| Action Date |
Action |
Description |
DEC Staff |
| 8/25/1995 |
Interim Removal Action Approved |
Action date used is the date of the Air Force Relative Risk Evaluation Worksheet, which indicates the site is in the interim remedial action phase. |
Former Staff |
| 1/24/1997 |
Site Added to Database |
Site added by Shannon and Wilson. See also Reckey 198331X107301. |
S&W |
| 11/26/2004 |
Update or Other Action |
Staff received a risk assessment workplan titled Draft Final Human Health and Ecological Risk Assessment at OT08 and SS10 Work Plan. Staff is putting out a request for proposal to have a term contractor review the workplan. |
Emily Youcha |
| 2/16/2005 |
Update or Other Action |
Staff and term contractor (Oasis Environmental) reviewed the risk assessment workplan and requests more information before approval. The workplan needs to better describe the location of the contamination and whether or not it is migrating. The workplan needs to evaluate whether the data is sufficient for use in risk assessment and provide a discussion of data gaps. |
Emily Youcha |
| 2/16/2005 |
Meeting or Teleconference Held |
Staff held a comment resolution meeting with the Air Force and contractors regarding the risk assessment workplan. The Air Force will address most of our comments in the next version of the workplan. |
Emily Youcha |
| 6/15/2005 |
Update or Other Action |
The spring Restoration Advisory Board (RAB) meeting in Hughes for the Indian Mountain LRRS was cancelled by the 611th Civil Engineer Squadron due to difficulty obtaining permission for travel from the Air Force. A RAB meeting has not been held in Hughes since 2003. Additionally, a field visit that was to be conducted in July by the Air Force and Contaminated Sites staff was cancelled due to similar problems. |
Emily Youcha |
| 7/11/2005 |
Update or Other Action |
Risk Assessment workplan approved.
Because the Air Force expects to retain management of this land, this risk assessment is tailored to the industrial-use scenario. However, if there is ever a change in land use, the Air Force will be required to re-evaluate risk at the site under residential and subsistence land-use scenarios. |
Emily Youcha |
| 9/23/2005 |
Update or Other Action |
Staff received a copy of the Draft Risk Assessment. Staff forwarded ac copy of the document to the ADEC Risk Assessor for review. |
Emily Youcha |
| 9/30/2005 |
Update or Other Action |
Staff visited the Indian Mtn LRRS and visited the IRP and compliance sites with the contractor operating the radar station (Arctec). Weather conditions limited a visit to the top of Upper Camp. |
Emily Youcha |
| 9/30/2005 |
Update or Other Action |
Staff commented on the Indian Mtn Draft Risk Assessment for SS10/OT08. Comments include the following: 1) the likelihood of contaminant spreading during demolition activities and the implications this would have on the risk estimate, 2) subsistence users of the site would be better represented by the ADEC standard default exposure duration for residents of 30 years, 3) If the future land use or ownership changes, the risk estimates presented for OT08 and SS10 will need to be reevaluated 4) ADEC was able to replicate dose calculations for surface soil, but not for subsurface soil, and 5) PCB concentration in excess of 1 mg/kg is an appreciable level from a human health perspective. Since PCBs are bioaccumulative, concentrations below 1 mg/kg may also be considered appreciable from an ecological perspective. |
Emily Youcha |
| 1/26/2006 |
Risk Assessment Report Approved |
The human health risk assessment evaluated potential risks for present and future industrial site use for adult site workers, adult site visitors, and the subsistence fisher/hunter/gatherer. The residential scenario was not evaluated because the current industrial scenario is not anticipated to change. Contract personnel (site workers) operating the minimally attended radar facility at Upper Camp were assumed to be the reasonable maximum exposure scenario for the human health risk assessment. The risk assessment compared its findings with the State of Alaska risk management standards. These standards specify that cumulative cancer risk cannot exceed 1 in 100,000 (1.0 x 10–5) across all exposure pathways, and that non-cancer risks cannot exceed a hazard index (HI) of 1.0 for each exposure pathway. (18 AAC 75.325 (h)) The conclusions below are based on the reasonable maximum exposure risks reported in the risk assessment for the site worker.
Based on the information currently available, DEC concurs with the following specific human health risk assessment conclusions in this report:
1. Lifetime cancer risks do not exceed the risk management standard of 1 in 100,000 (1.0 x 10-5) for the SS10 site worker.
2. Non-cancer risks do not exceed the risk management standard of hazard index of 1.0 for the SS10 site worker.
A two-tiered approach was used for the ecological risk assessment. Conservative screening (Tier I) was first conducted to evaluate whether the chemical concentrations exceed protective screening criteria. A more detailed Tier II assessment would be performed if chemical concentrations exceeded protective screening criteria. However, it was found in the Tier II qualitative exposure analysis that the contaminants of potential ecological concern did not pose a significant ecological hazard. Therefore a quantitative Tier II ecological risk assessment was not performed.
