Site Report: Alyeska PS 05 Tank Farm
| Site Name: | Alyeska PS 05 Tank Farm |
|---|---|
| Address: | Mile 137 Dalton Highway, Pipeline Mile 274.7, Coldfoot, AK 99701 |
| File Number: | 330.38.064 |
| Hazard ID: | 3114 |
| Status: | Cleanup Complete - Institutional Controls |
| Staff: | IC Unit, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 66.813083 |
| Longitude: | -150.665028 |
| 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 1998, Alyeska conducted inspection and repair of boot liners within the tank farms and discovered that a seam between a boot liner at the concrete support labeled IP 13 and the tank farm liner was not sealed. Therminol impacted gravel was identified during that investigation thought to be due to a 1992 release and other historice releases. Following the 1992 release, soil was excavated to 3 feet bgs. This excavation was then lined and backfilled with clean soil. In 1998, that clean fill, liner and impacted soil below removed to the extent practical Later in 1998, seven borings were drilled and sampled to a maximum depth of 31 feet below ground surface. Six of the borings were converted to Monitoring Wells. Groundwater was encountered at MW-4 and MW-6. BTEX and PAH compounds were detected at concentrations below ADEC groundwater cleanup levels. PS 05 drinking water supply well is located ~ 3,000 feet NW of the tank farm and set at a depth of 38 ft bgs within the thaw bulb of Jim River.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 12/31/1998 | Update or Other Action | Final Soil Excavation and Sampling Results for Therminol Release Site Report - Analytical results for DRO varied from ND in samples S-4 and S-5 to 15,000 mg/kg in sample S-11. There remains impacted soil in the tank farm (above the PS5 tank farm liner) above ADEC cleanup levels. Due to the proximity of remaining Therminol impact to tank farm structures, further excavation is impractical. | Deborah Williams |
| 2/22/1999 | Update or Other Action | PS 5 Tank Farm Contamination Assessment Report received 4/12/1999. Six borings were advanced along the west and south perimeter of the tank farm and these were converted into monitoring wells. One boring was advanced within the tank farm, however this was not in the area where the liner was unseamed. Ten soil samples were collected from these borings and analyzed for DRO with one detected result of 707 mg/kg at 10 feet in B-1/MW-1. BTEX and PAH compounds were detected at concentrations much less than Table C values in the GW samples from MW-4 and MW-6 (only wells containing groundwater) and catchment water collected from within the tank farm. The one exception is dibenzo(a,h)anthracene which was detected in the catchment water sample at 0.2 ug/L which is 0.1 ug/L over the GW cleanup standard. The aquifer appears to be confined by a layer of frozen soil as noted by changes in GW elevations in MW-4 and MW-6. Recommend continued annual GW monitoring of MW-4 and MW-6. | Deborah Williams |
| 12/13/1999 | Update or Other Action | PS5 Tank Farm GW Monitoring Report - BTEX and PAH compounds were detected at concentration below the ADEC GW cleanup levels in the GW samples from MW-1, MW-4, MW-5, and MW-6. The presence of seasonal frost influenced GW elevations in 1998, but did not appear to have the same impact of GW elevations in 1999. IT/Emcon recommends continued annual GW monitoring of all MWs for the year 2000. | Deborah Williams |
| 11/24/2000 | Site Added to Database | Therminol contamination. | Bruce Wanstall |
| 11/24/2000 | Site Ranked Using the AHRM | Preliminary ranking, Therminol contamination. SW Exposure Index Value changed from 0.4 to 0.0 on DB entry. | Deborah Williams |
| 12/29/2000 | Update or Other Action | PS 5 Tank Farm GW Monitoring Report - BTEX and PAH compounds were not detected in the GW samples from MW-4, MW-5, and MW-6. IT Alaska recommends that no remedial action be taken at this time. The 2000 GW data represents the 3rd consecutive GW sampling at this site. No off-site migration has been documented and no GW cleanup standards are exceeded. IT recommends discontinuing GW monitoring at this site. Soil impacted above the method 2 cleanup levels remains in place below the tank farm liner. IT recommends that the contaminated soil be addressed when the tank farm is decommissioned. | Deborah Williams |
| 1/28/2008 | Exposure Tracking Model Ranking | Initial ranking with ETM completed. | Pam Clemens |
| 2/1/2008 | GIS Position Updated | Position verified using Arc GIS SPAR_StatewideLocator (ArcReader) | Grant Lidren |
| 3/14/2008 | Update or Other Action | Received Trans Alaska Pipeline System: 2007 Monitoring Well Decommissioning Report. All six of the monitoring wells that had been installed for this site were successfully located and decommissioned. | Keather McLoone |
| 3/17/2010 | 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 05 Tank Farm. Based on the information provided to date, the ADEC has 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 as long as the site is in compliance with established institutional controls. This decision is based on the administrative record for Alyeska PS 05 Tank Farm, which is located in the offices of the ADEC in Anchorage, Alaska. | Keather McLoone |
| 3/19/2010 | Institutional Control Record Established | Institutional Controls established and entered into the database. | Keather McLoone |
| 12/1/2011 | Update or Other Action | The current project manager chose to retain management of this site with the Cleanup Complete Determination that has Institutional Controls. | Kristin Thompson |
| 11/12/2013 | Institutional Control Compliance Review | IC compliance review conducted and staff changed from Linda Nuechterlein to IC Unit. Reminder system set-up to follow-up with the responsible party in 2015. | Kristin Thompson |
| 3/19/2015 | Institutional Control Update | An IC reminder letter was issued to the responsible party on this date. | Kristin Thompson |
| 10/12/2015 | Institutional Control Periodic Reporting | The responsible party informed ADEC that there have been no changes in land use or ownership at this site since the 2010 Record of Decision. Reminder system re-set to follow up in another five years. | Kristin Thompson |
| 6/19/2018 | Institutional Control Compliance Review | IC compliance review conducted. Closure/IC Details updated. Reminder system already set for next follow-up in 2023. | 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 |
|---|---|---|---|
| DRO | > Human Health/Ingestion/Inhalation | Soil | one result above health based above the liner |
Control Type
| Type | Details |
|---|---|
| Signed CS Determination |
Requirements
| Description | Details |
|---|---|
| Advance approval required to transport soil or groundwater off-site. | Standard condition. |
| When Contaminated Soil is Accessible, Remediation Should Occur | Soil contamination is located in the area of the Alyeska PS 05 Tank Farm. When the remaining contamination in this area becomes available, the contaminated soil must be evaluated and/or addressed in accordance with an ADEC approved work plan. |
| Other | Alyeska shall 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. |
| 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. |
No associated sites were found.