ACAT FOIA Repository 3

FinalREMEDIAL INVESTIGATIONGambellSt. Lawrence Island, Alaska(Volume I - Report)Contract No.Delivery Order No.DACA85-93-D-00110003January 1995Prepared for:Mr. Douglas Blaisdell, Project ManagerDepartment of the ArmyUnited States Army Engineer District, AlaskaCorps of EngineersP.O. Box 898Anchorage, Alaska 99506-0898Prepared by:Montgomery Watson4000 Credit Union Drive, Suite 600Anchorage, Alaska 99503200-leF10AK069603J)3.10_0001NPDL WO#95-360Executive Summary1.0 Introduction1.1Project Objectives1.2Site Background1.2.1Location1.2.2Site History1.2.3Previous Investigations1.3Regional Setting1.3.1Climate1.3.2Topography1.3.3Geology1.3.4Groundwater1.3.5Surface Water1.3.6Demography1.3.7Ecology & Sensitive Environments1.3.7.1 Vegetation1.3.7.2 Birds1.3.7.3 Mammals1.3.7.4 Fish1.3.7.5 Endangered or Threatened Species1.4Site Descriptions1.4.1Site 1-North Beach1.4.2Site 2-Former Military Housing/Operations Site1.4.3Site 3-Former Communications Facility1.4.4Site 4-Sevuokuk Mountain1.4.5Site 5-Former Tramway Site1.4.6Site 6-Military Landfill1.4.7Site 7-Former Military Power Facility1.4.8Site 8-West Beach/Army Landfill1.4.9Site 9-Asphalt Barrel Cache1.4.10 Site 10-Sevuokuk Mountain Trail System1.4.11 Site 11-Communication Cable Route1.4.12 Site 12-Nayvaghaq Lake Disposal Site1.4.13 Site 13-Former Radar Power Station1.4.14 Site 14-Navy Plane Crash Site1.4.15 Site 15-Troutman Lake Ordnance Burial Site1.4.16 Site 16-Gambell Municipal Building Site1.4.17 Site 17-Army Landfills1.4.18 Site 18-Former Main Camp1.4.19 Background SiteRemedial Investigation for Gambell/01C.31A (January 25,1995,2:2E-l1-11-11-31-31-31-41-41-41-41-51-51-51-51-61-61-61-6-..l-l1-71-71-71-81-81-81-91-91-101-101-111-111-111-111-111-111-121-121-121-121-12O page i2.0 Investigation Approach and Procedures2.1Site Investigation Methods and Procedures2.1.1Sample Numbering System2.1.2Headspace Screening2.1.3Geophysical Surveys2.1.4Surface Soil Sampling and Analysis2.1.5Subsurface Soil Sampling and Analysis2.1.6Surface Water and Sediment Sampling and Analysis2.1.7Monitoring Well Installation and Development2.1.8Groundwater Sampling and Analysis2.1.9Groundwater Elevations, Slug Tests, and Specific Capacity Tests2.1.10 Asbestos Sampling and Analysis2.2Quality Assurance/Quality Control2.2.1QA and QC Samples2.2.2Data Validation2.2.3Laboratory Method Blank Analysis2.2.4Trip Blanks2.2.5Equipment Rinsate Blanks2.3Investigation-Derived Waste2.3.1Soils2.3.2Water2.3.3Disposable Protective Clothing and Supplies2-12-12-12-22-22-32-42-52-62-72-82-92-92-102-102-112-112-112-122-132-132-133.0 Site Characteristics3.1Regional Geology and Soils3.1.1Surface Soils3.1.2Subsurface Soils3.1.3Soil Chemistry3.1.4Bedrock Geology3.2Regional Hydrogeology3.2.1Hydrogeology3.2.2Ice and Permafrost3.3Surface Water3-1..3-13-13-13-23-23-23-23-33-44.04-14-24-24-24-34-34-34-44-44-54-54-5<U1- ?'-- sw^t. -^'-" * *•• f-f*" ••V' • - , ' •,*^X *'X Vf *• > ••V.V>.U page ix•.,-UstofTqbtes5--"V ""' J X,-S-W*-1-11-2Investigative Sites and Historic Functions1985 URS Investigation Results1-191-202-12-22-32-42-52-62-72-82-92-102-11Summary of the Site Investigation ActivitiesSummary of Analytical Program-SoilSummary of Analytical Program-WaterSummary of Investigative ActivitiesSummary of Field ActivitiesGeophysical CoverageMonitoring Well Construction InformationSummary of Asbestos Containing Material SamplingQA/QC ListingTrip Blank and Rinsate ResultsSummary of IDW Results2-192-212-222-232-242-252-262-272-282-292-313-13-2Summary of Soil CharacterizationSummary of Groundwater Elevations/Measurements3-93-114-14-24-34-44-54-64-74-84-94-104-114-124-134-14Background Criteria for Priority Pollutant MetalsMetal Concentrations for Melted Pore Water at Site 6General Inorganic Compounds - Melted Pore Water at Site 6DRO, GRO, TRPH, Metals Results - Soils at Site 2DRO, GRO, TRPH, Metals Results - Soils and Water at Site 3Sulfate and pH Results - Soil and Water at Site 3Total Recoverable Petroleum Hydrocarbons Results - Soil at Site 4/Area 4BDioxin and Furan Results - Soil at Site 4/Area 4BMetals Results - Soil at Site 4/Area 4BDRO, TRPH Results - Soil at Site 5Soil and Water Results at Background SiteDRO and TRPH Results - Soil at Site 7VOCs, GRO, DRO, TRPH Results - Water at Site 7DRO, TRPH Results - Water at Site 134-124-134-154-264-294-314-404-414-454-524-534-624-634-766-16-26-36-46-56-66-76-8Regulatory Benchmarking at Site 1Regulatory Benchmarking at Site 2Regulatory Benchmarking at Site 3Regulatory Benchmarking at Site 4Regulatory Benchmarking at Site 5Regulatory Benchmarking at Site 6Regulatory Benchmarking at Site 7Regulatory Benchmarking at Site 86-216-236-256-276-296-306-326-35;(,,„,,,,,^"V,VCI%'^'•••.