Site Report: North River RRS Area C SS001 & SO001

Site Name:	North River RRS Area C SS001 & SO001
Address:	12 Miles from Unalakleet on Gravel Road, Road to Cabin, Unalakleet, AK 99684
File Number:	630.38.001
Hazard ID:	4367
Status:	Active
Staff:	Axl LeVan, 9074512156 axl.levan@alaska.gov
Latitude:	63.886613
Longitude:	-160.521717
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

SS001 - Very high levels PCBs found on road to cabin. Source is from inproper disposal of PCB and used lube oil from the Air Force Radio Relay Station site activities. One very hot spot was found on road to cabin (>40,000 ppm PCBs) and contamination emanated in several directions, tracked by either ATVs or foot. Over 80 cubic yards contaminated soil have been excavated and disposed of. The North River institutional control consists of fencing and warning signs surrounding Areas A and C, excavation cover (liner and backfill), and the agreement to maintain these site controls. The site controls will be maintained until Areas A and C meet DEC Method 2 or site specific risk-based cleanup levels. A Record of Decision (ROD) was signed on September 13, 2010. The ROD describes the Air Forces proposed remedy for this site as excavation and offsite disposal. The goal of the proposed remedial action is to completely remove PCB contaminated soil above 1.0 mg/kg. The remedial action is scheduled for 2012. VMF SO001- This area also includes site SO001 the Vehicle Maintenance Facility. Soil samples were analyzed for PCB, VOCs, SVOCs, POL, pesticides and RCRA metals. DRO was detected to 11,900 ppm (in 1995) and groundwater was encountered at 6 - 8 feet below ground surface. GRO and VOC soil concentrations also exceeded ADEC Method Two criteria. Groundwater samples exceeded the ADEC Method Two groundwater cleanup criterion for DRO (1.5 milligram per liter [mg/L])with a concentration of 4.6 mg/L. A Decision Document for site SO001 was signed on September 13, 2010. The Decision Document describes the Air Force's selected remedy for soil and groundwater at SO001. The proposed remedy for contaminants exceeding Method 2 Migration to groundwater, and Table C groundwater cleanup levels is excavation and landfarming of contaminated soil, longterm monitoring of groundwater contamination, and implementation of Institutional controls to prohibit exposure to groundwater. The remedy will be implemented in 2012.

