Cleaning Up the Anaconda Mine

Millions of tons of mineral-rich ore were processed at the Anaconda Mine, leaving tailings heaps and leach ponds contaminated with elevated levels of copper and uranium. These compounds can contaminate ground water and windblown dust. Since 2005, EPA has overseen more than $10 million worth of cleanup work at the site.

A former copper mining pit that has filled with groundwater at the Anaconda Mine site in Nevada.

The mine began operation around 1918 and was acquired in 1953 by Anaconda Minerals. From 1977 to 1982 the mine was owned by ARCO, and later sold to Arimetco Inc., which recovered copper from ore heaps in the 1990s before going bankrupt in 1999. Mining raised levels of copper and uranium at the ground surface. Low pH fluids in the heap leach ponds can harm water birds and other wildlife.

EPA’s Tom Dunkelman oversees cleanup work at the Anaconda Mine site.

Since 2004, EPA has conducted five actions to reduce imminent health and environmental threats while studies of permanent solutions are underway. These cleanup actions included capping more than 70 acres of mine tailings to prevent erosion and windblown dust, removing transformers containing PCBs, building a large evaporation pond to contain heap leach fluids, and closing and repairing other heap leach ponds.

In 2010, EPA oversaw further cleanup work by ARCO under a legal agreement with EPA, including:

• Covering former evaporation ponds to prevent windblown dust and contaminated water
• Removing radioactive materials to a safe level for site workers
• Abating threats from abandoned electrical systems
• Removing asbestos-laden pipes
• Operating the heap leach fluid collection system to prevent catastrophic acid discharges.