EPA Protects the Little Colorado River from Impacts of Abandoned Uranium Mines, Announces Removal Action to Advance Cleanup of Contamination

EPA Protects the Little Colorado River from Impacts of Abandoned Uranium Mines, Announces Removal Action to Advance Cleanup of Contamination

September 25, 2025

Today, U.S. Environmental Protection Agency (EPA) announced a removal action decision that will protect the Little Colorado River from uranium contamination by safely moving mine waste from two abandoned uranium mines and a portion of a third into an on-site repository one mile from the river.

The Section 9 Lease Mine Site is located in Coconino County, Arizona, and is adjacent to the Little Colorado River in the Cameron Mining District near the Navajo Nation Indian Reservation. EPA coordinated closely with the State of Arizona's Department of Environmental Quality to ensure the protection of public resources and the consideration of local stakeholder priorities.

"Today's announcement marks major progress on the cleanup of abandoned uranium mines in the region," said EPA Pacific Southwest Region Superfund Division Director Mike Montgomery. "By safely relocating this waste away from the Little Colorado River, we're reducing the footprint of legacy uranium contamination in Navajo communities and throughout the watershed."

"I applaud EPA's efforts to address legacy uranium mine waste issues in Arizona and look forward to our ongoing partnership to protect Arizona residents," said Arizona Department of Environmental Quality Director Karen Peters.

The removal design process is estimated to commence in 2026 and will safely remove and relocate waste to the repository, while protecting human health and the environment from ionizing radiation caused by historic mining activities. Once removal is complete, the former mine areas will be restored to natural conditions, protecting the river's critical habitat and important cultural resources. The new repository may also serve as a regional repository for waste from other abandoned uranium mines in the Cameron Mining District, streamlining future cleanup efforts in the region.

Read more about EPA's Abandoned Uranium Mine program on EPA's Navajo Nation Uranium CleanupExit EPA's websitewebpage.

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