Action Information

Action Date	Action	Description	DEC Staff
3/23/2007	Exposure Tracking Model Ranking	Initial ranking.	Lisa Maserjian
3/23/2007	Site Added to Database	Site added to the database.	Mitzi Read
6/18/2007	Meeting or Teleconference Held	See meeting notes under OT01.	Lisa Maserjian
9/15/2008	Site Characterization Report Approved	Approved the August 2008 Final Site Characterization and Remedial Investigation Report. PCBs remain within the fenced in area on the trail to the cabin, but the adjacent area to the North of the fence was investigated one sample detected PCBs>1 ppm in this area. Based on 2004 results, a separate area located on the access road just west of the pumphouse road intersection was also investigated. PCBs below 1 ppm were detected on the road in this area.	Kim DeRuyter
3/20/2009	Meeting or Teleconference Held	Staff met with the Air Force and their contractor to discuss a Tech Memo, and the path forward for the North River Radio Relay Station site. PCBs have infiltrated the cracks in the bedrock on an all terrain vehicle trail (site SS001), the Air Force intends to attempt another excavation at this site, but may not be able to achieve cleanup levels.	Kim DeRuyter
9/13/2010	Cleanup Level(s) Approved	A Decision Document for site SO001 was signed on September 13, 2010. The Decision Document describes the Air Force's selected remedy for soil and groundwater at SO001 the Vehicle Maintenance Facility. The proposed remedy for contaminants exceeding Method 2 Migration to groundwater, and Table C groundwater cleanup levels is excavation and landfarming of contaminated soil, longterm monitoring of groundwater contamination, and implementation of Institutional controls to prohibit exposure to groundwater. The remedy will be implemented in 2011.	Kim DeRuyter
9/13/2010	CERCLA ROD Approved	A Record of Decision (ROD) was signed on September 13, 2010. The ROD describes the Air Forces proposed remedy for PCBs at SS001 as excavation and offsite disposal. The goal of the proposed remedial action is to completely remove PCB contaminated soil above 1.0 mg/kg. The Method 2 Ingestion cleanup levels are the proposed cleanup level for POL contaminated soil. The remedial action is scheduled for 2011.	Kim DeRuyter
9/13/2010	Exposure Tracking Model Ranking	Initial ranking with ETM completed for source area id: 78948 name: SO001 Vehicle Maintenance Facility	Kim DeRuyter
6/3/2011	Update or Other Action	Staff provided comments on the Pre-draft Cleanup Plan for SO001 (aka: former vehicle maintenance facility). Petroleum contaminated soil at the site will be excavated and landfarmed at the OT001 site. When the soil meets the Migration to Groundwater cleanup levels it will be returned to the excavation. The excavated area will be fenced to prevent access until the soil is returned to the excavation. Groundwater monitoring wells will be installed to monitor attenuation of the groundwater contamination.	Kim DeRuyter
7/14/2011	CERCLA Remedial Design/Remedial Action Plan Approved	The Air Force has submitted two seperate Quality Assurance Project Plans for the two source areas documented under this entry. SO001 the Vehicle Maintenance Facility is covered under the QAPP/Cleanup plan for petroleum contamination. The departments comments on this QAPP have been incorporated in the final document and the approval letter was issued today. The plan for the vehicle maintenance facility is excavation and landfarming of contaminated soil, additional groundwater monitoring wells will be installed and the groundwater will be monitored for natural attenuation. AT SS001 the trail to the cabin where the PCBs were removed during the interim removal, additonal excavation will be conducted to remove PCBs north of the previous excavation. The excavation will be uncovered and sampled and evaluated for additional excavation. The excavation was reported to have been terminated at the bedrock interface, and the Air Force is currently uncertain if more excavation to remove the remaining PCB contamination will be possible. The QAPP for the SS001 site is undergoing final revision to incorporate the Departments comments.	Kim DeRuyter
12/8/2011	Update or Other Action	The Air Force submitted a draft Tech memo which states that the remedial action planned for this site has been postponed until next summer. The cleanup effort, and confirmation sampling will be described in the Remedial Action Report to be submitted at the end of the 2012 field season	Kim DeRuyter
3/23/2012	Update or Other Action	Project manager changed from DeRuyter to Dooley	Rebecca Bryan
5/24/2012	Document, Report, or Work plan Review - other	ADEC recieved the draft PCB Soil Removal QAPP Revision 1 on May 14 and sent comments on May 23. A removal action is planned for all contaminated soil above cleanup levels.	Meghan Dooley
7/29/2013	Document, Report, or Work plan Review - other	ADEC sent comments on the draft Standard of Operating Procedure for Excavation Dewatering. Groundwater was encountered at the Area C excavation where PCB and 1,2,4 trichlorobenzene are present above cleanup levels in soil. The excavation will have to be dewatered in order to access PCB-contaminated soil that remains above cleanup levels.	Meghan Dooley
9/9/2013	Site Characterization Workplan Approved	Jacobs Engineering submitted, on behalf of the Air Force, and DEC approved a final North River Area C ATV Trail Workplan Addendum. The plan describes how and where soil samples will be collected along the trail between Area C and the private cabin and analyzed for PCBs to further evaluate that adequacy of prior cleanup activities. Two wipe samples for PCBs will also be collected from inside the cabin. Sampling is planned for September 2013.	John Halverson
11/4/2013	Update or Other Action	ADEC recieved and reviewed a Draft Site SS001 (Area C) ATV Trail Technical Memorandum, North River RRS, on November 8, 2013. The report was reviewed but ADEC will wait for full 2013 report before commenting. In response to landowner concerns a privately owned cabin and the ATV access trail to the cabin were assessed for PCB contamination. Analysis of soil samples taken from the ATV trail and around the cabin were all less than ADEC Method Two cleanup levels. Analysis results were non-detect for PCB wipe samples taken from the floor of the cabin.	Meredith Savage
11/26/2013	Meeting or Teleconference Held	ADEC met with Jacobs Engineering at Jacobs' offices for a status update of the North River RRS sites. Decisions reached include: 1. The Draft 2013 North River Report will be submitted in January 2014; 2. Site closure will be sought for the WACS, Area B, and the ATV Trail and Cabin; 3. Additional sampling will be conducted at Area C to delineate the extent of TCB and ADEC will consider a proposal for the installation of groundwater wells to monitor potential PCB and TCB groundwater contamination; 4. A Risk Assessment may be necessary in order to leave PCB contamination in place at Area A; 5. The ROD will need to be amended for change in approach to Area C and Area A cleanup;	Meredith Savage
3/27/2014	Update or Other Action	PCBs above cleanup levels remain on bedrock in Areas A and C at depths of 8 to 19 feet bgs; ROD amendment will be needed to allow site closure with ICs. March 27, 2014, meeting between ADEC, USAF, and Jacobs. In this meeting it was decided that the ROD amendment process will be undertaken in 2015. A work plan will be drafted for work to be conducted during the 2014 field season and a community meeting will be scheduled to get community input on the draft. The work plan will include: 1) installing groundwater monitoring wells at Area C and conducting GW sampling; 2) removing 1,2,4-TCB from two grids and a bedrock ridge, if possible, in Area C; 3) excavation of the floor of grid 31I in the WACS area for remaining PCBs;backfilling Areas A and C; 4) further investigation for DROs and RROs at the drum site south of the cabin; 5) removing contaminated soils from the VMF area and land farming them at the WACS site; and 6) transporting the 640+ super sacks down to Unalakleet.	Meredith Savage
5/6/2014	Meeting or Teleconference Held	Public meeting held at 1:00pm in the Village of Unalakleet to discuss data from 2013 field season and field work proposed for 2014. Attending: Meredith Savage-ADEC,Robert Johnston-USAF, Jennifer Anderson and Forrest Janukajtis-Jacobs Engineering. Discussion was held with community members regarding the information that PCB concentrations above ADEC Table B1, Method 2 cleanup levels still remain onsite at bedrock level at Area A and Area C. Community members voiced concern over the potential that those PCBs would migrate down gradient via groundwater and indicated they would like to see cleanup at site continue. Community members also asked that vegetation be sampled for PCBs. It was agreed that although Areas A and C are at bedrock, additional cleanup efforts would take place this summer, as well as installation of groundwater monitoring wells. Vegetation sampling would be considered.	Meredith Savage
5/13/2014	Document, Report, or Work plan Review - other	ADEC approves as final North River Radio Relay Station 2013 Cleanup Report for PCB- and POL Contaminated Soils.	Meredith Savage
7/14/2014	Document, Report, or Work plan Review - other	Provided comments on Soil Delineation and Drum Removal Work Plan Addendum, received electronically on 7/01/2014. The work plan a)proposes additional sampling in the location of a 55-gallon drum that was found (and removed) from near Area C in August of 2013, and b)proposes to sample and remove any other USAF drums found in the general area of the site.	Meredith Savage
7/29/2014	Document, Report, or Work plan Review - other	Received the draft Vegetation Sampling Work Plan Addendum to the North River Radio Relay Station Cleanup Plan for PCB-Contaminated Areas. The work plan describes the project approach and methodology for sampling vegetation within Site SS001 (Area C) and SS003 (Area A).	Meredith Savage
8/4/2014	Document, Report, or Work plan Review - other	Comments provided the draft Vegetation Sampling Work Plan Addendum to the North River Radio Relay Station Cleanup Plan for PCB-Contaminated Areas.	Meredith Savage
8/7/2014	Document, Report, or Work plan Review - other	Received final Soil Delineation and Drum Removal Work Plan Addendum to North River RRS Cleanup Plan for PCB-Contaminated Areas; work plan approved as final.	Meredith Savage
8/7/2014	Document, Report, or Work plan Review - other	Received final Vegetation Sampling Work Plan Addendum to North River RRS Cleanup Plan for PCB-Contaminated Areas; work plan approved as final.	Meredith Savage
5/20/2015	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (ADEC) received an electronic copy of the document titled 2014 North River Radio Relay Station Site Activities Technical Memorandum on May 19, 2015. The document describes the vegetation sampling, drum investigation, and excavation activities at the North River Radio Relay Station (RRS) site during the 2014 field season. Vegetation sampling was conducted to address concerns raised by the community of Unalakleet about the potential for polychlorinated biphenyl (PCB) contamination in vegetation and to evaluate the potential for transmission through the food chain. Samples were collected from the roots, leaves, and fruits of various plants in the vicinity of the Site SS003 (Area A) excavation, in the vicinity of the Site SS001 (Area C) excavation, and along the ATV trail to the recreational cabin located to the southeast of the Area C excavation. Of the 111 total samples, 88 of the samples had no detection of PCBs and the remaining samples had detections that were less than the PCB soil cleanup level of 1 mg/kg. Detections were limited to root samples and one leaf sample; the highest detection was 0.44 mg/kg. The site of a drum removed in 2013 was sampled for petroleum hydrocarbon contamination. ADEC Method Two Soil Cleanup Levels were exceeded for diesel range organics (DRO) in each of the four samples. Because of suspected biogenic interference (organic matter), a silica gel cleanup was run on the samples and although the results showed that DRO concentrations for the four samples were below soil cleanup levels, a recommendation was made that 1.5 cubic yards of soil be removed from the vicinity of the drum during the 2015 field season and that no further investigation is required. Analytical results from the 2013 remedial action activities at Site OT001 (WACS) showed one remaining small area of PCB concentration exceeding the 1mg/kg soil cleanup level (a 1.18 mg/kg result). The contaminated soil was removed and confirmation sample results were below the soil cleanup levels for PCB. With this action all PCB-contaminated soil has been removed from Site OT001 (WACS), no further remediation is necessary, and site closure is recommended. ADEC has reviewed this report and accepts it as final.	Meredith Savage
6/8/2015	Update or Other Action	Received draft Technical Memorandum titled "Backfill and Restoration for Site SS003 (Area A) and SS001 (Area C)Work Plan, North River Radio Relay Station (RRS).	Meredith Savage
6/11/2015	Update or Other Action	A drum has been found at the Vehicle Maintenance Facility Site SO001(VMF) the drum is filled with soil and no odor was detected. Sampling of drum contents and surrounding area will be added to the field activities being conducted under the Cleanup Plan for Petroleum Areas work plan. Samples will be collected for GRO, DRO, SVOC, and VOC analysis.	Meredith Savage
6/12/2015	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (ADEC) received a document titled North River Radio Relay Station Cleanup Plan for Petroleum Areas on May 29, 2015. The work plan describes the project approach and methods to be used while conducting cleanup activities for petroleum-contaminated soil and groundwater at the North River Radio Relay Station (RRS) site during the 2014 field season. Fuel-contaminated soil exceeding ADEC Method Two Cleanup Levels, Migration to Groundwater, will be removed from the Vehicle Maintenance Facility Site SO001 (VMF) located less than ¼ mile south of the former White Alice Communications System facility, Site OT001 (WACS), and transported to Site OT001 for landfarming. Following excavation of contaminated soil, six groundwater monitoring wells will be installed at the VMF site, and long term monitoring of the groundwater will occur annually for at least two consecutive years or until groundwater cleanup levels are reached and discontinuing monitoring is approved by ADEC. This work plan was approved.	Meredith Savage
6/17/2015	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (ADEC) received an electronic copy of a document titled Site SS001 (Area C) Work Plan Addendum: Berm Soil Sampling, North River Radio Relay Station (RRS) Cleanup Plan for PCB-Contaminated Areas on June 17, 2015. The work plan describes the project approach and methods to be used to conduct soil sampling of the stockpile/berm surrounding the Site SS001 (Area C) excavation. The sampling will be conducted to locate and delineate any remaining areas within the stockpile/berm where concentrations of polychlorinated biphenyl (PCB) and 1,2,4-trichlorobenze (TCB) exceed ADEC cleanup levels. ADEC has reviewed this report and accepts it as final.	Meredith Savage
