Skip to content Skip to content

Alaska Department of Environmental Conservation

You are here: DEC / SPAR / CSP / SPAR Online Services / Contaminated Sites Search / Site Report

Site Report: Swanson River Tank Setting 3-9

Site Name: Swanson River Tank Setting 3-9
Address: Mi. 17.5 Swanson River Rd, Sterling, AK 99672
File Number: 2334.38.024
Hazard ID: 446
Status: Active
Staff: Peter Campbell, 9072623412 peter.campbell@alaska.gov
Latitude: 60.706667
Longitude: -150.877778
Horizontal Datum:NAD83

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

Extensive petroleum contamination of soil and groundwater at this site resulting from the tank setting and an adjacent flare stack. Light non-aqueous phase liquid (LNAPL) recovery and annual groundwater monitoring on-going. Under current site conditions, risk to human health and the environment is minimal. The contaminant plume appears stable and not expanding. Due to the facility infrastructure, excavation and remediation of the contaminated soil is not feasible. Cleanup will occur at abandonment of pad.

Action Information

Action Date Action Description DEC Staff
5/23/1990 Update or Other Action (Old R:Base Action Code = SI - Site Investigation). Arco sent in Phase II Investigation Report. All locations investigated except 1-9 have glacial drift which strongly limited the vertical/horizontal migration of hydrocarbons in subsurface soils. At 1-9 tank setting, permeable coarse grained soils have allowed hydrocarbons to migrate substantially in the subsurface soils/groundwater. Former Staff
11/1/1991 Update or Other Action (Old R:Base Action Code = TOTH - Treatment, Other). Results of Bioventing treatability test provided to the Department. Former Staff
7/15/1992 Update or Other Action (Old R:Base Action Code = TAS - Treatment Alternative Study (CS)). ARCO submitted results of evaluation remediation alternatives for SRF. Report identified numerous potential remediation methods for the contaminated soil and groundwater. Report concluded that in-situ bioventing was the optimum alternative for soil remediation, and disposal of contaminated groundwater at class II wells was optimum method for mitigating contaminated groundwater concern. Former Staff
8/24/1992 Update or Other Action (Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). ADEC provided conditional approval of bioventing pilot study. Former Staff
12/6/1993 Site Added to Database Petroleum contamination. Site broken out of Swanson River Field Tank Setting that was formerly inclusive of all Swanson River Field Tank Setting sites. Former Staff
12/6/1993 Site Ranked Using the AHRM Initial ranking. Former Staff
9/20/2000 Meeting or Teleconference Held Meeting at the oil field with Unocal, Chevron, USFWS to discuss past sampling results, improvements to sampling this year and approach to addressing problems. Will have meeting after this years monitoring report has been reviewed to discuss approach for the sites. Informed participants that in order to comply with USFWS regulations, Method 2 cleanup levels (Tables B and C) must be met, not 10 times or risk assessment. Donald Seagren
10/9/2000 Update or Other Action Re-reviewed the 1999 GW Monitoring Report. Final decision will wait until fall 2000 sampling event. At minimum, Unocal will have to determine extent of free product migration and begin free product recovery where needed. Donald Seagren
5/14/2001 Update or Other Action Reviewed 2000 monitoring report; discussed free product recovery work plan with John Hammelman. Donald Seagren
8/31/2001 Interim Removal Action Approved In consultation with USFWS/KNWR, the workplan to test a product recovery system was approved. Stipulations included with the approval include that the test run for no longer than 6 months at which time the system is evaluated an improved if necessary. A workplan submitted by 30 April 02 for installation of systems at remaining FS/TS. Recovery systems installed and operating at all remaining FS/TS by 1 July 02. Donald Seagren
2/11/2002 Update or Other Action Reviewed request for extension of installation of test product recovery system. After consultation with USFWS, reluctantly agreed to extension. Product recovery must be a priority with systems installed this summer and in full operations by freeze up 2002. Donald Seagren
8/5/2002 Meeting or Teleconference Held Site inspection with Unocal, Dave Brailey, USFWS to observe and discuss free product recovery system. Donald Seagren
9/12/2002 Site Characterization Workplan Approved Review and approve Work Plan for Monitoring Well Installation. Coordinate with USFWS. Donald Seagren
4/23/2003 Meeting or Teleconference Held Annual meeting to discuss 2002 work and 2003 plans. Donald Seagren
4/29/2003 Update or Other Action Reviewed 2003 free product recovery report and MW installation report. Donald Seagren
6/9/2003 Update or Other Action Reviewed Free Product Recovery report dated 30 April 03. Little oil recovered, but at end of 02, free product had not returned to MWs that had been evacuated. Donald Seagren
4/27/2004 Update or Other Action Approved NAPL recovery plan and amended plan for all TS with MW's containing NAPL. Donald Seagren
4/30/2004 Update or Other Action File number assigned and entered into the Fileroom DB and CS DB. Alyce Hughey
