UNITED STATES ENVIRONMENTAL PROTECTION AGENCYREGION 101200 Sixth Avenue, Suite 900Seattle, WA 98101-3140OFFICE OFENVIRONMENTALCLEANUPFEB 14 2013Ms. Valerie PalmerU.S. Army Corps of Engineers District, AlaskaCEPOA-PM-ESP (Y. Palmer)P.O. Box 6898JBER, Alaska 99506-0898Re:EPA's Evaluation of the Army Corps of Engineers Cleanup of the Formerly Used Defense Sitesat NE Cape and Gambell, St. Lawrence Island, AlaskaDear Ms. Palmer:This is to inform you that the EPA has completed its evaluation of the Army Corps of Engineers'cleanup of the Formerly Used Defense Sites at NE Cape and Gambell on St. Lawrence Island, Alaska.The conclusions we reached have not changed significantly from those that were presented during theDecember 2011 public meetings at the villages of Savoonga and Gambell. In general, the cleanup by theCorps of the Gambell and the NE Cape FUDS is consistent with CERCLA and the NationalContingency Plan. While the EPA may have done some of the analysis differently, the conclusions arenot appreciatively different.However, there are some additional actions that are necessary to fully comply with CERCLA and theNCP. The main issue is associated with those actions that left hazardous substances on site above levelsthat allow for unlimited use and unrestricted exposure. Section 300.430(f)(4)(ii) of the NCP requires thereview of such actions no less than every five years after the initiation of the selected remedy. This isnecessary to insure that the selected remedy remains protective of human health and the environment.Such reviews are necessary at several sites within the two FUDS and are noted in the EPA's attachedevaluation. Examples of these sites include the Cargo Beach Landfill at NE Cape and the Beach BurialSite along Troutman Lake at Gambell.Another outstanding issue relates to the use of monitored natural attenuation to clean up the diesel rangeorganics in the groundwater at the NE Cape Main Operations Complex. Continued monitoring of thegroundwater in this area must be done to track the degradation of the DRO. In addition, a conceptual sitemodel of the hydrogeology must be developed in order to determine the number of wells and theirlocation necessary to properly monitor the degradation of the DRO as well as to develop a timeframe forwhen natural attenuation will clean up the contamination at the site. This model should be shared withthe affected community and the regulatory agency. These issues and others are discussed in more detailin the attached evaluation report.F10AK096903_01.07_0011_a200-1eF10AK069603_01.07_0500_a200-1eFinally, it is important to note that under CERCLA if new infonnation comes to light that may call intoquestion the investigation or cleanup at a site, the site can be reopened. There are a variety of ways thatthis new infonnation can be discovered, for example, through the periodic reviews of an implementedremedy, monitoring data or observations of changes in the site conditions. The EPA expects that theCorps will continue to respond to changes in site conditions in a manner that is protective of humanhealth and the environment. Also, the EPA trusts that the Corps will continue to work with thecommunities and their representatives on StLawrence Island and to work cooperatively with Alaska' sDepartment of Environmental Conservation.If you have any questions regarding the evaluation report, please contact the EPA's project manager,Matt Wilkening, at 208-378-5760.Sincerely,·chard Albright, DirectorOffice of Environmental CleanupEnclosurecc:Mitchell Kiyuklook, President, Native Village of SavoongaEddie Ungott, President, Native Village of GambellMyron Kingeekuk, Mayor of SavoongaErika Apatiki, Mayor of GambellRodney Ungwiluk, Jr., President of Sivuqaq, IncCurtis Duncan, ADEC-AnchoragePam Miller, Alaska Community Actions on ToxicsRon ScrudatoJoe Sarcone, ATSDR-AnchorageEnvironmental Protection Agency (EPA) Region 10’s Evaluation ofArmy Corps of Engineers Cleanup ofFormerly Used Defense Sites (FUDS) atNE Cape and Gambell,St. Lawrence Island, Alaska(Final Report February, 2013)1Forward to EPA’s EvaluationIn the spring of 2010 EPA Region 10 was tasked by EPA’s Office of Solid Waste and EmergencyResponse to review the Army Corps of Engineers’ cleanup of the two Formally Used Defense Sites,Gambell and NE Cape. This review was in response to the concerns raised by the communities ofGambell and Savoonga and Alaska Community Action on Toxics. EPA Region 10’s task was to reviewthe cleanup at these sites to determine if the cleanup was consistent with CERCLA regulations and EPAguidance. The FUDS cleanup was completed at Gambell and is ongoing at NE Cape. The cleanup atboth sites was/is performed under the Defense Environmental Restoration Program for Formerly UsedDefense Sites. DERP provides authority and funds