| Action Date |
Action |
Description |
DEC Staff |
| 8/25/1999 |
Interim Removal Action Approved |
ADEC received the final report titled "1998 SI, RI, IRA Amaknak and Unalaska Islands" dated August 1999, by Jacobs Engineering. The report documents site investigation work, locating buried fuel tanks at the former mess hall, dispensary, power plant and two latrines. The fuel, tanks and contaminated soil were excavated. Contaminated soil was thermally treated in Unalaska. A fifth UST was located but not removed due to the isolated location and inability to remove it. Three of the four sites where tanks were removed have residual soil contamination at levels higher than ten times the method two migration to groundwater levels and soil was excavated to the water table. Visible groundwater contamination was present in two excavations. Well points were installed, but subsequent water level measurements indicate they may not be downgradient. Further investigation and possibly cleanup are needed. |
John Halverson |
| 2/11/2000 |
Update or Other Action |
Staff reviewed and commented on the draft Comprehensive Remedial Investigation Report for Amaknak and Unalaska Islands, dated December 1999. The report evaluated cleanup levels for this area using an assumption that groundwater is not a potential future drinking water source, however, the necessary steps to make such a determination have not been undertaken. ADEC requested the report be revised to consider groundwater as a drinking water source or that steps in 18 AAC 75.350 be addressed. Further groundwater monitoring was recommended and is necessary. |
John Halverson |
| 6/5/2000 |
Site Characterization Report Approved |
ADEC received the final Comprehensive Remedial Investigation Report, dated May 2000, by Jacobs Engineering under contract to the Corps.
Humpy Cove Mess Hall UST - a 300 gallon heating oil tank and ~200 cubic yards of diesel contaminated soil were removed. Contaminated soil was removed to a depth of 26 feet below the ground surface (bgs). Contaminated soil was thermally treated off-site. A sample from 26' bgs contained 400 mg/kg DRO. Sidewall samples met the cleanup levels. Approximately 50 cubic yards of soil used to backfill the excavation contained up to 890 mg/kg DRO. An alternative soil cleanup level, based on the migration to groundwater pathway, may be proposed later.
Dispensary UST - a 680 gallon UST and ~430 cubic yards of contaminated soil were removed. DRO contaminated soil extended to the water table with the highest concentration measured being 7100 mg/kg at ~13' bgs. Groundwater was encountered at 13' bgs. Three well points were installed and sampled; no groundwater contamination was found above the Table C levels, however, none of the well points were directly downgradient from the source area. Additional groundwater monitoring is planned.
Power Plant - a 1600 gallon UST and ~540 cubic yards of petroleum contaminated soil were removed. Diesel range organics (DRO) contaminated soil extends to the water table at ~14' bgs. A soil sample from 14' bgs contained 11,000 mg/kg DRO. Well points installed at the site did not contain contaminants above regulatory levels, however, no well points were installed within or directly downgradient of the source area. Further groundwater characterization is recommended.
Latrine #3 - a 300 gallon UST and ~35 cubic yards of petroleum contaminated soil were removed. Soil containing up to 3,800 mg/kg DRO was used to backfill the excavation. Confirmation samples collected from the limits of the excavation contained up to 3,400 mg/kg DRO at a depth of 9' bgs. Groundwater characterization is recommended.
Latrine #1 - a UST estimated to be ~300 gallons in capacity, was located about 250' up a vegetated hillside from the road. A soil sampled collected from ~5' bgs and 5' downhill from the tank contained 10,000 mg/kg DRO. Another sample collected about 10' further downhill and 5' bgs did not contain measurable DRO. The tank was emptied and left in place due to limited access (would need to cut in a road). The report recommends in-place closure of this UST. |
John Halverson |
| 9/5/2001 |
Update or Other Action |
DEC received the final 2000 Island-wide SI/IRA/RI Report for Amaknak/Unalaska Islands, dated August 2001, by Jacobs Engineering. It documents the following work in the Humpy Cove area:
Power Plant site - one soil boring was drilled to 24.5' and did not encounter water. A second boring was drilled to ~30' and groundwater rose to ~21.5' bgs in the well. Field screening indicated contaminated soil between 18 and 30' bgs. The water sample from MW1 did not contain measurable levels of DRO and only 640 ug/l RRO. The report recommends no further action with institutional controls.
Dispensary - two soil borings were drilled to refusal at ~11' bgs, no water was observed in either and the borings were backfilled. The report recommends no further action.
Latrine 1 - a soil boring was installed to 28.5' bgs. The boring was dry, but a MW was installed. The well remained dry in September and October, but did contain water in December. A water sample from the well contained 230 ug/l DRO and PAHs below applicable cleanup levels. The UST was emptied and filled with gravel. The report recommends no further action.
