Site Report: Dutch Hbr-Unalaska Vly UST 3075
| Site Name: | Dutch Hbr-Unalaska Vly UST 3075 |
|---|---|
| Address: | Bldg 3075 Near Upper End, Broadway, Unalaska, AK 99685 |
| File Number: | 2542.38.023 |
| Hazard ID: | 2888 |
| Status: | Cleanup Complete |
| Staff: | No Longer Assigned, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 53.842751 |
| Longitude: | -166.504116 |
| Horizontal Datum: |
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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
Diesel fuel contamination from abandoned underground fuel storage tanks, most related to heating fuel. UST-3075 was a 300 gallon heating oil tank at the former latrine Building 3075 located near the upper end of south Broadway Avenue where the road has been washed out. It is located on a small bluff bound by the Iliuliuk River and a small creek. The tank and 45 cubic yards of impacted soil were removed in 1997. Confirmation sampling indicated DRO remaining up to 7800 mg/kg. Amaknak and Unalaska Islands were used by the military during World War II. The Japanese bombed Dutch Harbor and Fort Mears in 1941. Following the bombing the military dispersed its troops moving back up into Unalaska Valley and Pyramid Valley to minimize the potential for damage if future air raids occurred. The Corps of Engineers had a contractor tear down the abandoned buildings and debris and dispose of them in various landfills during the mid - late 1980s. Underground fuel tanks were abandoned in place. In the mid-1990s the Corps started working on the sites again under the Formerly Used Defense Sites (FUDS) program. Site inspections were done around the former buildings to look for remaining underground fuel tanks and other potential contaminant sources.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 6/5/2000 | Site Characterization Report Approved | Comprehensive Remedial Investigation Report, dated May 2000 and prepared by Jacobs Engineering, documents the UST was removed in Aug. 1997; approximately 45 cy of petroleum contaminated soil were removed and thermally treated. The site is adjacent to Illiuliuk River and another small creek. Four soil samples and one groundwater sample, from a well point, were collected and analyzed for DRO, RRO, PAHs and BTEX. DRO was found above cleanup levels in soil and groundwater. The maximum DRO concentration in the soil samples was 7,800 mg/kg and in groundwater was 16 mg/L. The report recomends further action including soil removal and groundwater/surface water monitoring. Bedrock and groundwater limited further excavation. Ten soil samples were collected at the limits of the excavation and analyzed for DRO, RRO, PAHs, and BTEX. All analytical results met the most stringent method 2 soil cleanup levels with the exception of DRO. Two of the ten samples contained DRO at 5,200 and 7,000 mg/kg, exceeding the migration to groundwater cleanup levels but not the ingestion or inhalation levels. Residual soil contamination appears to be isolated in extent; due to shallow bedrock and a surface water reservoir that supplies most of the City water, it is unlikely that drinking water wells would be installed in the future. | John Halverson |
| 1/23/2003 | Site Added to Database | Unalaska Valley expanded into a total of 26 unique sites from one. | John Halverson |
| 6/13/2003 | CERCLA SI | The 2001/2002 Islandwide SI/RI/IRA Report was received. The report documents the work completed during the 2001 and 2002 field seasons at various sites throughout Amaknak and Unalaska. One groundwater sample was collected at UST 3075 to determine is DRO concentrations were below cleanup levels. DRO was non detect in the sample collected from WP-1. The site is recommended for No Further Action and that institutional controls be implemented to manage the residual soil contamination. | Meghan Dooley |
| 12/8/2003 | GIS Position Updated | TopoZone | Debra Caillouet |
| 6/10/2005 | Update or Other Action | File number issued 2542.38.023. | Aggie Blandford |
| 7/3/2008 | Exposure Tracking Model Ranking | Initial ranking with ETM completed. | Daniel Fremgen |
| 9/14/2010 | CERCLA Proposed Plan | ADEC received the draft final Proposed Plan #7 addressing Unalaska Valley Management Area 11. The plan recommends Alternative 1 (Corrective Action Complete/Cleanup Complete with NDAI) for UST 3075. The sources has been removed to the extent practicable, remaining soil contamination concentrations are less than the Method 3 ACLs, and it does not appear to be migrating. Groundwater had exceedences for DRO and RRO in 1997, however in 2000 and 2001 the concentrations were below cleanup levels. Contamination does not appear to be migrating to the sediment and surface water. | Meghan Dooley |
| 11/1/2017 | Exposure Tracking Model Ranking | A new updated ranking with ETM has been completed for source area 73864 UST. | Linda (Qi) Liu |
| 4/22/2021 | Update or Other Action | Updated GPS coordinates based on figures from 2888_Amaknak 2001-2002 SI-RI-IRA Report.pdf | Ginna Quesada |
| 11/6/2023 | Cleanup Complete Determination Issued | On this date, a cleanup complete determination was issued for the Dutch Harbor - Unalaska Valley UST 3075 site. Based on the information provided to date, it has been determined that the contaminant concentrations remaining on site do not pose an unacceptable risk to human health or the environment, and no further remedial action will be required unless information becomes available that indicates residual contaminants may pose an unacceptable risk | Cascade Galasso-Irish |
| 11/6/2023 | Institutional Control Record Established | Institutional Controls established and entered into the database. | No Longer Assigned |
| 11/6/2023 | Exposure Tracking Model Ranking | A new updated ranking with ETM has been completed for source area 73864 UST. | 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 |
Contaminant Information
| Name | Level Description | Media | Comments |
|---|---|---|---|
| DRO | Other | Soil | Residual DRO concentrations are below the site-specific Method 3 ACL of 8,300 mg/kg. |
| RRO | < Table C | Groundwater | |
| Ethylbenzene | < Method 2 Most Stringent | Soil |
Control Type
| Type | Details |
|---|---|
| No ICs Required |
Requirements
| Description | Details |
|---|---|
| Advance approval required to transport soil or groundwater off-site. | |
| Movement or use of contaminated material (including on site) in a manner that results in a violation of the water quality standards is prohibited (18 AAC 70) |
No associated sites were found.