to investigate and contain, remove, or dispose ofhazardous and toxic materials at active and formerly owned military properties. It is important to knowthat DERP restricts the investigation and cleanup to contaminants associated with military properties.EPA’s evaluation of the cleanup was based on the review of select documents written by the Corps andtheir contractor that discussed site conditions or discussed the cleanup as well as documents written byindependent parties such as ACAT. EPA also reviewed select meeting minutes from the variousRestoration Advisory Board meetings. The Agency also participated in the community meetings inSavoonga and Gambell in December 2011 and several conference calls with all the parties over the lasttwo years.After reviewing the information, EPA also assessed how the cleanup would have been performed if thesite had been a formal Superfund Site. EPA’s conclusion is that generally the approach would not besignificantly different. Some specific differences, such as the need for long term monitoring at specificsites, are noted and actions the Corps should take are recommended. The communities requested EPAperform some actions that the Agency does not commonly perform at Superfund Site. Such actionsinclude independent sampling and analysis of media and long term monitoring of the remedy. EPA’sapproach at other sites is to make the responsible party perform these actions and then review the data toinsure that data meets the criteria in the workplan. In the case of the FUDS on St Lawrence Island,Alaska’s Department of Environmental Conservation performed that role, providing regulatory oversightof the Corps investigation and of the cleanup of the Gambell and NE Cape sites.The communities of Savoonga and Gambell have repeatedly expressed concerns in public meetings,conference calls and at RAB meetings about general health issues of the residents. These includecontamination of subsistence food sources from Persistent Organic Pollutants such as PCBs, site-widerisks, potential threats to the drinking water at Gambell and possible residual contamination underbuildings at Gambell. As stated in the opening paragraph above DERP provides authority and funds toinvestigate and address hazardous and toxic materials associated with military properties only. It cannotaddress contamination from global deposition from POPs.Furthermore it is difficult to tease out the risk posed by site-specific contamination associated with theFUDS from the cumulative impact from regional deposition of similar contaminants, see the POPs issuediscussed in this report. EPA understands that the communities are planning to meet with the Corps andADEC to discuss whether ADEC’s established cleanup concentrations are appropriate for the sitespecific conditions at St Lawrence Island. Beginning in 2013 ATSDR will assess potential healthimpacts to residents from the FUDS using the ATSDR methodology which is different from theCERCLA process. ATSDR plans to look at potential impacts from these FUDS to accustomed andtraditional sites.2Finally EPA is aware that we were unable to meet with individual residents of Savoonga and Gambellwhen we were there in December 2011. We did intend to do so but the extended length of the meetingsand weather affected travel prevented these interviews from occurring. EPA understands that theATSDR will try to fill this gap in gathering direct information from the community during theirupcoming health assessment. Also ATSDR plans to meet with the Norton Sound Health Cooperativeafter they visit the island this winter in an attempt to make the Health Cooperative aware of the issuesthat ATSDR is hearing from the residents of St Lawrence Island.The communities and ACAT requested that these sites be listed on the National Priorities List, i.e. theSuperfund List. This evaluation indicates that the Corps is generally following the CERCLA processand that Alaska DEC is performing adequate oversight. In addition the cleanup is in the latter stages ofon-the-ground work. The listing of these sites on the NPL would not result in additional investigation orcleanup, or get additional funding from the EPA. As stated in this report, EPA does have severalrecommendations that we strongly encourage the Corps to implement to improve the protectiveness ofthe cleanup.3IntroductionThe military began constructing sites in Alaska to provide early warning of possible Soviet attacks in thelate 1940s. In 1948 the military established the Gambell site, the first defense site on the island, adjacentto the village of Gambell. The Gambell site continued to be used until the late 1950s when a similarfacility was constructed at NE Cape. The NE Cape facility was operated from 1958 until 1972, when thesite was closed. When the military abandoned