Arsenic and Lead in Tacoma's Soil

For nearly 100 years, the American Smelter and Refining Company (ASARCO) operated a copper smelter in the city of Ruston, in North Tacoma. Smoke stack emissions polluted the surrounding neighborhoods and a 1,000 square mile area called the Tacoma Smelter Plume. In the early 1980s, the U.S. Environmental Protection Agency (EPA) began a Superfund cleanup of the site. Arsenic, lead and other heavy metals are still in Tacoma's soil. For details on the smelter's history, visit this History Link page.

The Washington State Department of Ecology maintains several initiatives to educate the public, monitor contamination, and replace soil in residential yards. Soil samples collected between 2002 and 2019 were compiled to show the most current levels of arsenic and lead. Each sample location represents multiple samples taken throughout the property, at different depths, and for some, different times before and after soil remediation. The average scores from the most recent tests were interpolated over the city of Tacoma to create this visualization.