Site Description
Terminal 18 (T-18) is located on the eastern side of Harbor Island at 1050 SW Spokane St, Seattle, Washington, and makes up a majority of the Harbor Island Superfund Cleanup Operational Unit (OU) 01 – Soil and Groundwater (S&G-OU1 or just OU1). It is bordered by East Waterway and spans approximately 106-acres of Harbor Island. T18 is zoned for industrial use and is covered by an asphalt cap. The site is currently leased to SSA Marine, Inc. for shipping container storage, rail lines, roadways, and administrative buildings.
Site History
Harbor Island was constructed in 1909 by the Puget Sound Bridge and Dredging Company for the purpose of commercial and industrial ocean and rail transport operations. Historic use on the site included bulk fuel storage, secondary lead smelting, lead fabrication, ship building, and metal plating.
Harbor Island was listed as a United States Environmental Protection Agency (EPA) Superfund site in 1983 due to elevated concentrations of hazardous substances. Harbor Island was divided into seven OUs, with OU1 containing T-18. By the late 1990s, all hot spot contaminated soils had been removed and disposed of offsite.
The Port acquired an additional 90 acres of the island in 2003 to expand T-18. Contaminated soils within the expanded area were capped with asphalt paving. Soil hotspot excavation and capping was officially completed across T-18 in 2011.
Contamination Issue
A smelter, used on-site until 1984, has been identified as a source of high metal concentrations on the property. Spills and leaks from petroleum tanks from historical operations led to localized soil contamination. The contaminants of concern in OU1 included lead, arsenic, and petroleum hydrocarbons.
Why did the Port do this Cleanup?
As the property owner, the Port is responsible for monitoring the remedy at the site.
In 1993, the EPA required the excavation and treatment of all organic contaminant “hot spots” in soil, and capping of all areas where contaminants exceeded cleanup goals with impervious pavement.
Status
T-18 is currently in long-term groundwater monitoring through 2035. Groundwater contamination has been found in some wells, but the contamination has remained localized and stable since 2015. Five-year reviews are still being conducted on the site.
Contact Information
Brick Spangler | Senior Environmental Program Manager | [email protected]
Additional Resources
Visit EPA’s Harbor Island Superfund Cleanup page for more information and updates on the East Waterway cleanup.