^•.f-.Remedial Investigation for Gambell/01C.31A (January 25.1995,2:20 PM)rt..---^•••• -V, -j ^ s , , , , . . s ^ . w v^^,/j,%>t^f,,,*„,,' ' • - . . <"'--yQ page x6-96-106-116-126-136-146-156-166-176-18Regulatory Benchmarking at Site 12Regulatory Benchmarking at Site 13Regulatory Benchmarking at Site 16Regulatory Benchmarking at Site 17Regulatory Benchmarking at Site 18DERP-FUDS EligibilityComparison of Remedial Alternatives for POL Contaminated SoilsComparison of Remedial Options for Petroleum Hydrocarbons in GroundwaterComparison of Remedial Alternatives for Lead-Contaminated SoilsRemediation AlternativesRemedial Investigation for Gambell/01C.31A (January 25,1995,2:20 PM)6-376-396-416-426-446-466-486-496-506-51O pagexiList of Acronyms/AbbreviationsAACAC&WSACMADECARARAsASTMATVBabgsBHBLMBNABODCACaCASCDAPCERCLACFRCMECODCOECQARCrCuCWADERADERPDODDROE&EEM-31EPAeV°FFeft/ftFUDSgpmGPRGROIDWkWMgmg/kgmg/1mphMSLMWAlaska Administrative CodeAircraft Control and Warning StationAsbestos Containing MaterialAlaska Department of Environmental ConservationApplicable or Relevant and Appropriate RequirementsArsenicAmerican Society for Testing MaterialsAll Terrain VehicleBariumBelow Ground SurfaceBoreholeBureau of Land ManagementBase Neutral Acid (compounds)Biological Oxygen DemandCorrective ActionCalciumColumbia Analytical ServicesChemical Data Acquisition PlanComprehensive Environmental Response, Compensation and Liability ActCode of Federal RegulationsCentral Mining EquipmentChemical Oxygen DemandU.S. Army Corps of Engineers - Alaska District.Chemical Quality Assurance ReportChromiumCopperClean Water ActDefense Environmental Restoration AccountDefense Environmental Restoration ProgramDepartment of DefenseDiesel Range OrganicsEcology and Environment, Inc.Electro-Magnetic Terrain ConductivityU.S. Environmental Protection AgencyElectron VoltDegrees FahrenheitIronFoot per FootFormerly Used Defense SiteGallons per MinuteGround Penetrating RadarGasoline Range OrganicsInvestigation-Derived WasteKilowattMagnesiumMilligrams per KilogramMilligrams per LiterMiles per HourMean Sea LevelMonitoring WellRemedial Investigation for Gambell/01C.31A (January 25.1995,2:20 PM)page xiiNH4-NNiNIOSHNO2-NNO3NPDNPDNPLNTUOSHAPbPCBpg/gPIDPLMPOLppbppmpptPVCQAQA/QCQCRCRARfDRIRPDSARASBSbSeSOWTCTCLPTEQTlTOCTRPHTSCATSS/TDSU.S.ug/kgURSUSGSUSKHUSTVOCpmhos/cmAmmonia as NitrogenNickelNational Institute for Occupational Safety and HealthNitrite as NitrogenNitrate as NitrogenNorth Pacific DivisionNorth Pacific Division (Laboratories)National Priorities ListNephelometric Turbidity UnitsOccupational Safety and Health AdministrationLeadPplychlorinated BiphenylPicogram per GramPhotoionization DetectorPolarized Light MicroscopyPetroleum Oil and LubricantsParts Per BillionParts per MillionParts Per TrillionPoly-vinyl ChlorideQuality AssuranceQuality Assurance/Quality ControlQuality ControlResource Conservation and Recovery ActReference DoseRemedial InvestigationRelative Percent DifferenceSuperfund Amendment and Reauthorization ActSoil BoringAntimonySeleniumScope of WorkToxicity CharacteristicToxicity Characteristic Leachate ProcedureToxicity EquivalencyThalliumTotal Organic Carbon or Top of CasingTotal Recoverable Petroleum HydrocarbonsToxic Substance Control ActTotal Suspended Solids/Total Dissolved SolidsUnited StatesMicrograms per KilogramURS CorporationUnited States Geological SurveyUSKH, Inc.Underground Storage TankVolatile Organic CompoundMicromhos per centimeterRemedial Investigation for Gambell/01C.31A (January 25,1995,2:20 