Site Description
Terminal 115 Plant 1 site (T-115) is in the industrial area along the western shore of the Lower Duwamish Waterway (LDW) at 6000 West Marginal Way SW, Seattle, Washington. T-115 comprises approximately 94 acres over two parcels owned by the Port. Currently, the property is used by 4 tenants who perform seafood processing, storage, and shipping; marine cargo shipping; and commercial vehicle fueling.
Site History
Historical industrial and commercial operations at the terminal began in the early 1900s. These activities included airplane production at the Former Boeing Plant 1; several historical and existing gas and service stations; releases from former underground storage tanks; gravel, concrete, and cement production; car wash operations; and extensive filling of historically submerged land.
Over the past century, the LDW shoreline was reshaped and realigned to better fit the needs of industrial tenants and maritime navigation. Sediment from these realignment projects was used to fill low spots and smaller channels at T-115, increasing the overall footprint and elevation of the terminal. The Port purchased the property in approximately 1970.

Contamination Issue
Past operations and filling activities led to soil and groundwater contamination. Chemicals of potential concern will be identified during the remedial investigation study, which began in 2024. Early data collection indicates potential localized groundwater and soil contamination from petroleum hydrocarbons, volatile organic compounds, and metals.
Why is the Port Doing this Cleanup?
As the current property owner, the Port is partly responsible for addressing contamination at the site. The Port is performing a remedial investigation to support cleanup action, if needed, at T-115 Plant 1. This work is being performed under an Agreed Order between the Port, The Boeing Company, and the Department of Ecology (Ecology).
T-115 Plant 1 is located along the LDW, which is a Superfund site with cleanup being led the U.S. Environmental Protection Agency. As part of source control efforts by Ecology, the Remedial Investigation will determine whether the T-115 is a source of contamination to the LDW. The Superfund cleanup will enhance the health of the LDW for Tribes and community members, support the local economy, and provide a healthier habitat for fish and wildlife.
Status
A Remedial Investigation Work Plan was approved by Ecology in February 2024. Site remedial investigation work commenced in June 2024 and will continue through 2026. Remedial Investigation and Feasibility Study activities and reporting are anticipated to take approximately 3 to 4 years.
Contact Information
Jalyn Buckley | Environmental Management Specialist | [email protected]
Additional Resources
Visit the project website and Ecology’s Terminal 115 Plant 1 Cleanup Site for more information.