5 mi.

to confluence with small unnamed stream.

18.4 0.41/ 262 0.47

18.4 0.43/ 274 0.49

The above estimates are based on a multiple linear regression equation using precipitation and drainage area as independent variables (Parks, 1985).

GEOLOGY: The Bethel BIA site is underlain by Quaternary silt deposits of the Yukon-Kuskokwim delta, which consist chiefly of light to dark grey silt and sandy silt containing abundant permafrost, organic muck, which become sandier with depth and locally contain pebbles and wood fragments (HMTC, 1989). Organic material, including wood chips and bark, suggest that these are freshwater estuarine deposits. These deposits apparently thicken westward, and at Bethel have a minimum thickness of 450 feet. The silt deposits may also include eolian and marine members in some areas. Silt underliesmuch of the Yukon-Kuskokwim delta, where it forms a wide plain at a general altitude of i0 to 150 feet above sea level. The best exposures of these deposits are cut-bank outcrops along major rivers (HMTC, 1989).

Approximately 3.3 miles east of the BIA site is the Kuskokwim River ii

3 2:1 and its Pleistocene deposits of flood plain and low terrace alluvium.

These deposits consist mainly of mud, silt, sand, gravel, boulders, and considerable organic matter (HMTC 1989). The alluvium ranges from

230 to 360 feet in thickness. These deposits are related to glacial advances from the nearby Alaska Range. In Illinoian time, considerable deposition of alluvium occurred which were later eroded and dissected by streams and rivers in Sangamon time. In Wisconsinan time, deposits of fluvial origin were predominant in this area (Pewe, 1975).

SOILS: Soils at the site and vicinity are considered unsuitable for agricultural production because of poor soil structure, poor soil drainage, frozen or near frozen conditions, and a relatively short growing season. On-site soils may be acidic and have naturally high organic content, as is typical of arctic tundra soils. The adjacent tundra is an environmentally sensitively area. It is generally treeless, and covered with about 1 foot of matted vegetation. The vegetation is not resilient to surface activities such as traffic or construction. Traffic, construction, or excavation destroys the vegetative cover, exposes the soil to erosion and permafrost thawing, and potentially creates thermokarst which do not naturally heal, leaving long-term surficial scars. According to the United States

Department of Agriculture Soil Conservation Service, the site is underlain by the Kuskokwim - Kwethluk Complex. The complex is intertwined such that mapping them separately is not feasible. The

Kwethluk soils occur in small areas from 3 to I0 acres on low knolls, convex slopes bordering drainage ways, and areas between the slopes and knolls of the Kwethluk soils. Permeability of both t_e Kuskokwim and the Kwethluk solls is slow (4.24 x i0 _ to 1.41 x 10-"cm/sec) and the erosion hazard is none to slight. In the field, the two soils can be identified by their differences in slope, vegetation, drainage, and texture. The Kuskokwim soils have a thick surface mat and a large proportion of sedges and sphagnum moss; the water table is generally near the surface, and the texture is silty in the upper part. The

Kwethluk soils have a thin mat with polytrichum moss and low growing shrubs; the water table is several feet deep by mid-summer; and the texture is sandy throughout. A typical profile of the Kuskokwim soil consist of a peaty mat of approximately 12 inches over dark gray silt loam mottled with dark brown silt loam in the upper few inches, changing to gray silt loam with sand lenses to depths of 60 inches.

The soil has a moderate thin platy structure and is friable and very strongly acid. A typical Kwethluk soil profile consist of a thin mat of organic materials and dark brown to brown sandy surface horizons, changing to olive gray to olive with depth.

PERMA%FROST: Alaska's generally cold climate regime results in a broad distribution of permanently frozen ground termed permafrost.

Permafrost is defined in the Glossary of Geology (American Geological

Institute 1966) as;

"any soil, subsoil, or other surficial soil occurring in the arctic or subarctic regions at a variable depth beneath the earth's surface in which a temperature below freezing has existed continuously for a long time (from 2 years to thousands of years). This definition is based exclusively on temperature and disregards the texture, degree of compaction, water content, and lithologic character of the material".

Permafrost occurs in both unconsolidated sediments and bedrock, and its distribution includes most of the state, with exception of the Pacific Coastal area. The distribution of Alaska's permafrost areas are shown on Figure 5.

