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Public Health - Seattle & King County

What is the Tacoma Smelter Plume (TSP) Project?
The plume is a 1,000 square mile area of arsenic and lead soil contamination from the former Asarco smelter in Tacoma.

For almost 100 years, the Asarco Company operated a copper smelter in Tacoma. Pollution blown from the smelter's 571-foot smokestack settled on the surface soil over 1,000 square miles in Puget Sound. Arsenic, lead, and other heavy metals are still in the soil as a result of this pollution, and will continue to be a health risk for years to come.

The Tacoma Smelter Plume covers parts of King, Thurston, and Pierce counties. The three county health departments and the Department of Ecology are working to reduce harm from soil contaminated with lead and arsenic.

Interactive map to search affected areas

Levels of lead and arsenic soil contamination can be different from place to place. It is based on:

  • Distance from the smelter
  • Wind currents
  • Geographic features (such as hills)
  • If soil has been disturbed during construction, gardening, or other activities

With funding from the Department of Ecology's settlement with Asarco, we are:

  • Collecting soil samples from residential yards, within a defined service area
  • Providing soil sample results to homeowners, along with an explanation of what that means
  • Providing outreach and education to residents
  • Partnering with community and gardening groups to increase education
  • Providing outreach to schools and child care facilities

The Department of Ecology is also:

More information can be found on the Washington State Department of Ecology TSP website.

For more information, contact us at 206-477-DIRT (3478); email us at dirtalert@kingcounty.gov; or use our online form.