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Navajo Nation: Cleaning Up Abandoned Uranium Mines

Cyprus Amax and Western Nuclear Mines

In 2017, the United States, on behalf of EPA and other federal agencies, entered into a historic settlement with Cyprus Amax Minerals Company (Cyprus Amax) and Western Nuclear, Inc. (Western Nuclear), subsidiaries of mining company Freeport-McMoRan, Inc., to clean up 94 mines on the Navajo Nation. This agreement addresses almost 20 percent of the abandoned uranium mines on the Navajo Nation.
Cyprus Amax’s Monument No. 2 mine is located in Cane Valley

Background

The mines are primarily located in the Four Corners area of the Navajo Nation and produced ore from the 1940s to 1985. One of these mines, Monument No. 2, near Monument Valley, Arizona, produced over 770,000 tons of ore and was the largest uranium mine in Arizona. The Ruby mines in Eastern Navajo produced a total of 790,000 tons of ore. The other mines covered by the settlement are relatively small and produced less ore.

Beginning in the 1990s, the Navajo Abandoned Mine Lands Reclamation Program eliminated the physical hazards at many of these mines by closing mine openings, burying mine waste, and reclaiming dangerous high walls. Cyprus Amax and Western Nuclear will clean up the mines after conducting detailed assessments and evaluating cleanup alternatives. EPA and the Navajo Nation Environmental Protection Agency (NNEPA) oversee all aspects of the work.

EPA and NNEPA prioritized 10 of these mines because they have elevated radiation and are near where people may live. In 2018, Cyprus Amax started conducting detailed assessments at these priority mines and an additional 22 mines to evaluate the extent of the area with potential mine waste contamination. Field work completed to date includes:

  • Biological and cultural resource surveys
  • Radiation surveys and soil samples
  • Legal Settlement

    In 2017, the United States on behalf of EPA and other federal agencies entered into a historic settlement with Cyprus Amax and Western Nuclear to clean up 94 mines on the Navajo Nation. The settlement requires Cyprus Amax and Western Nuclear to perform the cleanup work, including paying EPA and NNEPA their costs in overseeing the cleanup work. The United States will pay for a portion of all costs through a $335 million trust fund. It is expected that the cleanup of the 94 mines will cost approximately $600 million.

    This work will be performed over many years. Cyprus Amax and Western Nuclear worked with EPA and NNEPA to develop a schedule for performing work. That schedule includes conducting detailed assessments at 32 mines in 2018, including 10 priority mines.

    The settlement includes cleanup of the Ruby Mines in Eastern AUM Region of the Navajo Nation. Separate legal agreements between EPA and Western Nuclear funded assessment of the Ruby Mines and evaluation of cleanup alternatives. Visit the Ruby Mines webpage for more information.
Map of Abandoned Uranium Mines on the Navajo Nation

Site Facts

  • Cyprus Amax and Western Nuclear will assess and clean up 94 abandoned uranium mines on the Navajo Nation
  • Ten of these mines are priority mines
  • The first part of the work will include assessments of 32 mines, including 10 priority mines located in the Cove Chapter, and the Tse Tah and Monument Valley areas

Site Documents

Related Documents

Site Photographs

Cyprus Amax and Western Nuclear GalleryView the Photo Gallery »

Site Contacts

Remedial Project Manager

Linda Reeves (reeves.linda@epa.gov)
(415) 972-3445

Community Involvement Coordinator

Elsa Johnson (johnson.elsa@epa.gov)
(480) 250-0990

Cleanup Progress Timeline

Cyprus Amax and Western Nuclear mines were operated from the 1940s to 1985. In 2017, the United States on behalf of EPA and other federal agencies entered into a historic settlement with Cyprus Amax and Western Nuclear Inc. for the cleanup of 94 mines on the Navajo Nation. Click on the different years below to learn about recent and upcoming activities.

  • Diné Uranium Remediation Advisory Commissioners review engineering drawings of reclamation work performed by the Navajo Abandoned Mine Lands ProgramThe Navajo Nation Abandoned Mine Lands Program performs reclamation activities to address physical hazards at most of the mine sites.
  • Cyprus Amax’s Monument No. 2 mine is located in Cane ValleyThe United States on behalf of EPA and other federal agencies entered into a historic settlement with Cyprus Amax and Western Nuclear for the cleanup of 94 mines on the Navajo Nation.
  • Cyprus Amax using a drill rig to take subsurface soil samples at the Climax Transfer Station in the Shiprock Chapter.Cyprus Amax conducted detailed investigations at 32 mines, including 10 priority mines. These mines are in the Cove Chapter, and the Tse Tah and Monument Valley areas.
  • EPA, NNEPA, Cyprus Amax and others hosted Uranium Informational meetings in Red Valley, Red Mesa, Sweetwater, Monument Valley and Kayenta.