The local distribution of permafrost in the Bethel area is determined largely by surface insulation and subsurface drainage.

In general it may be said that permafrost lies at most shallow depths in areas mantled with peat, organic silt, or a dense mat of living vegetation, and it lies at greatest depths beneath bare soil.

Permafrost is absent or lies at great depths beneath lakes and ponds. Bodies of standing water readily absorb the sun's heat during the summer; agitation caused by waves carries the heated water to the bottom and sides of the shallow lakes and ponds. Heat loss during the winter is largely absorbed in converting the water in the ponds into surface ice. Heat is distributed through earth materials more rapidly by circulating water than by direct conduction. Thus, active circulation of water, both at the surface and at depth, promotes thawing of permafrost, and retards the formation of permafrost. Owing to more active water movements, streams generally are underlain by deeper and wider unfrozen areas than are lakes, and coarse, permeable sand or gravel is more likely to be free of permafrost than is impermeable silt (Hopkins, 1655).

As predicted, permafrost at the BIA site was shallowest (6') beneath the tundra vegetation near the sewage lagoon, and was found at depth between 12 and 32 feet in areas with mineral surface soils.

Permafrost has a significant impact on both surface and ground water flow in the area. Permafrost can act as an impermeable barrier to the movement of groundwater, because pore spaces are ice-filled in.

the zone of saturation. Recharge and discharge are limited to unfrozen channels in the permafrost zone. Permafrost restricts the downward percolation of water and increases runoff, enhancing, the creation of lakes and swamps.

GROUNDWATER: Ground water in Bethel is obtained from the flood plain and low-terrace alluvium deposits of the Kuskokwim River in permafrost-free areas close to the river, and from deep sands beneath the permafrost. The flood plain and low terraces are bounded on the west by a terrace escarpment that separates these deposits from an older portion of the coastal lowlands. Frozen

166 ° 158 ° 150 ° 142 °

60 °

166 °

/ I I t

I

UOUS I

o ° o o oO _0 0 _'_'_ 0 | 0 ol o o o o o o o o o

DISCONTINUOUS PERMAFROST

. _ NO PERMAFROST

158 °

EXPLANATION

Limit of WlscOnSlRan glacial ice

_ ° _Area closed- Area ofopan- Area of system plngo$ systsm plngos marine Dlngos

Permafrost zone boundaries

100 200 MILES......... I I

I ........ '1 I

0 100 200 KILOMETRES

180 ° 142 °

FIGURE 5

,J' 24 ground in wells less than 20 feet deep occurs in flood plain and low terrace alluvium on an island in the Kuskokwim River and near Hangar

Lake. In the village, between the creek and the terrace escarpment, these deposits are frozen to depths of 337 feet. At the site water well, permafrost was reported to extend from near the surface to a depth of 603 feet (COE, 1963). In wells that penetrate the permafrost the ground water is under considerable hydrostatic pressure. It rises in wells near Bethel, to a static water level approximately equal to that of the kuskokwim River, and its level fluctuates with tides and stages of the river. The water below the permafrost at Bethel is potable (Williams 1980). Available water well data from the village wells, including the drill logs for the site well is included in Appendix B). Potable water supplied to the majority of the Bethel population is pumped from a manned pumphouse located near the center of town. The well was put into operation about 1970, and the water is pumped into water transfer trucks, delivered to the Bethel population and pumped into water holding tanks inside or adjacent to the houses. There are no known ground water uses for farming, aquaculture, or for major recreation areas.

Ground water is used for food preparation at local restaurants and fish processing plants. The number of water wells and their distance from the BIA site are listed below.

TABLE 3

WATER WELL DISTANCE RINGS

DISTANCE NUMBER OF WELLS REMARKS

0 - 0.25 MILE 1 ABANDONED

0.25 0.5 MILE 2 ABANDONED

0.5 - 1 MILE 0

1 - 2 MILE 2 AIRPORT WELLS

2 - 3 MILE 0

3 - 4 MILE 5 VILLAGE WELLS

CRITICAL HABITATS/ENDANGERED OR THREATENED SPECIES: The BIA site is located within an area which provides suitable habitat to a wide range of birds and small game. According to the U.S. Fish and

Wildlife Service, Alaska Division, there are no endangered or threatened species, and federally or state designated critical habitats or wilderness areas within a 1-mile radius of the BIA site.

