Department of Ecology News Release - Oct. 24, 2019

Port plans environmental studies at Terminal 90-91

Prepares for cleanup of contaminated sediments

The Port of Seattle will study contamination in sediments surrounding Piers 90 and 91 to prepare for future cleanup work under an agreement with Ecology. Photo: Port of Seattle


SEATTLE – The Port of Seattle will investigate contamination in Smith Cove sediments at its Terminal 90 and 91 complex under a legal agreement with the Washington Department of Ecology.

The port has previously conducted cleanup work on the terminal’s uplands.

Ecology seeks public comment through Nov. 25, 2019 on the agreement, called an agreed order, under which the port will conduct the sediment studies. The public is invited to view information and ask questions at two open houses in adjoining neighborhoods at Seattle Public Library branches from 3 to 6:30 p.m.:

  • Magnolia: Oct. 22; 2801 34th Ave. W

  • Queen Anne: Nov. 5; 400 W. Garfield St.

The terminal began more than a century ago as a cargo facility. It later was home to oil company bulk fuel facilities and a U.S. Navy supply depot before the port purchased the property in the 1970s. The port cleaned up soil and groundwater contamination at a four-acre former tank farm site on the property in 2016, and continues to monitor groundwater there to ensure that contaminant levels meet state cleanup standards.

The U.S. Army Corps of Engineers conducted a partial cleanup of the terminal’s sediments in 2012 when it removed World War II-era munitions that had been discovered at the site. That project and other preliminary studies have identified the presence of substances that are harmful to fish and other marine life:

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

The port’s studies under the proposed agreement with Ecology will provide information needed to evaluate cleanup options and to plan the site’s final cleanup.

Ecology also seeks comment on:

An Ecology fact sheet provides more information about the site and the cleanup process.

Contact information

Larry Altose
Ecology communications
425-649-7009 or
Twitter: ecyseattle
Tom Makie
Ecology site manager
509-575-2803 or
Peter McGraw
Port of Seattle communications
206-787-3446 or