If the land-use scenario or ownership at this site changes, this risk assessment should be reevaluated. This risk assessment does not propose risk-based cleanup levels. Therefore, DEC approval of cleanup levels is not included in approval of this risk assessment. |
Emily Youcha |
| 2/1/2006 |
Institutional Control Record Established |
The 611th CES Base General Plan indicates land-use controls for this site. LUCs are not final but state that no action or activity should occur at this site. The 611 CES should be contacted if any work is proposed in the vicinity of the site. |
Emily Youcha |
| 8/22/2006 |
GIS Position Updated |
Updated site coordinates based on USGS Quad Map. |
Emily Youcha |
| 4/1/2008 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed. |
Tamar Stephens |
| 3/19/2013 |
CERCLA ROD Approved |
The ROD for LF006, SS002 and SS010 was signed by DEC and the Air Force. The selected remedies were No Further Action under CERCLA and institutional controls (ICs)/Land Use Controls (LUCs) under State regulations.
At SS010, groundwater is impacted with DRO (up to 29 mg/L), GRO (up to 8.1 mg/L), trichloroethane (up to 0.022 mg/L) and benzene and pentachlorophenol (both up to 0.0056 mg/L). Soil at the site contains residual DRO, GRO and PAHs. Groundwater beneath the site is not currently used as a drinking water source and the Air Force has no plans to use it as one in the future; however, ICs/LUCs will be implemented to document the residual soil and groundwater contamination and restrict future use until the soil/groundwater meet applicable cleanup levels. The Air Force will add ICs/LUCs to the Base Master Plan and the 611 Air Support Group LUC Management Plan; the site will not be used for residential purposes; installation of water wells will be prohibited; dig permits will be required for any soil exacavation and will include requirements for proper characterization and management of contaminated media. The AF will inspect the sites anually for at least five years to ensure the ICs/LUCs are effective and will submit annual inspection reports to DEC. The inspection and reporting frequency may be modified by mutual agreement after five years. |
John Halverson |
| 11/6/2013 |
Document, Report, or Work plan Review - other |
DEC recieved a Draft Work Plan for 2013 Environmental Long Term Monitoring (LTM) at Indian Mountain, Long Range Radar Station. |
Dennis Shepard |
| 11/26/2013 |
Document, Report, or Work plan Review - other |
DEC received a Draft Report for 2013 Environmental Long Term Monitoring (LTM) at Indian Mountain, Long Range Radar Station. The Report describes field work including groundwater sampling at site SS009, and a land survey to identify site boundaries of eight of the eleven contaminant areas (SD001, LF004, LF005, LF006, SS002, SS009, SS010, and SS011) at the Indian Mountain LRRS. |
Dennis Shepard |
| 11/27/2013 |
Document, Report, or Work plan Review - other |
DEC provided preliminary comments for the 2013 Environmental Long Term Monitoring (LTM) report for Indian Mountain, Long Range Radar Station. The Report describes field work including groundwater sampling at site SS009, and a land survey to identify site boundaries of eight of the eleven contaminant areas (SD001, LF004, LF005, LF006, SS002, SS009, SS010, and SS011) at the Indian Mountain LRRS. The report did not included a complete laboratory analytical report. DEC has requested the laboratory analytical report be submitted prior to completing its review. |
Dennis Shepard |
| 11/27/2013 |
Document, Report, or Work plan Review - other |
DEC provided review comments for the 2013 Environmental Long Term Monitoring (LTM) Work Plan at Indian Mountain, Long Range Radar Station. |
Dennis Shepard |
| 12/23/2013 |
Update or Other Action |
Site transferred to Guy Warren. |
Rebecca Bryan |
| 3/22/2016 |
Update or Other Action |
Submit approval letter for 2015 Environmental Long Term Monitoring at the Indian Mountain LRRS site. Activities at SS010 included an IC inspection. Warning signs are not present and need to be installed. Weather conditions made ground inspection difficult. No evidence of unauthorized digging or excavation activities was observed. Recommendation include posting of warning signs. |
Guy Warren |
| 9/7/2016 |
Document, Report, or Work plan Review - other |
ADEC reviewed the "Draft Supplemental Work Plan- 2016 RAO, Land Use/IC" for several sites within the Indian Mountain LRRS. ADEC accepted all comment responses and requested a final document for approval. According to the March 2016 LTMR, additional signage is needed and ground cover may be appropriate to reduce ecological exposure to the exposed debris at SS010. The USACE PM stated this will be included in future work. |