6/18/2015	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (ADEC) received an electronic copy of a document titled Backfill and Restoration for Site SS003 (Area A) and SS001 (Area C) Work Plan, North River Radio Relay Station (Final) on June 17, 2015. The work plan describes the project approach and methods to be used to backfill the excavations at Site SS001 (Area C) and Site SS003 (Area A). Contamination with polychlorinated biphenyls (PCB) and residual range organics (RRO) remains at bedrock approximately 17 feet below ground surface (bgs) at Area A. Concentrations of the remaining PCBs exceeding the cleanup level of 1 mg/kg range from 1.1 to 320.30 mg/kg, and the concentration of the remaining RRO exceeding the cleanup level of 10,000 mg/kg is up to 41,000 mg/kg. Due to depth and presence of fractured bedrock, no further excavation was recommended for Area A. Contamination with PCB and 1,2,4-trichlorobenzene (TCB) remains in Area C at approximately 10 feet bgs (on floor-PCB) and 8 feet bgs (on sidewalls-TCB). Concentrations of PCBs exceeding cleanup level range from 3.58 to 119.05 mg/kg. The concentration of TCB exceeding the cleanup level of 0.85 mg/kg ranges from 4.8 to 9.4 mg/kg. Excavation at Area C was discontinued due to the presence of groundwater and bedrock. Both sites will be restored to surrounding grade and seeded using an arctic grow mix to aid in minimizing erosion. ADEC has reviewed this report and accepts it as final.	Meredith Savage
6/19/2015	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (ADEC) received an electronic copy of a document titled Site SS001 (Area C) Work Plan Addendum: Berm Soil Sampling, North River Radio Relay Station (RRS) Cleanup Plan for PCB-Contaminated Areas on June 18, 2015. The work plan describes the project approach and methods to be used to conduct soil sampling of the stockpile/berm surrounding the Site SS001 (Area C) excavation. The sampling will be conducted to locate and delineate any remaining areas within the stockpile/berm where concentrations of polychlorinated biphenyl (PCB) and 1,2,4-trichlorobenze (TCB) exceed ADEC cleanup levels. ADEC has reviewed this report and accepts it as final.	Meredith Savage
8/5/2015	Site Characterization Workplan Approved	On July 10, 2015, the Alaska Department of Environmental Conservation (DEC) received a Soil Boring and Well Installation at Site SS001 (Area C) and Site SS003 (Area A) Work Plan Addendum (North River Radio Relay Station Cleanup Plan for Petroleum Areas). The work plan describes the project approach and methods to be used to conduct soil boring advancement and groundwater well installation at Sites Area C and Area A associated with the North River Radio Relay Station in Unalakleet, Alaska. DEC sent comments to the work plan addendum on July 15 and received a response to comments on July 24, 2015. A final work plan with all revisions incorporated was received on August 5, 2015. DEC approved the final work plan on August 5, 2015.	Joy Whitsel
8/6/2015	Update or Other Action	Transferred entire file to Fairbanks 8/7/2015 Cert Return Receipt 7015 0640 0006 5878 3860 3877 3891	Susan Carberry
9/11/2015	Site Characterization Workplan Approved	On September 10, 2015, DEC received an updated figure (Figure 3A) of the proposed groundwater monitoring well installation locations for Area C (Site S0001). This was a modification to the work plan addendum approved by DEC on August 5, 2015. DEC accepts this modification to the work plan.	Joy Whitsel
10/30/2015	Site Visit	Conducted site visit of Areas A and C (SS001) and the VMF (SO001) in coordination with the Oct 29 public RAB meeting. Monitoring wells around the perimeter of Area C and the VMF were successfully established. Area C was backfilled and graded but not seeded prior to snowfall. Five thousand cubic yards (cy) of contaminated soil were excavated from the VMF and were being treated at the landfarm. Approximately 3,000 cy of soil remain at the VMF. Further excavation is anticipated, provided available funding. The excavation area was appropriately sloped and fenced.	Joy Whitsel
4/20/2016	Update or Other Action	DEC approved the 2015 Berm Sampling Tech Memo. The Technical Memorandum describes the stockpile/berm sampling activities that took place at the North River Radio Relay Station (RRS) Site SS001 (Area C) during June 2015. Analytical results from the stockpile/berm sampling at resulted in concentrations below the cleanup levels. Soil from the stockpile/berm was spread out onsite and the area was re-graded and seeded.	Joy Whitsel
7/22/2016	Document, Report, or Work plan Review - other	DEC approved 2015 Site Activities Report, which included the following work at each site: - OT001 (WACS): construction and maintenance of the landfarm for petroleum, oil and lubricants (POL) contaminated soil. - SO001 (VMF): excavating POL-contaminated soil and transporting this soil to the landfarm at Site OT001, collection of soil samples, and installation and sampling of groundwater monitoring wells. All groundwater results were below DEC cleanup levels. - SS001 (Area C): lining and backfilling the existing excavation, drilling, and site restoration; installation and sampling of groundwater monitoring wells. All groundwater results were below DEC cleanup levels. - SS003 (Area A): lining and backfilling the excavation, drilling, and site restoration; soil sampling. All soil results were less than ADEC cleanup levels, which indicates no contamination is present downgradient.	Joy Whitsel
12/16/2016	Site Visit	DEC Project Manager (PM) attended public Restoration Advisory Board (RAB) meeting on 9/20 where US Air Force (USAF) and their contractor provided update of work completed in 2016, including landfarming, excavation and stockpiling of approximately 3,000 cy of petroleum-contaminated soil, and groundwater monitoring. On 9/21, the DEC PM, USAF PM, and contractors conducted a field visit to observe the work completed over the summer at the VMF, landfarm, and Area C, and to check on vegetative re-growth at the sites closed with institutional controls – Areas A and B. Re-growth at Area B is robust; re-growth at Area A is patchy due to large amounts of gravel in the surface soil.	Joy Whitsel
12/16/2016	Document, Report, or Work plan Review - other	DEC received Draft 2016 Site Activities Report. The objective of work conducted at the North River RRS included construction of a stockpile at SS001 (Area C), the removal of petroleum, oil, and lubricant (POL)-contaminated soil from SO001 (vehicle maintenance facility [VMF]), and the operation of a landfarm at OT001 (White Alice Communications System [WACS]). Groundwater monitoring wells were sampled to determine if contamination had migrated to site groundwater at SO001 (VMF) and SS001 (Area C).	Joy Whitsel
2/2/2017	Final Cleanup Report Reviewed	DEC has reviewed and approves as final the 2016 Site Activities Report for North River RRS. DEC agrees with the recommendations of the report – namely: a) further delineation of the extent of and removal of petroleum, oil, and lubricant- (POL) contaminated soil at the vehicle maintenance facility (VMF); b) a minimum of two years of groundwater monitoring upon completion of excavation activities at the VMF; c) continued landfarming activities as described in the report; d) and discontinuation of groundwater monitoring at Area C due to two consecutive years of sampling that indicated contaminants were below DEC groundwater cleanup levels.	Joy Whitsel
8/11/2017	Site Characterization Workplan Approved	DEC approved the work plan addendum for Site Investigation Activities at Site SO001 (Vehicle Maintenance Facility). The purpose of the 2017 field effort is to: perform landfarm maintenance at Site OT001; collect incremental sampling methodology (ISM) samples from the landfarm for analysis of contaminants of concern; remove treated soil from the landfarm, place it back in the SO001 excavation, and prepare the landfarm for additional soil in the following field season; advance test pits around Site SO001 to investigate the extent of petroleum contamination; and to inspect and perform maintenance on the SS001 stockpile.	Joy Whitsel
3/27/2018	Document, Report, or Work plan Review - other	DEC evaluated the draft “Technical Memorandum: 2017 North River Test Pit Sampling” dated January 2018. The memorandum presents the results of sampling 13 test pits at Site SO001 (Vehicle Maintenance Facility) during August 2017. The test pits were dug down to groundwater, and soil was sampled for petroleum-related contaminants. The sampling confirmed contamination above DEC’s cleanup levels left in place at SO001, and the memorandum recommends excavation and landfarming of an additional 1,800 cubic yards of contaminated soil. Comments on the draft memo were given to the U.S. Air Force on 03/27/2018.	Melinda Brunner
5/2/2018	Document, Report, or Work plan Review - other	DEC evaluated the U.S. Air Force's response to DEC's 03/27/18 comments on the draft “Technical Memorandum: 2017 North River Test Pit Sampling” dated January 2018. DEC sent the evaluation to the U.S. Air Force on 05/02/18.	Melinda Brunner
5/4/2018	Document, Report, or Work plan Review - other	DEC evaluated the U.S. Air Force's revised response to DEC's 03/27/18 and 05/02/18 comments on the draft “Technical Memorandum: 2017 North River Test Pit Sampling” dated January 2018. DEC sent the evaluation to the U.S. Air Force on 05/04/18	Melinda Brunner
5/18/2018	Update or Other Action	DEC evaluated the draft “Revised Proposed Plan, North River RRS – Unalakleet, Alaska” dated April 2018 and provided comments to the U.S. Air Force on the document. The proposed plan describes the U.S. Air Force’s intent to amend the September 2010 “Record of Decision, North River Radio Relay Station, Alaska” so that soil contaminated with polychlorinated biphenyls (PCBs) and petroleum, which could not be completely removed, can remain onsite. DEC requested that the U.S. Air Force obtain written concurrence from the U.S. Environmental Protection Agency that the PCBs could remain onsite.	Melinda Brunner
5/22/2018	Meeting or Teleconference Held	DEC (Brunner) attended a public meeting convened by the U.S. Air Force (USAF) in Unalakleet. The public meeting was convened to discuss the "Revised Proposed Plan, North River RRS - Unalakleet, Alaska" dated May 2018	Melinda Brunner
5/22/2018	Update or Other Action	DEC approved the "Revised Proposed Plan, North River RRS - Unalakleet, Alaska" dated May 2018 on May 22, 2018. The document describes the describes the U.S. Air Force’s (Air Force) intent to amend the September 2010 “Record of Decision, North River Radio Relay Station, Alaska” so that soil contaminated with polychlorinated biphenyls (PCBs) and petroleum, which could not be completely removed, can remain onsite in the fractured bedrock, covered with a permeable liner and minimum of eight feet of clean fill to prevent exposure and migration. The 2010 Record of Decision (ROD) indicated all soil with PCB concentrations above the cleanup level (1 milligram per kilogram and petroleum constituents above their respective cleanup levels would be excavated and shipped off the installation for disposal in a landfill located in the contiguous United States. This has been done to the extent practicable at both Sites SS001 (Area C) and SS003 (Area A); however, the selected remedy described in the 2010 ROD did not account for the volume and extent of contamination that has been identified at the Sites SS001 or SS003, nor did it anticipate the presence of fractured bedrock. The proposed change of leaving contamination onsite above the Method Two cleanup levels as described in 18 AAC 75.341 is a fundamental change from the 2010 ROD, hence the need to present the revised remedy to the public for comment.	Melinda Brunner
5/23/2018	Site Visit	DEC (Brunner) conducted a site visit to SS001, SS003 and OT001 with R. Johnston of the U.S. Air Force. The landfarm containing contaminated soil from SO001 at OT001 showed signs of minor stormwater runoff to the surrounding land that the USAF shall address. The contaminated soil stockpile from SO001 currently located atop SS001 had a damaged top cover that the USAF shall replace/repair.	Melinda Brunner
8/14/2018	Update or Other Action	DEC approved the “Technical Memorandum: 2017 North River Test Pit Sampling” dated 10 May 2018. The memorandum presents the results of sampling 13 test pits at Site SO001 (Vehicle Maintenance Facility) during August 2017.	Melinda Brunner
12/21/2018	Update or Other Action	Site location updated following consultation with USAF. Location provided (63.886613, -160.521717) is for SO001.	Eric Breitenberger
2/5/2019	Update or Other Action	DEC evaluated the “North River Radio Relay Station Record of Decision Amendment, Unalakleet, Alaska, Draft” dated November 2018. The record of decision (ROD) amendment describes proposed revisions to the remedies for Site SS001 and Site SS003, to include leaving residual contamination in place with land use controls implemented to ensure protection of human health and the environment. DEC provided comments on the draft ROD amendment to the U.S. Air Force.	Melinda Brunner
5/9/2019	Document, Report, or Work plan Review - other	DEC reviewed and had no comments on the “Draft Supplemental Work Plan, 2019 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003” dated March 2019.	Bri Clark
6/18/2019	Document, Report, or Work plan Review - other	DEC approved the Final Supplemental Work Plan, 2019 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003” dated May 2019. The work plan documents IC inspections and proposed groundwater sampling/monitoring of sites SO001 & SS001. IC inspection is planned for site SS003.	Dennis Shepard
11/18/2019	CERCLA ROD Approved	The Alaska Department of Environmental Conservation (DEC) provided approval of the North River Radio Relay Station, Record of Decision (ROD) Amendment, Unalakleet, Alaska, Final 2019. The ROD amendment documents a change to the remedy selected for two of the three sites addressed in the 2010 ROD that was signed on 13 September 2010 for Sites OT001 (WACS),SS001 (Area C), and SS003 (Area A) (USAF 2010b). Excavation activities were not able to remove all the contaminants above cleanup levels from the site. The ROD amendment presents the new selected remedy: Offsite Disposal of Contaminated Soil, Capping, and Land-Use Controls (LUCs), for Sites SS001 (Area C) and SS003 (Area A).	Dennis Shepard
12/19/2019	Document, Report, or Work plan Review - other	DEC provided review comments for the Draft Technical Project Report, 2019 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003 dated November 2019. The Technical Project Report presents the results of the 2019 Environmental Long Term Management program at North River RRS, Alaska, conducted 17 - 18 June 2019.	Dennis Shepard