The Bethel area has not been mapped by the National Wetland

Inventory. However, "virtually the entire area qualifies as wetlands and, therefore, comes under U.S. Army Corps of Engineers permitting jurisdiction" (Newman, 1982).

3 25, FOOD CHAIN: Information regarding the human food chain productions from the Bethel area was provided by Kim Francisco, Bethel area manager for the Alaska State Fish and Game Division.

TABLE •

COMMERCIAL FISHING HARVEST STATISTICS FOR 1991:

SPECIES NO. HARVESTED AVERAGE LBS/FISH

CHINOOK 48,170 16.8

SOCKEYE 202,441 7.1

COHO 556,818 7.1

PINK 522 3.5

CHUM 501,692 7.1

TOTAL 1,309,643

TABLE 5

TOTAL LBS

809,256

1,437,331

3,953,•07

1,827

3,562,013

9,763,834

SUBSISTENCE FISHING HARVEST STATISTICS FOR 1991:

SPECIES NO. HARVESTED AVERAGE LBS/FISH TOTAL LBS

CHINOOK 85,1•3 16.8 1,430,•02

SOCKEYE 51,821 7.1 367,929

COHO 53,478 7.1 379,693

PINK ...... 3.5

CHUM 93,037 7.1 660,562

TOTAL 283,479 2,838,586

KILBUCK CARIBOU HERD (GAME MANAGEMENT UNIT 18): This Caribou herd has been spotted 40 miles to the east of the BIA site.

MAINLAND MUSK-OX HERD (GAME MANAGEMENT UNIT 18}: This Musk-ox herd has been spotted 20 miles to the west of the BIA site.

PTARMIGAN: Local residents hunt this grouse on a small scale on the

BIA access road.

BLUE BERRIES: Are hand picked by local residents on the tundra surrounding the BIA site.

PAST REMEDIAL ACTIONS: During 1989 and 1990 the Air Force demolished the neighboring Radio Relay Station. At the request of the local residents, one radio tower was left as a navigational aid for local pilots. At the time of the demolition, approximately 700 drums of POL related liquids and asphalt were shipped off the BIA property for disposal at the Defense Reutilization and Marketing

Office, Elmendorf AFB, Alaska. Figure 6 is a sketch of the site showing the areas of drum storage and visible contamination as they existed in 1989, before the demolition.

FIELD INVESTIGATION

A field investigation was conducted during August through December of 5991 to help in defining areas of hazardous contamination associated with the BIA site. The investigation consisted of a visual inventory, a terrain conductivity survey in the sand pits, test borings, and monitor well installations.

WALK THROUGH SURVEY: To help locate and define obvious or suspected areas of contamination, the buildings and grounds within the property boundaries were visually inspected to identify any existing or potential problems. Priority was given to the identification of possible sources of contamination that may have occurred over the operational history of the site. The information collected helped to define the extent of the problems and where to concentrate the work effort. For convenience, The BIA property was sectioned into three distinct sites for investigation, (Figure 7).

Slte 1: This site includes building 413, and eleven 300 to 500 gallon small above ground fuel storage day tanks located adjacent to the buildings, and a 130 foot by 130 foot sewage lagoon located about 375 feet north of building 413. A number of chemical hazards, including household chemicals, petroleum products, water purification chemicals, etc., were found in the buildings.

Petroleum stained soils are present under the fill spouts at these small day tanks. No containment structures are found around these tanks. Waste water was discharged from building 413 into an unlined earthen treatment lagoon. At the time of the survey, the integrity of the lagoon was intact and showed no evidence of imminent failure.

site 2: This site includes three large 400,000 gallon above ground tanks north of building 413. Each tank has a unlined earthen containment dike. No visible signs of contamination were present inside the dikes or in the immediate vicinity outside the dikes. A fuel transfer station located near the center of the three large tanks has four 2-inch fuel transfer lines that converge and enter the station on the west, down-gradient side. POL staining and fuel odor was very evident at that location. The opposite, eastern side l

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FIGURE 6

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3' 29 has heavy POL staining where tanker trucks fill and transfer fuel.

Staining is minimal at the northern and southern sides. POL containment structures are not present at the fuel transfer station.