PM)O pagexiiiCONVERSION FACTORSSOILS AND SEDIMENTS1 mg/kg is equal to 1 part per million (ppm)1 ug/kg is equal to 1 part per billion (ppb)1 pg/g is equal to 1 part per trillion (ppt)1,000 pg/g= lug/kg1,000 ug/kg =1 mg/kgWATER1 mg/1 is equivalent to 1 part per million (ppm)1 ug/1 is equivalent to 1 part per billion (ppb)1,000 ug/1 = 1 mg/1Remedial Investigation for Gambell/01C.31A (January 25,1995,2:20 PM)O page xivExecutive SummaryMONTGOMERY WATSONExecutiveThis report presents the results of Remedial Investigation (RI) studies performed at eighteen sitesnear the village of Gambell, St. Lawrence Island, Alaska (Figure ES-1). The RI was conductedas part of the Alaska District Corps of Engineers (COE) Defense Environmental RestorationProgram (Contract No. DACA85-93-D-0011). The Gambell site was used by the military in the1940s and 1950s but was largely dismantled in the early 1960s. The area around the Village ofGambell is classified as a Formerly Used Defense Site (FUDS) under the Defense EnvironmentalRestoration Program (DERP) of the Department of Defense (DOD). Gambell is located on thenorthwest tip of St Lawrence Island, in the western portion of the Bering Sea approximately 200air miles southwest of Nome, Alaska. Gambell is 39 air miles from the Siberian ChukchiPeninsula. The village of Gambell is built on a gravel spit which projects northward andwestward from the island. St. Lawrence Island is owned jointly by Sivuqaq, Inc., located inGambell, Alaska, and Savoonga Native Corporation, located in Savoonga, Alaska. Non-nativeland on St. Lawrence Island is limited to State lands used for airstrips and related facilities inGambell.Gambell is relatively flat, with an elevation range from sea level to approximately 30 feet abovemean sea level (MSL). Sevuokuk Mountain forms the eastern boundary of the gravel spit, andrises steeply to a height of approximately 619 feet. The 1990 year-round population of Gambellwas 525 persons, with 505 of Yupik descent (U.S. Census Bureau, 1994). There are 132 homesin the village, two stores, and municipal, community, and educational building.Based upon DOD background information, site visits, and previous investigations, seventeensites and a background site were targeted for environmental investigation. At fourteen of thesesites, samples were submitted for laboratory analysis. Surface and subsurface soils, surfacewater, sediment, groundwater, and building materials were submitted for laboratory analysis todefine the location and extent of contamination associated with the former DOD site activities.The dominant soil lithologies underlying the Gambell area are unconsolidated, poorly to wellsorted gravels with sand, and poorly to well-sorted sand with gravels. These soils are interpretedas washed beach gravels deposited on a wave-cut platform. Groundwater was encountered atdepths ranging from 2.5 feet below ground surface (bgs) south of Troutman Lake to 16.5 feet bgsalong the North Beach Area. Sevuokuk Mountain is composed of Cretaceous quartz monzonite,a gray rock rich in quartz and feldspars.The following seventeen sites (plus a background site) were evaluated during the investigationbased on investigative sites identified hi the Ecology and Environment Site Inventory datedFebruary, 1993 (Figure ES-1):••Site 1-North BeachArea lA-Army Landing Area- Area IB-Air Force Landing AreaSite 2-Former Military Housing/Operations SiteRemedial Investigation for Gambell (January 25.1995,2:10 PM)U pageE-1•••••••••••••••••Site 3-Former Communications FacilitySite 4-Sevuokuk Mountain- Area 4A-Quonset Hut Area- Area 4B-Former Radar Station- Area 4C-Stream Drainage at South End of Mountain- Area 4D-Transformers in Mountainside DrainageSite 5-Former Tramway SiteSite 6-Military LandfillSite 7-Former Military Power Site/Former Motor PoolSite 8-West/Beach/Army LandfillSite 9-Asphalt Barrel Cache (site walk-through only)Site 10-Sevuokuk Mountain Trail System (site walk-through only)Site 11-Communications Cable Route (site walk-through only)Site 12-Nayvaghaq Lake Disposal SiteSite 13-Former Radar Power StationSite 14-Navy Plane Crash Site (not visited during this investigation)Site 15-Troutman Lake Ordnance Burial Site (site walk-through only)Site 16-Gambell Municipal Building SiteSite 17-Army LandfillsSite 18-Former Main CampBackground SiteBased on field sampling and analytical data from the sites listed above, the nature and extent ofcontamination in each of the investigative areas can be summarized as follows:V•Elevated levels of lead, chromium, copper, and zinc were found at Site 2. Lead wasdetected at a maximum concentration of 749 mg/kg in surface soil.