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Site Report: Dutch Hbr-Pyramid Valley USTs 1

Site Name: Dutch Hbr-Pyramid Valley USTs 1
Address: Pyramid Valley Bldg. 5181, Unalaska Island, Unalaska, AK 99685
File Number: 2542.38.017
Hazard ID: 2867
Status: Active
Staff: Sarah Bernhardt, 9072697527 sarah.bernhardt@alaska.gov
Latitude: 53.848962
Longitude: -166.555755
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.

Problems/Comments

Many of the abandoned WWII buildings were suspected to have underground storage tanks (USTs) associated with them. Based on experience with other military buildings on the islands, many of the tanks are suspected of still containing fuel and having contaminated soil around them. Three tanks: A, an 1000 gallon-used oil; B, a 675 gallon-heating oil; and C, a 200 gallon-solvent, were removed from Building 5181 located in the Pyramid Valley hospital area. 36 cy yards of impacted soil was excavated and transported offsite for treatment. Excavation was to bedrock. The maximum DRO found was 800 mg/kg. During WWII, after the Japanese bombed Dutch Harbor, the military dispersed troops and facilities to minimize the risk from future bombing raids. Construction in Pyramid Valley included: a hospital and support facilities, garages, maintenance shop, mess halls, power plant, and other unidentified buildings. During the mid- to late-1980s, the U.S. Army Corps of Engineers removed most of the buildings and debris from the area and buried it in a landfill. The cleanup work did not include removal of underground storage tanks or conducting extensive sampling for potential contaminants of concern. Starting in the mid-1990s the Corps returned to the area to investigate and cleanup remaining contaminants from past military activities on Amaknak and Unalaska Island. Site investigation were conducted around all the former buildings to search for underground storage tanks and other potential contaminant sources. Tanks were found at two sites and were removed. About 14 WWII era drums were removed from another area. Sampling in the area did not identify any releases of hazardous substances.

Action Information

Action Date Action Description DEC Staff
3/9/1999 Interim Removal Action Approved ADEC received the final 1997 Report - "Interim Removal Actions, Site Investigations, Remedial Investigations Amaknak and Unalaska Islands", dated March 1999 (Jacobs Engineering). The report described site inspections at 43 former buildings; ~23 of these still had structural remains present; two were confirmed as having buried tanks. Also identified an area with abandoned drums in and adjacent to a pond. USTs were removed from the former power shop (3 tanks) and gas station (1 tank). Approximately 36 cubic yards of contaminated soil removed from the power shop and 225 cubic yards removed from the gas station. Samples from the power shop contained petroleum above the matrix cleanup levels. Samples from the gas station met the matrix cleanup levels. These site areas being evaluated in a comprehensive RI report that is being prepared for the Corps. John Halverson
8/25/1999 Update or Other Action ADEC received the 1998 SI/IRA/RI Report Amaknak and Unalaska Islands. It documents the following: Fourteen drums were removed from the upper pyramid valley; About 380 drums were removed from the Port Levashef Drum Groups - below Pyramid Valley, off Captains Bay. Evaluation of need for further work to be included in comprehensive RI report. John Halverson
11/24/1999 Site Added to Database Diesel fuel contamination. John Halverson
2/11/2000 Update or Other Action ADEC reviewed and commented on the draft December 1999 Comprehensive Remedial Investigation Report for Amaknak and Unalaska Islands. It documented removal of three USTs at one site and one at another location. The report proposed using total organic carbon data from Margaret Bay and the Pre WWII tank farm sites as representative of the site at Building 5181. Since Pyramid Valley is upland and the other sites are coastal lowlands, ADEC requested site specific data be used if method three is proposed to develop soil cleanup levels. Confirmation samples from the tank removal excavation at Building 5286 met all applicable cleanup levels. Further work is requested at Building 5181. John Halverson
6/5/2000 Site Characterization Report Approved ADEC received the final Comprehensive Remedial Investigation Report - Amaknak and Unalaska Island, May 2000, by Jacobs Engineering under contract to the Corps. No further action is recommended for the two sites where underground storage tanks were removed. One cleaned to method 2 soil levels, the other (Building 5181) had up to 800 mg/kg DRO in a sample collected at the soil/bedrock interface; further excavation was not feasible. John Halverson
11/21/2003 GIS Position Updated Using Topozone, NAD 27 Debra Caillouet
6/10/2005 Update or Other Action File number issued 2542.38.017. Aggie Blandford
6/6/2008 Exposure Tracking Model Ranking Initial ranking with ETM completed. Jill Taylor
9/14/2010 CERCLA Proposed Plan ADEC received Proposed Plan #8 that addressed Pyramid Valley management Area 12. The plan recommends Alternative 1 (Corrective Action Complete/Cleanup Complete) because remaining contamination is below Method 3 ACLs and confined to bedrock. Meghan Dooley
9/14/2010 CERCLA Proposed Plan The draft Final Proposed Plan #8 was recieved addressing Pyramid Valley Management Area 12. The plan recommends Alternative 1 (Corrective Action Complete/Cleanup Complete with NDAI) for the Building 5181 and USTs A, B and C becuase the remaining contamination is minimal, confined to bedrock, and below Method 3 ACLs. Meghan Dooley
8/14/2019 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
1/31/2024 Document, Report, or Work plan Review - other Per the review of the Draft Restoration Summary Report, Containerized Hazardous, Toxic, and Radioactive Waste. 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 (2023), this site AKA Pyramid Valley Building 5181 UST A; is anticipated for FY24 Contract. Cascade Galasso-Irish

Contaminant Information

Name Level Description Media Comments

Control Type

Type Details

Requirements

Description Details

There are no documents for this site report.

No associated sites were found.

Missing Location Data

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