A medium i0,000 gallon above ground tank is located about 360 feet north east of building 413. Fuel stained soils and a strong odor were evident. No spill containment structures are present.

Site S: This site includes a drum storage area, and the sand pits designated pits 1,2, and 3. The drum storage area and pit 3 are the areas shown as site contamination in Figure 6. The drum storage area includes an area about 250 feet south east of building 413 where about 50 percent of the drummed asphalt and POL products were stored prior to disposal (Figure 6). No liners or containment structures were found in these areas. This area now exhibits POL surface staining in an area about 40 feet in diameter and also contains a collapsed wooden building, engine parts, sheet metal, old wooden crates, dog houses, an empty 4,000 gallon fuel tank, and discarded electrical wire.

Pit 3 at one time appears to have been used as a borrow source.

Inside the pit is an area of POL stained soil and asphalt. The source of the contamination is from the leaking drums previously stored in this area. The area measures about 150 feet by 60 feet and is located about 900 feet south east of building 413. No containment structures were used at this site.

Pit 2 is located approximately 1,700 feet south of building 413 and was used primarily as a borrow source. No visible evidence of contamination were found.

Pit 1 is located about 2,100 feet south of building 413 and was also used primarily as a borrow source. Pit 1 contained a few small items such as tin cans, old rusted barrels, broken 12 and 6 volt auto batteries, auto parts, lumber, and rotten cloth and canvas.

TERRAIN CONDUCTIVITY SURVEY: A terrain conductivity survey was conducted at the three sand pits between 18-19 September 1991, using a Geonics EM-31DL Terrain Conductivity Meter. Historical records of the site indicate that at least one sand pits was used as a waste storage area. The primary objective for the survey was to identify areas where drums, tanks,etc., may be buried. A secondary objective was to assist in choosing the optimal drilling locations for soil borings and monitoring wells.

The survey lines were established using a cloth tape and a right angle prism. Survey lines were tied to existing structures, building corners, and road intersections. Distances along survey lines are taped distances rather than true horizontal distances.

The level of accuracy achieved was considered sufficient for the purpose of the survey. The results of the conductivity survey are

2O presented in Appendix H as a map of apparent conductivity for each pit. The shaded areas on the map indicate areas where we believe buried debris may be located.

TEST BORINGS: Forty three test borings were drilled with a CME-55 track mounted drill. Additionally, 5 hand dug test pits were excavated in areas of visible surface contamination, and in areas suspected of having contaminated soils. The test boring and monitoring well logs, describing the soils, depth to ground water, permafrost (if encountered), field organic vapor readings, and field observations are included in Appendix A. The test boring and monitoring well locations are shown on Figures 8 and 9. The test borings were located in the field with a cloth tape using existing building, tanks etc. as reference. Without the benefit of an accurate survey the test boring locations should be considered approximate.

SOILS FIELD SAMPLING PROCEDURE: Seventy-seven soil sample_were collected for laboratory analysis. Standard sample collection and transfer (i.e. chain-of-custody) were followed. Briefly, the procedures for collecting soil samples were as follows: The eight-inch hollow stem augers, center rods, and samplers were steam cleaned between each test boring. The down-hole sampler was decontaminated before each use using a detergent wash, followed by a distilled water, methanol, and hexane rinse. Sample collection consisted of drilling to the desired depth, pulling the center rods and attaching a 24 inch long 3 inch I.D. split spoon sampler to the bottom of the center rods. The rods were lowered down the hole and a 300 pound drive hammer was attached to the top center rod. The split spoon was driven 24 inches and the number of blow counts per every 6 inches of penetration were recorded. The center rods and sampler were withdrawn and the split spoon was removed. The split spoon was immediately opened and a portion of the soils were scooped out with a sterile spoon and placed into a pre-labeled amber glass jar with a Teflon lined top. The containerized sample was placed into a cooler. The cooler provides protection from breakage, direct sunlight and can helps maintain the samples at 4 degrees C during transport to the laboratory. A second duplicate sample was placed into a heavy duty Zip-loc bag and warmed to a temperature approximately 20 degrees C. The Zip-loc bag was opened just enough to insert the probe of an organic vapor monitor. By warming the sample, organic compounds which are readily volatilized can be detected by the instrument. The resulting values represent the total organic vapor concentration of parts per million.