Latrine #3 - two soil borings were installed to 8 and 9 feet bgs. Neither well encountered water or evidence of soil contamination. A soil sample from 7.5' bgs contained only 2.9 mg/kg DRO. The report recommends no further action. |
John Halverson |
| 1/23/2003 |
Site Added to Database |
DRO. Humpy Cove expanded into five unique sites from one. |
John Halverson |
| 1/23/2003 |
Site Ranked Using the AHRM |
Initial ranking. |
Debra Caillouet |
| 11/21/2003 |
GIS Position Updated |
Using Topozone, NAD 27. |
Debra Caillouet |
| 6/10/2005 |
Update or Other Action |
File number issued 2542.38.013. |
Aggie Blandford |
| 6/17/2008 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed. |
Evonne Reese |
| 9/14/2010 |
CERCLA Proposed Plan |
ADEC recieved Proposed Plan # 8 which addressed Summer Bay Management Area 13. The Corps recommended Alternative 2 (Corrective Action Complete/Cleanup Complete with ICs) for the Humpy Cove Latrine 1 UST becuase the primary source of contamination was removed. Remaining contamination is localized, remote, and on a steep slope. They determined the cost of additional excavation to not be supported by reduction of risk, and therefore the site did not pose unacceptable risk to human health or the environment. |
Meghan Dooley |
| 8/13/2019 |
Update or Other Action |
Site location was updated on this date. Coordinates for this site are used to determine the presence and position of the site on BLM’s ANCSA Conveyed Land web map. |
Rebekah Reams |
| 1/25/2024 |
Document, Report, or Work plan Review - other |
Bulk action entry for review of the Draft Restoration Summary Report Containerized Hazardous, Toxic, and Radioactive Waste, Amaknak Formerly Used Defense Sites, recommending closure at 53 sites. DEC received the draft summary report on April 2023, and provided comments on June 2023. On January 15, 2024, FUDS submitted a final summary report. Comment resolution has not been performed and is not complete. Further coordination is necessary with FUDS. |
Cascade Galasso-Irish |
| 2/22/2024 |
Document, Report, or Work plan Review - other |
On this date, DEC reviewed and approved the redline final, RTCs, and final Restoration Summary Report for the Amaknak Formerly Used Defense Sites F10AK0841-13, -14, -15, -16, -18, -20, Unalaska Valley, Pyramid Valley-Port Levashef, Summer Bay-Humpy Cove, Margaret Bay-Airport, Mount Ballyhoo, and Little South America in Unalaska, Alaska.
Of the 53 sites included in this report, 39 of these sites are either closed in the Contaminated Sites database or are not eligible active sites. Fourteen (14) sites remain open in the CS database, either pending further coordination on the pathway to closure or are currently with DEC management for closure decision. This letter is documenting the approval of the final document but does not preclude the need for further investigation of sites included in the report. |
Cascade Galasso-Irish |
| 7/16/2024 |
Document, Report, or Work plan Review - other |
DEC recieved the final report CON/HTRW Limited Removal Action, Amaknak FUDS-F10AK0841-15 Summerr Bay-Humpy Cove and Amaknak FUDS F10AK0841-20 Little South America, Unalsaka, Alaska dated April 2024. The work plan describes the project approach and methods to be used while conducting environmental removal actions at select Amaknak Formerly Used Defense Sites (FUDS) on Unalaska and Amaknak Islands, Alaska during the 2024 field season; specifically Amaknak FUDS: F10AK0841-15 Summer Bay-Humpy Cove and F10AK0841-20 Little South America (LSA). The primary project objectives are to remove petroleum, oil, and lubricant (POL)-contaminated soil and conduct limited environmental investigations at two Amaknak FUDS: Humpy Cove Power Plant underground storage tank (UST) (ADEC Hazard Identification Number [ID]: 3066) and LSA Latrine 1 UST (ADEC Hazard ID: 25836). Additional limited environmental investigation will occur at a third FUDS: LSA Building 1154, Mess Hall (ADEC Hazard ID: 25833). The limited environmental investigation activities will be completed by advancing soil borings, collecting soil samples, installing and developing temporary wells, and collecting groundwater samples. |
Kathleen Iler-Galau |
| 9/4/2024 |
Meeting or Teleconference Held |
August 27, 2024
Qawalangin Restoration Advisory Board (RAB) Meeting
USACE sites
Several DEC staff attended the Qawalangin RAB meeting on October 27, 2024. Sites include Amaknak, Chernofski, Cape Wislow, Fort Learnard, and Ugadaga Bay FUDS. The meeting was both in person and virtual, and held at the Unalaska Public Library. In attendance was the United States Army Corp of Engineers (USACE), ADEC, representatives of the Ounalashka Corporation, the RAB members, and several members of the public. The meeting focused on public comments regarding specific sites of concern and how sites are selected for upcoming seasonal work by the USACE. There is public concern regarding a site with contamination that could impact areas that have been cleaned, and questions regarding health issues of community members. The USACE listened to the public comments and answered questions. USACE will be working with the RAB to receive more public input, and they also agreed to meet with the Ounalashka Corporation.
|
Kathleen Iler-Galau |