Gambell, the structures were demolished, burned orsalvaged and the debris buried on site. At NE Cape, the military just walked away, leaving everythingbehind. This resulted in various contaminants being left at these two facilities. In 1985 the Army Corpsof Engineers, as the lead agency for cleanup of Department of Defense sites, began cleanupinvestigations at Gambell and NE Cape under the Formerly Used Defense Sites (FUDS) program. Thiscleanup is being performed under the Defense Environmental Restoration Program for Formerly UsedDefense Sites. DERP provides authority and funds to investigate and contain, remove, or dispose ofhazardous and toxic materials at active and formerly owned military properties. It must be noted thatDERP restricts the investigation and cleanup to contaminants associated with military properties.When the Alaska Native Claims Settlement Act was passed in 1971, Gambell and Savoonga opted fortitle to the 1.136 million acres of land in the former St. Lawrence Island Reserve instead of participatingin the corporate profits of the other Alaska Native Regional Corporations. The Gambell NativeCorporation and Savoonga Native Corporation received title to all of St. Lawrence Island (except USSurveys 4235, 4237, 4340, 4369, 3728) by Interim Conveyance No. 203 dated 21 June 1979. Thus, theisland is jointly owned (surface and subsurface rights) by the Savoonga and Gambell NativeCorporations, now known as Kukulget, Inc. and Sivuqaq, Inc., respectively.The Gambell FUDS consisted of 2,543 acres obtained by public land order and special use permits fromthe Bureau of Land Management. The site is south and east of the village of Gambell (populationapproximately 800). This site was used by the military for housing and operations, aircraft radar,communications and other functions. Based on the Corps’ investigation, 38 sites of suspectcontamination were located throughout these acres (Figure 1), and CERCLA cleanup was required atthree sites located around Troutman Lake. In 2008 the Corps declared cleanup of the Gambell FUDScompleted with a cost of approximately $11.5 million. ($7.3M. for CERCLA cleanup; $4.2M underNALEMP). The St. Lawrence Island (SLI) leaders and residents have stated that the FUDS cleanup wasclosed prematurely, that the site was not adequately characterized and requires long term monitoring.The NE Cape site was an established village and was displaced when the military established thesurveillance station in the mid-1950s. ACAT and village leaders state that the military in 1951 had anagreement to not leave waste behind and that this agreement was violated by the military. The residentsof SLI stated that they would like to restore the community at NE Cape, but that contamination in thearea makes it unsafe to do so. The residents also stated that currently the fish populations and habitat ofthe Suqi River remains severely impaired.The NE Cape FUDS is included in lands selected for withdrawal by Sivuqaq Inc. and Savoonga NativeCorporation (now known as Kukulget, Inc.). The site is about 60 miles SE of Savoonga (populationapproximately 800). The NE Cape site is not connected to the village of Savoonga by roads, althoughthe site is accessible by boat, ATV or snowmobile. The military left behind an airstrip that is seasonallyimproved by FUDS contractors. A trail network in the NE Cape area is used for ATV travel during4hunting and fishing season, and camping. The site is also accessed in the winter during inclementweather and as a stop to collect drinking water during spring whaling.The NE Cape study area encompasses 2,560 acres and includes the areas used for housing site personnel(up to 200 people during the peak of activity), power plant facilities, fuel storage tanks and distributionlines, maintenance shops, waste water treatment facilities, landfills, etc. The known and potentialsources of environmental contamination from activities at the site include, but are not limited to,petroleum products used for heating and fuel, polychlorinated biphenyls (PCBs) from electricaltransformers, pesticides, metals and organic chemicals from paint, solvents and other common industrialproducts and associated debris disposed in the facility’s landfill or abandoned on the tundra as debrispiles.At NE Cape, the Corps’ investigation located 33 distinct sites of possible contamination. Furthersampling and investigation determined that 11 sites required No Further Action, i.e. they contained deminimus concentrations of diesel range organics (DRO) and residual range organics (RRO), PCBs (2sites) or no detects. Of the 22 sites requiring cleanup, 11 were due to DRO/RRO contamination, andseven sites were contaminated by PCBs (Figure 2). During the 2010 field season, 2,730 tons ofpetroleum-contaminated soil and 1,245 tons of PCB-contaminated soil were excavated and removed.Also, 21 bulk bags of PCB-contaminated soil were staged for future off-site removal, as well as 16.7tons of arsenic-contaminated soil. Cost of cleanup through the end of the 2010 field season was$62 million.