Site Report: Unalakleet Air. Warning - Main Radar Site

Site Name:	Unalakleet Air. Warning - Main Radar Site
Address:	3.5 Miles NNE of Unalakleet, Unalakleet, AK 99684
File Number:	630.38.003
Hazard ID:	849
Status:	Active
Staff:	Axl LeVan, 9074512156 axl.levan@alaska.gov
Latitude:	63.918435
Longitude:	-160.752205
Horizontal Datum:	WGS84

We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.

Site Chronology
IC / Closure Details
Documents
Associated Sites

Problems/Comments

The former Unalakleet Aircraft Control and Warning (AC&W) Site was operational between 1958 and 1978. While the AC&W Site was a facility of the US Air Force, control of the site has been relinquished to the US Army Corps of Engineers (USACE) cleanup under the Formerly Used Defense Sites Defense Environmental Restoration Program. The AC&W site was placed on a 740-acre parcel of land which was relinquished to the Bureau of Land Management in 1970. The Unalakleet Native Corporation currently has custody of the land. ACOE# F10AK003601, F10AK003602 (rpltr3.1). The site inventory in 1986 reported nine buildings, six generators, two above ground fuel tanks (7,700 barrel capacity each), two USTs, lead batteries, contaminated soil, and miscellaneous debris. Demolition of the site infrastructure, removal of underground storage tanks, removal of debris, and excavation and on-site treatment of contaminated soil occurred in 1993 and 1995. Contractor bankruptcies and incomplete reporting complicated the efforts, which culminated in the USACE creating a final remedial action report in 2001 that documents the 1993 and 1995 site work. Additional investigations by USACE took place annually between 1999 and 2006 to locate and remove thousands of barrels spread the Unalakleet vicinity by flooding and inappropriate disposal. Soil contamination is primarily from diesel fuel, with some areas exceeding cleanup levels for PAHs, PCBs, DDT, benzene, trichloroethene, and mercury. Hazard ID 849 is used for the site wide information repository. ---Updated 2011-- Removal actions under the 2010 Work Plan for Remedial Actions was initiated in 2010. Additional removal activities and site characterization activities continue sitewide in 2011. Preliminary data has not been submitted to ADEC, however the USACE indicates that the estimated quantity of contamination at the site was been under estimated initially. The USACE will submit a report to ADEC at the end of this field season presenting all the data collected in 2010 and 2011, as well as present alternative remedial actions at this site. ---Updated 2021--- Currently the primary contaminants of concern remaining for treatment are PAHs, PCB, and TCE. PAHs include over 10,000 CY of soil with an average depth of 2 ft bgs. The current treatment plan outlined in the decision document is phytoremediation. PCB contaminated soil involves only 26 CY that will be fully removed as part of the preferred treatment. TCE contamination occurs at greater depths and will include excavation of hot spots and phytoremediation. All contamination involved is still in place.

