Site Report: Alyeska PS 01 Back 40 Staging Area
| Site Name: | Alyeska PS 01 Back 40 Staging Area |
|---|---|
| Address: | Spine Road; Alyeska Pump Station 1, Deadhorse, AK 99734 |
| File Number: | 330.38.126 |
| Hazard ID: | 26246 |
| Status: | Cleanup Complete - Institutional Controls |
| Staff: | IC Unit, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 70.255683 |
| Longitude: | -148.629849 |
| Horizontal Datum: | WGS84 |
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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
In August 2013, a black, tar-like product was discovered in the soil at the pad edge of the back 40 staging area at Alyeska Pump Station 1. ADEC issued a "Waste Disposal Permit, a restricted use landfill DS 138-3," Permit No. NR-4-77 for the back 40. The permit describes the location as NE 1/4, Section 4, T10N, R15E, U.M. The permit prohibited the disposal of hydrocarbon substances. Multiple drums were found in the vicinity and were removed during initial remedial activities. DRO, GRO, RRO, and xylenes were confirmed in subsurface soil above DEC Method 1 cleanup levels; and xylenes were also above Method 2 cleanup levels.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 6/3/2014 | Site Characterization Report Approved | On this date, ADEC received the Pump Station 1 Back 40 Area 2013 Investigation Report submitted by SLR dated May 2014. Contaminated soil was excavated 3 to 4 feet below ground surface (bgs) where seven drums containing tar like substances were encountered. Samples collected from the drums’ tar substance and analyzed for toxicity characteristic leaching procedure (TCLP) metals, TCLP semi-VOCs, TCLP VOCs, polychlorinated biphenyls (PCBs), and halogens contained detectable concentrations, but below applicable regulatory criteria. A total of 19 drums of grossly contaminated soil were generated during excavation activities and another 10 cubic yards (cy) of impacted soil were stockpiled onsite. Nine confirmation soil samples collected from the sidewall and bottom of the excavation contained GRO up to 882 mg/kg, DRO up to 7,420 mg/kg, RRO up to 13,500 mg/kg, and xylenes up to 138.6 mg/kg. The excavation was then backfilled with clean fill and sloped for safety and drainage. Surface water samples collected from the nearest water body 150 feet away and analyzed for total aromatic hydrocarbons (TAH) and total aqueous hydrocarbons (TAqH) contained detectable levels of toluene but below Alaska water quality standards (WQS). The seven drums of tar like substances and the 19 drums of grossly contaminated soil were disposed of as non-hazardous. The 10 cubic yard stockpile was stockpiled at pump station 1 for future remediation in accordance with the Alyeska Soil Stockpile Management Plan TAPS EN-21-01. | Grant Lidren |
| 6/23/2014 | Site Characterization Report Approved | The Alaska Department of Environmental Conservation (ADEC) Contaminated Sites Program (CSP) has received and reviewed the 2014 Remediation Work Plan Pump Station 1 submitted by SLR and dated May 2014. ADEC has no objections to the Work Plan and Alyeska may proceed with the following condition: SLR stated in an email correspondence dated June 19, 2014 that there is a 10 cubic yard stockpile onsite from previous field work. This stockpile will need to be placed in the long-term stockpile at PS01 on the Back 40 pad or transported offsite for thermal remediation pending CSP’s approval. | Grant Lidren |
| 7/2/2014 | Site Added to Database | A new site has been added to the database | Mitzi Read |
| 7/2/2014 | Spill Transferred from Prevention Preparedness and Response Program | Spill transferred by PERP staff John Ebel. Spill no. 13399922602; spill date = 8/13/13; substance = unknown petroleum; quantity = unknown; PERP file no. 330.02.032. | Mitzi Read |
| 7/2/2014 | Exposure Tracking Model Ranking | Initial ranking with ETM completed for source area id: 79642 name: Tar-like Substance Release | Mitzi Read |
| 7/10/2014 | Potentially Responsible Party/State Interest Letter | PRP letter sent to Alyeska on this date. | Grant Lidren |
| 1/9/2015 | Site Characterization Report Approved | On this date, ADEC received the 2014 Remediation Report Pump Station 1 Back 40 Area submitted by SLR dated December 2014. Clean overburden was removed to a lens of soil impacted by tar-like petroleum substance and drums. Five test pits were then advanced to determine extent of contamination. A total of seven drums containing free product were removed from the excavation and disposed of as non-hazardous. A total of 400 cy of soil were removed and segregated into a 200 cy assumed dirty pile and a 200 cy assumed clean pile. The 200 cy assumed dirty pile was stockpiled at pump station 01 for future remediation in accordance with the Alyeska Soil Stockpile Management Plan TAPS EN-21-01. The 200 cy assumed clean pile was stockpiled for later use as backfill. A one foot wide lens of impacted soil was observed where the drums were located. The excavation was halted upon encountering solid waste presumed to represent the retired class III camp Alyeska Pump Station #1 (DS 138-3) landfill and at the gravel pad tundra interface. The dimensions of the final excavation was approximately 28 feet by 47 feet by up to 8 feet high where the drums were located. A total of 15 confirmation soil samples collected from the excavation bottom and sidewalls contained GRO up to 191 mg/kg, DRO up to 4,170 mg/kg, and RRO up to 8,410 mg/kg. Six soil samples collected from the 200 cy assumed clean pile contained DRO at 1,560. This 200 cy stockpile was then put back in the excavation and later capped with 2 feet of clean fill and contoured to match the surrounding slope in 2015 | Grant Lidren |
| 9/9/2015 | Update or Other Action | Alyeska completed the backfill and grading at the PS 1 “back 40” excavation site. The cap is at least 2’ where debris was encountered and the material was contoured to match the surrounding slope. | Grant Lidren |
| 10/6/2015 | Cleanup Complete Determination Issued | The Alaska Department of Environmental Conservation (ADEC), Contaminated Sites Program, has completed a review of the environmental records associated with the Alyeska PS 01 Back 40 Staging Area. Based on the information provided to date and the administrative record, the ADEC has determined that the contaminant concentrations remaining on site do not pose an unacceptable risk to human health or the environment. No further remedial action will be required as long as the site is in compliance with established institutional controls. | Grant Lidren |
| 10/6/2015 | Institutional Control Record Established | Institutional Controls established and entered into the database. | Grant Lidren |
| 10/8/2015 | Update or Other Action | On this date, ADEC received the signed CC-IC agreement and signature page from Alyeska | Grant Lidren |
| 11/23/2015 | Institutional Control Compliance Review | IC compliance review conducted, staff changed from Lidren to IC unit, and reminder system set to review the site record in October 2020. | Nathan Maxwell |
| 6/18/2018 | Institutional Control Compliance Review | IC compliance review conducted. Closure/IC Details updated. | Kristin Thompson |
| 3/15/2020 | Institutional Control Compliance Review | IC verification letter from Alyeska was received on this date which documents that there have been no changes in land use. | Evonne Reese |
Contaminant Information
| Name | Level Description | Media | Comments |
|---|---|---|---|
| Xylenes (total) | < Method 2 Most Stringent | Soil | |
| DRO | > Method 1 (Arctic only) | Soil | |
| GRO | > Method 1 (Arctic only) | Soil | |
| RRO | > Method 1 (Arctic only) | Soil |
Control Type
| Type | Details |
|---|---|
| Signed CS Determination |
Requirements
| Description | Details |
|---|---|
| Advance approval required to transport soil or groundwater off-site. | Standard condition. |
| 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) | Standard condition. |
| Other | The landowner will report to ADEC every five years to document land use or report as soon as they become aware of any changes in land ownership and/or use. |
No associated sites were found.