•At Site 3, diesel range organics (DRO) were found in soils at one monitoring welllocation at depths to 5.0 feet. The maximum detected concentration was 522 mg/kg.•At the Former Radar Station, Site 4/Area 4B, elevated concentrations of priority pollutantmetals were found. Lead was detected at a maximum concentration of 3,249 mg/kg.These metals could pose a potential threat to the nearby bird rookery or to the nativeswho consume these birds for subsistence. Dioxins and furans were also detected at thislocation, but at relatively low levels.•Polychlorinated biphenyls (PCBs) were detected in one soil sample taken upslope ofthree transformers located in a drainage above the water reservoir (pump house) at Site4/Area 4D. The detected concentration was 194 micrograms per kilogram (ug/kg).•At Site 5, DRO and total recoverable petroleum hydrocarbons (TRPH) were detected insubsurface soils at maximum concentrations of 1,800 mg/kg and 1,430 mg/kg,respectively. The contaminants were detected at depths to 5 feet. Groundwater waspresent at 5 feet, indicating the petroleum contamination is in contact with groundwater.Groundwater showed elevated levels of TRPH up to 0.5 mg/1, suggesting thatgroundwater may be impacted.V'••,'C?,'^ : : - . ' ' • • ':^..,VRemedial Investigation for Gambell (January 25,1991,2:20 PM),''•: ' • • • • , . ,'•'"•'?.>,'••'*"" fQ page E-2•At Site 6, DRO were detected in melted pore water encountered at two soil borings at amaximum concentration of .709 mg/1. The samples were taken through a hollow stemauger.•At Site 7, DRO and TRPH were detected in soils at maximum concentrations of 6,040mg/kg and 13,000 mg/kg, respectively. DRO, TRPH and low concentrations of volatileorganics compounds (VOCs) were found in groundwater. The petroleum hydrocarbonscontamination appears continuous from the surface to groundwater.The following investigative areas did not have significant contamination and/or all analyticalresults were below regulatory benchmark levels:••••••••Site I/Area lA-Army Landing AreaSite I/Area IB-Air Force Landing AreaSite 2-Former Military Housing/Operations SiteSite 4/Area 4A-Quonset Hut AreaSite 4/Area 4C-Stream Drainage at South End of MountainSite 8-West Beach/Army LandfillSite 9-Asphalt Barrel Cache (site walk-through only)Site 10-Sevuokuk Mountain Trail System (site walk-through only)Site 11-Communications Cable Route (site walk-through only)Site 12-Nayvaghaq Lake Disposal SiteSite 13-Former Radar Power StationSite 14-Navy Plane Crash Site (not visited during this investigation)Site 15-Troutman Lake Ordnance Burial Site (site walk-through only)Site 16-Gambell Municipal Building SiteSite 17-Army LandfillsSite 18-Former Main CampBackground SiteComparison of contamination levels found at the Gambell site to regulatory benchmarks and/orsite specific factors has resulted in the retention the following discrete areas that are identified forfurther investigation or remedial action:•••••Site 3-Former Communications FacilitySite 4-Sevuokuk Mountain- Area 4B-Former Radar Station- Area 4D-Transformers in Mountainside DrainageSite 5-Former Tramway SiteSite 6-Military LandfillSite 7-Former Military Power Site/Former Motor PoolThe majority of these areas involve elevated levels of petroleum hydrocarbons in soil and/orgroundwater. The remaining areas involve surface soils with elevated levels of lead and otherpriority pollutant metals.Remedial Investigation for Gambell (January 25,1995,2:20 PM)U pageE-3Petroleum hydrocarbon contamination found at Site 5 is of particular concern due to theproximity of Gambell's