Action Information

Action Date	Action	Description	DEC Staff
8/1/1986	Update or Other Action	(Old R:Base Action Code = SI - Site Investigation). Alaska District site investigation resulted in three chemical reports and one inventory report (March 1989).	Former Staff
1/1/1989	Update or Other Action	(Old R:Base Action Code = RIFS - Remedial Investigation / Feasibility Study). Conducted in 1989, with options to include design work.	Former Staff
1/31/1992	Site Added to Database	Asbestos, PCB, and petroleum contamination.	Former Staff
9/8/1992	Update or Other Action	(Old R:Base Action Code = RPL2 - Site Information Request Letter). ADEC sent PRP-CS Database Notification letter to RP requesting update and more environmental information concerning contaminated site. Jim Levine\COE called 10-5-92 and responded by returning updated DECRPTs.	Jeff Peterson
3/3/1993	Meeting or Teleconference Held	Markey report pre-construction meeting in Fairbanks describing DERP project at Unalakleet and North River sites.	Rielle Markey
3/3/1993	Site Characterization Workplan Approved	(Old R:Base Action Code = MP - Management Plan (CERCLIS)). Markey received specifications describing scope of project at Unalakleet and North River sites. Martech is the contractor.	Rielle Markey
3/26/1993	Update or Other Action	(Old R:Base Action Code = CORR - Correspondence (General)). Markey sent letter to COE describing ADEC concerns with project.	Rielle Markey
7/29/1993	Update or Other Action	(Old R:Base Action Code = RECN - Site Reconnaissance (CS)). Field inspection. AWS site demolition and clean up by Martech under contract to ACOE. Thermal Desorption Unit on site, will burn TPH soils and PCBs less than 50ppm. Asbestos landfill permit to COE. Gary Lawley is Martech onsite Manager. See also file # 630.15.002.	Ronan Short
12/27/1993	Meeting or Teleconference Held	Visit to COE verified that project is on-going (shut down for winter), the contractor is MARTEC - Dave Maiero, Project Manager, telephone 561-1970.	Bob Couch
4/5/1994	Site Ranked Using the AHRM	Initial ranking.	Former Staff
2/1/1995	Update or Other Action	USACE has new contractor, Aman Environmental Construction, Inc. (Martec went bankrupt). Following 4 documents were submitted: Quality Control Plan, Chemical Data Acquisition Plan, Asbestos Abatement Plan, Disposal Plan.	Tamar Stephens
5/23/1995	Update or Other Action	Risk Assessment received: reevaluates cleanup levels, proposes raising cleanup levels for DRO from 100 to 2000 in non-wetland areas.	Tamar Stephens
12/21/1995	Update or Other Action	(Old R:Base Action Code = CORR - Correspondence (General)). ADEC was contacted by Carl Overpeck, hired by Unalakleet Native Corporation as independent consultant due to community concern about proposed changes in cleanup levels. He asked for, and received, permission to review ADEC files on Unalakleet.	Tamar Stephens
3/20/1997	Update or Other Action	Site updated by Shannon and Wilson, based on the FUDS Site Summary dated 2/21/96.	S&W
4/14/2000	Meeting or Teleconference Held	Staff traveled to Unalakleet April 13-14 to tour sites of concern and attend public meeting. The meeting is to comment on a site investigation of 15 areas outside the White Alice facilities that the community has stated the military had used in the past. The Corps of Engineers did site investigations on 15 sites last summer.	Patrice Buck
6/16/2000	Update or Other Action	Staff accompanied the Corp of Engineers to areas around the village of Unalakleet to count drums that were scattered during flooding and storms. They estimated approximately 2,000 drums most are badly deteriorated with very few with any content. The Corp also did additional sampling in areas contamination was found last year. The Corp plan to award a contract for drum removal for next summer. There are two Air Force site near Unalakleet one is managed by the 611th and the other is a FUDs site managed by the Corp. Staff visited both sites which were torn down in 1995. The contractor doing the project went bankrupt and a final report was never produced. Lack of documentation of the remediation activities prevents ADEC approval of the clean up.	Patrice Buck
2/22/2001	Update or Other Action	Staff commented on Work Plan and Field Sampling Approval for Site Investigation at Unalakleet. Action entered by Sarah Riddle.	Patrice Buck
6/11/2001	Proposed Plan	Staff approved Work Plan and Field Sampling Approval for Site Investigation at Unalakleet. Action entered by Sarah Riddle.	Patrice Buck
7/15/2002	Update or Other Action	Staff traveled to Unalakleet to attend meeting with the Native Council of Unalakleet and representatives from BIA, COE, and AF 611th. Also attending were contractors for DoD‘s Native American Lands Environmental Mitigation Program (NAEMLP). Various sites that the Native council is concerned about were visited. NAEMLP provides funding through a cooperative agreement for FUD projects on Native lands that have not been given high priority by the COE. NAEMLP is looking into a possible UXO disposal site outside of the village and a vehicle burial site. The COE will begin a drum removal project in August 2002. Staff is currently reviewing the work plan.	Patrice Buck
7/30/2002	Proposed Plan	Staff conditionally approved Draft Work Plan for Unalakleet Drum Removal. Action entered by Sarah Riddle.	Patrice Buck
4/3/2003	Meeting or Teleconference Held	Staff travel to Unalakleet to meet with Tribal Environment Technician, Corps of Engineers, and the Air Force. The drum removal report for the worked done last summer was discussed. Removal of contaminated soil related to leaking drums is schedule for 2004. The Air Force plans to hold a public meeting and site investigation June 26-27. After the meeting, the Corps informed us the drum removal report was rejected due to sampling data problems.	Patrice Buck
10/24/2003	Update or Other Action	Staff reviewed and commented on Draft Final Remedial Action Report Unalakleet Drum Removal Project at Formerly Used Defense Site, Unalakleet, AK. U.S. Army Corps of Engineers, Alaska District (COE) contractor conducted a drum removal project in 2002 near Unalakleet. The project included removing over 3,000 drums scattered around the Unalakleet area, analyzing the contents (if any) of the drums, and collecting soil samples where leaks were suspected. Staff also reviewed and commented on the Draft Engineering Evaluation and Cost Analysis Remedial Action. This document presents the results of the COE evaluation of alternatives for removing leaking 55-gallon drums and associated contaminated soil from various locations around Unalakleet. The COE’s preferred alternative is removal of drums and contaminated soil using a truck and an all- terrain vehicle. This effort, currently scheduled for 2004, is a continuation of drum removal work initiated by the COE in 2002. The COE estimates that there are 210 drums left to remove.	Patrice Buck
1/28/2005	GIS Position Updated	Updated the site location. Location inferred from maps submitted in reports and based on site visits.	Colin Craven
1/28/2005	Update or Other Action	Staff reviewed the draft Work Plan for the 2005 site activities ("Contaminated Soil, Barrel Removal, Site Characterization") and submitted comments to the Army Corps of Engineers. The main site restoration occurred in 1993 and 1995 during building demolition and debris removal, and thousands of barrels were removed in 2002. The scope of the activities proposed for 2005 is to finalize the excavation of contaminated soil and remove the remaining barrels in the vicinity of the former Aircraft Control and Warning site. Comment resolution will soon proceed to finalize the Work Plan.	Colin Craven
2/18/2005	Update or Other Action	A comment resolution meeting was held at Elmendorf Air Force Base between the US Army Corps of Engineers, their contractors, and DEC. The meeting was held to provide clarification on comments and discuss plans for Site Characterization and contaminated soil/barrel removal from the Unalakleet sites in the summer of 2005. Numerous issues on the details of sampling and analysis, stockpile location, additional sites for characterization were discussed and will be resolved amongst all parties before finalizing the work plan.	Colin Craven
6/13/2005	Site Characterization Workplan Approved	The work plan for the 2005 site activities was approved with minor stipulations resolved verbally with USACE contractors.	Colin Craven
9/14/2005	Update or Other Action	ADEC conducted a site inspection of the areas where US Army Corps of Engineers contractors performed site characterization and contaminated soil removal during the summer. The main work locations were near the shore of Norton Sound (the Drum Dump and Communications Building), and along Air Force Road (former main radar installation and nearby generator infrastructure). A local resident accompanied the site inspection to relay concerns about flooding due to gravel extraction and excavation of contaminated soil near the shore. Areas of petroleum contaminated soil at the Drum Dump couldn’t be removed without undermining the nearby road base, and backfilling at some areas of the main radar installation were poorly completed. Otherwise, the site work appears to have achieved the project objectives.	Colin Craven
12/7/2005	Meeting or Teleconference Held	The first official meeting of the Unalakleet RAB was held in the new community hall. Attendees included co-chairs from the community, USACE, and Air Force, as well as approximately six of the community RAB members. Despite a shift in the meeting schedule due to flight delays, the RAB meeting was also well attended by other members of the community. After summarizing the recent site characterization and debris removal work at both former Air Force installations (Aircraft Control & Warning, and North River White Alice), discussion revolved around several unpermitted dumps and other Air Force sites that are not included in the current scope of work by either the Air Force or USACE. Many local residents have knowledge of these site locations, although it was difficult to determine whether these areas had already been investigated due to the different names given to the sites by the locals and the Department of Defense. The frequency of future RAB meetings was not determined, but is expected to be approximately biannual.	Colin Craven
2/1/2006	Update or Other Action	ADEC received the draft report documenting the 2005 site activities.	Colin Craven
3/28/2006	Update or Other Action	ADEC submitted comments on the draft report documenting the 2005 site work. The removal actions succeeded in removing petroleum contaminated soil from the Communications Building and Drum Dump to the extent practicable. Site characterization performed at the former main radar installation helped fill data gaps left from incomplete work in the 1990s. Requested changes include submission of conceptual site models, reconsideration of calculated site-specific background concentrations of arsenic and chromium, additional clarification on former infrastructure locations in relation to documented soil contamination, and differentiation between biogenic interference and petroleum contamination in diesel range organic soil sample results. Comment resolution is scheduled for April 2006.	Colin Craven