MONITOR WELLS: Eleven of the test boring were completed as ground water monitoring wells. The wells were placed in areas of surface contamination, in areas down gradient of the surface contamination, and in areas suspected of contamination.

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MONITOR WELL CONSTRUCTION: Upon completion of a test boring the center rods are pulled for the last time and a steam cleaned 2 inch

I.D. schedule 40 pvc casing and screen is assembled and lowered down the center of the augers. The well screen is placed to intersect the water level atthe center of the screen slots. Clean No.16 slllca sand is _ored down the annular space between the augers and the well screen as the augers are pulled out of the ground. The sand is 6ored to 1 foot above the well screen. Generally, 1 to 2 feet of No.30 silica sand is added on top of the No.16 sand, followed by 1 foot of bentonite chips. Clean fill is placed to within 1 foot of the surface. Bentonite fills the remaining annular space. An aluminum protective casing with locking top is placed over the monitor well and a 2 foot by 2 foot concrete pad is poured around the casing. The specific details of monitoring well construction are provided on the boring logs.

MONITOR WELL SAMPLING: The monitor well was left to stabilize for a

24 hour period. Prior to collecting a water sample, the static water level was measured using an oil/water interface probe. Most petroleum products are light non-aqueous phase liquids in water. If present in sufficient quantities, petroleum occurs as a separate layer floating on the water surface, in a properly constructed well.

None of the monitor wells at the BIA site exhibited a POL layer.

The wells were then hand bailed until the temperature, conductivity, and pH stabilized. Generally, this condition was reached after three to five well casing volumes were removed from the well. The well development and purge data for the wells is shown in Appendix

G. The samples were then preserved and transferred to the laboratory using the method described in the soil sampling procedures.

FINDINGS

CHEMICALS: Typical household, office, cleaning, and maintenance chemicals were found in the buildings. Appendix F presents a listing of the chemicals found. These sources of possible contamination are contained inside of the buildings.

CONSOLIDATING CHEMICALS: The chemical products inventoried in building 413 were placed into four separate rooms according to their hazardous classification. The caustics and oxidizers were placed in the dirt floored room south of the tire room. The flammables were placed in the concrete floored tire room. The spontaneous combustibles (steel wool) was placed in the main garage. The iodoform was placed in the small bathroom next to the generator switchboard room.

The Water Treatment Plant (WTP) contains about 670 pounds of calcium hypochlorite. Care should be taken not to wet this chemical with any P0L product as this could produce a flammable reaction. The WTP

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,,3' 3'4 also contains about 100 pounds of potassium permanganate. Care should be taken not to wet this chemical with any POL product as this could result in an explosion. With the exception of building

413, chemicals inventoried in the remaining buildings were left in place. At the time of the survey, all doors and windows were either locked or boarded shut.

PETROLEUM RELATED CONTAMINATION: One hundred and six samples were collected from forty-three test borings (TB) and monitor wells (MW).

Most of the samples are shown to be relatively free of contamination. Samples were taken from areas suspected of the highest contamination or in areas where fuel staining was most evident. Some show excessive hydrocarbons, but these were taken at fuel tanker areas near discharge spouts and in areas of visible surface stains. Most of the spill areas tend to be quite small in area and volume and do not extend vertically below the top of permafrost. Two borings indicated POL contamination to permafrost.

TB-4 encountered permafrost at 14 feet, while TB-12 encountered permafrost at 12 feet. Pit 3 and the drum storage area have large areas of visibly contaminated soils.

_.large visibly stained area in pit 3 covers approximately 9000 Five test boring/monitoring wells were drilled in this area.

TPH and benzene contamination was found in most of the soil samples collected. Ground water samples collected from these wells showed

TPH and benzene contamination up to 59 ppm and 1.36 ppm, respectively. Trace levels of l,l,2,2-tetrachlorethane and chlorobenzene were detected in the soil samples from MWRRS-58.

Twelve ppm of Aroclor 1260, a type of PCB, were reported in the ground water sample from that well.

Five test borings and one monitoring well were drilled in a contaminated site at the drum storage area. TPH was detected in all borings, the maximum concentrations reported at less than or equal to i00 ppm. The ground water sample from MWRRS-63 had 3.98 ppm TPH and 0.082 ppm PCB's.