1/14/2020	CERCLA ROD Approved	The Air Force provided a signed Final version of the North River Radio Relay Station, Record of Decision (ROD) Amendment, Unalakleet, Alaska, Final 2019. The ROD amendment documents a change to the remedy selected for two of the three sites addressed in the 2010 ROD that was signed on 13 September 2010 for Sites OT001 (WACS),SS001 (Area C), and SS003 (Area A) (USAF 2010b).The ROD amendment documents a change to the remedy selected for two of the three sites addressed in the 2010 ROD that was signed on 13 September 2010 for Sites OT001 (WACS),SS001 (Area C), and SS003 (Area A) (USAF 2010b). Excavation activities were not able to remove all the contaminants above cleanup levels from the site. The ROD amendment presents the new selected remedy: Offsite Disposal of Contaminated Soil, Capping, and Land-Use Controls (LUCs), for Sites SS001 (Area C) and SS003 (Area A).	Dennis Shepard
3/5/2020	Document, Report, or Work plan Review - other	DEC approved the Final 2019 Technical Project Report North River RRS, 2019 Remedial Action Operations, Land Use/Institutional Control North River Radio Relay Station, Alaska, Sites SO001, SS001, SS003, March 2020. The Technical Project Report presents the results of the 2019 Environmental Long Term Management program at North River RRS, Alaska, conducted 17 - 18 June 2019. Work was performed for the following three sites: Area A (SS003), Area C (SS001), and Vehicle Maintenance Facility (SO001).	Dennis Shepard
8/17/2020	Document, Report, or Work plan Review - other	DEC accepted all responses to comments submitted August 3, 2020 on a supplemental work plan developed to address the Institutional Controls (IC) inspections, and groundwater sampling activities associated with the 2020 Long Term Management (LTM) at the North River Radio Relay Station (RRS) Sites SO001, SS001, and SS003, located in Unalakleet, Alaska.	Dennis Shepard
8/27/2020	Risk Assessment Workplan Approved	DEC provided approval for the Final Supplemental Work Plan, 2020 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003” dated August 2020.	Dennis Shepard
4/2/2021	Document, Report, or Work plan Review - other	DEC provided review comments for the Draft Technical Project Report, 2020 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003 dated March 2021. The document presents the results of work performed at North River Radio Relay Station in August and September 2020 to fulfill the inspection and monitoring requirements described in the Land Use Control Management Plan for Sites SO001, SS001, and SS003.	Axl LeVan
5/25/2021	Document, Report, or Work plan Review - other	Staff provided comments on the Draft 2021 Remedial Action-Operation and Long-Term Management Work Plan, North River Radio Relay Station, Sites OT004, SD003, SS007, ST005, and ST006, April 2021. The document was received on May 5, 2021. The Work Plan describes the approach and procedures for site-specific long-term management and remedial action-operation activities at Sparrevohn long-range radar site, including annual groundwater sampling event at site SO001. The WP covers work being performed over a 5-year period and will be reviewed on an annual basis between field seasons. DEC commented that sampling of SS001 Monitoring Wells should be added to the plan.	Axl LeVan
8/2/2021	Document, Report, or Work plan Review - other	Staff approved the Final 2021 Remedial Action-Operation and Long-Term Management Work Plan, North River Radio Relay Station, Sites OT004, SD003, SS007, ST005, and ST006, July 2021. The document was received on August 2, 2021. The Work Plan describes the approach and procedures for site-specific long-term management and remedial action-operation activities at Sparrevohn long-range radar site, including annual groundwater sampling event at site SO001. The WP covers work being performed over a 5-year period and will be reviewed on an annual basis between field seasons. DEC noted that a workplan addendum or field change form will be required to address well decommissioning based on the current work plan.	Axl LeVan
10/7/2021	Document, Report, or Work plan Review - other	DEC reviewed and provided comments on the Draft 2021 CERCLA Five-Year Review for Site SS001 and Second CERCLA Five-Year Review for Site SS003 at the North River Radio Relay Station Unalakleet, Alaska, dated August 2021. The document was received on September 7. The Five-Year Review (FYR) evaluates the implementation and performance of the remedies for the sites in order to determine if the remedies are, and will continue to be, protective of human health and the environment. The FYR covers a period between 6/30/2015 and 9/30/2020.	Axl LeVan
10/20/2021	Document, Report, or Work plan Review - other	DEC approved review comments for the Final Technical Project Report, 2020 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003 dated October 2021. The document presents the results of work performed at North River Radio Relay Station in August and September 2020 to fulfill the inspection and monitoring requirements described in the Land Use Control Management Plan for Sites SO001, SS001, and SS003.	Axl LeVan
12/17/2021	Document, Report, or Work plan Review - other	DEC reviewed and approved the Final 2021 CERCLA Five-Year Review for Site SS001 and Second CERCLA Five-Year Review for Site SS003 at the North River Radio Relay Station Unalakleet, Alaska, dated December 2021. The document was received on December 16th. The Five-Year Review (FYR) evaluates the implementation and performance of the remedies for the sites in order to determine if the remedies are, and will continue to be, protective of human health and the environment. The FYR covers a period between 6/30/2015 and 9/30/2020.	Axl LeVan
1/4/2022	Document, Report, or Work plan Review - other	DEC reviewed the "Draft-Final 2021 Technical Memorandum, 2021 north River Landfarm Confirmation Sampling, North River RRS, November 2021". This report summarizes the results of landfarm confirmation sampling conducted at Sites OT001 and SS001 associated with the North River Radio Relay Station (RRS). Both discrete and Incremental Sampling Methodology (ISM) samples were used to determine the remaining levels of contaminants after landfarming efforts. The report also made a recommendation for the decommissioning of the landfarm based on the sampling results. Based on a review of the document DEC requires additional information to make a determination on decommissioning. Update 3/7/2021: DEC reviewed a second round of USAF response to comments on the technical memorandum.	Axl LeVan
3/24/2022	Meeting or Teleconference Held	DEC, USAF, and contractors had a comment resolution meeting for the Draft-Final 2021 Technical Memorandum. The focus of the discussion was on the path forward to site closure and landfarm decommissioning based on the most recent sampling results. DEC proposed two potential paths forward dependent on the availability of previous data. USAF and contractors accepted the proposals as a path to pursue going forward.	Axl LeVan
4/28/2022	Meeting or Teleconference Held	DEC, USAF, and contractors had a second meeting regarding both the decommissioning of the SO001 Landfarm and the eventual closure of site SO001. In this meeting it was determined by all that the landfarm was ready for decommissioning provided that additional background samples of Total Organic Carbon were collected at the site.	Axl LeVan
5/13/2022	Document, Report, or Work plan Review - other	DEC received the "Draft-Final Remedial Action-Operations and Long-Term Management Report, North River Radio Relay Station, Alaska, SO001, SS001, and SS003, March 2022" on April 14, 2022. This report describes results of the site-specific long-term management (LTM) and remedial action-operation (RA-O) activities at North River radio relay station (RRS), including annual groundwater sampling at site SO001. The report also includes recommendations for future LTM work as part of the five-year work plan. DEC provided comments to USAF.	Axl LeVan
5/24/2022	Document, Report, or Work plan Review - other	DEC approved the "Final 2021 Technical Memorandum, 2021 North River Landfarm Confirmation Sampling, North River RRS, May 2022". This report summarizes the results of landfarm confirmation sampling conducted at Sites OT001 and SS001 associated with the North River Radio Relay Station (RRS). The report also made a recommendation for the decommissioning of the landfarm based on the sampling results.	Axl LeVan
5/24/2022	Exposure Tracking Model Ranking	A new updated ranking with ETM has been completed for source area 75351 Area C - Trail to Cabin.	Axl LeVan
7/6/2022	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (DEC) received "2022 North River RRS Landfarm Technical Memorandum – Work Plan Addendum, June 2022" on June 27, 2022 and provided comments on July 6, 2022. The work plan addendum provides information to guide total organic carbon (TOC) sampling in preparation for landfarm decommissioning at Sites OT001 and SS001 associated with North River Radio Relay Station. The addendum also provides information on the Post-Treatment Sampling and Site Restoration at the landfarm footprints.	Axl LeVan
7/13/2022	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (DEC) approved "2022 North River RRS Landfarm Technical Memorandum – Work Plan Addendum, July 2022" on July 13, 2022. The work plan addendum provides information to guide total organic carbon (TOC) sampling in preparation for landfarm decommissioning at Sites OT001 and SS001 associated with North River Radio Relay Station. The addendum also provides information on the Post-Treatment Sampling and Site Restoration at the landfarm footprints.	Axl LeVan
8/9/2022	Document, Report, or Work plan Review - other	DEC approved the "Final Remedial Action-Operations and Long-Term Management Report, North River Radio Relay Station, Alaska, SO001, SS001, and SS003, August 2022" received on August 9, 2022. This report describes results of the site-specific long-term management (LTM) and remedial action-operation (RA-O) activities at North River radio relay station (RRS), including annual groundwater sampling at site SO001. The report also includes recommendations for future LTM work as part of the five-year work plan. DEC provided comments to USAF.	Axl LeVan
10/26/2022	Document, Report, or Work plan Review - other	DEC reviewed draft Method Three Migration to Groundwater calculations provided in the "2022 North River ACL Approval Memerandum (Draft)". DEC provided comments to USAF on 10/26/2022.	Axl LeVan
1/3/2023	Document, Report, or Work plan Review - other	DEC has completed a review of the "2022 North River RRS Landfarm Decommissioning Report (draft), November 2022". The report summarizes the activities conducted as part of landfarm decommissioning at Sites Ot001 and SS001. This included the backfilling of the site, SO001.	Axl LeVan
3/31/2023	Document, Report, or Work plan Review - other	DEC reviewed and provided comments on the "2023 North River RRS, Groundwater Investigation Work Plan - Draft, March 2023" received March 13th, 2023. The workplan presents information regarding the VOC groundwater investigation at North River RRS Site SS001. The site was identified during the Five-year Review as requiring further sampling of groundwater before a protectiveness determination could be made.	Axl LeVan
4/4/2023	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (DEC) has completed a review of the "2022 Draft Final 2022 Remedial Action-Operation and Long-Term Management Report North River Radio Relay Site, Sites SO001, SS001, SS003, March 2023" received March 22, 2023. This report presents the 2022 annual remedial action-operation and long-term management (LTM) activities conducted between 30 August and 31 August 2022 at the North River Radio Relay Station (RRS). This work included groundwater monitoring at site SO001 and LTM activities at sites SS001, SO001, and SS003.	Axl LeVan
5/18/2023	Document, Report, or Work plan Review - other	DEC reviewed and approved the "2022 North River RRS Landfarm Decommissioning Report (Final), January 2023". This report summarizes the results of landfarm confirmation sampling conducted at Sites OT001 and SS001 associated with the North River Radio Relay Station (RRS). Both discrete and Incremental Sampling Methodology (ISM) samples were used to determine the remaining levels of contaminants after landfarming efforts.	Axl LeVan
7/13/2023	Document, Report, or Work plan Review - other	The Alaska Department of Environmental Conservation (DEC) has completed a review of and approved the "Final Groundwater Investigation: Site SS001 Work Plan – North River Radio Relay Station, July 2023", received July 13, 2023. The workplan presents information regarding the groundwater investigation at North River RRS Site SS001. The site was identified during the Five-year Review as requiring further sampling of groundwater before a protectiveness determination could be made.	Axl LeVan
7/27/2023	Document, Report, or Work plan Review - other	DEC reviewed and approved a work plan (Follow-On Post-Construction Sampling at SO001 (Vehicle Maintenance Facility) Landfarm Sites (Draft), North River Radio Relay Station, Alaska, June 2023) to sample at the former SO001 landfarm footprints located at Site OT001 and SS001. The sampling will investigate whether remaining naphthalene at the footprints require further investigation or are below site specific cleanup levels.	Axl LeVan
10/31/2023	Document, Report, or Work plan Review - other	DEC reviewed and approved the "2023 Follow-On Post-Construction Sampling at SO001 (Vehicle Maintenance Facility) Landfarm Sites (Final), October 2023". The sampling report determined that contamination remaining at the SS001 Landfarm location for SO001 is de minimus. SS001 is currently subject to land-use controls for remaining polychlorinated biphenyl in subsurface soils and ongoing investigation related to VOC contaminants. SO001 will be evaluated for closure following groundwater monitoring results from a separate contract.	Axl LeVan
5/22/2024	Long Term Monitoring Workplan or Report Review	DEC reviewed and provided comments on the "Draft Final 2023 Remedial Action-Operation and Long-Term Management Report, North River Radio Relay Site, May 2024". This Report presents the work performed during long-term management (LTM) activities at the North River RRS.	Axl LeVan
6/10/2024	Long Term Monitoring Workplan or Report Review	DEC reviewed and approved the "Final 2023 Remedial Action-Operation and Long-Term Management Report, North River Radio Relay Site, May 2024". This Report presents the work performed during long-term management (LTM) activities at the North River RRS.	Axl LeVan
6/18/2024	Document, Report, or Work plan Review - other	DEC reviewed and provided comments on the "Draft Groundwater Investigation: Site SS001, North River Radio Relay Site, April 2024". The draft report documents the groundwater investigation at North River Radio Relay Site to evaluate human health and ecological risk associated with volatile organic compounds (VOCs) in the groundwater.	Axl LeVan