drinking water wells. Frequent monitoring is recommended in order toassess the quality of the village drinking water supply and potential contamination by petroleumproducts.The Gambell site is unique for several reasons with respect to subsistence food sources andecological receptors. Local inhabitants are reported to depend on the mammals as a food source.Site 4/Area 4B is adjacent to a bird rookery. The birds and bird eggs serve as a subsistence foodsource as well.Further risk assessment is recommended to assess whether the existing concentrations would belikely to adversely impact the local wildlife. If impacted, determination could be made whetherthere are significant additional pathways for impact on human health given the subsistencelifestyle of the local inhabitants.Remediation alternatives for DRO-contaminated soils include:• risk or leaching assessments to define the human or ecological risk at the site and supportalternative cleanup levels;• bioventing;• land farming, and• excavation and off-site disposal.Alternatives for remediation of groundwater with elevated concentrations of dissolved petroleumhydrocarbons include:• risk assessment;• in-situ biodegradation (air sparging);• ex-situ treatment, and• water supply well-head treatment (no aquifer remediation).Remediation alternatives for soils with elevated concentrations of lead and other prioritypollutant metals include:• risk assessment;• soil stabilization;• capping, and• excavation and off-site disposal.In addition to the chemical contaminants identified above, much of the surface debris lying atdifferent investigative sites around Gambell was identified as "inherently dangerous" accordingto DERP-FUDS guidelines. This debris includes: runway landing mat, sheet metal, batteries, andQuonset hut frames.Remedial Investigation for Gambell (January 25,1995,2:20 PM)U page E-4SITE 14(Navy Plane Crash approx. 7 miles south), Note 21. Mapping taken fr^mEnvironment (199:photography taken^Tical Data Aquisition Plan by Ecology &g believed to be sketched from $erial5. Accuracy unknown.,','2. Navy Plane Crash Site was not visited during 1994 Rl.LEGEND:MONTGOMERY WATSONAnchorage, AlaskaI1 Boundary of SiteFIGURE ES-12SCALE IN FEET1200ALASKA DISTRICT - CORPS OF ENGINEERSGAMBELL, ST. LAWRENCE ISLAND, ALASKAGAMBELL INVESTIGATIVE SITESpage ES-5 J.Section 1.0MONTGOMERY WATSON1.0 IitfrocJudbnThis report presents the results of the Remedial Investigation (RI) performed at 17 sites and abackground site near the village of Gambell, St. Lawrence Island, Alaska (Figures 1-1 and 1-2).The area around the village of Gambell is classified as a Formerly Used Defense Site (FUDS)under the Defense Environmental Restoration Program (DERP) of the Department of Defense(DOD) (E&E, 1993). This work was performed by Montgomery Watson under contract to theU.S. Army Corps of Engineers (COE) as per the requirements of the Scope of Work (SOW) forContract No. DACA85-93-D-0011, Delivery Order No. 0003. Field work was performed duringthe months of June and July, 1994.This report is comprised of seven sections which describe the remedial investigation activities,analytical results, data interpretation and recommendations for remedial actions. These sectionsare:1234567IntroductionInvestigation Approach and ProceduresSite Characteristics and Background MetalsSite Specific FindingsFate and TransportRemedial ActionConclusionsSection 1 (Introduction) contains information on project objectives, site background, regionalsetting, and individual site descriptions. Section 2 explains investigation methods andprocedures. Section 3 describes the physical site conditions at the Gambell site, includingregional geology and soils and hydrology. Representative cross-sections and groundwatercontours are also shown in Section 3 as well as information on background metals concentrationsat Gambell. Section 4 contains specific information on geophysical surveys conducted, geologiccharacteristics, laboratory analytical results, and possible source of contamination. Section 5explains possible fate and transport of contamination in various