One of Leviathan Mine's former owners has agreed to an Environmental Protection Agency order to help stop the runoff of pollutants into the Carson River.
"We agreed to study the remainder of the problem - the seeps not captured by California's program," said Sandra Stash, vice president for environmental management for ARCO.
She said the EPA asked the company as one of the former owners of the mine to add its expertise and funding to that committed by the State of California which years ago agreed to take over the cleanup.
"Basically, we agreed to divide up the work and sort out who's responsible later," said Stash.
She said California made great progress with a new treatment and filtering system this year, cleaning up much of the sulphur-poisoned water that overflows the holding ponds at Leviathan during spring runoff.
"They've actually done a fairly effective job," she said. "But you get so much water in a couple of weeks in spring runoff that those ponds are just undersized."
The runoff contains large amounts of sulphur as well as heavy metals.
Stash said the company will put about $1 million into a study and pilot program this coming year to try to capture and clean up the smelly, orange-tinted water leaking from beneath the mine tailings. She said with the EPA's permission, both the company and the state will be trying different new techniques to clean up the mine runoff.
"The EPA's been very open that you don't study something for 10 years before doing anything but try things as you go," she said. "So we'll try out some techniques next year."
The company is also heavily involved at the old Anaconda site near Yerington because, according to Stash, "there are a lot of former owners but we're about the only one with any money." Federal law allows environmental officials to go back through former owners to find some one to help pay for cleanup at dangerous mine sites. ARCO got involved less than a year ago when Arimetco filed for bankruptcy. State officials asked some help paying electric bills for the pumps that keep the old leach pads from leaking into the Wabuska Drain which eventually dumps into the Walker River.
The problem at the Yerington mine, she said, is that it could conceivably be sold to a company which could start mining copper there again.
"The question is how much cleanup do you do on a site that is a mine and can be mined again," said Stash. "If we knew for sure this property would not be mined again, we would be willing to do it."
The problem at Yerington, which was an active mine for about 100 years, is that the leach piles containing the heavy metals and acids cover hundreds of acres.
The company has a third site it is responsible for doing clean up on in Nevada - the Rio Tinto Mine in Elko County. That site, however, ARCO shares with three other companies. She said they have spent four years doing reclamation at Rio Tinto.