Action Date

Action

Description

DEC Staff

3/23/2007

Exposure Tracking Model Ranking

Initial ranking.

Lisa Maserjian

3/23/2007

Site Added to Database

Site added to the database.

Mitzi Read

6/18/2007

Meeting or Teleconference Held

See meeting notes under OT01.

Lisa Maserjian

9/15/2008

Site Characterization Report Approved

Approved the August 2008 Final Site Characterization and Remedial Investigation Report. PCBs remain within the fenced in area on the trail to the cabin, but the adjacent area to the North of the fence was investigated one sample detected PCBs>1 ppm in this area. Based on 2004 results, a separate area located on the access road just west of the pumphouse road intersection was also investigated. PCBs below 1 ppm were detected on the road in this area.

Kim DeRuyter

3/20/2009

Meeting or Teleconference Held

Staff met with the Air Force and their contractor to discuss a Tech Memo, and the path forward for the North River Radio Relay Station site. PCBs have infiltrated the cracks in the bedrock on an all terrain vehicle trail (site SS001), the Air Force intends to attempt another excavation at this site, but may not be able to achieve cleanup levels.

Kim DeRuyter

9/13/2010

Cleanup Level(s) Approved

A Decision Document for site SO001 was signed on September 13, 2010. The Decision Document describes the Air Force's selected remedy for soil and groundwater at SO001 the Vehicle Maintenance Facility. The proposed remedy for contaminants exceeding Method 2 Migration to groundwater, and Table C groundwater cleanup levels is excavation and landfarming of contaminated soil, longterm monitoring of groundwater contamination, and implementation of Institutional controls to prohibit exposure to groundwater. The remedy will be implemented in 2011.

Kim DeRuyter

9/13/2010

CERCLA ROD Approved

A Record of Decision (ROD) was signed on September 13, 2010. The ROD describes the Air Forces proposed remedy for PCBs at SS001 as excavation and offsite disposal. The goal of the proposed remedial action is to completely remove PCB contaminated soil above 1.0 mg/kg. The Method 2 Ingestion cleanup levels are the proposed cleanup level for POL contaminated soil. The remedial action is scheduled for 2011.

Kim DeRuyter

9/13/2010

Exposure Tracking Model Ranking

Initial ranking with ETM completed for source area id: 78948 name: SO001 Vehicle Maintenance Facility

Kim DeRuyter

6/3/2011

Update or Other Action

Staff provided comments on the Pre-draft Cleanup Plan for SO001 (aka: former vehicle maintenance facility). Petroleum contaminated soil at the site will be excavated and landfarmed at the OT001 site. When the soil meets the Migration to Groundwater cleanup levels it will be returned to the excavation. The excavated area will be fenced to prevent access until the soil is returned to the excavation. Groundwater monitoring wells will be installed to monitor attenuation of the groundwater contamination.

Kim DeRuyter

7/14/2011

CERCLA Remedial Design/Remedial Action Plan Approved

The Air Force has submitted two seperate Quality Assurance Project Plans for the two source areas documented under this entry. SO001 the Vehicle Maintenance Facility is covered under the QAPP/Cleanup plan for petroleum contamination. The departments comments on this QAPP have been incorporated in the final document and the approval letter was issued today. The plan for the vehicle maintenance facility is excavation and landfarming of contaminated soil, additional groundwater monitoring wells will be installed and the groundwater will be monitored for natural attenuation. AT SS001 the trail to the cabin where the PCBs were removed during the interim removal, additonal excavation will be conducted to remove PCBs north of the previous excavation. The excavation will be uncovered and sampled and evaluated for additional excavation. The excavation was reported to have been terminated at the bedrock interface, and the Air Force is currently uncertain if more excavation to remove the remaining PCB contamination will be possible. The QAPP for the SS001 site is undergoing final revision to incorporate the Departments comments.

Kim DeRuyter

12/8/2011

Update or Other Action

The Air Force submitted a draft Tech memo which states that the remedial action planned for this site has been postponed until next summer. The cleanup effort, and confirmation sampling will be described in the Remedial Action Report to be submitted at the end of the 2012 field season

Kim DeRuyter

3/23/2012

Update or Other Action

Project manager changed from DeRuyter to Dooley

Rebecca Bryan

5/24/2012

Document, Report, or Work plan Review - other

ADEC recieved the draft PCB Soil Removal QAPP Revision 1 on May 14 and sent comments on May 23. A removal action is planned for all contaminated soil above cleanup levels.

Meghan Dooley

7/29/2013

Document, Report, or Work plan Review - other

ADEC sent comments on the draft Standard of Operating Procedure for Excavation Dewatering. Groundwater was encountered at the Area C excavation where PCB and 1,2,4 trichlorobenzene are present above cleanup levels in soil. The excavation will have to be dewatered in order to access PCB-contaminated soil that remains above cleanup levels.

Meghan Dooley

9/9/2013

Site Characterization Workplan Approved

Jacobs Engineering submitted, on behalf of the Air Force, and DEC approved a final North River Area C ATV Trail Workplan Addendum. The plan describes how and where soil samples will be collected along the trail between Area C and the private cabin and analyzed for PCBs to further evaluate that adequacy of prior cleanup activities. Two wipe samples for PCBs will also be collected from inside the cabin. Sampling is planned for September 2013.

John Halverson

11/4/2013

Update or Other Action

ADEC recieved and reviewed a Draft Site SS001 (Area C) ATV Trail Technical Memorandum, North River RRS, on November 8, 2013. The report was reviewed but ADEC will wait for full 2013 report before commenting. In response to landowner concerns a privately owned cabin and the ATV access trail to the cabin were assessed for PCB contamination. Analysis of soil samples taken from the ATV trail and around the cabin were all less than ADEC Method Two cleanup levels. Analysis results were non-detect for PCB wipe samples taken from the floor of the cabin.

Meredith Savage

11/26/2013

Meeting or Teleconference Held

ADEC met with Jacobs Engineering at Jacobs' offices for a status update of the North River RRS sites. Decisions reached include: 1. The Draft 2013 North River Report will be submitted in January 2014; 2. Site closure will be sought for the WACS, Area B, and the ATV Trail and Cabin; 3. Additional sampling will be conducted at Area C to delineate the extent of TCB and ADEC will consider a proposal for the installation of groundwater wells to monitor potential PCB and TCB groundwater contamination; 4. A Risk Assessment may be necessary in order to leave PCB contamination in place at Area A; 5. The ROD will need to be amended for change in approach to Area C and Area A cleanup;

Meredith Savage

3/27/2014

Update or Other Action

PCBs above cleanup levels remain on bedrock in Areas A and C at depths of 8 to 19 feet bgs; ROD amendment will be needed to allow site closure with ICs. March 27, 2014, meeting between ADEC, USAF, and Jacobs. In this meeting it was decided that the ROD amendment process will be undertaken in 2015. A work plan will be drafted for work to be conducted during the 2014 field season and a community meeting will be scheduled to get community input on the draft. The work plan will include: 1) installing groundwater monitoring wells at Area C and conducting GW sampling; 2) removing 1,2,4-TCB from two grids and a bedrock ridge, if possible, in Area C; 3) excavation of the floor of grid 31I in the WACS area for remaining PCBs;backfilling Areas A and C; 4) further investigation for DROs and RROs at the drum site south of the cabin; 5) removing contaminated soils from the VMF area and land farming them at the WACS site; and 6) transporting the 640+ super sacks down to Unalakleet.

Meredith Savage

5/6/2014

Meeting or Teleconference Held

Public meeting held at 1:00pm in the Village of Unalakleet to discuss data from 2013 field season and field work proposed for 2014. Attending: Meredith Savage-ADEC,Robert Johnston-USAF, Jennifer Anderson and Forrest Janukajtis-Jacobs Engineering. Discussion was held with community members regarding the information that PCB concentrations above ADEC Table B1, Method 2 cleanup levels still remain onsite at bedrock level at Area A and Area C. Community members voiced concern over the potential that those PCBs would migrate down gradient via groundwater and indicated they would like to see cleanup at site continue. Community members also asked that vegetation be sampled for PCBs. It was agreed that although Areas A and C are at bedrock, additional cleanup efforts would take place this summer, as well as installation of groundwater monitoring wells. Vegetation sampling would be considered.

Meredith Savage

5/13/2014

Document, Report, or Work plan Review - other

ADEC approves as final North River Radio Relay Station 2013 Cleanup Report for PCB- and POL Contaminated Soils.

Meredith Savage

7/14/2014

Document, Report, or Work plan Review - other

Provided comments on Soil Delineation and Drum Removal Work Plan Addendum, received electronically on 7/01/2014. The work plan a)proposes additional sampling in the location of a 55-gallon drum that was found (and removed) from near Area C in August of 2013, and b)proposes to sample and remove any other USAF drums found in the general area of the site.

Meredith Savage

7/29/2014

Document, Report, or Work plan Review - other

Received the draft Vegetation Sampling Work Plan Addendum to the North River Radio Relay Station Cleanup Plan for PCB-Contaminated Areas. The work plan describes the project approach and methodology for sampling vegetation within Site SS001 (Area C) and SS003 (Area A).

Meredith Savage

8/4/2014

Document, Report, or Work plan Review - other

Comments provided the draft Vegetation Sampling Work Plan Addendum to the North River Radio Relay Station Cleanup Plan for PCB-Contaminated Areas.

Meredith Savage

8/7/2014

Document, Report, or Work plan Review - other

Received final Soil Delineation and Drum Removal Work Plan Addendum to North River RRS Cleanup Plan for PCB-Contaminated Areas; work plan approved as final.

Meredith Savage

8/7/2014

Document, Report, or Work plan Review - other

Received final Vegetation Sampling Work Plan Addendum to North River RRS Cleanup Plan for PCB-Contaminated Areas; work plan approved as final.