5/27/2004 Meeting or Teleconference Held Monthly progress meeting. Revised NAPL recovery plan to be submitted by 30 June 04. Donald Seagren
6/18/2004 Cleanup Plan Approved reviewed and approved NAPL recovery plan. Donald Seagren
3/21/2005 Update or Other Action Reviewed 2004 GW monitoring report. No appreciable change in the risk to human health or the environment. Donald Seagren
10/7/2005 GIS Position Updated Using a Swanson River Layout Map from Unocal, in conjunction with TopoZone Pro and the KPB Parcel Lookup, entered the coordinates for this site. Metadata includes No Topo Basemap, TopoZone Pro Street Maps, Black and White Aerial Photo, on a Medium Size Map, View Scale 1:24,000, Coordinate Datum NAD83. High degree of confidence in accuracy of location. Alyce Hughey
3/9/2006 Update or Other Action Reviewed 05 monitorinng rpeort. No significant change to risk to human health or the environment. LNAPL recovery and annual monitoring to continue. Donald Seagren
4/2/2007 Update or Other Action Reviewd 06 monitoring report. No significant change to risk to human health or the environment. Annual monitoring & LNAPL revoery to continue. Donald Seagren
5/8/2007 Exposure Tracking Model Ranking Donald Seagren
6/11/2008 Update or Other Action Site transferred from Don Seagren to Paul Horwath per Linda Nuechterlein. On 6-30-08 transferred from Paul Horwath to Don Fritz per Paul Horwath. Alyce Hughey
9/30/2011 Document, Report, or Work plan Review - other Reviewed the 2010 Groundwater Monitoring Report Swanson River Tank Setting and Flare Pit, dated July 2011, from OilRisk Consultants. During the 2010 groundwater sampling event conducted at Tank Setting 3-9 in November through December, thirteen of the fourteen monitoring wells were sampled for BTEX. Well FS3-9B was not sampled because it was found dry. Analytical results detected Benzene in three of the monitoring wells above the groundwater cleanup levels at concentrations of 0.0201 mg/L to 0.276 mg/L. Alyce Hughey
11/16/2011 Update or Other Action Site transferred from Don Fritz to Peter Campbell per Paul Horwath. Alyce Hughey
7/2/2015 Update or Other Action Cleanup in delayed status. Peter Campbell
9/19/2017 Document, Report, or Work plan Review - other SRF Tank Setting 3-9 groundwater wells are monitored on a biennial and a four-year schedule. All viable wells are gauged during each sampling event. 2017 field activities will include: Decommission and replace TS3-9C. The well has an obstruction preventing replacement of the absorbent sock. Monitor and remove LNAPL and replace LNAPL-absorbent socks in wells TS3-9A, TS3-9CR (replacement well for TS3-9C), TS3-9U, and FS3-9E. If LNAPL is not present, sample TS3-9A, TS3-9CR, and FS3-9E for 8260C and PAH. If LNAPL is not present, gauge groundwater level in TS3-9U; this well will be sampled every four years, with the next sampling planned for 2019. Sample four wells for 8260C and PAH: TS3-9F, TS3-9T, TS3-9V, and TS3-9BB. Four wells are sampled every four years and will be sampled next in 2019: TS3-9AA, FS3-9DD, FS3-9B, and FS3-9G. See 2017 Kenai Groundwater Monitoring Program Work Plan. Peter Campbell
11/12/2019 Document, Report, or Work plan Review - other Reviewed the 2017 Groundwater Monitoring Program Report for the Swanson River Field. Monitoring well TS3-9C was replaced with monitoring well TS3-9CR. The new replacement well did not contain LNAPL and analyte concentrations were significantly less than the original well. Four monitoring wells contained LNAPL and were not sampled. There were exceedances for 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, benzene, ethylbenzene, naphthalene and xylenes. Biennial sampling will continue. Peter Campbell
3/25/2020 Document, Report, or Work plan Review - other Review the 2019 Groundwater Monitoring Report. Contaminant distribution does not necessarily match the groundwater flow patterns presented in the report, with several data points not being honored. ADEC asked that the source of contamination at well TS3-9V be identified, as no source is readily apparent. Peter Campbell
5/27/2021 Document, Report, or Work plan Review - other Review the Contaminated Soil & Water Management Plan for the 2021 Flowline Installation and Inspection. ADEC Approval Peter Campbell
7/21/2021 Document, Report, or Work plan Review - other 2021 Groundwater Monitoring Program Work Plan ADEC Approval Letter Peter Campbell
8/1/2022 Document, Report, or Work plan Review - other 2021 Groundwater Monitoring Program Report ADEC Report Plan Approval Peter Campbell
6/1/2023 Long Term Monitoring Workplan or Report Review Review and approve 2023 Groundwater Monitoring Program Work Plan Addendum. Peter Campbell

Contaminant Information

Name Level Description Media Comments

Control Type

Type Details

Requirements

Description Details

No associated sites were found.

Missing Location Data

Because the GIS location data for this site has not been entered, we cannot direct you to its position on the map. Click "Continue" to proceed to the Contaminated Sites Web Map or "Close" to return to the site report.
Continue     Close

Public Notices  •  Regulations  •  Statutes
Press Releases  •  Contact

 

State of Alaska Department of Environmental Conservation

P.O. Box 111800
Juneau, AK 99811-1800
Phone: 907-465-5066
Fax: 907-465-5245
TDD: 800-770-8973
Physical Location: 410 Willoughby