Holly Weiss-Racine |
| 6/15/2017 |
Document, Report, or Work plan Review - other |
The Final 2016 Long Term Monitoring (LTM) Activities report dated May 2017 is approved. The 2016 LTM activities included collecting analytical groundwater, surface water and sediment samples from LF004 for metals, and collecting analytical groundwater samples from SS009 for diesel range organics (DRO) and trichloroethylene (TCE). Institutional control (IC) inspections were carried out at LF005, LF006, SS002 and SS011. Due to winter conditions at SD001 and SS010, IC inspections could not be completed. The purpose of the groundwater monitoring and IC inspections is to verify the effectiveness of the approved remedies found in each site's Record of Decision (ROD). |
Erica Blake |
| 9/19/2017 |
Document, Report, or Work plan Review - other |
DEC has approved the 'Final Supplemental Work Plan 2017-2018 Remedial Action Operations, Land Use/Institutional Control, Indian Mountain Long Range Radar Station (LRRS), dated September 2017. This Work Plan presented long-term monitoring (LTM) activities at nine Indian Mountain LRRS sites; LF004, LF005, LF006, SD001, SS002, SS009, SS010, SS011 and OT008. LTM activities were; institutional control inspections [land use control (LUC) inspections and installation of signs] at all sites, analytical groundwater, surface water and sediment sampling at Site LF004, and analytical groundwater sampling at Site SS009. |
Erica Blake |
| 3/6/2018 |
Meeting or Teleconference Held |
DEC met with US Air Force (USAF) staff to review and discuss cleanup progress at all the Indian Mountain sites. The only ongoing work is the long-term monitoring (LTM) work at eight sites (SD001, LF004, LF005, LF006, SS011, SS002, SS009, SS010). Tentatively, there is additional work at OT008, Upper Camp PCB Spill and MMRP sites planned for 2019, pending funding from the USAF. The other sites; LUST, 2004 Spill Arctec, Fuel Offload Area (PL510) and the Incinerator Fuel Line were reviewed and discussed for a cleanup path forward. |
Erica Blake |
| 7/13/2018 |
Document, Report, or Work plan Review - other |
DEC approved the 2017 Five-Year Review Report for Sites LF004, LF005, LF006, SS002, SS009 and SS010 at the Indian Mountain Long Range Radar Station (LRRS) site. This is the first Five-Year Review for Indian Mountain. The remedy at LF004, LF005 and LF006 was determined to be not protective. The remedy at SS002, SS009 and SS010 was determined to be short-term protective. The next five-year review will be 5 years from the US Air Force signature date on this approved Five-Year Review. |
Erica Blake |
| 8/31/2018 |
Site Visit |
DEC conducted a brief 4-hour site visit at the Indian Mountain Long Range Radar Station sites. DEC observed sites at both the Upper and Lower Camp areas. A lot of the Lower Camp sites extend into thick brush and wooded areas, and because time on the ground was limited, not all of those areas were inspected closely. At the Upper Camp, some of the sites are on the sides of very steep slopes, and were not visited. Warning signs were recently installed, and were visible at all the areas of concern. |
Erica Blake |
| 6/10/2019 |
Document, Report, or Work plan Review - other |
Report approved: 2017-2018 long term monitoring (LTM) activities at the Indian Mountain LRRS site which is located 18 miles east of Hughes, Alaska. Eight sites are included in this report; LF004, LF005, LF006, SS002, SS009, SS010, SS011 and OT008. Sites SS010 and OT008 are located in an area called Upper Camp and sites LF004, LF005, LF006, SS002, SS009, and SS011 are located in an area called Lower Camp. Groundwater and water samples from LF004 showed no exceedances for metals, although sediment samples showed lead over the probable effects level. Groundwater samples from SS009 showed exceedances of DRO and TCE. DRO contamination was stable or decreasing, but TCE was found to be increasing. The institutional control (IC) inspection found that IC’s were properly in place. One groundwater monitoring well had no water and thus was not sampled. |
Kevin Fraley |
| 6/11/2019 |
Document, Report, or Work plan Review - other |
A 2019 supplemental work plan was approved, and presents proposed 2019 work and institutional control inspections at Indian Mountain Long Range Radar Station sites SS002, LF004, LF005, LF006, SS009, SS010, SS011, and OT008. Groundwater samples will be collected from monitoring wells at site SS009 and analyzed for diesel range organics (DRO) and trichloroethylene (TCE). Additionally, an institutional control inspection will be conducted at sites SS002, LF004, LF005, LF006, SS009, SS010, SS011, and OT008.
