Atlantic Richfield to Spend $10.2 M for Anaconda Mine Cleanup

In a recent settlement, Atlantic Richfield Company (ARC) agreed to perform clean-up work, estimated at $8 million, at the former Anaconda Copper Mine site in Yerington, Nev., 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 ARC 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:

  • Cover expanses of former evaporation ponds to prevent the accumulation of standing water that threatens wildlife and to prevent the migration of hazardous dust from the site;
  • Remove radiological materials in the former process areas to a level that is safe for permanent workers at the site;
  • Abate threats from abandoned electrical systems;
  • Remove asbestos-laden transite pipe within the site;
  • Continue operation and maintenance of the heap leach fluid system to prevent catastrophic discharges of acidic fluids and operate a system to deter wildlife from approaching the acidic fluids.

EPA has spent approximately $10 million at the Anaconda Copper Mine site investigating and addressing wastes abandoned at the site. Specific work includes a spring 2006 action 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 agency completed additional repairs to the heap leach system in 2007 and 2008 to prevent discharges to groundwater. ARC is performing other response actions at the site, including broad investigation of the nature and extent of groundwater contamination, under two previous EPA Orders. Last year, ARC reimbursed EPA for $2.77 million in costs.

Originally known as the Empire Nevada Mine, the site began operation around 1918 and was acquired in 1953 by Anaconda Minerals. From 1977 to 1982, the company was owned by ARC and then sold to Don Tibbals, a local resident, who subsequently sold most of his interests to Arimetco Inc.

Arimetco operated a copper recovery operation from existing ore heaps within the site from 1989 to November 1999. Arimetco has terminated operations at the site and is currently managed under the protection of the U.S. Bankruptcy Court in Tucson, Ariz.

The threats on the site come from metals contaminating the groundwater and fugitive dust that could impact human health and surface water. Mining operations enhanced levels of naturally occurring uranium, making the radiological substance more pervasive and mobile in and around the site. Additional concerns include contaminated surface water that can impact wildlife.

For a video of site conditions before EPA’s removal actions, visit