Atlantic Richfield agrees to clean up Anaconda Copper Mine

In a settlement announced Wednesday, Atlantic Richfield Co. agreed to perform cleanup work, estimated at $8 million, at the former Anaconda Copper Mine site in Yerington, and pay the U.S. Environmental Protection Agency $2.2 million for response and oversight work conducted by the agency in areas of the mine formerly operated by the company or its predecessor, Anaconda Minerals.

"With this agreement ARC will address the most critical contamination at the Anaconda mine," said Keith Takata, director of the EPA's Pacific Southwest Superfund division. "EPA will use the recovered costs to further reduce the environmental and health impacts from this contamination."

The settlement specifically requires ARC to conduct the following activities with EPA's oversight and approval:

n Cover expanses of ARC's former evaporation ponds to prevent the accumulation of standing water that threatens wildlife and to prevent the migration of hazardous dust from the site;

n Remove radiological materials in the former process areas to a level that is safe for permanent workers at the site;

n Abate threats from abandoned electrical systems;

Remove asbestos laden transite pipe within the site;

n Continue operation and maintenance of the heap leach fluid system at the site to prevent catastrophic discharges of acidic fluids and operate a system to deter wildlife from approaching the acidic fluids.

The EPA has spent approximately $10 million at the Anaconda Copper Mine site investigating and addressing wastes abandoned at the site. 

Specific actions include a spring 2006 action by the EPA to cap 100 acres of mine tailings to prevent erosion and dust blowing from the site, remove transformers, and build a collection pond to improve the Arimetco heap leach fluid system. The EPA completed additional repairs to the heap leach system in 2007 and 2008 to prevent discharges to ground water. ARC is performing other response actions at the site, including broad investigation of the nature and extent of ground water contamination, under two previous EPA Orders. Last year, ARC reimbursed EPA for $2.77 million in costs.