Meredith Savage

5/20/2015

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (ADEC) received an electronic copy of the document titled 2014 North River Radio Relay Station Site Activities Technical Memorandum on May 19, 2015. The document describes the vegetation sampling, drum investigation, and excavation activities at the North River Radio Relay Station (RRS) site during the 2014 field season. Vegetation sampling was conducted to address concerns raised by the community of Unalakleet about the potential for polychlorinated biphenyl (PCB) contamination in vegetation and to evaluate the potential for transmission through the food chain. Samples were collected from the roots, leaves, and fruits of various plants in the vicinity of the Site SS003 (Area A) excavation, in the vicinity of the Site SS001 (Area C) excavation, and along the ATV trail to the recreational cabin located to the southeast of the Area C excavation. Of the 111 total samples, 88 of the samples had no detection of PCBs and the remaining samples had detections that were less than the PCB soil cleanup level of 1 mg/kg. Detections were limited to root samples and one leaf sample; the highest detection was 0.44 mg/kg. The site of a drum removed in 2013 was sampled for petroleum hydrocarbon contamination. ADEC Method Two Soil Cleanup Levels were exceeded for diesel range organics (DRO) in each of the four samples. Because of suspected biogenic interference (organic matter), a silica gel cleanup was run on the samples and although the results showed that DRO concentrations for the four samples were below soil cleanup levels, a recommendation was made that 1.5 cubic yards of soil be removed from the vicinity of the drum during the 2015 field season and that no further investigation is required. Analytical results from the 2013 remedial action activities at Site OT001 (WACS) showed one remaining small area of PCB concentration exceeding the 1mg/kg soil cleanup level (a 1.18 mg/kg result). The contaminated soil was removed and confirmation sample results were below the soil cleanup levels for PCB. With this action all PCB-contaminated soil has been removed from Site OT001 (WACS), no further remediation is necessary, and site closure is recommended. ADEC has reviewed this report and accepts it as final.

Meredith Savage

6/8/2015

Update or Other Action

Received draft Technical Memorandum titled "Backfill and Restoration for Site SS003 (Area A) and SS001 (Area C)Work Plan, North River Radio Relay Station (RRS).

Meredith Savage

6/11/2015

Update or Other Action

A drum has been found at the Vehicle Maintenance Facility Site SO001(VMF) the drum is filled with soil and no odor was detected. Sampling of drum contents and surrounding area will be added to the field activities being conducted under the Cleanup Plan for Petroleum Areas work plan. Samples will be collected for GRO, DRO, SVOC, and VOC analysis.

Meredith Savage

6/12/2015

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (ADEC) received a document titled North River Radio Relay Station Cleanup Plan for Petroleum Areas on May 29, 2015. The work plan describes the project approach and methods to be used while conducting cleanup activities for petroleum-contaminated soil and groundwater at the North River Radio Relay Station (RRS) site during the 2014 field season. Fuel-contaminated soil exceeding ADEC Method Two Cleanup Levels, Migration to Groundwater, will be removed from the Vehicle Maintenance Facility Site SO001 (VMF) located less than ¼ mile south of the former White Alice Communications System facility, Site OT001 (WACS), and transported to Site OT001 for landfarming. Following excavation of contaminated soil, six groundwater monitoring wells will be installed at the VMF site, and long term monitoring of the groundwater will occur annually for at least two consecutive years or until groundwater cleanup levels are reached and discontinuing monitoring is approved by ADEC. This work plan was approved.

Meredith Savage

6/17/2015

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (ADEC) received an electronic copy of a document titled Site SS001 (Area C) Work Plan Addendum: Berm Soil Sampling, North River Radio Relay Station (RRS) Cleanup Plan for PCB-Contaminated Areas on June 17, 2015. The work plan describes the project approach and methods to be used to conduct soil sampling of the stockpile/berm surrounding the Site SS001 (Area C) excavation. The sampling will be conducted to locate and delineate any remaining areas within the stockpile/berm where concentrations of polychlorinated biphenyl (PCB) and 1,2,4-trichlorobenze (TCB) exceed ADEC cleanup levels. ADEC has reviewed this report and accepts it as final.

Meredith Savage

6/18/2015

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (ADEC) received an electronic copy of a document titled Backfill and Restoration for Site SS003 (Area A) and SS001 (Area C) Work Plan, North River Radio Relay Station (Final) on June 17, 2015. The work plan describes the project approach and methods to be used to backfill the excavations at Site SS001 (Area C) and Site SS003 (Area A). Contamination with polychlorinated biphenyls (PCB) and residual range organics (RRO) remains at bedrock approximately 17 feet below ground surface (bgs) at Area A. Concentrations of the remaining PCBs exceeding the cleanup level of 1 mg/kg range from 1.1 to 320.30 mg/kg, and the concentration of the remaining RRO exceeding the cleanup level of 10,000 mg/kg is up to 41,000 mg/kg. Due to depth and presence of fractured bedrock, no further excavation was recommended for Area A. Contamination with PCB and 1,2,4-trichlorobenzene (TCB) remains in Area C at approximately 10 feet bgs (on floor-PCB) and 8 feet bgs (on sidewalls-TCB). Concentrations of PCBs exceeding cleanup level range from 3.58 to 119.05 mg/kg. The concentration of TCB exceeding the cleanup level of 0.85 mg/kg ranges from 4.8 to 9.4 mg/kg. Excavation at Area C was discontinued due to the presence of groundwater and bedrock. Both sites will be restored to surrounding grade and seeded using an arctic grow mix to aid in minimizing erosion. ADEC has reviewed this report and accepts it as final.

Meredith Savage

6/19/2015

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (ADEC) received an electronic copy of a document titled Site SS001 (Area C) Work Plan Addendum: Berm Soil Sampling, North River Radio Relay Station (RRS) Cleanup Plan for PCB-Contaminated Areas on June 18, 2015. The work plan describes the project approach and methods to be used to conduct soil sampling of the stockpile/berm surrounding the Site SS001 (Area C) excavation. The sampling will be conducted to locate and delineate any remaining areas within the stockpile/berm where concentrations of polychlorinated biphenyl (PCB) and 1,2,4-trichlorobenze (TCB) exceed ADEC cleanup levels. ADEC has reviewed this report and accepts it as final.

Meredith Savage

8/5/2015

Site Characterization Workplan Approved

On July 10, 2015, the Alaska Department of Environmental Conservation (DEC) received a Soil Boring and Well Installation at Site SS001 (Area C) and Site SS003 (Area A) Work Plan Addendum (North River Radio Relay Station Cleanup Plan for Petroleum Areas). The work plan describes the project approach and methods to be used to conduct soil boring advancement and groundwater well installation at Sites Area C and Area A associated with the North River Radio Relay Station in Unalakleet, Alaska. DEC sent comments to the work plan addendum on July 15 and received a response to comments on July 24, 2015. A final work plan with all revisions incorporated was received on August 5, 2015. DEC approved the final work plan on August 5, 2015.

Joy Whitsel

8/6/2015

Update or Other Action

Transferred entire file to Fairbanks 8/7/2015 Cert Return Receipt 7015 0640 0006 5878 3860 3877 3891

Susan Carberry

9/11/2015

Site Characterization Workplan Approved

On September 10, 2015, DEC received an updated figure (Figure 3A) of the proposed groundwater monitoring well installation locations for Area C (Site S0001). This was a modification to the work plan addendum approved by DEC on August 5, 2015. DEC accepts this modification to the work plan.

Joy Whitsel

10/30/2015

Site Visit

Conducted site visit of Areas A and C (SS001) and the VMF (SO001) in coordination with the Oct 29 public RAB meeting. Monitoring wells around the perimeter of Area C and the VMF were successfully established. Area C was backfilled and graded but not seeded prior to snowfall. Five thousand cubic yards (cy) of contaminated soil were excavated from the VMF and were being treated at the landfarm. Approximately 3,000 cy of soil remain at the VMF. Further excavation is anticipated, provided available funding. The excavation area was appropriately sloped and fenced.

Joy Whitsel

4/20/2016

Update or Other Action

DEC approved the 2015 Berm Sampling Tech Memo. The Technical Memorandum describes the stockpile/berm sampling activities that took place at the North River Radio Relay Station (RRS) Site SS001 (Area C) during June 2015. Analytical results from the stockpile/berm sampling at resulted in concentrations below the cleanup levels. Soil from the stockpile/berm was spread out onsite and the area was re-graded and seeded.

Joy Whitsel

7/22/2016

Document, Report, or Work plan Review - other

DEC approved 2015 Site Activities Report, which included the following work at each site: - OT001 (WACS): construction and maintenance of the landfarm for petroleum, oil and lubricants (POL) contaminated soil. - SO001 (VMF): excavating POL-contaminated soil and transporting this soil to the landfarm at Site OT001, collection of soil samples, and installation and sampling of groundwater monitoring wells. All groundwater results were below DEC cleanup levels. - SS001 (Area C): lining and backfilling the existing excavation, drilling, and site restoration; installation and sampling of groundwater monitoring wells. All groundwater results were below DEC cleanup levels. - SS003 (Area A): lining and backfilling the excavation, drilling, and site restoration; soil sampling. All soil results were less than ADEC cleanup levels, which indicates no contamination is present downgradient.

Joy Whitsel

12/16/2016

Site Visit

DEC Project Manager (PM) attended public Restoration Advisory Board (RAB) meeting on 9/20 where US Air Force (USAF) and their contractor provided update of work completed in 2016, including landfarming, excavation and stockpiling of approximately 3,000 cy of petroleum-contaminated soil, and groundwater monitoring. On 9/21, the DEC PM, USAF PM, and contractors conducted a field visit to observe the work completed over the summer at the VMF, landfarm, and Area C, and to check on vegetative re-growth at the sites closed with institutional controls – Areas A and B. Re-growth at Area B is robust; re-growth at Area A is patchy due to large amounts of gravel in the surface soil.

Joy Whitsel

12/16/2016

Document, Report, or Work plan Review - other

DEC received Draft 2016 Site Activities Report. The objective of work conducted at the North River RRS included construction of a stockpile at SS001 (Area C), the removal of petroleum, oil, and lubricant (POL)-contaminated soil from SO001 (vehicle maintenance facility [VMF]), and the operation of a landfarm at OT001 (White Alice Communications System [WACS]). Groundwater monitoring wells were sampled to determine if contamination had migrated to site groundwater at SO001 (VMF) and SS001 (Area C).

Joy Whitsel

2/2/2017

Final Cleanup Report Reviewed

DEC has reviewed and approves as final the 2016 Site Activities Report for North River RRS. DEC agrees with the recommendations of the report – namely: a) further delineation of the extent of and removal of petroleum, oil, and lubricant- (POL) contaminated soil at the vehicle maintenance facility (VMF); b) a minimum of two years of groundwater monitoring upon completion of excavation activities at the VMF; c) continued landfarming activities as described in the report; d) and discontinuation of groundwater monitoring at Area C due to two consecutive years of sampling that indicated contaminants were below DEC groundwater cleanup levels.