* Approximately $83.5 million has been spent through FY2011 under the FUDS program.*Notes: Remedial efforts through fall 2011 include the excavation of approximately 12,500 tonsof petroleum-contaminated soil and 4,500 tons of PCB-contaminated soil. The Corps awarded a$19.1 million contract during FY11 to continue site remediation activities during the summers of2011 and 2012. Fieldwork implemented during the summer of 2011 included: excavation/removal of PCB-contaminated soils, excavation/removal of petroleum-contaminated soils fromthe Main Complex, miscellaneous debris removal, sampling for monitored natural attenuationand additional delineation of sediment contamination at Site 28.Work during the 2011 and 2012 field seasons at NE Cape was to include groundwater monitoring forpetroleum related compounds at nine monitoring wells located in the Main Operations Complex (MOC).These data will be used to help determine the amount of DRO degradation in the shallow groundwater.Additional work for the 2011 and 2012 field seasons included further excavation of PCBs andpetroleum-contaminated soil at the MOC, the Power and Heating Building and the White Alice Site. Thesoil at the Waste Water Treatment Tank was sampled for arsenic. Concentrations of arsenic are greaterthan background, so all soil with arsenic concentrations above cleanup levels are scheduled to beexcavated.As these last paragraphs indicate work is ongoing at the NE Cape site. Accordingly, this evaluationrepresents conditions at the point in time that it was written, the summer and fall of 2011.As the cleanup continues, conditions may change. The removal of contamination from the FUDS willresult in an improving eco-system as the system responds to the cleanup. However, it must beremembered that this will be slow process. EPA anticipates that this additional work will generatereports that document the cleanup etc., and that these reports will be routed to the parties for their reviewand comments. Also, EPA anticipates that the RAB will continue to provide a forum for the local5communities to raise concerns to the Corps and the Corps will continue to provide the RAB with supportfor technical resources.It is also important to note that under CERCLA, if new information comes to light that may call intoquestion the investigation/cleanup at a site, the site can be reopened. There are a variety of ways thatthis new information can be discovered, for example, through the periodic reviews of an implementedremedy, monitoring data, or observations of changes in the site conditions. EPA expects that the Corpswill continue to respond to changes in site conditions in a manner that is protective of human health andthe environment.EPA’s Review of Army Corps of Engineers Cleanup DocumentsIn the fall of 2009, a delegation of leaders, elders and youth from St Lawrence Island, along with staff ofthe Alaska Community Action on Toxics (ACAT), wrote a letter to Mathy Stanislaus (AssistantAdministrator of EPA’s Office of Solid Waste and Emergency Response) and visited EPA headquartersregarding their concerns about the Corps’ cleanup of the Gambell and NE Cape FUDS. Mr. Stanislausasked EPA Region 10 to take the lead in responding to the issues raised by the communities of Gambelland Savoonga and ACAT and assess the EPA’s future role at these sites. EPA’s evaluation was limitedin scope. EPA’s task was to review the cleanup of the FUDS and determine if it was consistent withCERCLA regulations and EPA guidance. EPA’s evaluation of the cleanup was based on the review ofselect documents written by the Corps and their contractor that discussed site conditions or discussed thecleanup and results. EPA also review meeting minutes from the various Restoration Advisory Boards.The Agency also attended two site meetings in December 2011 and was on several conference calls withthe all the parties.Previously in 2002, EPA Region 10 reviewed the work by the Corps at the NE Cape site and determinedthat the Corps was proceeding in a manner consistent with EPA’s expectation for cleaning up hazardouswaste sites. Once again, EPA Region 10 has agreed to evaluate the Corps’ cleanup work at the NE Capeand Gambell FUDS to determine if their cleanup work is consistent with EPA’s expectations forhazardous waste sites.EPA’s review has determined that the Corps’ documents on the work at Gambell and NE Cape FUDSindicate that they generally followed the EPA rules and regulations 1 with a few noted exceptions that arediscussed below. Since the Corps has worked directly with Alaska Department