4/21/2006	Update or Other Action	Comment resolution between the Army Corps, Jacobs Engineering, and ADEC. All of DEC's comments and suggested changes to the draft 2005 report were accepted. Based upon the results from the 2005 work, the Corps will have Jacobs perform additional site work in 2006. This additional work tentatively includes backfilling of old excavations, additional soil and surface water sampling at selected sites, and further development of the background metals in soil study. DEC has requested further clarification from the Corps about their goals for site closure and work planned for 2006.	Colin Craven
7/12/2006	Meeting or Teleconference Held	RAB meeting in Unalakleet. Attendees included USACE and contractors, 611th Air Force, local RAB members, public representatives, and a representative from ACAT by teleconference. Meeting minutes will soon be made available on the Contaminated Sites RAB web page.	Colin Craven
8/1/2006	Site Characterization Report Approved	ADEC received the final report titled "Barrel Removal, Contaminated Soil Removal, and Site Characterization Report", dated July 2006. The report documents work conducted in summer 2005. ADEC's comments on the draft report were adequately addressed in the final version. First draft conceptual site models were included in the report, but won't be revised to include ADEC input until the 2006 field activities are complete and can be included in an upcoming remedial investigation report.	Colin Craven
8/18/2006	Site Characterization Workplan Approved	ADEC received the final workplan addendum titled "Contaminated Soil Removal, Barrel Removal, and Site Characterization Activities", dated August 2006. The work plan describes additional activities to be conducted at selected sites investigated previously in 2005. Activities include further soil removal at areas where recovered barrels had leaked, and additional sampling at sites where DRO and metal concentrations in soil are suspected to be mostly due to biogenic interference or background contributions, respectively. ADEC's comments on the draft report were adequately addressed in the final version.	Colin Craven
11/24/2006	Update or Other Action	ADEC received the draft report documenting the 2006 site activities at Unalakleet FUDS prepared by Jacobs Engineering. Work conducted included additional barrel removal, cleanup of diesel and pentachlorophenol contamination from leaking barrels, background metal sampling, and other miscellaneous tasks.	Colin Craven
3/19/2007	Exposure Tracking Model Ranking	Initial ranking. Break site into following subsites: Kouwegok Slough, Barrel Disposal Area, Landfill by Air Force Road, Barrel Bluff, Army Hill, and Quarry/Gravel Pit.	Lisa Maserjian
4/2/2007	Update or Other Action	Project Closure signed by DEC and Air Force for the Containerized Hazardous, Toxic, or Radiological Waste (CON?HTRW) for the Unalakleet Air Force Station FUDS project. This closure decidion involves only the structures left by Air Force, not removal of contaminated soil.	Lisa Maserjian
4/7/2008	Exposure Tracking Model Ranking	Initial ranking with ETM completed.	Kim DeRuyter
5/16/2008	Document, Report, or Work plan Review - other	Received the Draft 2008 Feasibility Study.	Kim DeRuyter
6/13/2008	Update or Other Action	Sent letter in response to the Draft FS, the letter describes ADECs proposed remedial actions at each source area.	Kim DeRuyter
6/18/2008	Update or Other Action	A draft Feasibility Study and Draft Proposed Plan were received May 16 and June 2, 2008. DEC concurred with the no further remedial action recommendation for: Site 8 - Barrel Bluff, Site 13 - Gravel Pit, Site 14 - Beach Road Drum Dump, Site 17 - Landfill by Air Force Road, Site 18 - Abandoned Fuel Truck, Site 23 - Barrel Disposal Area, Site 25A&B - Water Pump House 1 & 2, Site 25G - South Dome Tower, Site 25H - North & South Radar Buildings, Site 25L - Fuel Filling Station, Site 25M - Sewage Treatment Plant Building and Outfall. Site 25N - Former Landfill. Remedial alternatives are being discussed for the remaining sites.	Kim DeRuyter
6/20/2008	Proposed Plan	Reviewed and provided comments on the Draft Proposed Plan, a Draft/Final was received on June 30, 2008 but they was not time to comment and create a final document prior to the July 7 RAB meeting. Excavation and off site treatment is the the proposed remedial action at most sites. ADEC stated agreement in the June 13, 2008 Draft FS comment letter to NFA for the Barrel Bluff, Gravel Pit, Beach Road Drum Dump, Landfill by Air Force Road, Abandoned Fuel Truck, Barrel Disposal Area, Pump House 1 & 2, South Dome Tower, North and South Radar Buildings, Fuel Filling Station, Sewage Treatment Plant and Outfall, and Former Landfill sites. After the letter was sent ADEC took a second look at the Tranformer Storage Area and determined site characterization for this area was adequate, and NFA was required at this former source area. This was addressed in a teleconference with the ACOE.	Kim DeRuyter
7/7/2008	Meeting or Teleconference Held	The Army Corps and the Air Force held a joint RAB meeting in Unalakleet to discuss the FUDS Proposed Plan, and the North River release investigation. Colin Craven (DEC), Kim DeRuyter (DEC), Todd Fickle (AF), Ron Pflum (ACOE), Scott McKean(ACOE), Mike Jones and Kyle Waldron (ENSR), Jennifer Anderson (Jacobs) attended the RAB meeting. The new community co-chair Teri Panipichuk set up the meeting hall, but the meeting was not well attended due to the opening of fishing season. The RAB members that attended had questions about the cleanup levels, and concerns about migration of contaminants to surface water. The community is gradually moving up Army Hill, and several new wells have been drilled, and more are planned for the near future. ACAT had tested the wells, and DEC will request a copy of the well data.	Kim DeRuyter
7/7/2008	Site Visit	A site visit was conducted to most of the source areas prior to the RAB meeting. The Communication Building site which had DRO Contamination up to 14,000 ppm could not be located, it appears to have been covered with pavement by ADOT during improvements to the access road to the airport. The consultant will review the records to determine if GPS data is available for the site. An additional drum with product, and numerous lead-acid batteries and a compressed gas tank were found near one of the Musk Ox Farm buildings. It is unclear if this potential source area is of military origin.	Kim DeRuyter
9/17/2008	Update or Other Action	Approved the Final Feasibility Study. The FS describes the proposed remedial alternative for all of the sites. Excavation and off site treatment or disposal was the selected remedial alternative for the sites that still have contamination above the ingestion and inhalation cleanup levels. In addition to removing contaminated soil the ACOE will remove additional drums located in 2007 and 2008, sample groundwater wells, gather information on existing and proposed groundwater wells and assess the need for further groundwater characterization.	Kim DeRuyter
11/26/2008	Document, Report, or Work plan Review - other	Staff provided comments on the 2008 Draft Decision Document for the Unalakleet Air Craft Warning Site. The Air Force's preferred selected remedy is excavation and offsite treatment/disposal of the remaining petroleum and PAH soil contamination. ADEC requested ICs on the unpermitted landfills, evaluation of the extent of DDT contamination at the thermal treatment site, sampling of private drinking water wells located near the former installation, and a groundwater evaluation to determine the current and anticipated future use of groundwater as a drinking water source near the formerly used defense site. Impacts to groundwater were not previously investigated due to dense bedrock underlying the site, but community members have begun developing lots and drilling wells along the hillside and the entire community plans to relocate closer to the former installation in response to the impacts of coastal erroion at the current townsite.	Kim DeRuyter
3/20/2009	Meeting or Teleconference Held	Staff and Jennifer Currie with the Department of Law met with the Army Corps of Engineers (ACOE) and their contractor to resolve DECs comments to the Decision Document for the Unalakleet Air Craft Warning Formerly Used Defense Site. The ACOE had included language in the Applicable or Relevant and Appropriate Requirements (ARARs) section of the Decision Document which stated that ADEC’s cleanup standards were neither legally applicable nor relevant, but those state standards that were more stringent than Federal requirements might be considered applicable for the site. CS suggested revisions to the document which the ACOE legal advisor will review. Jennifer Currie offered to work with the ACOE’s legal advisor to develop language that would be acceptable to both parties. All of the remaining comments were resolved and following the completion of the action items, the Final DD will be completed and submitted for signature. The remedial action and clean sweep are scheduled for 2009.	Kim DeRuyter
6/1/2009	Document, Report, or Work plan Review - other	Further revisions to the DD were received on 4/17/08, but some comments were not addressed and DEC provided comments to additional changes to the DD on 4/30/09. These comments were addressed and DEC received and approved of the Final DD on 5/12/09. The approved document was signed by John Halverson on June 1, 2009.	Kim DeRuyter
10/22/2009	Document, Report, or Work plan Review - other	Provided comments on the remedial action work plan received on October 2nd, only minor changes need addressed prior to approval.	Kim DeRuyter
6/10/2010	Site Visit	Staff traveled to Unalakleet for a public meeting and site visit. The public meeting was cordial. Members of the community thanked the Army Corps for conducting the soil remediation and drum removal. Staff visited all of the sites with the exception of the drums along the river and the lead sheild cable due to time constraints.	Kim DeRuyter
7/2/2010	Site Visit	Staff conducted a site visit with the Army Corps QA officer and their contractors. The remedial action was underway, and the contractor had located the two sites which had not been located during the previous site visit. These were the lead shield cable and site 7 which were in separate areas in the wetlands East of the slough. The contractor in charge of the excavations was keeping excellent site notes, had a thorough understanding of the work plan, and appeared to be very conscientious. Contaminated soil from each excavation was either still next to the excavation or placed in well labeled super sacks. Staff felt that the work was being conducted in a manner that met State goals and regulations for the site. However, many of the hilltop excavations were into fractured bedrock, and meeting cleanup concentrations may prove difficult or impossible due to the fine soil sifting down between the rock.	Kim DeRuyter
3/1/2011	Update or Other Action	Request report from USACE regarding field activites completed in 2010. USACE PM Ron Pflum sent SOW for the contract modification stating that a report for this last season's field work will not be developed. He also stated that there may not be funding available, and cleanup may be post poned until 2012.	Amanda Loomis
6/10/2011	Document, Report, or Work plan Review - other	Recieved and reviewed the Work Plan Addendum	Amanda Loomis
