Site Report: ADOT&PF Unalaska South Channel Bridge Midden Site
| Site Name: | ADOT&PF Unalaska South Channel Bridge Midden Site |
|---|---|
| Address: | Airport Beach Road & Henry Swanson Drive, SW Corner of Intersection, Unalaska, AK 99685 |
| File Number: | 2661.38.009 |
| Hazard ID: | 4507 |
| Status: | Cleanup Complete |
| Staff: | No Longer Assigned, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 53.874031 |
| Longitude: | -166.548723 |
| 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
Petroleum-contaminated soil found during an archeological dig and pre-construction work for realigning the road and constructing a new bridge between Amaknak and Unalaska Islands. The site housed a World War II barracks building or warehouse. While the source of the DRO contaminated soil is unknown, it may be associated with the Formerly Used Defense Site (FUDS). Ounalashka Corporation owned the land; apparently DOT acquired it as a right of way for the road and bridge realignment.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 11/28/2006 | Update or Other Action | Field Activities Documentation Report was received for the excavation, sampling, and stockpiling of soil at the south channel bridge midden site. Approximately 18cy of soil was excavated and segregated based on field observations of potential petroeum contamination. Contaminated soil was stored in super sacks, and confirmation samples were taken. DRO was found at a range of 327-4560 mg/kg. 6 confirmation samples were taken in the excavation pit and all found below cleanup levels, ranging from 17.1-32.8 mg/kg DRO. Approximately 10cy of excavated soil was determined unimpacted and taken to the midden storage facility. The super sacks of stockpiled contaminated soil was stored in a DEC approved liner until disposal. The contractor recommended off-site disposal. | Meghan Dooley |
| 11/15/2007 | Offsite Soil or Groundwater Disposal Approved | Offsite disposal of the petroleum contaminated soil approved. | Meghan Dooley |
| 11/30/2007 | Exposure Tracking Model Ranking | Initial ranking completed. | Mitzi Read |
| 11/30/2007 | Site Added to Database | Site added to the database. | Mitzi Read |
| 2/5/2021 | Update or Other Action | After speaking with the Alaska Mental Health Trust Land Office and the Ounalashka Corporation, both entities were removed from the site file affiliates section on this date. The Trust Office was formerly listed as RP, and Ounalashka was listed as a landowner. Correspondence with Jeff Green at the Land Trust Office indicated no land interest in Dutch Harbor, currently or historically, and the cause of historical contamination at the site is reportedly unknown. Ounalashka provided the deed to ADOT&PF in 2006, effectively making DOT the current landowner. | Cascade Galasso-Irish |
| 4/30/2021 | Update or Other Action | Updated lat/long on CSP application. Location verified using figures from: 2006.11.26 FieldActivitesDocumentationRpt (in this folder: \\An-svrfile\groups\SPAR\CS\38 FilesCS\2661 Unalaska\2661.38.009 ADOT&PF Unalaska South Channel Bridge Midden Site\Scanned Hardcopy files). Site location was slightly off on CSP database previous coordinates: 53.875278 -166.546667. | Ginna Quesada |
| 7/30/2021 | Update or Other Action | Correspondence attempted with ADOT&PF South Coast Region and the Columbia Ridge Landfill in Arlington, Oregon. Site closure is awaiting on disposal verification of excavated soils in super-sacks that were stored at the Dutch harbor Airport. Transport and Disposal was approved by previous PM John Halvorson to DOT contacts via email correspondence in file, however the Solid Waste Disposal Site Permit for the disposal facility was expired at the time of planned transport. No verification was ever received on the TTD. | Cascade Galasso-Irish |
| 8/18/2021 | Exposure Tracking Model Ranking | A new updated ranking with ETM has been completed for source area 75494 DRO - Unknown Source. | Cascade Galasso-Irish |
| 11/16/2021 | Cleanup Complete Determination Issued | Cleanup Complete determination letter sent to the DOT&PF South coast Right of Way Division on this date. 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. Confirmation samples along the excavation boundaries demonstrate residual soil contamination at the site is below the most stringent cleanup levels as specified under 18 AAC 75.341. The maximum concentration of DRO in soil remaining on site is 32.8 milligrams per kilogram (mg/kg). RRO and VOCs, including naphthalene, were not detected in in any of the confirmation samples. Soil contamination at the site has been cleaned up to concentrations below the approved cleanup levels suitable for residential land use. This site will receive a “Cleanup Complete” designation on the Contaminated Sites Database. | Cascade Galasso-Irish |
Contaminant Information
| Name | Level Description | Media | Comments |
|---|---|---|---|
| DRO | < Method 2 Most Stringent | Soil | The maximum concentration of DRO in soil remaining on site is 32.8 milligrams per kilogram (mg/kg). RRO and VOCs, including naphthalene, were not detected in in any of the confirmation samples. |
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.