New cleanup efforts proving successful at Sierra Nevada mine

Thursday, Sept. 30, 1999 | 10:06 a.m.

State water quality officials say they are optimistic the new treatment process at the Leviathan Mine will prevent toxins from spilling into the tributaries of the Carson River this year.

The new chemical procedure has been up and running for about a month. It's costing about $1 million.

So far, work crews have treated about 2 million gallons of dirty brown water laced with toxic metals and acids. They are working 16-hour shifts, seven days a week in hopes of treating another 3 million gallons by Oct. 15.

The mine, closed for 37 years, is located in Alpine County, Calif., about 25 miles southwest of Gardnerville. The new process converts a toxic stew of contaminants into clean water which is then discharged into Leviathan Creek.

"It's great to have a treatment system that's working," said Ranjit Gill, a water quality scientist who has been working to solve pollution problems at Leviathan Mine since 1983. "I wish we had a little more time because the more you treat, the less the chances of an overflow."

The goal is to prevent holding ponds full of toxins from overflowing into Leviathan creek, which has happened in the winter and spring each of the last two years.

"It's working fine," said Harold Singer, executive director of California's Lahontan Regional Water Quality Control Board. "We have a very strong likelihood of not having an overflow next year."

While pollution is largely diluted by the time it flows downstream and enters the Carson River in Douglas County, officials remain concerned over the ultimate threat to the area's primary water supply. The Washoe Tribe has also expressed continuing worry over pollution from the mine.

"It's quite concerning," said Douglas County Commissioner Bernie Curtis, expressing hope the new treatment effort will work better than ones in the past.

The once-underground mine produced copper sulfate from 1863 until 1872, then was reopened for a six-year period to produce sulfur beginning in 1935. From the 1950s to early 1960s, open pit mining was used to extract sulfur until the mine was finally shut down in 1962.

California water quality officials have struggled to stop mine drainage pollution since the site was acquired by the state in the early 1980s. More than $6 million has been spent on the problem.

The U.S. Environmental Protection Agency is considering listing Leviathan Mine as a Superfund site - a designation reserved for the nation's most polluted spots.