ASARCO Smelter Site slag locality, Tacoma, Pierce County, Washington, USAi

Regional Level Types
ASARCO Smelter Site slag locality	Slag Locality
Tacoma	City
Pierce County	County
Washington	State
USA	Country

Slag dumps of a smelter facility operated from 1887 to 1985 (GPS coordinates are approximate.)

For much of the 20th century, a large smelting facility was operated by ASARCO on the shore of Commencement Bay near Point Defiance.

The town of Ruston surrounds the former ASARCO plant.

Tailing waste was dumped into the bay, eventually forming a long peninsula.

Today, it is a project area within the Commencement Bay Superfund site.

The Thea Foss Waterway, an arm of Commencement Bay near downtown Tacoma, was declared a Superfund site in 1983.

In 1991, the Environmental Protection Agency announced that the St. Paul Waterway, once among the most contaminated parts of Commencement Bay, had been the first marine Superfund site in the nation to be cleansed of pollution.

This was the only tidewater smelter in the United States, and the last to close in Washington.

Originally a lead smelter, the plant was enlarged to handle copper in 1903 and by 1910 lead smelting had ceased.

ASARCO handled ores from Washington, Montana, Oregon, Alaska, and the Cour D'Alene mining district in Idaho, as well as from Mexico, Central America, Chile, Peru, Japan, Korea, and the Phillipines.

High silica flux was brought in to aid in the smelting process.

These fluxes were ores of gold, silver, and copper and contained small amounts of pyrite, calcium-magnesium carbonates, and wall rock such as feldspars, clays, and micas.

In 1902 slag pots were used to remove slag from the lead/copper furnaces and used to create a synthetic bedrock peninsula around the site.

Later slags were then poured molten over the older slag.

Some slag has been exposed to groundwater, saltwater, and oxygen for more than a century.

The site is now undergoing cleanup and closure.

Mines that shipped ore to the Asarco Smelter include:

- Canada: Chalco Mine, Vancouver Island, British Columbia;

- USA: Mineral Creek Mine, Mineral Creek, Kittitas Co., Washington;
Bonanza Queen Mine, Silverton, Snohomish Co., Washington.

Other Regions, Features and Areas containing this locality

References