Agencies agree on plan to clean up old Sierra mine

Brendan Riley

Thursday, July 20, 2000 | 3:41 a.m.

CARSON CITY, Nev. - An agreement on a new cleanup at an abandoned Sierra sulfur mine that's polluted nearby streams for years was announced Thursday by the federal Environmental Protection Agency.

Keith Takata, head of the EPA's Superfund program for the Pacific Southwest, said his agency reached the Leviathan Mine agreement with California's Lahontan Regional Water Quality Control Board.

Takata said contractors hired by the water board began this week to treat five ponds which store up to 16 million gallons of acidic waste at the mine, near Markleeville in Alpine County, Calif.

He termed the work "an effective stopgap measure to address polluted runoff while we continue to forge ahead on a long-term cleanup plan."

Takata said it's important to get the work done before summer ends, adding, "At 7,000 feet, the summer work season at the mine is fairly limited."

Harold Singer, the water board's executive officer, said the water treatment should eliminate any threat of toxic overflows from the ponds next winter or spring into nearby Leviathan and Bryant creeks, which flow into the East Fork Carson River.

The EPA also is continuing its negotiations with Atlantic Richfield Corp., the successor to the former mine operator, to deal with other sources of acid drainage from the mine. ARCO acquired the mine from the Anaconda Corp. in 1978, and the state of California took over the site in 1983.

The cleanup involves treatment of the ponds with lime to make toxic metals settle out. If that's not done, sulfuric acid can form and dissolve arsenic and other metals to cause more pollution.

Once the water is treated, it can be safely turned into Leviathan Creek, Takata said. Some solids with high levels of toxic metals will have to be hauled off.

This is the latest of several efforts since the mid-1980s to stop acid drainage that has killed off aquatic life in the adjacent creeks. Pollutants also have reached the downstream Carson River, which runs eastward into Nevada.

The EPA designated the mine a federal Superfund site last May - a status reserved for the most polluted places in the nation.

Leaders from Douglas County, Nev., and other downstream water users, including the Washoe Tribe, have worried for years over the long-term impacts of the rust-colored stew of contaminants.

The mine produced copper sulfate from 1863 until 1872. It was reopened to produce sulfur beginning in 1936, and finally shut down in 1962.