7/14/2011	Meeting or Teleconference Held	Meeting to discuss initial 2011 sample results and to discuss an appropriate path forward at the site.	Amanda Loomis
7/27/2011	Document, Report, or Work plan Review - other	Surface Water Sampling Work Plan recieved and reviewed	Amanda Loomis
8/19/2011	Update or Other Action	ADEC reply to USACE response to comment on the Surface Water Work Plan and the Work Plan Addendum	Amanda Loomis
11/4/2011	Meeting or Teleconference Held	A teleconference was held to resolve issues with the 2011 Draft Workplan for Remedial Action Addendum and Surface Water workplan.	Dennis Shepard
1/4/2012	Meeting or Teleconference Held	ADEC staff attanded a meeting with US Corps of Engineers (USACE)representatives and contractors to hear an update on 2010 and 2011 remedial action results. The USACE stated that much more Trichloroethene (TCE) and Polynuclear Aromatic Hydrocarbon (PAH) contamination above decision document levels has been identified. The extent of TCE and PAH contamination on site 25 remains un-determined.	Dennis Shepard
2/6/2012	Document, Report, or Work plan Review - other	ADEC received a copy of the draft document, 2010-2011 Remedial Action Report, Formerly Used Defense Site, Unalakleet, Alaska	Dennis Shepard
2/29/2012	Document, Report, or Work plan Review - other	ADEC submitted preliminary comments on the draft document, 2010-2011 Remedial Action Report, Formerly Used Defense Site, Unalakleet, Alaska.	Dennis Shepard
3/1/2012	Meeting or Teleconference Held	ADEC staff attended a meeting at Joint Base Elmendorf Richardson to discuss the 2010 and 2011 remedial action progress report. The workplan agenda for 2012 remedial action was also discussed. Removal of up to 2,900 cubic yards of Trichloroethene contaminated soil is planned for 2012.	Dennis Shepard
3/6/2012	Update or Other Action	Project manager changed from Vreeman to Shepard.	Rebecca Bryan
3/16/2012	Document, Report, or Work plan Review - other	ADEC provided comments on the draft document, 2010-2011 Remedial Action Report, Formerly Used Defense Site, Unalakleet, Alaska	Dennis Shepard
3/27/2012	Document, Report, or Work plan Review - other	ADEC received a draft UFP-QAPP for the 2012 RA Workplan. Complete Workplan not yet received.	Dennis Shepard
5/2/2012	Document, Report, or Work plan Review - other	ADEC received the draft 2012 Remedial Action Workplan for Formerly Used Defense Site, Unalakleet Alaska, Draft April 2012	Dennis Shepard
5/30/2012	Document, Report, or Work plan Review - other	ADEC provided comment on the Draft 2012 Remedial Action Workplan for Unalakleet.	Dennis Shepard
5/31/2012	Meeting or Teleconference Held	ADEC staff attended a technical project planning meeting at the Bethyl Services offices in Anchorage, Alaska. The meeting was held to discuss the 2012 Remedial Action Workplan and workplan objectives for the Unalakleet cleanup.	Dennis Shepard
6/20/2012	Meeting or Teleconference Held	On June 20, 2012, a public meeting was held in Unalakleet to discuss the remedial actions and remaining concerns for contaminated sites at the Unalakleet FUDS Aircraft Warning Site. The Unalakleet Public meeting was attended by U.S. Army Corps of Engineers (USACE), the USACE consultants, BSI- OASIS, ADEC Project Manager, and members of the Unalakleet community.	Dennis Shepard
6/21/2012	Site Visit	Alaska Department of Environmental Conservation (ADEC) Project Manager, conducted a site visit on June 21, 2012.	Dennis Shepard
12/5/2013	Meeting or Teleconference Held	Scoping meeting held between ADEC and USACE on sites associated with the FUDS former Aircraft Control & Warning Station. Discussed potential sampling of the onsite landfill, groundwater sampling locations, addition of PCB sampling to the landfill, and delineating the lateral extent of PAH and TCE potential contamination beyond the landfill.	Meredith Savage
11/26/2014	Update or Other Action	Received copy of Scope of Work from USACE concerning a Remedial Investigation/Feasibility Study for the former Unalakleet Air Force Station, Aircraft Control & Warning Site 25 FUDS. The Remedial Investigation would include groundwater evaluation, soil sampling at the Martech landfill, and soil sampling at other areas throughout the project area. The Feasibility Study would include a Development and Screening of Alternatives and a Detailed Analysis of Alternatives.	Meredith Savage
2/12/2015	Update or Other Action	Received document titled Draft Remedial Investigation Work Plan/QAPP Former Aircraft Control & Warning Station Main Complex FUDS.	Meredith Savage
6/5/2015	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (ADEC) approved a work plan titled Final Remedial Investigation Work Plan/Quality Assurance Project Plan, Unalakleet Air Force Station Formerly Used Defense Site, received on June 4, 2015. The document outlines the activities to be conducted to carry out a remedial investigation (RI) of the Unalakleet Aircraft Control and Warning (AC&W) main complex located approximately 3.5 miles north of the Village of Unalakleet. The objective of the RI is to collect adequate data to supplement existing data from previous investigations for purposes of completing a feasibility study. Activities this field season will include installation of four groundwater monitoring wells and sampling of the wells and down gradient seeps for trichloroethene (TCE) and breakdown products, surface and sub-surface sampling (including near surface sampling of the onsite landfill) for diesel range organics (DRO), volatile organic compounds (VOCs), polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and dioxins.	Meredith Savage
8/27/2015	Update or Other Action	Staff assigned changed to Joy Whitsel	Joy Whitsel
1/19/2017	Site Characterization Report Approved	The United States Army Corps of Engineers – Alaska District (USACE-AK) conducted a remedial investigation in 2015 at the Unalakleet FUDS, Site 25, Aircraft Control and Warning Main Complex in Unalakleet, Alaska. The purpose of the investigation was to refine the nature and extent of contamination, update the conceptual site model, and develop alternative cleanup levels for preparation of a dedicated feasibility study for the site. The final report addresses all DEC comments and DEC concerns raised at a meeting held with USACE-AK on July 21, 2016. DEC approves the final report.	Joy Whitsel
6/12/2017	Public Notice	A public meeting was held in Unalakleet, where the US Army Corps of Engineers presented the draft Feasibility Study (FS) for public comment. The preferred alternative identified in the FS was targeted, limited removal of PCBs and deep TCE-contaminated soil combined with phytoremediation (planting willows and grasses) to remediate PAHs and TCE within the upper 8 feet of soil.	Joy Whitsel
12/29/2017	CERCLA FS	DEC received the U.S. Army Corps of Engineers’(USACE) response to DEC’s July 24, 2017 comments on the "Draft Feasibility Study, Unalakleet Air Force Station, Formerly Used Defense Site Aircraft Control and Warning Main Complex (F10AK003605), Unalakleet, Alaska" dated June 2017 via email on November 17, 2017. DEC evaluated the response to comments, and provided said evaluation to USACE on December 29, 2017.	Melinda Brunner
12/10/2018	CERCLA FS	DEC has reviewed the United States Army Corps of Engineers’ (USACE) September 17, 2018 response to DEC’s supplementary comments on the “Draft Feasibility Study, Unalakleet Air Force Station Formerly Used Defense Site Aircraft Control and Warning Station Main Complex (F10AK003605), Unalakleet, Alaska” dated June 2017. DEC sent an evaluation letter with attached comments to the USACE via email on December 10, 2018.	Melinda Brunner
3/5/2019	CERCLA FS	DEC sent the United States Army Corps of Engineers a letter acknowledging receipt of the “Final Feasibility Study, Unalakleet Air Force Station Formerly Used Defense Site Aircraft Control and Warning Main Complex (F10AK003605), Unalakleet, Alaska” dated December 2018. As noted in the letter, DEC disagrees with the exclusion of 18 AAC 60.015, 18 AAC 75.340(k), 18 AAC 75.355(b), 18 AAC 75.355(d), 18 AAC 75.355(e), and 18 AAC 75.360 from the list of applicable or relevant and appropriate requirements (ARARs)to be considered at the site within the framework of CERCLA.	Melinda Brunner
7/3/2019	Update or Other Action	Site location was updated on this date. Coordinates for this site are used to determine the presence and position of the site on BLM’s ANCSA Conveyed Land web map.	Rebekah Reams
8/16/2021	Document, Report, or Work plan Review - other	DEC reviewed the Draft Decision Document for the Unalakleet ACW Main Complex. DEC provided comments on the plan which was received on 7/8/2021. The document outlined the preferred altrernative for treatment at Unalakleet Air Force Station Site 25. Remaining contaminants of concern at the site include polychlorinated biphenols (PCBs), polycyclic aromatic hydrocarbons (PAHs), and trichloroethylene (TCE). The treatment of the site will consist of excavation and removal of all PCBs above Cleanup levels (1 mg/kg). TCE below 8' below ground surface and lower will also be removed. Remaining TCE and PAH contamination on site will be addressed by Phytoremediation using native willow species over an expected 20 year time frame.	Axl LeVan
12/2/2021	Exposure Tracking Model Ranking	Initial ranking with ETM completed for source area id: 79426 name: Site 25 - Main AC&W Station	Axl LeVan
12/23/2021	Update or Other Action	DEC sent a non-concurrence letter to USACE regarding the final decision document. The letter described DEC concerns with changes to the previously proposed alternatives and the lack of information regarding plant tissue sampling. The letter outlined a potential path forward for DEC to concur with the plan moving forward.	Axl LeVan
5/17/2022	Document, Report, or Work plan Review - other	DEC received and reviewed responses to the Non-Concurrence letter regarding the Final Decision Document. DEC is currently waiting for the a memorandum for the record to record these responses in the site administrative record.	Axl LeVan
5/27/2022	Exposure Tracking Model Ranking	A new updated ranking with ETM has been completed for source area 79426 Site 25 - Main AC&W Station.	Axl LeVan
5/30/2023	CERCLA Removal Action Plan	The Alaska Department of Environmental Conservation (DEC) has completed a review of the "Draft Remedial Action Work Plan, Unalakleet Aircraft Control and Warning Complex FUDS, Unalakleet, Alaska, May 2023". The work Plan presents actions planned for 2023 and 2024 to address contamination associated with the former Unalakleet Air Force Station (AFS) Formerly Used Defense Site (FUDS). The remedial action will include the removal of all remaining polychlorinated biphenyl (PCB) contaminated soil and hot spot removal of trichloroethylene (TCE) contaminated for offsite disposal. Remaining TCE and polycyclic aromatic hydrocarbons (PAH) contaminated soil will be placed into a willow phytoremediation cell for soil treatment at the site. The plan includes details for initial and continuing sampling of soil contaminants.	Axl LeVan
12/13/2023	Meeting or Teleconference Held	Discussed the status of the phytoremediation work at the site with the USAF representative. Discussed potential adjustments to the work plan based on the site conditions that were discovered during 2023 work.	Axl LeVan