of EnvironmentalConservation (ADEC) throughout this project, the Corps more closely follows ADEC guidance. Forexample, the approach for incorporating ambient/background concentrations in the risk assessment isnot the same approach as used by the EPA. The Corps compared the maximum concentration ofinorganic contaminants only to a calculated 95% background upper tolerance limit, i.e., an ambientconcentration. If the maximum concentration of a site-related chemical was less than the ambientconcentration, the chemical was dropped. EPA guidance recommends that any contaminant be carriedthrough the risk analysis and then the impact of elevated concentrations of contaminants in backgroundcan be addressed in the uncertainty discussion of the risk management section.1The Comprehensive Environmental Response Compensation Liability Act (CERCLA) is the overall Act that provides theEPA and the Corps the authority to clean up hazardous waste sites. From this Act, implementing regulations (i.e. the NationalContingency Plan – NCP) and guidance have been developed to provide the cleanup authorities with more specific directionson the rules for cleanup. EPA’s evaluation of the Corps’ cleanup is based on these regulations and guidance.6In reviewing the March 2004 Human Health and Ecological Risk Assessment for the NE Cape FUDS itwas noted that ecological risk assessment did not include an aquatic species. In addition, the ecologicalrisk assessment appears to be done more to supplement the human health risk assessment than to directlyassess impacts to biota. For example, in the risk assessment the presence of PCBs in ambient fish isnoted and used in the calculation of human health risk. But the impacts of the PCBs on the fish in theSuqitughneq (Suqi) River were not directly evaluated. The Corps did consider using a marine fish, butdecided not to since they are migratory and would only be exposed to site conditions a portion of thetime. However, there are non-migratory freshwater fish species that could have been used, such assculpin or blackfish.The approach the Corps took to calculate both human health and ecological risk is not as protective asthe approach the EPA would use. As noted earlier, the Corps did not directly calculate a risk to anaquatic organism. However, EPA’s risk assessors did not find that any additional cleanup would havebeen necessary had the risk assessment process more closely followed EPA guidance. In addition, allecological risk sites are co-located with human health risk sites. Thus cleaning up to protect humanhealth should also protect the potentially affected species, which is commonly a vole.There is also the issue of long-term monitoring at these sites. If contamination is removed to allowunrestricted use, long-term monitoring is not required. However, if contamination remains on site atconcentrations that do not allow for unlimited use and unrestricted exposure, then periodic reviews ofthe site are necessary until the site conditions change to allow unlimited use and unrestricted exposure.Five-year reviews are required under section 121 (c) of the Comprehensive Environmental Response,Compensation, and Liability Act, which states that "If the President selects a remedial action that resultsin any hazardous substances, pollutants, or contaminants remaining at the site, the President shall reviewsuch remedial action no less often than each five years after the initiation of such remedial action toassure that human health and the environment are being protected by the remedial action beingimplemented."The Corps has stated that five-year reviews are anticipated at the MOC site at NE Cape only, due togroundwater contamination with COCs (e.g., benzene and lead) other than just petroleum. However,they plan to do "periodic reviews" at sites with residual petroleum-oil-lubricant (POL) contamination(e.g., Site 8), in conjunction with the evaluation of the MOC. EPA would approach POL contaminationdifferently. It would look at the individual chemical constituents, such as benzene, and determine if theindividual compounds pose a risk rather than the fuel as a group of compounds. However, thedifferences in approach would not result in a different cleanup.At NE Cape the Corps will also conduct periodic visual monitoring of the capped area at the Site 9Housing and Operations Landfill and Site 7 Cargo Beach Road Landfill for settling and erosion for fiveyears post implementation of the remedy. Additional visual monitoring, up to 30 years, may beconducted if deemed necessary based on the results of the site inspections. The Decision Documentapproved by ADEC required limited removal of drums debris and stained soil in the upper one foot,capping and institutional controls without further characterization. Since there was no sampling