EPA seeks year-around treatment of Leviathan Mine drainage

A proposal to treat drainage from the Leviathan Mine Superfund Site year-round is in the works.

Environmental Protection Agency Project Manager Freyja Knapp said Thursday that in preparation for implementing the treatment they were reaching out for information on how best to communicate the effort to the public.

The main challenge to working on the site, which is around 7,500 feet above sea level, is the Sierra winter.

“There are a lot of needs to operate in the winter,” Knapp said. “Including heat, power and access.”

Work has been underway at the site for decades and it has officially been a superfund site since 2000.

Knapp said that more than two decades of data have been gathered while clean-up efforts have continued.

While the treatment systems at the mine capture drainage year around, treatment can only occur seasonally.

“Making the decision to move year around and sitewide will involve formal consultation with the tribe and includes inviting public comment on a plan,” Knapp said.

Once a plan is developed the EPA will respond to comments and issue a record of decision before negotiating with those involved to design and implement the process.

Mining at the site began in the middle of the Civil War and continued on and off until 1962. In the mid-20^th Century, owners dug an open pit sulfur mine, disturbing 250 acres and generating 22 million tons of waste rock, overburden and sub-economic ore.

Much of that material was dumped into Leviathan Creek where water leached out the sulfur, creating sulfuric acid. The creek drains into Bryant Creek and then the East Fork of the Carson River.

The current owners of the land are the State of California and Atlantic Richfield Company, which ended up taking responsibility for the clean-up.

Knapp said photos of the confluence of Leviathan and Mountaineer creeks showed the melt-off was dark and muddy after the winter but clears as the high-density sludge treatment facility has been operating.

“These studies have been looking at sensitive insects that live in the stream,” she said. “They show there has been recovery overall during the last 25 years, but also seasonal dips and that correlates with the operating of that particular system.”

She said some sampling will be done to see if there’s more impact further downsteam, including on the East Fork, which could bring the clean-up to Douglas County’s doorstep.

Commissioner Walt Nowosad said he visited the site in the fall of 2001.

“Those pits are a muddy brown color,” he said. “They’re very striking. “I guess I can say it needs cleanup.”