Action Date

Action

Description

DEC Staff

8/1/1986

Update or Other Action

(Old R:Base Action Code = SI - Site Investigation). Alaska District site investigation resulted in three chemical reports and one inventory report (March 1989).

Former Staff

1/1/1989

Update or Other Action

(Old R:Base Action Code = RIFS - Remedial Investigation / Feasibility Study). Conducted in 1989, with options to include design work.

Former Staff

1/31/1992

Site Added to Database

Asbestos, PCB, and petroleum contamination.

Former Staff

9/8/1992

Update or Other Action

(Old R:Base Action Code = RPL2 - Site Information Request Letter). ADEC sent PRP-CS Database Notification letter to RP requesting update and more environmental information concerning contaminated site. Jim Levine\COE called 10-5-92 and responded by returning updated DECRPTs.

Jeff Peterson

3/3/1993

Meeting or Teleconference Held

Markey report pre-construction meeting in Fairbanks describing DERP project at Unalakleet and North River sites.

Rielle Markey

3/3/1993

Site Characterization Workplan Approved

(Old R:Base Action Code = MP - Management Plan (CERCLIS)). Markey received specifications describing scope of project at Unalakleet and North River sites. Martech is the contractor.

Rielle Markey

3/26/1993

Update or Other Action

(Old R:Base Action Code = CORR - Correspondence (General)). Markey sent letter to COE describing ADEC concerns with project.

Rielle Markey

7/29/1993

Update or Other Action

(Old R:Base Action Code = RECN - Site Reconnaissance (CS)). Field inspection. AWS site demolition and clean up by Martech under contract to ACOE. Thermal Desorption Unit on site, will burn TPH soils and PCBs less than 50ppm. Asbestos landfill permit to COE. Gary Lawley is Martech onsite Manager. See also file # 630.15.002.

Ronan Short

12/27/1993

Meeting or Teleconference Held

Visit to COE verified that project is on-going (shut down for winter), the contractor is MARTEC - Dave Maiero, Project Manager, telephone 561-1970.

Bob Couch

4/5/1994

Site Ranked Using the AHRM

Initial ranking.

Former Staff

2/1/1995

Update or Other Action

USACE has new contractor, Aman Environmental Construction, Inc. (Martec went bankrupt). Following 4 documents were submitted: Quality Control Plan, Chemical Data Acquisition Plan, Asbestos Abatement Plan, Disposal Plan.

Tamar Stephens

5/23/1995

Update or Other Action

Risk Assessment received: reevaluates cleanup levels, proposes raising cleanup levels for DRO from 100 to 2000 in non-wetland areas.

Tamar Stephens

12/21/1995

Update or Other Action

(Old R:Base Action Code = CORR - Correspondence (General)). ADEC was contacted by Carl Overpeck, hired by Unalakleet Native Corporation as independent consultant due to community concern about proposed changes in cleanup levels. He asked for, and received, permission to review ADEC files on Unalakleet.

Tamar Stephens

3/20/1997

Update or Other Action

Site updated by Shannon and Wilson, based on the FUDS Site Summary dated 2/21/96.

S&W

4/14/2000

Meeting or Teleconference Held

Staff traveled to Unalakleet April 13-14 to tour sites of concern and attend public meeting. The meeting is to comment on a site investigation of 15 areas outside the White Alice facilities that the community has stated the military had used in the past. The Corps of Engineers did site investigations on 15 sites last summer.

Patrice Buck

6/16/2000

Update or Other Action

Staff accompanied the Corp of Engineers to areas around the village of Unalakleet to count drums that were scattered during flooding and storms. They estimated approximately 2,000 drums most are badly deteriorated with very few with any content. The Corp also did additional sampling in areas contamination was found last year. The Corp plan to award a contract for drum removal for next summer. There are two Air Force site near Unalakleet one is managed by the 611th and the other is a FUDs site managed by the Corp. Staff visited both sites which were torn down in 1995. The contractor doing the project went bankrupt and a final report was never produced. Lack of documentation of the remediation activities prevents ADEC approval of the clean up.

Patrice Buck

2/22/2001

Update or Other Action

Staff commented on Work Plan and Field Sampling Approval for Site Investigation at Unalakleet. Action entered by Sarah Riddle.

Patrice Buck

6/11/2001

Proposed Plan

Staff approved Work Plan and Field Sampling Approval for Site Investigation at Unalakleet. Action entered by Sarah Riddle.

Patrice Buck

7/15/2002

Update or Other Action

Staff traveled to Unalakleet to attend meeting with the Native Council of Unalakleet and representatives from BIA, COE, and AF 611th. Also attending were contractors for DoD‘s Native American Lands Environmental Mitigation Program (NAEMLP). Various sites that the Native council is concerned about were visited. NAEMLP provides funding through a cooperative agreement for FUD projects on Native lands that have not been given high priority by the COE. NAEMLP is looking into a possible UXO disposal site outside of the village and a vehicle burial site. The COE will begin a drum removal project in August 2002. Staff is currently reviewing the work plan.

Patrice Buck

7/30/2002

Proposed Plan

Staff conditionally approved Draft Work Plan for Unalakleet Drum Removal. Action entered by Sarah Riddle.

Patrice Buck

4/3/2003

Meeting or Teleconference Held

Staff travel to Unalakleet to meet with Tribal Environment Technician, Corps of Engineers, and the Air Force. The drum removal report for the worked done last summer was discussed. Removal of contaminated soil related to leaking drums is schedule for 2004. The Air Force plans to hold a public meeting and site investigation June 26-27. After the meeting, the Corps informed us the drum removal report was rejected due to sampling data problems.

Patrice Buck

10/24/2003

Update or Other Action

Staff reviewed and commented on Draft Final Remedial Action Report Unalakleet Drum Removal Project at Formerly Used Defense Site, Unalakleet, AK. U.S. Army Corps of Engineers, Alaska District (COE) contractor conducted a drum removal project in 2002 near Unalakleet. The project included removing over 3,000 drums scattered around the Unalakleet area, analyzing the contents (if any) of the drums, and collecting soil samples where leaks were suspected. Staff also reviewed and commented on the Draft Engineering Evaluation and Cost Analysis Remedial Action. This document presents the results of the COE evaluation of alternatives for removing leaking 55-gallon drums and associated contaminated soil from various locations around Unalakleet. The COE’s preferred alternative is removal of drums and contaminated soil using a truck and an all- terrain vehicle. This effort, currently scheduled for 2004, is a continuation of drum removal work initiated by the COE in 2002. The COE estimates that there are 210 drums left to remove.

Patrice Buck

1/28/2005

GIS Position Updated

Updated the site location. Location inferred from maps submitted in reports and based on site visits.

