Former Anaconda Mine Site revitalization and restoration work continue on schedule; comprehensive gr

Mason Valley, NV – The Nevada Division of Environmental Protection (NDEP) is pleased to announce that work to revitalize and restore the former Anaconda Copper Mine site continues to progress on schedule. The first phase of the project began in August 2019, and all necessary construction work at the site is on track to be complete by 2029.

Helping propel this critical project forward is the completion of an updated comprehensive groundwater study. Today, NDEP approved the Anaconda groundwater investigation report, which combines 15 years of scientific data collected from over 350 monitoring wells. The study 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 Yerington Paiute Tribe has an existing reliable drinking water system, and the past seven years of testing demonstrates the system meets all drinking water standards. For more information regarding the Yerington Paiute Tribe’s drinking water system and water quality, please contact the Tribe or the US Environmental Protection Agency, Region 9, which oversees environmental protection on Tribal lands. Community members who live within the identified mine-related plume boundary have access to City of Yerington municipal water.

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.  

“As part of our mission, the Nevada Division of Environmental Protection remains committed to continuously engaging area community members and stakeholders, every step of the way, throughout the Anaconda Mine remediation project,” said Greg Lovato, NDEP Administrator. “Finalizing the groundwater study marks a significant milestone in characterizing the complex hydrogeological conditions and extent of groundwater contamination at the Anaconda Mine Site. This report is critical to continuing the successful cleanup of the site and helps chart a path forward based on the best available science to ensure that current and future activities are protective of public health and the environment. We look forward to continuing a phased cleanup approach to ensure a healthy future for Mason Valley residents.”

In February 2018, the EPA and the State of Nevada entered into a deferral agreement, designating NDEP as the lead regulatory agency to oversee and expedite the Anaconda Mine remediation project while maintaining EPA equivalent protection standards. Since transferring the Anaconda Mine remediation project from the EPA to NDEP oversight, numerous project activities have been completed, with funding provided by Atlantic Richfield Company. As a foundation of the project, NDEP developed a definitive and transparent project timeline that 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.

Based on findings from a recent EPA report, the nation’s backlog of unfunded Superfund projects is at its largest in 15 years, due to a significant and growing lack of funding for the Superfund program. The Superfund program, established in 1980, authorized a tax on oil and chemical industries to fund cleanups nationwide. In 1995, the tax expired and was never reauthorized by Congress. The expiration of this tax has increased the nation’s backlog of unfunded Superfund sites. The deferral and associated agreements between NDEP and Atlantic Richfield Company ensures funding will remain available for the cleanup. 

Information from the last public meeting and a timeline of site closure activities are available online at

For more information about the Anaconda Copper Mine Site cleanup project, please visit