Researchers at the University of New Mexico say uranium mining near the Grand Canyon could pose a greater threat to groundwater than previously shown. In a recent paper, they call for a halt in mining operations.
The scientists say aquifers and other groundwater systems near the canyon are interconnected in ways that aren’t totally understood. As a result, uranium mining and other contaminants could threaten public health and the environment, and impact the Grand Canyon’s springs along with the Havasupai Tribe’s sole water source and other tribal sacred sites.
The Pinyon Plain Mine near the South Rim began producing ore in early 2024 and the researchers warn uranium mining represents a quote “considerable risk of contamination” in parts of the regional aquifer system. The paper continues, "... the authors favor abundant caution and no mining in this sensitive region."
"This is unsurprising for anyone who has looked at the mixing of rivers, but similar processes are more hidden and incompletely understood in groundwater," said lead author Karl Karlstrom in a press release. "Water flows down gradient, and fault pathways control where groundwater ponds in sub-basins. In the Grand Canyon region, these sub-basins are each vented by major springs on tribal or Park lands."
The mine is located within the Baaj Nwaavjo I'tah Kukveni - Ancestral Footprints of the Grand Canyon National Monument declared last summer by President Joe Biden. It banned new uranium mining claims on almost a million acres but the Pinyon Plain Mine was exempt from the designation.
Curtis Moore, senior vice president for marketing and corporate development for Pinyon Plain’s owner, Energy Fuels Resources, says previous studies have shown there are no faults or fractures near the mine, and that it poses no risk to groundwater.
"The UNM report does not reveal any new science or facts," says Moore. "… Scientists know there no faults, fractures, or similar conduits near the Pinyon Plain mine. It is also known that there is no real potential for the mine to even contaminate the perched groundwater zones. The science remains crystal clear: the risk to groundwater is zero."
The Arizona Department of Environmental Quality, which issued the mine’s aquifer protection permit in 2022, says it’s reviewing the study but that the operation is among the most highly regulated uranium mines in the nation.
"Studied, scrutinized, and litigated for over 30 years, the mine has an extensive record," says ADEQ spokesperson Caroline Oppleman. "The record demonstrated, and ADEQ agreed, that adverse impacts to groundwater from the mine are extremely unlikely."