Colin Craven

1/28/2005

Update or Other Action

Staff reviewed the draft Work Plan for the 2005 site activities ("Contaminated Soil, Barrel Removal, Site Characterization") and submitted comments to the Army Corps of Engineers. The main site restoration occurred in 1993 and 1995 during building demolition and debris removal, and thousands of barrels were removed in 2002. The scope of the activities proposed for 2005 is to finalize the excavation of contaminated soil and remove the remaining barrels in the vicinity of the former Aircraft Control and Warning site. Comment resolution will soon proceed to finalize the Work Plan.

Colin Craven

2/18/2005

Update or Other Action

A comment resolution meeting was held at Elmendorf Air Force Base between the US Army Corps of Engineers, their contractors, and DEC. The meeting was held to provide clarification on comments and discuss plans for Site Characterization and contaminated soil/barrel removal from the Unalakleet sites in the summer of 2005. Numerous issues on the details of sampling and analysis, stockpile location, additional sites for characterization were discussed and will be resolved amongst all parties before finalizing the work plan.

Colin Craven

6/13/2005

Site Characterization Workplan Approved

The work plan for the 2005 site activities was approved with minor stipulations resolved verbally with USACE contractors.

Colin Craven

9/14/2005

Update or Other Action

ADEC conducted a site inspection of the areas where US Army Corps of Engineers contractors performed site characterization and contaminated soil removal during the summer. The main work locations were near the shore of Norton Sound (the Drum Dump and Communications Building), and along Air Force Road (former main radar installation and nearby generator infrastructure). A local resident accompanied the site inspection to relay concerns about flooding due to gravel extraction and excavation of contaminated soil near the shore. Areas of petroleum contaminated soil at the Drum Dump couldn’t be removed without undermining the nearby road base, and backfilling at some areas of the main radar installation were poorly completed. Otherwise, the site work appears to have achieved the project objectives.

Colin Craven

12/7/2005

Meeting or Teleconference Held

The first official meeting of the Unalakleet RAB was held in the new community hall. Attendees included co-chairs from the community, USACE, and Air Force, as well as approximately six of the community RAB members. Despite a shift in the meeting schedule due to flight delays, the RAB meeting was also well attended by other members of the community. After summarizing the recent site characterization and debris removal work at both former Air Force installations (Aircraft Control & Warning, and North River White Alice), discussion revolved around several unpermitted dumps and other Air Force sites that are not included in the current scope of work by either the Air Force or USACE. Many local residents have knowledge of these site locations, although it was difficult to determine whether these areas had already been investigated due to the different names given to the sites by the locals and the Department of Defense. The frequency of future RAB meetings was not determined, but is expected to be approximately biannual.

Colin Craven

2/1/2006

Update or Other Action

ADEC received the draft report documenting the 2005 site activities.

Colin Craven

3/28/2006

Update or Other Action

ADEC submitted comments on the draft report documenting the 2005 site work. The removal actions succeeded in removing petroleum contaminated soil from the Communications Building and Drum Dump to the extent practicable. Site characterization performed at the former main radar installation helped fill data gaps left from incomplete work in the 1990s. Requested changes include submission of conceptual site models, reconsideration of calculated site-specific background concentrations of arsenic and chromium, additional clarification on former infrastructure locations in relation to documented soil contamination, and differentiation between biogenic interference and petroleum contamination in diesel range organic soil sample results. Comment resolution is scheduled for April 2006.

Colin Craven

4/21/2006

Update or Other Action

Comment resolution between the Army Corps, Jacobs Engineering, and ADEC. All of DEC's comments and suggested changes to the draft 2005 report were accepted. Based upon the results from the 2005 work, the Corps will have Jacobs perform additional site work in 2006. This additional work tentatively includes backfilling of old excavations, additional soil and surface water sampling at selected sites, and further development of the background metals in soil study. DEC has requested further clarification from the Corps about their goals for site closure and work planned for 2006.

Colin Craven

7/12/2006

Meeting or Teleconference Held

RAB meeting in Unalakleet. Attendees included USACE and contractors, 611th Air Force, local RAB members, public representatives, and a representative from ACAT by teleconference. Meeting minutes will soon be made available on the Contaminated Sites RAB web page.

Colin Craven

8/1/2006

Site Characterization Report Approved

ADEC received the final report titled "Barrel Removal, Contaminated Soil Removal, and Site Characterization Report", dated July 2006. The report documents work conducted in summer 2005. ADEC's comments on the draft report were adequately addressed in the final version. First draft conceptual site models were included in the report, but won't be revised to include ADEC input until the 2006 field activities are complete and can be included in an upcoming remedial investigation report.

Colin Craven

8/18/2006

Site Characterization Workplan Approved

ADEC received the final workplan addendum titled "Contaminated Soil Removal, Barrel Removal, and Site Characterization Activities", dated August 2006. The work plan describes additional activities to be conducted at selected sites investigated previously in 2005. Activities include further soil removal at areas where recovered barrels had leaked, and additional sampling at sites where DRO and metal concentrations in soil are suspected to be mostly due to biogenic interference or background contributions, respectively. ADEC's comments on the draft report were adequately addressed in the final version.

Colin Craven

11/24/2006

Update or Other Action

ADEC received the draft report documenting the 2006 site activities at Unalakleet FUDS prepared by Jacobs Engineering. Work conducted included additional barrel removal, cleanup of diesel and pentachlorophenol contamination from leaking barrels, background metal sampling, and other miscellaneous tasks.

Colin Craven

3/19/2007

Exposure Tracking Model Ranking

Initial ranking. Break site into following subsites: Kouwegok Slough, Barrel Disposal Area, Landfill by Air Force Road, Barrel Bluff, Army Hill, and Quarry/Gravel Pit.

Lisa Maserjian

4/2/2007

Update or Other Action

Project Closure signed by DEC and Air Force for the Containerized Hazardous, Toxic, or Radiological Waste (CON?HTRW) for the Unalakleet Air Force Station FUDS project. This closure decidion involves only the structures left by Air Force, not removal of contaminated soil.

Lisa Maserjian

4/7/2008

Exposure Tracking Model Ranking

Initial ranking with ETM completed.

Kim DeRuyter

5/16/2008

Document, Report, or Work plan Review - other

Received the Draft 2008 Feasibility Study.

Kim DeRuyter

6/13/2008

Update or Other Action

Sent letter in response to the Draft FS, the letter describes ADECs proposed remedial actions at each source area.

Kim DeRuyter

6/18/2008

Update or Other Action

A draft Feasibility Study and Draft Proposed Plan were received May 16 and June 2, 2008. DEC concurred with the no further remedial action recommendation for: Site 8 - Barrel Bluff, Site 13 - Gravel Pit, Site 14 - Beach Road Drum Dump, Site 17 - Landfill by Air Force Road, Site 18 - Abandoned Fuel Truck, Site 23 - Barrel Disposal Area, Site 25A&B - Water Pump House 1 & 2, Site 25G - South Dome Tower, Site 25H - North & South Radar Buildings, Site 25L - Fuel Filling Station, Site 25M - Sewage Treatment Plant Building and Outfall. Site 25N - Former Landfill. Remedial alternatives are being discussed for the remaining sites.

Kim DeRuyter

6/20/2008

Proposed Plan

Reviewed and provided comments on the Draft Proposed Plan, a Draft/Final was received on June 30, 2008 but they was not time to comment and create a final document prior to the July 7 RAB meeting. Excavation and off site treatment is the the proposed remedial action at most sites. ADEC stated agreement in the June 13, 2008 Draft FS comment letter to NFA for the Barrel Bluff, Gravel Pit, Beach Road Drum Dump, Landfill by Air Force Road, Abandoned Fuel Truck, Barrel Disposal Area, Pump House 1 & 2, South Dome Tower, North and South Radar Buildings, Fuel Filling Station, Sewage Treatment Plant and Outfall, and Former Landfill sites. After the letter was sent ADEC took a second look at the Tranformer Storage Area and determined site characterization for this area was adequate, and NFA was required at this former source area. This was addressed in a teleconference with the ACOE.