todetermine if contamination above cleanup goals were left behind, EPA would work under theassumption that waste is left in place and that longer monitoring, including periodic review, e.g. FiveYear Review, be required; see additional discussion later in this report.In a May 2002 Overview Report, it was noted that the Agency for Toxic Substances and DiseaseRegistry (ATSDR) was involved in a review of fish tissue analysis from fish collected from the Suqi7River during previous investigations. The report states the ATSDR will work with the communities andthe Corps as more data is available to help evaluate if there are any likely adverse impacts fromsubsistence level consumption of fish from the Suqi River. Such coordination with other agencies withspecialized expertise is an approach the EPA employs at their site cleanup work. The EPA is aware thatin October 2011, the community of Savoonga petitioned ATSDR to conduct a health assessment due tothe contamination at the Gambell and NE Cape sites and because more information is available sinceATSDR last reviewed the data in 2002. In February 2012 ATSDR agreed to conduct this healthassessment and is expecting to initiate this assessment work in 2013.Community Issues and ConcernsThere are several site specific concerns that have been captured in notes from the Restoration AdvisoryBoards (RABs) meetings and/or concerns by leadership and other community members on St. LawrenceIsland as expressed in the 2009 ACAT letter to EPA.Gambell FUDSAt Gambell there were several concerns; residual munitions, buried debris, and protection of drinkingwater. Munitions, specifically 30-caliber rounds, were found at a beach burial pit between the BeringSea and Troutman Lake. In addition, there were statements that the Army disposed of a large volume ofordnance in the north end of Troutman Lake in the early 1960s. These oral statements said that crates ofammo were placed on the ice of Troutman Lake and with spring breakup they were “flushed away.”However, the geophysical survey of the lake combined with depth-sounding equipment, ice augers,underwater video cameras and dredging anchors failed to detect a large ordnance disposal site at thebottom of Troutman Lake.Geophysical investigations by the Army’s contractor for munitions and explosives of concern located thebeach burial site and removed several hundred rounds of ammunition. Following the investigation andremoval actions in the early 2000s, the Corps placed institutional controls on the site. However, ADECdid not agree with institutional controls as the final remedy. Later the Corps-funded NALEMP programinvestigated the beach burial site using Schonstedt metal detectors and visual surveys and removedadditional ammunition in the summer of 2006. It was during this action that two hand grenades werealso encountered. After using these detectors and visual surveys to sweep the area for two years, theCorps declared the site clear of munitions in September 2008 and removed the institutional controls withADEC’s concurrence. The Corps’ project closeout report states that all known munitions and explosivesof concern have been removed from the area and the residual small arms ammunition has been 100%cleared. Thus, institutional controls and any additional reviews were no longer necessary. The ADECconcurred that all necessary actions to address military munitions or explosives concerns have beencompleted at the Gambell site.These reports indicate a good faith effort on the part of the Corps to remove all munitions from the sites.However, it is hard to say with 100% certainty that all munitions were removed. The Schonstedtinstrument used by the NALEMP program is a hand-held magnetometer, which detects ferrous metals,but not non-ferrous metals. It could not detect brass casings nor the presumably copper-jacketed leadprojectiles that comprise a 30-caliber round. The Corps should have used an all-metals (ferrous and nonferrous) detector, such as an EM-61 hand-held instrument, for surveying sites with potential rifle rounds.While localized sampling of the lake bottom did not find any munitions, the potential for munitionsremains. The Corps did survey the entire lake via geophysical instruments. Also, this disposal event isbased on recollections by individuals, but is not documented in any Corps’ reports from the time. Given8this lack of documentation and the rigorous geophysical investigation, the EPA concurs that is it unlikelyMEC are present in the sediment of Troutman Lake. However, the EPA recommends additionalsurveying of the 30-caliber round site with an all-metals detector and continuing institutional controlsuntil surveying determines the site is clear of munitions.Besides the issue of munitions, another concern at Gambell is related to debris that remains