Joy Whitsel

8/11/2017

Site Characterization Workplan Approved

DEC approved the work plan addendum for Site Investigation Activities at Site SO001 (Vehicle Maintenance Facility). The purpose of the 2017 field effort is to: perform landfarm maintenance at Site OT001; collect incremental sampling methodology (ISM) samples from the landfarm for analysis of contaminants of concern; remove treated soil from the landfarm, place it back in the SO001 excavation, and prepare the landfarm for additional soil in the following field season; advance test pits around Site SO001 to investigate the extent of petroleum contamination; and to inspect and perform maintenance on the SS001 stockpile.

Joy Whitsel

3/27/2018

Document, Report, or Work plan Review - other

DEC evaluated the draft “Technical Memorandum: 2017 North River Test Pit Sampling” dated January 2018. The memorandum presents the results of sampling 13 test pits at Site SO001 (Vehicle Maintenance Facility) during August 2017. The test pits were dug down to groundwater, and soil was sampled for petroleum-related contaminants. The sampling confirmed contamination above DEC’s cleanup levels left in place at SO001, and the memorandum recommends excavation and landfarming of an additional 1,800 cubic yards of contaminated soil. Comments on the draft memo were given to the U.S. Air Force on 03/27/2018.

Melinda Brunner

5/2/2018

Document, Report, or Work plan Review - other

DEC evaluated the U.S. Air Force's response to DEC's 03/27/18 comments on the draft “Technical Memorandum: 2017 North River Test Pit Sampling” dated January 2018. DEC sent the evaluation to the U.S. Air Force on 05/02/18.

Melinda Brunner

5/4/2018

Document, Report, or Work plan Review - other

DEC evaluated the U.S. Air Force's revised response to DEC's 03/27/18 and 05/02/18 comments on the draft “Technical Memorandum: 2017 North River Test Pit Sampling” dated January 2018. DEC sent the evaluation to the U.S. Air Force on 05/04/18

Melinda Brunner

5/18/2018

Update or Other Action

DEC evaluated the draft “Revised Proposed Plan, North River RRS – Unalakleet, Alaska” dated April 2018 and provided comments to the U.S. Air Force on the document. The proposed plan describes the U.S. Air Force’s intent to amend the September 2010 “Record of Decision, North River Radio Relay Station, Alaska” so that soil contaminated with polychlorinated biphenyls (PCBs) and petroleum, which could not be completely removed, can remain onsite. DEC requested that the U.S. Air Force obtain written concurrence from the U.S. Environmental Protection Agency that the PCBs could remain onsite.

Melinda Brunner

5/22/2018

Meeting or Teleconference Held

DEC (Brunner) attended a public meeting convened by the U.S. Air Force (USAF) in Unalakleet. The public meeting was convened to discuss the "Revised Proposed Plan, North River RRS - Unalakleet, Alaska" dated May 2018

Melinda Brunner

5/22/2018

Update or Other Action

DEC approved the "Revised Proposed Plan, North River RRS - Unalakleet, Alaska" dated May 2018 on May 22, 2018. The document describes the describes the U.S. Air Force’s (Air Force) intent to amend the September 2010 “Record of Decision, North River Radio Relay Station, Alaska” so that soil contaminated with polychlorinated biphenyls (PCBs) and petroleum, which could not be completely removed, can remain onsite in the fractured bedrock, covered with a permeable liner and minimum of eight feet of clean fill to prevent exposure and migration. The 2010 Record of Decision (ROD) indicated all soil with PCB concentrations above the cleanup level (1 milligram per kilogram and petroleum constituents above their respective cleanup levels would be excavated and shipped off the installation for disposal in a landfill located in the contiguous United States. This has been done to the extent practicable at both Sites SS001 (Area C) and SS003 (Area A); however, the selected remedy described in the 2010 ROD did not account for the volume and extent of contamination that has been identified at the Sites SS001 or SS003, nor did it anticipate the presence of fractured bedrock. The proposed change of leaving contamination onsite above the Method Two cleanup levels as described in 18 AAC 75.341 is a fundamental change from the 2010 ROD, hence the need to present the revised remedy to the public for comment.

Melinda Brunner

5/23/2018

Site Visit

DEC (Brunner) conducted a site visit to SS001, SS003 and OT001 with R. Johnston of the U.S. Air Force. The landfarm containing contaminated soil from SO001 at OT001 showed signs of minor stormwater runoff to the surrounding land that the USAF shall address. The contaminated soil stockpile from SO001 currently located atop SS001 had a damaged top cover that the USAF shall replace/repair.

Melinda Brunner

8/14/2018

Update or Other Action

DEC approved the “Technical Memorandum: 2017 North River Test Pit Sampling” dated 10 May 2018. The memorandum presents the results of sampling 13 test pits at Site SO001 (Vehicle Maintenance Facility) during August 2017.

Melinda Brunner

12/21/2018

Update or Other Action

Site location updated following consultation with USAF. Location provided (63.886613, -160.521717) is for SO001.

Eric Breitenberger

2/5/2019

Update or Other Action

DEC evaluated the “North River Radio Relay Station Record of Decision Amendment, Unalakleet, Alaska, Draft” dated November 2018. The record of decision (ROD) amendment describes proposed revisions to the remedies for Site SS001 and Site SS003, to include leaving residual contamination in place with land use controls implemented to ensure protection of human health and the environment. DEC provided comments on the draft ROD amendment to the U.S. Air Force.

Melinda Brunner

5/9/2019

Document, Report, or Work plan Review - other

DEC reviewed and had no comments on the “Draft Supplemental Work Plan, 2019 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003” dated March 2019.

Bri Clark

6/18/2019

Document, Report, or Work plan Review - other

DEC approved the Final Supplemental Work Plan, 2019 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003” dated May 2019. The work plan documents IC inspections and proposed groundwater sampling/monitoring of sites SO001 & SS001. IC inspection is planned for site SS003.

Dennis Shepard

11/18/2019

CERCLA ROD Approved

The Alaska Department of Environmental Conservation (DEC) provided approval of the North River Radio Relay Station, Record of Decision (ROD) Amendment, Unalakleet, Alaska, Final 2019. The ROD amendment documents a change to the remedy selected for two of the three sites addressed in the 2010 ROD that was signed on 13 September 2010 for Sites OT001 (WACS),SS001 (Area C), and SS003 (Area A) (USAF 2010b). Excavation activities were not able to remove all the contaminants above cleanup levels from the site. The ROD amendment presents the new selected remedy: Offsite Disposal of Contaminated Soil, Capping, and Land-Use Controls (LUCs), for Sites SS001 (Area C) and SS003 (Area A).

Dennis Shepard

12/19/2019

Document, Report, or Work plan Review - other

DEC provided review comments for the Draft Technical Project Report, 2019 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003 dated November 2019. The Technical Project Report presents the results of the 2019 Environmental Long Term Management program at North River RRS, Alaska, conducted 17 - 18 June 2019.

Dennis Shepard

1/14/2020

CERCLA ROD Approved

The Air Force provided a signed Final version of the North River Radio Relay Station, Record of Decision (ROD) Amendment, Unalakleet, Alaska, Final 2019. The ROD amendment documents a change to the remedy selected for two of the three sites addressed in the 2010 ROD that was signed on 13 September 2010 for Sites OT001 (WACS),SS001 (Area C), and SS003 (Area A) (USAF 2010b).The ROD amendment documents a change to the remedy selected for two of the three sites addressed in the 2010 ROD that was signed on 13 September 2010 for Sites OT001 (WACS),SS001 (Area C), and SS003 (Area A) (USAF 2010b). Excavation activities were not able to remove all the contaminants above cleanup levels from the site. The ROD amendment presents the new selected remedy: Offsite Disposal of Contaminated Soil, Capping, and Land-Use Controls (LUCs), for Sites SS001 (Area C) and SS003 (Area A).

Dennis Shepard

3/5/2020

Document, Report, or Work plan Review - other

DEC approved the Final 2019 Technical Project Report North River RRS, 2019 Remedial Action Operations, Land Use/Institutional Control North River Radio Relay Station, Alaska, Sites SO001, SS001, SS003, March 2020. The Technical Project Report presents the results of the 2019 Environmental Long Term Management program at North River RRS, Alaska, conducted 17 - 18 June 2019. Work was performed for the following three sites: Area A (SS003), Area C (SS001), and Vehicle Maintenance Facility (SO001).

Dennis Shepard

8/17/2020

Document, Report, or Work plan Review - other

DEC accepted all responses to comments submitted August 3, 2020 on a supplemental work plan developed to address the Institutional Controls (IC) inspections, and groundwater sampling activities associated with the 2020 Long Term Management (LTM) at the North River Radio Relay Station (RRS) Sites SO001, SS001, and SS003, located in Unalakleet, Alaska.

Dennis Shepard

8/27/2020

Risk Assessment Workplan Approved

DEC provided approval for the Final Supplemental Work Plan, 2020 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003” dated August 2020.

Dennis Shepard

4/2/2021

Document, Report, or Work plan Review - other

DEC provided review comments for the Draft Technical Project Report, 2020 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003 dated March 2021. The document presents the results of work performed at North River Radio Relay Station in August and September 2020 to fulfill the inspection and monitoring requirements described in the Land Use Control Management Plan for Sites SO001, SS001, and SS003.

Axl LeVan

5/25/2021

Document, Report, or Work plan Review - other

Staff provided comments on the Draft 2021 Remedial Action-Operation and Long-Term Management Work Plan, North River Radio Relay Station, Sites OT004, SD003, SS007, ST005, and ST006, April 2021. The document was received on May 5, 2021. The Work Plan describes the approach and procedures for site-specific long-term management and remedial action-operation activities at Sparrevohn long-range radar site, including annual groundwater sampling event at site SO001. The WP covers work being performed over a 5-year period and will be reviewed on an annual basis between field seasons. DEC commented that sampling of SS001 Monitoring Wells should be added to the plan.

Axl LeVan

8/2/2021

Document, Report, or Work plan Review - other

Staff approved the Final 2021 Remedial Action-Operation and Long-Term Management Work Plan, North River Radio Relay Station, Sites OT004, SD003, SS007, ST005, and ST006, July 2021. The document was received on August 2, 2021. The Work Plan describes the approach and procedures for site-specific long-term management and remedial action-operation activities at Sparrevohn long-range radar site, including annual groundwater sampling event at site SO001. The WP covers work being performed over a 5-year period and will be reviewed on an annual basis between field seasons. DEC noted that a workplan addendum or field change form will be required to address well decommissioning based on the current work plan.

Axl LeVan

10/7/2021

Document, Report, or Work plan Review - other

DEC reviewed and provided comments on the Draft 2021 CERCLA Five-Year Review for Site SS001 and Second CERCLA Five-Year Review for Site SS003 at the North River Radio Relay Station Unalakleet, Alaska, dated August 2021. The document was received on September 7. The Five-Year Review (FYR) evaluates the implementation and performance of the remedies for the sites in order to determine if the remedies are, and will continue to be, protective of human health and the environment. The FYR covers a period between 6/30/2015 and 9/30/2020.