Kim DeRuyter

7/7/2008

Meeting or Teleconference Held

The Army Corps and the Air Force held a joint RAB meeting in Unalakleet to discuss the FUDS Proposed Plan, and the North River release investigation. Colin Craven (DEC), Kim DeRuyter (DEC), Todd Fickle (AF), Ron Pflum (ACOE), Scott McKean(ACOE), Mike Jones and Kyle Waldron (ENSR), Jennifer Anderson (Jacobs) attended the RAB meeting. The new community co-chair Teri Panipichuk set up the meeting hall, but the meeting was not well attended due to the opening of fishing season. The RAB members that attended had questions about the cleanup levels, and concerns about migration of contaminants to surface water. The community is gradually moving up Army Hill, and several new wells have been drilled, and more are planned for the near future. ACAT had tested the wells, and DEC will request a copy of the well data.

Kim DeRuyter

7/7/2008

Site Visit

A site visit was conducted to most of the source areas prior to the RAB meeting. The Communication Building site which had DRO Contamination up to 14,000 ppm could not be located, it appears to have been covered with pavement by ADOT during improvements to the access road to the airport. The consultant will review the records to determine if GPS data is available for the site. An additional drum with product, and numerous lead-acid batteries and a compressed gas tank were found near one of the Musk Ox Farm buildings. It is unclear if this potential source area is of military origin.

Kim DeRuyter

9/17/2008

Update or Other Action

Approved the Final Feasibility Study. The FS describes the proposed remedial alternative for all of the sites. Excavation and off site treatment or disposal was the selected remedial alternative for the sites that still have contamination above the ingestion and inhalation cleanup levels. In addition to removing contaminated soil the ACOE will remove additional drums located in 2007 and 2008, sample groundwater wells, gather information on existing and proposed groundwater wells and assess the need for further groundwater characterization.

Kim DeRuyter

11/26/2008

Document, Report, or Work plan Review - other

Staff provided comments on the 2008 Draft Decision Document for the Unalakleet Air Craft Warning Site. The Air Force's preferred selected remedy is excavation and offsite treatment/disposal of the remaining petroleum and PAH soil contamination. ADEC requested ICs on the unpermitted landfills, evaluation of the extent of DDT contamination at the thermal treatment site, sampling of private drinking water wells located near the former installation, and a groundwater evaluation to determine the current and anticipated future use of groundwater as a drinking water source near the formerly used defense site. Impacts to groundwater were not previously investigated due to dense bedrock underlying the site, but community members have begun developing lots and drilling wells along the hillside and the entire community plans to relocate closer to the former installation in response to the impacts of coastal erroion at the current townsite.

Kim DeRuyter

3/20/2009

Meeting or Teleconference Held

Staff and Jennifer Currie with the Department of Law met with the Army Corps of Engineers (ACOE) and their contractor to resolve DECs comments to the Decision Document for the Unalakleet Air Craft Warning Formerly Used Defense Site. The ACOE had included language in the Applicable or Relevant and Appropriate Requirements (ARARs) section of the Decision Document which stated that ADEC’s cleanup standards were neither legally applicable nor relevant, but those state standards that were more stringent than Federal requirements might be considered applicable for the site. CS suggested revisions to the document which the ACOE legal advisor will review. Jennifer Currie offered to work with the ACOE’s legal advisor to develop language that would be acceptable to both parties. All of the remaining comments were resolved and following the completion of the action items, the Final DD will be completed and submitted for signature. The remedial action and clean sweep are scheduled for 2009.

Kim DeRuyter

6/1/2009

Document, Report, or Work plan Review - other

Further revisions to the DD were received on 4/17/08, but some comments were not addressed and DEC provided comments to additional changes to the DD on 4/30/09. These comments were addressed and DEC received and approved of the Final DD on 5/12/09. The approved document was signed by John Halverson on June 1, 2009.

Kim DeRuyter

10/22/2009

Document, Report, or Work plan Review - other

Provided comments on the remedial action work plan received on October 2nd, only minor changes need addressed prior to approval.

Kim DeRuyter

6/10/2010

Site Visit

Staff traveled to Unalakleet for a public meeting and site visit. The public meeting was cordial. Members of the community thanked the Army Corps for conducting the soil remediation and drum removal. Staff visited all of the sites with the exception of the drums along the river and the lead sheild cable due to time constraints.

Kim DeRuyter

7/2/2010

Site Visit

Staff conducted a site visit with the Army Corps QA officer and their contractors. The remedial action was underway, and the contractor had located the two sites which had not been located during the previous site visit. These were the lead shield cable and site 7 which were in separate areas in the wetlands East of the slough. The contractor in charge of the excavations was keeping excellent site notes, had a thorough understanding of the work plan, and appeared to be very conscientious. Contaminated soil from each excavation was either still next to the excavation or placed in well labeled super sacks. Staff felt that the work was being conducted in a manner that met State goals and regulations for the site. However, many of the hilltop excavations were into fractured bedrock, and meeting cleanup concentrations may prove difficult or impossible due to the fine soil sifting down between the rock.

Kim DeRuyter

3/1/2011

Update or Other Action

Request report from USACE regarding field activites completed in 2010. USACE PM Ron Pflum sent SOW for the contract modification stating that a report for this last season's field work will not be developed. He also stated that there may not be funding available, and cleanup may be post poned until 2012.

Amanda Loomis

6/10/2011

Document, Report, or Work plan Review - other

Recieved and reviewed the Work Plan Addendum

Amanda Loomis

7/14/2011

Meeting or Teleconference Held

Meeting to discuss initial 2011 sample results and to discuss an appropriate path forward at the site.

Amanda Loomis

7/27/2011

Document, Report, or Work plan Review - other

Surface Water Sampling Work Plan recieved and reviewed

Amanda Loomis

8/19/2011

Update or Other Action

ADEC reply to USACE response to comment on the Surface Water Work Plan and the Work Plan Addendum

Amanda Loomis

11/4/2011

Meeting or Teleconference Held

A teleconference was held to resolve issues with the 2011 Draft Workplan for Remedial Action Addendum and Surface Water workplan.

Dennis Shepard

1/4/2012

Meeting or Teleconference Held

ADEC staff attanded a meeting with US Corps of Engineers (USACE)representatives and contractors to hear an update on 2010 and 2011 remedial action results. The USACE stated that much more Trichloroethene (TCE) and Polynuclear Aromatic Hydrocarbon (PAH) contamination above decision document levels has been identified. The extent of TCE and PAH contamination on site 25 remains un-determined.

Dennis Shepard

2/6/2012

Document, Report, or Work plan Review - other

ADEC received a copy of the draft document, 2010-2011 Remedial Action Report, Formerly Used Defense Site, Unalakleet, Alaska

Dennis Shepard

2/29/2012

Document, Report, or Work plan Review - other

ADEC submitted preliminary comments on the draft document, 2010-2011 Remedial Action Report, Formerly Used Defense Site, Unalakleet, Alaska.

Dennis Shepard

3/1/2012

Meeting or Teleconference Held

ADEC staff attended a meeting at Joint Base Elmendorf Richardson to discuss the 2010 and 2011 remedial action progress report. The workplan agenda for 2012 remedial action was also discussed. Removal of up to 2,900 cubic yards of Trichloroethene contaminated soil is planned for 2012.

Dennis Shepard

3/6/2012

Update or Other Action

Project manager changed from Vreeman to Shepard.

Rebecca Bryan

3/16/2012

Document, Report, or Work plan Review - other

ADEC provided comments on the draft document, 2010-2011 Remedial Action Report, Formerly Used Defense Site, Unalakleet, Alaska

Dennis Shepard

3/27/2012

Document, Report, or Work plan Review - other

ADEC received a draft UFP-QAPP for the 2012 RA Workplan. Complete Workplan not yet received.

Dennis Shepard

5/2/2012

Document, Report, or Work plan Review - other

ADEC received the draft 2012 Remedial Action Workplan for Formerly Used Defense Site, Unalakleet Alaska, Draft April 2012

Dennis Shepard

5/30/2012

Document, Report, or Work plan Review - other

ADEC provided comment on the Draft 2012 Remedial Action Workplan for Unalakleet.

Dennis Shepard

5/31/2012

Meeting or Teleconference Held

ADEC staff attended a technical project planning meeting at the Bethyl Services offices in Anchorage, Alaska. The meeting was held to discuss the 2012 Remedial Action Workplan and workplan objectives for the Unalakleet cleanup.