The Alaska Department of Environmental Conservation (ADEC) has published cleanup guidelines for non-underground storage tanks (UST) soil contamination. The cleanup levels are not regulations and are for guidance purposes only. The may be modified at the discretion of the regulatory agencies, depending on site-specific considerations. The ADEC has established a matrix scoring system to determine cleanup levels. The basic purpose of the matrix scoring is to ensure that ground water does not become impacted due to contaminate migration from the zone of contamination. The matrix score considers petroleum type, depth to ground water, precipitation, soil type, potential receptors, and the volume of contaminated soil in scoring a site. The higher the matrix score the more stringent the cleanup level. Since soil contamination is

3 3-5,3 close to the water table in some areas, and there is analytical evidence of ground water contamination at pit 3 and the drum storage area, the soil may need to be cleaned up to background levels or to the lowest practical and feasible level. Using the ADEC scoring matrix, the contaminated sites which may require some sort of remedial action are shown on Table 6.

TABLE 6

ALASKA DEPARTMENT ENVIRONMENTAL CONSERVATION

NON-UST SOIL CLEANUP LEVELS

MATRIX SCORING

CONTAMINATED

SITE

TB-15

TB-12

TB-7

TB-II

TB-17

MATRIX

SCORE

MAJOR FACTORS

DETERMINING

SCORE

EPH contamination to at least 5'. GW <5' from cont. soil. Cleanup level

200 ppm

High BTEX to 6.5' prob.

deeper. GW <5' from cont.

soil. Cleanup level 200 ppm

High field PID and field

Headspace readings. GW i<5' from cont. soil.

Cleanup level 200 ppm

High TPH contamination to at least 5'. GW <5' from cont. soil. Cleanup level

200 ppm.

BTEX cont. to 5'. GW

<5' from cont. soil

Cleanup level 200 ppm

RECOMMENDED ACTION

REMARKS

Remove approximately

220 c.y. of cont. soil

Remove approximately

131 c.y. of cont. soil

May require removal of approx. 20 c.y. cont.

!soil.

Remove approximately 6 c.y. cont. soil.

Remove approximately

6 c.y. cont. soil

3q

3 O'

TABLE 6 (CONT.)

ALASKA DEPARTMENT ENVIRONMENTAL CONSERVATION

NON-UST SOIL CLEANUP LEVELS

MATRIX SCORING

CONTAMINATED

SITE

TB-9

TB-6

TB-2

TB-4

TB-16

MWRRS-58

MWRRS-63

RRS-65

RRS-66

RRS-67

RRS-68

RRS-69

MATRIX

SCORE

3O

MA ORFACTORS

DETERMINING

SCORE

Low levels BTXE & TPH to

5'. GW <5' from cont.

soil. Cleanup level 200 ppm.

High levels BTEX & TPH.

GW <5' from cont. soil.

Cleanup level 200 ppm

TPH cont. to 5'. GW < 5' from cont. soil. Cleanup level 200 ppm.

EPH cont. to about i0'.

GW <5' from cont. soil.

Cleanup level 200 ppm.

BTXE & TPH cont. to 5'.

GW 5-15' from cont. soil.

Cleanup level i000 ppm.

TPH soil cont. to about I

GW 5-15' from cont. soil.

Large volume cont. soils.

Cleanup level 200 ppm.

BTXE & TPH cont. to 22" at MW-63. GW <5" from cont. soils. Large volume of cont. soils. Cleanup level 200 ppm.

RECOMMENDED ACTION

REMARKS

Cleanup levels above cont.level. Remediation probably not required.

Remove approximately 42 c.y. of cont. soil

Cleanup levels above cont.level, remediation probably not required.

Remove approximately 13 c.y. of cont. soil.

Cleanup levels above cont.level, remediation probably not required.

Remove approximately

1900 c.y. cont. soil.

Remove approximately

900 c.y. of cont. soil.

TABLE 6 (CONT.)

ALASKA DEPARTMENT ENVIRONMENTAL CONSERVATION

NON-UST SOIL CLEANUP LEVELS

MATRIX SCORING

CONTAMINATED

SITE

RRS-56

RRS-48

RRS-49

RRSMW-54

RRS-47

RRS-51

MATRIX

SCORE

3O

MAJOR FACTORS

DETERMINING

SCORE

TPH cont to within 5' of GW. Cleanup level

200 ppm.

