Tribe Fights Plan to Loosen Mine's Arsenic Limits

The Havasupai Tribe has voiced significant concerns regarding a proposed amendment that would permit higher arsenic levels in a groundwater monitoring well situated near the Pinyon Plain uranium mine, south of the Grand Canyon. Tribe leaders assert this modification jeopardizes Havasu Creek, their only source of water, which is vital for their community, culture, and tourism economy.

The Arizona Department of Environmental Quality (ADEQ) noted that increased arsenic concentrations in the well are naturally occurring, not a result of mine pollution. However, the proposed amendment to the state's Aquifer Protection Program permit would revise the mine's alert level and aquifer quality limit for arsenic. This change, allowing a 10% increase in the allowable arsenic limit from 0.05 to 0.055 milligrams per liter, has drawn criticism for potentially accommodating pollution rather than preventing it.

Environmental groups and elected officials have echoed the tribe's concerns. U.S. Rep. Adelita Grijalva urged ADEQ to deny the request, citing unverified claims of natural arsenic sources and potential risks to public health and environmental oversight. The Coconino County Board of Supervisors also called for a full amendment process with public comment, emphasizing the importance of certainty given the mine's proximity to crucial aquifers.

Beyond groundwater contamination, the mine's operations have also brought renewed attention to the transportation of uranium ore. A recent semitruck accident hauling ore in Shonto, Arizona, intensified longstanding tribal concerns about the risks associated with transporting such materials through or near their lands, highlighting the broader environmental and safety issues surrounding the Pinyon Plain Mine.