Dennis Shepard

6/20/2012

Meeting or Teleconference Held

On June 20, 2012, a public meeting was held in Unalakleet to discuss the remedial actions and remaining concerns for contaminated sites at the Unalakleet FUDS Aircraft Warning Site. The Unalakleet Public meeting was attended by U.S. Army Corps of Engineers (USACE), the USACE consultants, BSI- OASIS, ADEC Project Manager, and members of the Unalakleet community.

Dennis Shepard

6/21/2012

Site Visit

Alaska Department of Environmental Conservation (ADEC) Project Manager, conducted a site visit on June 21, 2012.

Dennis Shepard

12/5/2013

Meeting or Teleconference Held

Scoping meeting held between ADEC and USACE on sites associated with the FUDS former Aircraft Control & Warning Station. Discussed potential sampling of the onsite landfill, groundwater sampling locations, addition of PCB sampling to the landfill, and delineating the lateral extent of PAH and TCE potential contamination beyond the landfill.

Meredith Savage

11/26/2014

Update or Other Action

Received copy of Scope of Work from USACE concerning a Remedial Investigation/Feasibility Study for the former Unalakleet Air Force Station, Aircraft Control & Warning Site 25 FUDS. The Remedial Investigation would include groundwater evaluation, soil sampling at the Martech landfill, and soil sampling at other areas throughout the project area. The Feasibility Study would include a Development and Screening of Alternatives and a Detailed Analysis of Alternatives.

Meredith Savage

2/12/2015

Update or Other Action

Received document titled Draft Remedial Investigation Work Plan/QAPP Former Aircraft Control & Warning Station Main Complex FUDS.

Meredith Savage

6/5/2015

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (ADEC) approved a work plan titled Final Remedial Investigation Work Plan/Quality Assurance Project Plan, Unalakleet Air Force Station Formerly Used Defense Site, received on June 4, 2015. The document outlines the activities to be conducted to carry out a remedial investigation (RI) of the Unalakleet Aircraft Control and Warning (AC&W) main complex located approximately 3.5 miles north of the Village of Unalakleet. The objective of the RI is to collect adequate data to supplement existing data from previous investigations for purposes of completing a feasibility study. Activities this field season will include installation of four groundwater monitoring wells and sampling of the wells and down gradient seeps for trichloroethene (TCE) and breakdown products, surface and sub-surface sampling (including near surface sampling of the onsite landfill) for diesel range organics (DRO), volatile organic compounds (VOCs), polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and dioxins.

Meredith Savage

8/27/2015

Update or Other Action

Staff assigned changed to Joy Whitsel

Joy Whitsel

1/19/2017

Site Characterization Report Approved

The United States Army Corps of Engineers – Alaska District (USACE-AK) conducted a remedial investigation in 2015 at the Unalakleet FUDS, Site 25, Aircraft Control and Warning Main Complex in Unalakleet, Alaska. The purpose of the investigation was to refine the nature and extent of contamination, update the conceptual site model, and develop alternative cleanup levels for preparation of a dedicated feasibility study for the site. The final report addresses all DEC comments and DEC concerns raised at a meeting held with USACE-AK on July 21, 2016. DEC approves the final report.

Joy Whitsel

6/12/2017

Public Notice

A public meeting was held in Unalakleet, where the US Army Corps of Engineers presented the draft Feasibility Study (FS) for public comment. The preferred alternative identified in the FS was targeted, limited removal of PCBs and deep TCE-contaminated soil combined with phytoremediation (planting willows and grasses) to remediate PAHs and TCE within the upper 8 feet of soil.

Joy Whitsel

12/29/2017

CERCLA FS

DEC received the U.S. Army Corps of Engineers’(USACE) response to DEC’s July 24, 2017 comments on the "Draft Feasibility Study, Unalakleet Air Force Station, Formerly Used Defense Site Aircraft Control and Warning Main Complex (F10AK003605), Unalakleet, Alaska" dated June 2017 via email on November 17, 2017. DEC evaluated the response to comments, and provided said evaluation to USACE on December 29, 2017.

Melinda Brunner

12/10/2018

CERCLA FS

DEC has reviewed the United States Army Corps of Engineers’ (USACE) September 17, 2018 response to DEC’s supplementary comments on the “Draft Feasibility Study, Unalakleet Air Force Station Formerly Used Defense Site Aircraft Control and Warning Station Main Complex (F10AK003605), Unalakleet, Alaska” dated June 2017. DEC sent an evaluation letter with attached comments to the USACE via email on December 10, 2018.

Melinda Brunner

3/5/2019

CERCLA FS

DEC sent the United States Army Corps of Engineers a letter acknowledging receipt of the “Final Feasibility Study, Unalakleet Air Force Station Formerly Used Defense Site Aircraft Control and Warning Main Complex (F10AK003605), Unalakleet, Alaska” dated December 2018. As noted in the letter, DEC disagrees with the exclusion of 18 AAC 60.015, 18 AAC 75.340(k), 18 AAC 75.355(b), 18 AAC 75.355(d), 18 AAC 75.355(e), and 18 AAC 75.360 from the list of applicable or relevant and appropriate requirements (ARARs)to be considered at the site within the framework of CERCLA.

Melinda Brunner

7/3/2019

Update or Other Action

Site location was updated on this date. Coordinates for this site are used to determine the presence and position of the site on BLM’s ANCSA Conveyed Land web map.

Rebekah Reams

8/16/2021

Document, Report, or Work plan Review - other

DEC reviewed the Draft Decision Document for the Unalakleet ACW Main Complex. DEC provided comments on the plan which was received on 7/8/2021. The document outlined the preferred altrernative for treatment at Unalakleet Air Force Station Site 25. Remaining contaminants of concern at the site include polychlorinated biphenols (PCBs), polycyclic aromatic hydrocarbons (PAHs), and trichloroethylene (TCE). The treatment of the site will consist of excavation and removal of all PCBs above Cleanup levels (1 mg/kg). TCE below 8' below ground surface and lower will also be removed. Remaining TCE and PAH contamination on site will be addressed by Phytoremediation using native willow species over an expected 20 year time frame.

Axl LeVan

12/2/2021

Exposure Tracking Model Ranking

Initial ranking with ETM completed for source area id: 79426 name: Site 25 - Main AC&W Station

Axl LeVan

12/23/2021

Update or Other Action

DEC sent a non-concurrence letter to USACE regarding the final decision document. The letter described DEC concerns with changes to the previously proposed alternatives and the lack of information regarding plant tissue sampling. The letter outlined a potential path forward for DEC to concur with the plan moving forward.

Axl LeVan

5/17/2022

Document, Report, or Work plan Review - other

DEC received and reviewed responses to the Non-Concurrence letter regarding the Final Decision Document. DEC is currently waiting for the a memorandum for the record to record these responses in the site administrative record.

Axl LeVan

5/27/2022

Exposure Tracking Model Ranking

A new updated ranking with ETM has been completed for source area 79426 Site 25 - Main AC&W Station.

Axl LeVan

5/30/2023

CERCLA Removal Action Plan

The Alaska Department of Environmental Conservation (DEC) has completed a review of the "Draft Remedial Action Work Plan, Unalakleet Aircraft Control and Warning Complex FUDS, Unalakleet, Alaska, May 2023". The work Plan presents actions planned for 2023 and 2024 to address contamination associated with the former Unalakleet Air Force Station (AFS) Formerly Used Defense Site (FUDS). The remedial action will include the removal of all remaining polychlorinated biphenyl (PCB) contaminated soil and hot spot removal of trichloroethylene (TCE) contaminated for offsite disposal. Remaining TCE and polycyclic aromatic hydrocarbons (PAH) contaminated soil will be placed into a willow phytoremediation cell for soil treatment at the site. The plan includes details for initial and continuing sampling of soil contaminants.

Axl LeVan

12/13/2023

Meeting or Teleconference Held

Discussed the status of the phytoremediation work at the site with the USAF representative. Discussed potential adjustments to the work plan based on the site conditions that were discovered during 2023 work.

Axl LeVan

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Site Report: Unalakleet Air. Warning - Main Radar Site

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State of Alaska Department of Environmental Conservation