TPH cont. to 17". GW within 5' of cont. soil.

Cleanup level 200 ppm

THP cont. to 12'. GW within 5' of cont. soil.

Cleanup level 200 ppm.

THP cont. to 7'. GW within 5' of cont. soil.

Cleanup level 200 ppm.

RECOMMENDED ACTION

REMARKS

Remove approximately

32 c.y. of cont. soil

Remove approximately

62 c.y. of cont. soil.

Remove approximately

21 c.y. of cont. soil.

Remove approximately

25 c.y. of cont. soil.

The total volume of contaminated soil is estimated to be 3,378 cubic yards. Again, most of these sites are small in area and volume.

The estimated volumes of contaminated soils are based the data collected from generally a single test boring. The estimates tend to be conservative. The actual volumes of contaminated soil could be considerably smaller. The necessity for remedial action, and the extent of the cleanup required will ultimately be determined by the regulatory agencies.

MIGRATION PA_nwAYS: Based on the results of this investigation the vast majority of the contamination found on the site is the result of diesel fuel leaks and spills. The migration pathways for these contaminates from the BIA site are very limited. Diesel fuel is relatively insoluble in water. Furthermore, adsorption of diesel fuel constituents on organic soils can be significant. Thus, once fuel is spilled, especially on soils with high humic content such as the peats in Alaska tundra, migration is unlikely except where hydraulic gradients are sufficiently steep. Once infiltration has taken place, lateral migration is virtually negligible because of i ':0 3 38 the hydrophobic characteristics of petroleum compounds typical in diesel, and the adsorptive capacity of humic soils. Vertical migration in the BIA area is limited by shallow permafrost;

therefore, contamination of the drinking water aquifer is not a major problem. Because of the low volatility of diesel fuel, particularly after many years of weathering, air transport of hazardous substances from the spill is not a significant concern.

Because diesel fuel is a complex mixture of hydrocarbons, it is speculative to discuss the process contributing to its fate over time. Biodegradation and chemical transformations, as well as physical process such as volatilization and differential adsorption on soils, will occur in fuel spills. Alterations from physical, biological, or chemical processes can occur over time frames ranging from days to years; the magnitude of transformation increases with time. Although these processes proceed at slower rates in the arctic than in warmer climates, a substantial change in composition of materials spilled at the BIA site is likely to have occurred over time. Evaporation and dissolution are important physical processes.

In addition, photochemical and microbial oxidations are possible.

Weathered petroleum products generally exhibit the following characteristics:

Loss of 10w boiling hydrocarbons from evaporation

Loss of 10w boiling hydrocarbons from dissolution

Increase in relative proportions of naphthenic compounds

Increase in relative proportions of highly branched aliphatics from biodegradation relative to straight chain compounds

Increase in relative proportions of alkylated phenanthene compounds relative to other aromatics

Increase in proportions of polycyclic compounds relative to all saturated compounds, (Woodward-Clyde, 1988)

Once diesel fuel permeates deeply into soil or enters ground water it tends to be persistent. However, all of the aforementioned processes would be significant determinants of chemical fate at the

BIA site because the permafrost limits permeability to the upper 20 feet of soil.

LANDFILL: Conclusive evidence of a landfill were not found during the investigation. Information from local residents indicate solid waste was trucked to a pit approximately 3/4 mile north east of the site boundary. This site was not investigated as part of the PA.

3 39

SEWAGE LAGOON: One water sample was collected from the sewage lagoon and analyzed for total coliform bacteria. This is the standard test for bacteriologic quality. The common species

Escherichia coli occurs in great numbers in the intestinal tract of warm-blooded animals, and the presence of these and related bacteria is considered an index of fecal pollution. The coliform bacilli are not themselves directly harmful, but their presence in excessive numbers is considered suggestive of the presence of other species that are pathogenic. The results are presented on page C-24. Total coliform bacteria and fecal coliform bacteria results were negative.

Other bacteria (OB) were reported as greater than 200 colonies/100 ml.

No chemical testing was perfomed on the sample from the sewage lagoon. The sewage lagoon is unlined and may be a sink for the disposal of solvents, chemical, and petroleum waste. As such, the sewage lagoon may be a ground water contamination source. Ground water monitoring wells should be installed downgradient of the lagoon to assess the migration potential.

CHEMICAL…