on site,whether under buildings and other structures or just in the general area of the village. It appears that theCorps, through the NALEMP program, has actively addressed some of these concerns. However, theyhave not addressed issues where the debris is under structures with some exceptions. (There isdocumentation of the removal of debris in 2008 and 2009 from the area of the school.) Excavatingdebris from under existing structures does pose a host of additional issues, such as maintaining thestructural integrity of the building. Generally, the EPA would not remove such material either unless itposed an unacceptable risk to human health and the environment. It does not appear that this material,such as construction debris like rebar and/or metal from Marston matting, presents a health threat. TheEPA concurs with the Corps that presence of inert debris under buildings does not present a threat tohuman health and the environment and removal of such debris is not necessary.Also, concerns about the protection of the drinking water aquifer have been expressed. Based on the datareviewed in the June 2005 Decision Document for the Gambell FUDS, it appears that any contaminantsin the groundwater that exceeded the screening levels, i.e., the maximum contaminant levels (MCLs) fordrinking water are due to the turbidity of groundwater. This turbidity is representative of the poor qualityof the groundwater at Site 6 and Site 7. An August 2012 comment from the Corps notes the following:The 1994 RI included both filtered and unfiltered groundwater samples for metals, which arepresented as total and dissolved concentrations in the summary Table 7 of the DecisionDocument. It is the filtered or dissolved concentrations that represent drinking water in this caseand thus these concentrations were evaluated to see if groundwater levels will exceed screeninglevels. The only dissolved concentrations above detection levels are for chromium and lead andthese are below screening levels. The other analyses of filtered water samples were non-detectfor arsenic, beryllium, cadmium, and nickel.This additional information resolves EPA’s concern. Metals in the filtered groundwater do not exceedscreening level.One groundwater sample cross-gradient to Gambell’s water supply well had fuel contamination, butsubsequent sampling did not find any contamination. Other sites where groundwater was sampled didnot have contaminants above the MCLs. There were also some concerns expressed that other areaswhere contamination is found in the soil could pose a threat to the groundwater, specifically the radarstation on Sevoukuk Mountain. Based on a review of the documents, there does not appear to be ahydrogeological connection between the radar site and the drinking water source on the plain below themountain. Also, dioxins, the contaminant of concern at the radar site, do not travel very easily in thesubsurface because they bind tightly to the soil. In addition, the average concentration of dioxins in thesoil at the radar station is below EPA’s screening concentration and ADEC’s cleanup value. Thus,additional excavation at the radar site is not necessary since there is no risk to human health or theenvironment. In conclusion, reports reviewed indicated that this FUDS does not pose a threat to thegroundwater that serves as a drinking water source for the village of Gambell.9NE CapeThe local community has expressed concerns about whether the site has been adequately characterizedand about the cleanup at several sites located within the NE Cape FUDS. These concerns can be groupedinto some general categories: PCBs, contamination of the surface water and the Suqi River, failure toremove all contaminated material from the site and contamination of the groundwater.PCBs: As noted in the 2009 ACAT letter to EPA, PCB contamination at the NE Cape site was one of themajor concerns. This concern is driven by the subsistence lifestyle practiced by most of the localpopulation. An ACAT study on PCB concentrations in common food sources (marine mammal:Bowhead Whale and a land mammal: reindeer) used by residents on the island documented thefollowing:Bowhead whale (in ppb)Blubber (n=3)Meat (n=4)Mungtak (n=7)Rendered oil (n=3)Skin (n=1)PCBs317.6127.20142.61353.9585.91DDE+856.290.275.2626.430.93HCB23.820.5813.0916.914.36Mirex0.260.080.142.900.06DDE+8513.210.780.960.620.560.01HCB2.940.290.000.000.000.77Mirex0.000.000.000.000.000.00n= the number of samples collectedReindeer (in ppb)Fat (n=5)Meat (n=8)Liver (n=4)Kidney (n=4)Heart (n=2)Prepared meat (n=1)PCBs2.771.420.180.030.061.14(Note: these data represent results from food source throughout the area and are not specific to the NECape site.)The value established by the EPA for PCB concentration in fish that allows for unlimited consumption is