|
Kevin Fraley |
| 7/25/2020 |
CERCLA SI |
DEC approved the “Final Perfluorooctanoic Acid, Perfluoroctane Sulfonate, and Perfluorobutane Sulfonate Site Inspections, Uniform Federal Policy-Quality Assurance Project Plan Work Plan, Six Remote Radar Stations, Alaska” dated July 2020. This work plan was prepared by United States Air Force to guide investigation of the potential presence of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorobutane sulfonate (PFBS) at six remote radar sites in Alaska through the sampling of surface water, groundwater, soil and sediment. Sampling is planned for Cape Newenham, Cape Romanzof, Indian Mountain, Point Barrow, Sparrevohn and Tatalina, |
Melinda Brunner |
| 8/5/2020 |
Document, Report, or Work plan Review - other |
DEC received and provided comments for the 2020 Draft Supplemental Work Plan for sites LF004, LF005, LF006, SS002, SS009, SS010, SS011, and OT008. Work mainly involved IC management such as inspecting landfill caps. 5 monitoring wells will be sampled for DRO and TCE at SS009. DEC requested that debris exposed by erosion at LF004 be removed, as recommended by the 2019 Report. No other comments were necessary. |
Tim Sharp |
| 9/1/2020 |
Document, Report, or Work plan Review - other |
DEC Approved the 2020 Final Supplemental Work Plan for Remedial Action Operations, Land Use/Institutional Controls at LF004, LF005, LF006, OT008, SD001, SS002, SS009, SS010, and SS011. The Proposed LTM and LUC/IC inspection activities include sampling 5 groundwater monitoring wells for analysis of DRO and TCE at SS009, landfill cap inspection at LF005 and LF005, and general IC inspections at all sites. Debris removal from LF004 due to erosion is scheduled to occur in 2021. |
Tim Sharp |
| 4/14/2021 |
Document, Report, or Work plan Review - other |
DEC sent comments on the 2020 RAO LUC/IC Report for LF004, LF005, LF006, OT008, SD001, SS002, SS009, SS010, and SS011. The majority of these sites were subject to basic IC monitoring such as sign maintenance and cap inspections. Site specific information in next comment. |
Tim Sharp |
| 4/14/2021 |
Update or Other Action |
Recommendations include removing surface litter to prevent materials from migrating downslope and replacing the damaged notification sign. |
Tim Sharp |
| 5/12/2021 |
Document, Report, or Work plan Review - other |
DEC sent comments for the Draft Work Plan RAO/LTM. The report details current conditions at several sites. It proposes LUC and IC inspections, landfill inspections, MW repairs, and MW sampling at LF004 and SS009. The majority of the comments focused on discrepancies between the unfinalized 2020 LTM Report and this 2021 LTM WP. DEC intends to approve a final report before finalizing the work plan if at all possible. |
Tim Sharp |
| 5/18/2021 |
Institutional Control Periodic Reporting |
DEC Approved the Final 2020 RAO LUC/IC Report for sites LF004, LF005, LF006, OT008, SD001, SS002, SS009, SS010, and SS011. Recommendations for each site stayed largely the same as indicated previously. |
Tim Sharp |
| 7/12/2021 |
Document, Report, or Work plan Review - other |
DEC Approved the Final 2021 RAO and LTM Work Plan, with the understanding that several DEC recommendations put forward will be taken into consideration under a separate contract. This includes drum removal, potential installation of additional monitoring wells, and erosion control methods. |
Tim Sharp |
| 6/12/2023 |
Document, Report, or Work plan Review - other |
DEC reviewed and provided comments regarding the Draft Final Remedial Action-Operation and Long-Term Management Report Indian Mountain Long Range Radar Site Sites LF004, LF005, LF006, OT008, SD001, SS002, SS009, SS010, and SS011, dated May 2023.This report describes the long-term management and remedial action-operation activities performed at sites LF004, LF005, LF006, OT008, SD001, SS002, SS009, SS010, and SS011 at the Indian Mountain Long Range Radar Site (LRRS) during August of 2022. The report recommends continued monitoring at all the sites and the replacement of land use control signs at the LF006 and SS009 sites. |
Ginna Quesada |
| 9/13/2023 |
Document, Report, or Work plan Review - other |
DEC submitted responses to comments regarding the redline Final Remedial Action-Operation and Long-Term Management Report Indian Mountain Long Range Radar Site Sites LF004, LF005, LF006, OT008, SD001, SS002, SS009, SS010, and SS011, Dated September 2022. |
Ginna Quesada |
| 10/12/2023 |
Document, Report, or Work plan Review - other |
DEC approved the Final Remedial Action-Operation and Long-Term Management Report Indian Mountain Long Range Radar Site Sites LF004, LF005, LF006, OT008, SD001, SS002, SS009, SS010, and SS011, dated October 2023. |
Ginna Quesada |