media. Section 6 discusses theareas of concern to be addressed at Gambell and describes potential remediation alternatives (ifrequired). Section 7 summarizes the report conclusions.1.1PROJECT OBJECTIVESThe objectives of the RI were to gather sufficient chemical, geophysical, and hydrogeologicaldata to identify and characterize sites requiring remediation, and to develop remedial alternatives.This report presents the results of the field investigations, chemical sampling and analysis, andquality assurance/quality control (QA/QC) activities performed during the investigation. Acomparison of sample analytical results to selected regulatory cleanup benchmarks andrecommendations for remedial action are also presented for each site.,Remedial Investigation for Gambell (January 25,1995,2:20 PM).U page 1 -1Of the eighteen sites identified as part of this RI, seventeen were either sampled or observed andphotographed. Site 14, the Navy Plane Crash Site, was not visited during this investigation. Thesites and their historic functions and type of sampling performed during the 1994 RI are listed inTable 1-1. Each site was investigated to:•characterize the soils, geology, and hydrogeology of the site;•determine the presence or absence of contamination and, if present, the nature and extentof contamination;•develop a conceptual geologic and hydrogeologic model of the site;•evaluate possible migration pathways, and•develop preliminary remedial alternatives.To determine the impacts of the former military activities at the sites on the environment, thefollowing tasks were performed during this RI:•review of previous investigations prepared for the COE and other pertinent site data;•review of recent aerial photographs to determine site features;•geophysical surveys of 12 suspected covered disposal areas to locate and determine theextent of buried debris using electro-magnetic terrain conductivity (EM-31),magnetometer, and ground penetrating radar (GPR) instrumentation;•drilling and installation of 26 groundwater monitoring wells and 17 soil borings todetermine the presence or absence of contaminants, direction of potential contaminantmigration direction of contaminants, and determine the site geology and hydrogeology;•collection of 149 surface and subsurface soil, sediment, surface water, groundwater, andasbestos samples for chemical analysis and an additional 79 samples for quality assurance(QA) and quality control (QC);•measurement of static groundwater elevations to determine groundwater flow directionsand gradients;•in-situ permeability (slug) and specific capacity tests to determine aquifer characteristics;•compilation of hydrogeologic and geologic information to determine potentialcontaminant migration routes;•document investigation and results obtained at each site;•data interpretation and evaluation;Remedial Investigation for Gambell(January 25,1995,2:20 PM)U page 2-2•identification of preliminary benchmark regulatory criteria;•evaluation of investigation data against regulatory criteria, and•identification of potential remedial alternatives.All work was performed following the procedures stated in the Chemical Data Acquisition Plan(CDAP) prepared by Ecology and Environment (E&E, 1993), except as specifically noted herein.1.2SITE BACKGROUND1.2.1LocationGambell is located on the northwest tip of St. Lawrence Island, in the western portion of theBering Sea approximately 200 air miles southwest of Nome, Alaska. Gambell is 39 air milesfrom the Siberian Chukotsk Peninsula (Figure 1-1). The village of Gambell is built on a gravelspit which projects northward and westward from the island. Gambell is located at an elevationof approximately 30 feet above mean sea level (MSL). The village is inhabited mainly by nativeYupik people who lead a subsistence-based lifestyle.St. Lawrence Island is currently owned jointly by Sivuqaq, Inc., located in Gambell, Alaska andSavoonga Native Corporation, located in Savoonga, Alaska. Non-native land on St. LawrenceIsland is limited to state lands used for airstrips and related facilities in Gambell (E&E, 1993).1.2.2Site HistoryThe