Regulatory Alert – Canyon Uranium Mine (now called Pinyon Plain Mine)

The Arizona Department of Environmental Quality is in the process of renewing air and groundwater quality permits for the Pinyon Plain Mine (formerly the Canyon Mine), a uranium mine located south of the Grand Canyon National Park, 6.5 miles south of Tusayan.



Comments are due on the proposed Air Quality Permit no later than Monday, July 19, and may be submitted by email or letter, or by participating in ADEQ’s July 19 public hearing on the permit. To find instructions on how to submit comments, visit ADEQ’s webpage: PUBLIC NOTICE | Proposal to Issue Air Quality Control Renewal Permit for Pinyon Plain Mine in Coconino County | ADEQ Arizona Department of Environmental Quality (

The mining company, Energy Fuels Resources, plans to produce 109,500 tons of uranium ore each year. They will use trucks to haul the ore to their milling operation at the White Mesa Uranium Mill in San Juan County, Utah, near Blanding and the Ute Mountain Ute tribal reservation. Any ore that is not immediately hauled off will be stockpiled onsite. These activities will generate the following air pollutants, which can be harmful to human health and the environment if not limited and managed: particulate matter, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, hazardous air pollutants, and radionuclides. 

Several concerns to mention in your comments: the proposed restrictions on fugitive dust are based upon the “mean wind speed” and do not take into account the periodic strong winds that we experience, especially in the spring and fall, as well as the strong downdrafts associated with thunderstorms. The mining company uses fans to speed evaporation from its contaminated wastewater retention pond, and the wind blows the resulting contaminated mist onto adjacent national forest land. At a minimum, the mining company should be taking soil samples and performing biological monitoring of the adjacent areas. Another concern is that the permit does not address the potential for traffic accidents and any resulting releases as the ore trucks travel from the Tusayan area down to the Williams interchange, across the I-40 through to Flagstaff and then up through the Navajo Nation to White Mesa. 


Comments are due on the proposed Aquifer (Groundwater) Protection Permit no later than Saturday, August 7, and may be submitted by email or letter, or by participating in ADEQ’s Monday, August 9 public hearing. For instructions on how to participate, visit ADEQ’s webpage: PUBLIC NOTICE & PUBLIC HEARING | Preliminary Decision to Issue a New Aquifer Protection Permit for Pinyon Plain Mine in Coconino County | ADEQ Arizona Department of Environmental Quality (

The Pinyon Plain Mine presents a serious threat to the water quality and even the amount of water flowing into the Grand Canyon’s springs and seeps, as well as to groundwater resources that Tusayan and the Havasupai Tribe depend upon. The diversion of significant quantities of contaminated groundwater to a surface retention pond could alter the availability of water for springs and seeps that provide habitat and hydration for numerous plants and animals.

ADEQ has identified the following contaminants and indicators for monitoring: nitrate+nitrite, total dissolved solids, alkalinity, sulfate, pH, specific conductance, total metals, and radionuclides; however, with mining operations, monitoring for turbidity and total suspended solids and oil and grease would also be appropriate and necessary. While the proposed individual aquifer protection permit includes more stringent requirements than previous general permits, there is no certainty that the mining company’s proposal to plug and seal any contaminant pathways that might be found or that might develop in course of mining operations and closure would be successful. And the closure plan on file, which was prepared in the 1980s, is out-of-date and woefully inadequate, lacking even basic financial assurance requirements such as a surety bond or letter of credit to ensure that the mining company and not the taxpayers will be at risk for any groundwater contamination.

Please urge ADEQ to deny the proposed individual aquifer protection permit, and issue a permit only for the immediate closure and cleanup of the mine. At a minimum, the permit should require installation of at least three monitoring wells up- and down-gradient in both the Coconino and Redwall-Muav Aquifers to monitor for groundwater contamination; biological and habitat monitoring of all areas affected or that have the potential to be affected; monitoring of domestic animals dependent upon water coming from or affected by mining operations; groundwater monitoring in perpetuity; a detailed plan for stopping and cleaning up any groundwater contamination found at any time before, during, or after closure; preparation of up-to-date closure and post-closure plans; and the posting of a surety bond, letter of credit, or other financial assurance in an amount sufficient to manage subsurface and surface contamination and reclamation.


Learn about and potentially offer comments on the management of BLM lands in Arizona. The Bureau of Land Management holds responsibility for more than 12 million acres of public land in Arizona (even more in subsurface rights, i.e., minerals), including many popular recreational areas. The BLM Resource Advisory Council for Arizona will be meeting July 22, 8 am – 4 pm. You have the opportunity to observe and to offer public comments through the virtual meeting. Agenda items will include updates on US Department of Interior priorities; Lands, Minerals, and Energy update, including an update on renewable energy; Natural Resources and Conservation updates; Recreation and Maintenance updates; individual District updates. The final agenda will be posted on the Arizona RAC website at: 

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