Port of Seattle Terminal 91

Last updated: September 2026

A public comment period on the Interim Action Work Plan for deepening the berths to allow ships to connect to shore power ended on 7/17/26. Eight comments were received. These can be reviewed in the "Response to Comments" document in the "Documents" section at the bottom of this page. The documents were not changed based on the public comments, but Tribal feedback was incorporated into the work plan. The feedback required additional sampling and analysis.

Currently, Terminal 91 is completing the additional sampling needed to finish investigating sediment contamination. They also are developing a feasibility study that will compare ways to clean up the sediments. The two reports will be issued for public comment together, probably in early 2027, so that a more complete picture is presented for public comment. 

For more detailed information, click on the "View Documents" link on the left. 

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El Departamento de Ecología está comprometido a ofrecer servicios de idioma, incluidos traducción e interpretación, para personas cuyo idioma principal no es el inglés. Para solicitar estos servicios, envíe un correo electrónico a janelle.anderson@ecy.wa.gov o llame al 425-301-6454. Si llama, pida que le conecten con un intérprete.

In September 2016, Ecology and the Port of Seattle (Port) amended an existing Agreed Order (AO) for site cleanup. The AO required the Port to implement cleanup actions for the tank farm and affected areas. The amendment allowed the Port to address a narrow shoal along the south end of Pier 91.

The Terminal 91 Complex (T91 Complex) is located in an industrial area in the Interbay neighborhood of Seattle. Various railroads, land development companies, and private individuals owned the property from the late 1800s through 1920. The Great Northern Railroad began to develop the area in the early 1900s by filling in the area between Magnolia Bluff and Queen Anne Hill. Filling continued through the 1940's.
 
The T91 Complex was operated by several oil companies from 1926 until 1941, when the U.S. Navy took possession. The Port purchased the facility in the 1970s. A four-acre parcel of the T91 Complex is the site of a former tank farm. Constructed in the 1920s, it operated as a fuel storage facility until it was demolished in 2005. In 1992, the owner of the tank farm, Burlington Environmental Inc. (BEI), was issued a permit to operate as a dangerous waste treatment and storage facility (TSD). Although the permit is no longer active, the Port is responsible for cleanup of contamination at the site.

Activities conducted on site include:

• Storage of fuel and waste oil.
• Blending and storage of marine boiler fuel, diesel, and other petroleum products. 
• Treatment of wastewater from oil and coolant emulsions, industrial wastewater, and sludge.
• Treatment of bilge and ballast waters.

Submerged lands (sediments at the bottom of Elliot Bay): The Army Corps of Engineers (Corps) started cleaning up the marine sediments under the water in 2010 when discarded military munitions were discovered near T-90 and T-91. The Corps investigated to locate the discarded munitions and removed them in 2012.

When the Navy owned the facility, they sometimes disposed of munitions overboard without documentation while ships were in port. Occasionally law enforcement divers still find and remove munitions.

Historic land use and industrial practices also contaminated the sediments with chemicals and metals. Contaminants there include:

• Metals – arsenic, cadmium, chromium, copper, lead, mercury, silver, and zinc
• Tributyltin
• Poly Aromatic Hydrocarbons (PAHs)
• Phthalates
• Semi volatile organic compounds (SVOCs)
• Poly chlorinated biphenyls (PCBs)

Tank Farm: The Port removed above ground tanks and contaminated structures in 2014.  Under a restrictive covenant, the Port can only use the land in ways that prevent people from coming in contact with any remaining hazardous substances. Philip Services Corp. operated the former tank farm as a TSD. Other Port tenants used those same tanks for fuel storage and distribution.

Uplands: The Port cleaned up the remainder of the upland areas, other than the Tank Farm Area beginning in 1999. Soil in these areas was contaminated mostly with petroleum products.

Submerged Lands
The submerged lands are in the Remedial Investigation (RI) phase of Washington's cleanup process.


Uplands
The uplands portion of the site completed their Cleanup Action Plan (CAP). Long-term monitoring continues.