Officials hail cleanup efforts at Sierra Superfund site

Sunday, Nov. 20, 2005 | 12:51 p.m.

GARDNERVILLE, Nev. - Officials are hailing cleanup efforts at an eastern Sierra Superfund site, saying more than 10 million gallons of a toxic stew were treated this year - double that of any previous year.

Since making the Superfund list of the country's most polluted sites in 2000, the Leviathan Mine site 25 miles southwest of Gardnerville has been the focus of increased attention.

"In treating 10.5 million gallons of acid mine drainage, we prevented overflow this year and have reduced the possibility of overflow next year," said Harold Singer, executive officer of the Lahontan Regional Water Quality Control Board.

"Given that only five million gallons of treatment was contracted for at the start of this summer, it is extraordinary that we were able to get this job done," he said.

The stew of acid and dissolved heavy metals has collected at the abandoned sulfur mine in California's Alpine County for half a century and polluted streams in the upper Carson River basin.

Acidic waters discharged from the mine site are collected and stored in five lined evaporation ponds. All contaminated water in the ponds was treated, Singer said.

Treating the polluted water helps prevent the ponds from overflowing into Leviathan Creek - a tributary of the East Fork Carson River - and destroying aquatic life downstream, he added.

"Preventing overflows of acid mine drainage from the ponds at Leviathan Mine is critical to California's efforts to restore Leviathan Creek," Singer told Gardnerville's Record-Courier newspaper.

The water board successfully treated and discharged 530,000 gallons from one of the ponds in June. Treatment of the other ponds began in August.

The Leviathan Mine opened in 1863 as a source of copper sulfate for processing silver ore from Comstock Lode mines in the Virginia City area.

The mine closed but was reopened for sulfur mining from 1935 to 1941. After buying it in 1951, the Anaconda Co. used open-pit mining to extract sulfur for about 10 years.

The federal Environmental Protection Agency plans to complete installation next year of a $7 million system to provide year-round cleanup at the remote 7,000-foot mountain location.