Axl LeVan

10/20/2021

Document, Report, or Work plan Review - other

DEC approved review comments for the Final Technical Project Report, 2020 Remedial Action Operations, Land Use/Institutional Control, North River Radio Relay Station, Alaska, Site SO001, SS001, and SS003 dated October 2021. The document presents the results of work performed at North River Radio Relay Station in August and September 2020 to fulfill the inspection and monitoring requirements described in the Land Use Control Management Plan for Sites SO001, SS001, and SS003.

Axl LeVan

12/17/2021

Document, Report, or Work plan Review - other

DEC reviewed and approved the Final 2021 CERCLA Five-Year Review for Site SS001 and Second CERCLA Five-Year Review for Site SS003 at the North River Radio Relay Station Unalakleet, Alaska, dated December 2021. The document was received on December 16th. The Five-Year Review (FYR) evaluates the implementation and performance of the remedies for the sites in order to determine if the remedies are, and will continue to be, protective of human health and the environment. The FYR covers a period between 6/30/2015 and 9/30/2020.

Axl LeVan

1/4/2022

Document, Report, or Work plan Review - other

DEC reviewed the "Draft-Final 2021 Technical Memorandum, 2021 north River Landfarm Confirmation Sampling, North River RRS, November 2021". This report summarizes the results of landfarm confirmation sampling conducted at Sites OT001 and SS001 associated with the North River Radio Relay Station (RRS). Both discrete and Incremental Sampling Methodology (ISM) samples were used to determine the remaining levels of contaminants after landfarming efforts. The report also made a recommendation for the decommissioning of the landfarm based on the sampling results. Based on a review of the document DEC requires additional information to make a determination on decommissioning. Update 3/7/2021: DEC reviewed a second round of USAF response to comments on the technical memorandum.

Axl LeVan

3/24/2022

Meeting or Teleconference Held

DEC, USAF, and contractors had a comment resolution meeting for the Draft-Final 2021 Technical Memorandum. The focus of the discussion was on the path forward to site closure and landfarm decommissioning based on the most recent sampling results. DEC proposed two potential paths forward dependent on the availability of previous data. USAF and contractors accepted the proposals as a path to pursue going forward.

Axl LeVan

4/28/2022

Meeting or Teleconference Held

DEC, USAF, and contractors had a second meeting regarding both the decommissioning of the SO001 Landfarm and the eventual closure of site SO001. In this meeting it was determined by all that the landfarm was ready for decommissioning provided that additional background samples of Total Organic Carbon were collected at the site.

Axl LeVan

5/13/2022

Document, Report, or Work plan Review - other

DEC received the "Draft-Final Remedial Action-Operations and Long-Term Management Report, North River Radio Relay Station, Alaska, SO001, SS001, and SS003, March 2022" on April 14, 2022. This report describes results of the site-specific long-term management (LTM) and remedial action-operation (RA-O) activities at North River radio relay station (RRS), including annual groundwater sampling at site SO001. The report also includes recommendations for future LTM work as part of the five-year work plan. DEC provided comments to USAF.

Axl LeVan

5/24/2022

Document, Report, or Work plan Review - other

DEC approved the "Final 2021 Technical Memorandum, 2021 North River Landfarm Confirmation Sampling, North River RRS, May 2022". This report summarizes the results of landfarm confirmation sampling conducted at Sites OT001 and SS001 associated with the North River Radio Relay Station (RRS). The report also made a recommendation for the decommissioning of the landfarm based on the sampling results.

Axl LeVan

5/24/2022

Exposure Tracking Model Ranking

A new updated ranking with ETM has been completed for source area 75351 Area C - Trail to Cabin.

Axl LeVan

7/6/2022

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (DEC) received "2022 North River RRS Landfarm Technical Memorandum – Work Plan Addendum, June 2022" on June 27, 2022 and provided comments on July 6, 2022. The work plan addendum provides information to guide total organic carbon (TOC) sampling in preparation for landfarm decommissioning at Sites OT001 and SS001 associated with North River Radio Relay Station. The addendum also provides information on the Post-Treatment Sampling and Site Restoration at the landfarm footprints.

Axl LeVan

7/13/2022

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (DEC) approved "2022 North River RRS Landfarm Technical Memorandum – Work Plan Addendum, July 2022" on July 13, 2022. The work plan addendum provides information to guide total organic carbon (TOC) sampling in preparation for landfarm decommissioning at Sites OT001 and SS001 associated with North River Radio Relay Station. The addendum also provides information on the Post-Treatment Sampling and Site Restoration at the landfarm footprints.

Axl LeVan

8/9/2022

Document, Report, or Work plan Review - other

DEC approved the "Final Remedial Action-Operations and Long-Term Management Report, North River Radio Relay Station, Alaska, SO001, SS001, and SS003, August 2022" received on August 9, 2022. This report describes results of the site-specific long-term management (LTM) and remedial action-operation (RA-O) activities at North River radio relay station (RRS), including annual groundwater sampling at site SO001. The report also includes recommendations for future LTM work as part of the five-year work plan. DEC provided comments to USAF.

Axl LeVan

10/26/2022

Document, Report, or Work plan Review - other

DEC reviewed draft Method Three Migration to Groundwater calculations provided in the "2022 North River ACL Approval Memerandum (Draft)". DEC provided comments to USAF on 10/26/2022.

Axl LeVan

1/3/2023

Document, Report, or Work plan Review - other

DEC has completed a review of the "2022 North River RRS Landfarm Decommissioning Report (draft), November 2022". The report summarizes the activities conducted as part of landfarm decommissioning at Sites Ot001 and SS001. This included the backfilling of the site, SO001.

Axl LeVan

3/31/2023

Document, Report, or Work plan Review - other

DEC reviewed and provided comments on the "2023 North River RRS, Groundwater Investigation Work Plan - Draft, March 2023" received March 13th, 2023. The workplan presents information regarding the VOC groundwater investigation at North River RRS Site SS001. The site was identified during the Five-year Review as requiring further sampling of groundwater before a protectiveness determination could be made.

Axl LeVan

4/4/2023

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (DEC) has completed a review of the "2022 Draft Final 2022 Remedial Action-Operation and Long-Term Management Report North River Radio Relay Site, Sites SO001, SS001, SS003, March 2023" received March 22, 2023. This report presents the 2022 annual remedial action-operation and long-term management (LTM) activities conducted between 30 August and 31 August 2022 at the North River Radio Relay Station (RRS). This work included groundwater monitoring at site SO001 and LTM activities at sites SS001, SO001, and SS003.

Axl LeVan

5/18/2023

Document, Report, or Work plan Review - other

DEC reviewed and approved the "2022 North River RRS Landfarm Decommissioning Report (Final), January 2023". This report summarizes the results of landfarm confirmation sampling conducted at Sites OT001 and SS001 associated with the North River Radio Relay Station (RRS). Both discrete and Incremental Sampling Methodology (ISM) samples were used to determine the remaining levels of contaminants after landfarming efforts.

Axl LeVan

7/13/2023

Document, Report, or Work plan Review - other

The Alaska Department of Environmental Conservation (DEC) has completed a review of and approved the "Final Groundwater Investigation: Site SS001 Work Plan – North River Radio Relay Station, July 2023", received July 13, 2023. The workplan presents information regarding the groundwater investigation at North River RRS Site SS001. The site was identified during the Five-year Review as requiring further sampling of groundwater before a protectiveness determination could be made.

Axl LeVan

7/27/2023

Document, Report, or Work plan Review - other

DEC reviewed and approved a work plan (Follow-On Post-Construction Sampling at SO001 (Vehicle Maintenance Facility) Landfarm Sites (Draft), North River Radio Relay Station, Alaska, June 2023) to sample at the former SO001 landfarm footprints located at Site OT001 and SS001. The sampling will investigate whether remaining naphthalene at the footprints require further investigation or are below site specific cleanup levels.

Axl LeVan

10/31/2023

Document, Report, or Work plan Review - other

DEC reviewed and approved the "2023 Follow-On Post-Construction Sampling at SO001 (Vehicle Maintenance Facility) Landfarm Sites (Final), October 2023". The sampling report determined that contamination remaining at the SS001 Landfarm location for SO001 is de minimus. SS001 is currently subject to land-use controls for remaining polychlorinated biphenyl in subsurface soils and ongoing investigation related to VOC contaminants. SO001 will be evaluated for closure following groundwater monitoring results from a separate contract.

Axl LeVan

5/22/2024

Long Term Monitoring Workplan or Report Review

DEC reviewed and provided comments on the "Draft Final 2023 Remedial Action-Operation and Long-Term Management Report, North River Radio Relay Site, May 2024". This Report presents the work performed during long-term management (LTM) activities at the North River RRS.

Axl LeVan

6/10/2024

Long Term Monitoring Workplan or Report Review

DEC reviewed and approved the "Final 2023 Remedial Action-Operation and Long-Term Management Report, North River Radio Relay Site, May 2024". This Report presents the work performed during long-term management (LTM) activities at the North River RRS.

Axl LeVan

6/18/2024

Document, Report, or Work plan Review - other

DEC reviewed and provided comments on the "Draft Groundwater Investigation: Site SS001, North River Radio Relay Site, April 2024". The draft report documents the groundwater investigation at North River Radio Relay Site to evaluate human health and ecological risk associated with volatile organic compounds (VOCs) in the groundwater.

Axl LeVan

Contaminant Information

Name

Level Description

Media

Comments

Control Type

Type

Details

Requirements

Description

Details

2023 Site SS001 Groundwater Monitoring Work Plan

2022 Final Remedial Action Operations Land Use/Institutional Control Report

2021 Remedial Action Operation and Long Term Management Report Sites

2021 Signed Final Version Five-Year Review for Site SS001 and SS003

Signed Final version of the North River Radio Relay Station, Record of Decision Amendment, Unalakleet, Alaska

Site Summary

No associated sites were found.

Missing Location Data

Because the GIS location data for this site has not been entered, we cannot direct you to its position on the map. Click "Continue" to proceed to the Contaminated Sites Web Map or "Close" to return to the site report.

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Site Report: North River RRS Area C SS001 & SO001

Site Chronology

IC / Closure Details

Documents

Associated Sites

Problems/Comments

Action Information

Contaminant Information

Control Type

Requirements

2023 Site SS001 Groundwater Monitoring Work Plan

2022 Final Remedial Action Operations Land Use/Institutional Control Report

2021 Remedial Action Operation and Long Term Management Report Sites

2021 Signed Final Version Five-Year Review for Site SS001 and SS003

Signed Final version of the North River Radio Relay Station, Record of Decision Amendment, Unalakleet, Alaska

Site Summary

Missing Location Data

State of Alaska Department of Environmental Conservation