Department of Ecology News Release - Oct. 25, 2019

Cleanup proposed for site on Duwamish Waterway

Redevelopment of this property south of King County Airport will include environmental cleanup work. The Department of Ecology oversees the cleanup process.


The owner of 63 acres of land near the Duwamish River where past commercial and industrial activities contaminated soil and groundwater will conduct a partial cleanup and begin steps for a final cleanup. The Washington Department of Ecology is taking comments on documents that will guide both sets of cleanup work.


Prologis-Exchange 3301 South Norfolk LLC (Prologis) plans to do the partial cleanup work concurrently with redevelopment of the property, which straddles the city line between Seattle and Tukwila, just south of King County Airport.

Plans and reports available

Ecology is asking the public to review and comment on three documents through Nov. 26, 2019. These are available online (PDF files):

  • Interim action work plan – describes how Prologis will conduct a partial cleanup of contaminated soil.
  • Agreed order – describes the process Prologis will follow to study the site’s contamination, evaluate cleanup options and draft a final cleanup plan for the site.
  • Public participation plan – describes how Ecology will inform and involve the community about the cleanup process.

History and contamination

Different parts of the property have been used for warehousing, truck maintence, repair and fueling, a dry cleaner, a gas station and an auto wrecking yard. Previous studies have identified soil and groundwater contamination by petroleum products and related compounds, metals and polychlorinated biphenyls (PCBs) at levels above state cleanup standards.

Previous property owners have conducted partial cleanup actions under Ecology’s Voluntary Cleanup Program. These included removing underground storage tanks and contaminated soil and groundwater.

Part of the Lower Duwamish Waterway cleanup

The cleanup at this site will contribute to the larger Lower Duwamish Waterway cleanup. Ecology and the U.S. Environmental Protection Agency jointly manage that effort along the approximately 5 miles of waterway upstream from Harbor Island. 

Cleanup and commenting information

Information about the site’s contamination and cleanup process is available at:

  • Ecology’s website.
  • Seattle Public Library South Park Branch, 8604 Eighth Ave. S.
  • Ecology’s Northwest Regional Office, 3190 160th Ave. S.E., Bellevue. By appointment: 425-649-7190.

Comment through Nov. 26, 2019, by using Ecology’s online comment form. Or, submit comments or technical questions to Jing Liu, site manager, 425-649-4310, Department of Ecology, 3190 160th Ave. S.E., Bellevue WA, 98004-5452.

Contact information

Larry Altose
425-649-7009 or
Twitter: ecyseattle
Jing Liu
Site manager
425-649-4310 or