Port of Seattle Terminal 91

Last updated: May, 2024

Currently, Terminal 91 is completing the additional sampling needed to finalize the investigation of 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 2025, so that a more complete picture is presented for public comment. 

From April 6 - May 8, 2023 Ecology accepted comments on an Amended Agreed Order, Interim Action Work Plan and Public Participation Plan. 

Agreed Order: Legal agreement to ensure that a Remedial Investigation (RI) to determine the location and type of the contamination meets the requirements of the state cleanup law. 

Interim Action Work Plan: A plan outlining a partial cleanup that will be done before the final cleanup. Parts of the dock at Pier 90 need to be repaired but to do this work, sediments in that area must be cleaned up. 

Public Participation Plan: Creates a process to communicate with and receive feedback from the public about this cleanup.

View fact sheet

What happens next?

The Port will submit the Remedial Investigation (RI) of site sediments to Ecology for review. That RI is expected in June 2023. Ecology will review the report and decide the study is complete and ready for public notice or ask the Port to do more sampling. When Ecology believes the study is complete, it will go out for public review before it becomes final.

For more detailed information, visit our Electronic Documents section.

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.