Crews to remove 8,000 yards of arsenic-laced mud from Lake Union

SEATTLE - Cleanup crews are getting ready to remove thousands of yards of contaminated mud at the bottom of Lake Union after high levels of arsenic were discovered at the Northlake Shipyard.

According to the Washington State Department of Ecology, the pollution near the western pier and dry dock areas is the result of years of sandblasting by the facility's previous owner. In 1994, when Northlake Shipyard bought the property, it was required to set up a trust fund to help pay for future cleanup of the site. That fund now contains $1.5 million.

This week crews began preparing the site for cleanup, and dredging is expected to start in December.

A silt curtain suspended from floats in the water will be deployed around the work area, and the Department of Ecology will monitor water quality to make sure it meets state requirements.

A total of 8,000 cubic yards of contaminated materials will be removed from the lake bottom over the next three months.

Crews will then cover the site with 6 inches of clean sand. The dredged material will be taken by truck and disposed of at a solid waste facility.

According to the Department of Ecology, residents living near Northlake Shipyard should expect an increase in truck traffic during the cleanup.