Gambell site was used by the U.S. Army, U.S. Navy, and U.S. Air Force fromapproximately 1948 until the late 1950s. Various facilities around the village of Gambell wereconstructed to provide housing, communications, and other functions. The U.S. Air Forceoperated an Aircraft Control and Warning Station (AC&WS) as early as 1948, but the site wasabandoned about 1956 when a similar facility was constructed at Northeast Cape on the northeastend of St. Lawrence Island (E&E, 1992). Approximately 1,700 acres of land and two rights-ofway were withdrawn from the reservation for use by the Air Force from 1950 to 1960;subsequently, the Air Force retained no overriding interest in the area. The Army operated abase at Gambell that reportedly supported several hundred personnel. A search of historicalrecords failed to yield base plans or site information for the Army installation (URS, 1986).However, according to Winfred James, a local Gambell resident, the army was active in Gambellfrom 1954 to 1957 (E&E, 1992). Extensive background research into Naval activities atGambell yielded no pertinent information. The Air Force land was transferred to the Bureau ofLand Management (BLM) in 1962, and the Army's land was transferred to BLM in 1963. AllDOD structures were demolished, burned, or scavenged and the debris buried on-site.\ .. ^%%^••^ %% ••-^> >v ^ • v. ,' • • > • .'i. • ..v'Remedial Investigation for Gambell (January 25,1995,2:20 PM)v.^ 'Jw% V%V••. %U page 1-31.2.3Previous InvestigationsIn 1985, URS Corporation (URS) conducted a file search and preliminary reconnaissance of theGambell site (URS, 1986). The site reconnaissance included an inventory of materials left by themilitary and collection of a limited number of soil and water samples. The samples wereanalyzed for physical, biological, and chemical characteristics. Soil samples were analyzed forpolychlorinated biphenyls (PCBs); none were detected. Surface water and groundwater samplesfrom six wells were analyzed for oil and grease, PCBs, volatile organic compounds (VOCs),metals, and secondary water quality parameters. Oil and grease (EPA Method 503) weredetected in groundwater samples at the Communications Facility and the Radar Power Station(Figure 1-3) at concentrations of 14 mg/1 and 115 mg/1, respectively. Arsenic, barium, cadmium,chromium, and lead were also detected, as shown on Table 1-2, which summarizes the analyticalresults of the URS investigation. In general, elevated concentrations of metals in groundwaterfound by URS (Table 1-2) were not substantiated by this study.In 1991 and 1992, E&E conducted site reconnaissance visits and interviewed individuals livingat Gambell during the period of DOD occupation (E&E, 1992).1.3REGIONAL SETTING1.3.1ClimateSt. Lawrence Island has a cool, moist, subarctic maritime climate with some continentalinfluences during winter when much of the Bering Sea is capped with pack ice. Winds and fogare common; precipitation occurs approximately 300 days per year as light rain, mist, or snow.Annual snowfall is about 80 inches per year. Annual rainfall is about 16 inches per year, withmore than half falling as light rain between June and September. Summer temperatures averagebetween 34°F and 48°F, with a record high of 65°F. Winter temperatures range from -2°F to10°F, with an extreme low of -30°F (URS, 1985b).The wind is generally in a northerly to northeasterly direction from September to June, andsouthwesterly in July and August. The average wind speed is 16 knots with winds exceeding tenknots 70 percent of the time (USKH, 1993).1.3.2TopographyThe village of Gambell is located on a gravel spit which projects north and westward from theisland into the Bering Sea (Figure 1-2). Gambell is relatively flat, with an elevation range of sealevel to approximately 30 feet MSL (E&E, 1992). Sevuokuk Mountain forms the easternboundary of the gravel spit and rises steeply to a height of approximately 619 feet (URS, 1985b).The spit is relatively barren and is sparsely covered by beach grass. Tundra is present near moistareas at higher elevation, such as Sevuokuk Mountain."'„ *,/*"*