SR21 Gasoline Spill Site


FY 2015- 2016 Cenex/CHS Tanker: Gasoline Spill at SR21 location MP 136.5

This site is located on Washington State Highway 21 at Milepost 136.5 in Keller, WA.  An incident occurred on May 19, 2015 when a fuel tanker truck owned by CHS overturned and released a substantial volume of gasoline (~2700 gallons) and a lesser amount of diesel (~60 gallons) onto the ground surface immediately adjacent to SR21 and in close proximity to the San Poil River.  It is determined that CHS is the owner or person in charge of the facility which is the source of the release of threatened harmful substance(s) into a navigable water of the United States. In collaboration with EPA, CCT Environmental Trust has been involved in emergency response and interim actions at the site from the date of the incident until present, and we expect to remain involved in a regulatory and technical advisement capacity until final cleanup in complete.

Cenex/CHS Tanker spilled gasoline at mile post 136.5

Remediation of Vapor Phase Hydrocarbons:   Soil Vapor Extraction  GAC Filtration  Effluent Testing

Remediation of Vapor Phase Hydrocarbons:

Soil Vapor Extraction

GAC Filtration

Effluent Testing

Treated Groundwater Infiltration Gallery
Tribal Tract No. 101-T1766 via CBC Resolution No. 2015-456

Remedial Methods at SR21 Spill Site

5/19/2015 – 8/19/2015

  • Pump & Treat of LNAPL (liquid free product)

  • Plume Control

  • Soil Vapor Extraction

8/19/2015 – 9/11/2015

  • No Remediation, All Systems on Standby

9/11/2015 – Spring 2016

  • Prepare for winter operations

  • Air Sparging enhanced Soil Vapor Extraction

  • In-Situ Oxidation

5/19/2015 – Present

  • No detection of gasoline or diesel range hydrocarbons

SR21 Spill Site Closure Criteria for Groundwater:


Analytical results must document COPCs in all groundwater wells are less than CCT HSCA cleanup levels for:

  • 5 consecutive samples over > 2 weeks, and

  • 4 consecutive calendar quarters including samplesat seasonal high and seasonal low water levels, and No surface water detections of COCs

Tribal Tribune article update link

Tribal Tribune article "Sticky Situation" link