Unocal Edmonds Bulk Fuel Terminal 0178
11720 Unoco Road, Edmonds, WA 98020

Treatment System
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The 2017-2018 interim action construction work is complete.  The dual-phase extraction system is operating, and will be ongoing for a few years before cleanup is achieved.

Currently, a draft Cleanup Action Plan is being prepared to describe the final cleanup activities for the site.  Along with a draft Consent Decree, the public review documents are anticipated to be made available in late 2020.

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The Site is located at 11720 Unoco Road in Edmonds, Washington. The terminal operated from 1923 to 1991. It was used for storing, blending, and distributing petroleum products including gasoline, diesel, and bunker fuel. An asphalt plant operated on the Site between 1953 and the late 1970s.

The Terminal consisted of a dock and an Upper and a Lower Yard. Petroleum products were pumped from marine vessels moored at the dock to storage tanks in the Upper Yard, which was on a hill above the Lower Yard. Products were gravity-fed and pumped to loading racks in the Lower Yard for transport by truck and train to customers.

A number of Interim Actions have been conducted over the years to clean up oil floating on groundwater, remove arsenic-contaminated soil, and remove petroleum-contaminated soil.

Removal of petroleum-contaminated soil resulted in cleanup of groundwater. Most of the Site is now clean. Ecology certified the Upper Yard was suitable for residential use in 2003 and the Point Edwards Condominiums were subsequently constructed.

The 2017-2018 Interim Action was initiated to clean up two remaining areas of contamination. One is the stormwater Detention Basin 2 area and the other is the vicinity of a Washington State Department of Transportation (WSDOT) storm drain crossing the Site. The Interim Action Work Plan describes how these two areas will be cleaned up.  The stormwater Detention Basin 2 was excavated to remove the contamination, and a dual-phase extraction system was installed to continue remediating the WSDOT storm drain area.

The Lower Yard’s planned future use may be part of a multimodal transportation terminal. This is part of the Edmonds Crossing Project.

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Unocal Edmonds Bulk Fuel Terminal 0178 site is ranked the highest assessed risk and listed as a contaminated site by Washington State Department of Ecology (Ecology) Toxics Cleanup Program.



Unocal installed recovery wells in the Lower Yard and began removing petroleum product from the groundwater.



Union Oil of California (Unocal) enters into cleanup agreement (Agreed Order) under Model Toxics Control Act with Ecology.



Remedial Investigation began; sampling and analysis of soils and groundwater.

Product recovery continues until circa 2000 from wells in the Lower Yard; totals approximately 2000 gallons petroleum.



 Interim cleanup action plan for Upper Yard approved by Ecology.

All 23 fuel storage tanks removed from Upper Yard.

Interim cleanup action of select areas in the Lower Yard removed 10,000+ tons of petroleum contaminated soil and 2500+ gallons of product.




Approximately 100,000 tons of contaminated soil removed from Upper Yard.



Cleanup of Upper Yard complete.

Ecology determines that Upper Yard is suitable for residential use.

Construction on Point Edwards condominiums begin.

Interim cleanup action of more select areas in the Lower Yard (including stormwater Detention Basin No. 1) removed approximately 40,000 tons of metals and petroleum contaminated soils.



 Range of cleanup options for Lower Yard selected.



Phase 1 of Point Edwards opens on the site of former Upper Yard.

Unocal enters a Purchase and Sale Agreement with Washington State Department of Transportation for the Lower Yard.



 Ecology and Unocal enters into another cleanup agreement (Agreed Order) to conduct interim actions.

Interim cleanup action of Lower Yard begins.



 Interim cleanup action of Lower Yard complete, except for 2 areas intentionally excluded in the plan; 130,000 tons of petroleum contaminated soil/sediment and 9000 gallons of product was removed, along with some sand blast grit containing arsenic and lead.

Confirmational groundwater monitoring begins.




 Completed data collection and monitoring of Lower Yard cleanup.




 Ecology determines that additional cleanup steps are needed for Lower Yard; Ecology approved Feasibility Study Work Plan.

Groundwater monitoring continues.




 Unocal, a subsidiary of Chevron, submits draft Feasibility Study for full Lower Yard cleanup.



Wells installed and pilot test study for Dual-Phase Extraction System for Lower Yard area beneath a Washington State Department of Transportation stormwater line.



Interim Cleanup Action work plan approved for the 2 remaining areas on the Lower Yard.

Work delayed for NPDES Permit appeal for treated groundwater discharge to surface water.



Agreed Order amendment becomes effective after NPDES Permit issued to support interim action cleanup in 2 remaining areas on Lower Yard.

 Interim cleanup action begins; Excavation of one area (Detention Basin No. 2) completed; the other area (beneath a Washington State Department of Transportation stormwater line) had construction completed of a Dual-Phase Extraction System that could take up to 6 years to conclude cleanup.

Phase II of Point Edwards Condominiums begins on the Upper Yard.



 Draft Consent Decree and Draft Final Cleanup Action Plan prepared for the Site (including Upper Yard).

Monitoring of interim actions continues.



 Interim cleanup action monitoring continuing.

Limited re-design of Dual-Phase Extraction System to cover a few localized spots throughout the Lower Yard.



To see if electronic documents are available for this site, click “View Electronic Documents” in the right-hand column. Click for instructions on how to submit a public records request.


Map showing site location as Snohomish County, WA SITE INFORMATION


View Electronic Documents

Cleanup Site Details Report

Facility Site ID: # 2720

Cleanup Site ID: 5180

Edmonds, Snohomish County

Status: Cleanup Started   Get definitions of Status terminology

Tanner Bushnell
Site Manager
(425) 691-0571

Document Repositories:

Northwest Regional Office
3190 160th Ave SE
Bellevue, 98008-5452

Edmonds Public Library
650 Main Street
Edmonds, 98020