MASON VALLEY – Work to revitalize and restore the former Anaconda Copper Mine site near Yerington continues to progress on schedule. Phase one of the project began in August 2019 and construction work at the site is scheduled to be complete by 2029.
The Nevada Division of Environmental Protection (NDEP) approved the Anaconda groundwater investigation report May 14, which combines 15 years of scientific data collected from over 350 monitoring wells. The study, which is helping to propel the project forward, underwent exhaustive technical review by NDEP; and included thorough review from the Bureau of Land Management and Federally Recognized Tribes.
Key findings from the groundwater report include:
- The primary contaminants in groundwater at the site are uranium and sulfate.
- There are three main sources of uranium and sulfate in groundwater: historic mining practices, naturally occurring deposits, and agricultural activities.
- The extent of uranium and sulfate groundwater contamination that may potentially be mine-related has not impacted:
- the Yerington Paiute Tribe drinking water supply well;
- other residences currently receiving bottled water that do not have access to the City of Yerington municipal water supply.
NDEP will continue to require Atlantic Richfield Company to address all identified, as well as potential, mine-related groundwater contamination.
The bottled water program, first initiated as a protective measure in 2004 before the extent of groundwater contamination was defined, will be gradually phased out over a six-month period beginning May 2020 and ending in November 2020. NDEP is communicating directly with approximately 20 non-tribal residences located outside the area impacted by mine-related groundwater contamination who are currently receiving bottled water, but whom do not have access to a municipal water system. These residents will be given options for installation of point-of-use reverse osmosis water treatment systems, free of charge.
NDEP assumed the role as lead regulatory agency to oversee and expedite the remediation project from the EPA in 2018, and has since completed numerous project activities with funding provided by Atlantic Richfield Company. NDEP’s definitive and transparent project timeline has been key to initiating and accelerating construction work. Site activities completed in the last year include geotechnical and geochemical investigations in support of mine reclamation, cultural investigations, and construction of five new fluid management system ponds.
Information from the last public meeting and a timeline of site closure activities are available online at ndep.nv.gov/land/abandoned-mine-lands/anaconda-home/anaconda-whats-new.
For more information about the Anaconda Copper Mine Site cleanup project, please visit ndep.nv.gov/land/abandoned-mine-lands/anaconda-home.
