Home / Environment / State OKs Higher Arsenic Levels at Grand Canyon Area Mine
State OKs Higher Arsenic Levels at Grand Canyon Area Mine
7 Jul
Summary
- Arsenic limits for a mine monitoring well south of Grand Canyon were revised.
- Havasupai Tribe fears changes threaten Havasu Creek, their sole water source.
- Arizona ADEQ cites naturally occurring arsenic for approving higher levels.
The Arizona Department of Environmental Quality (ADEQ) has agreed to revise groundwater arsenic limits for a monitoring well at the Pinyon Plain uranium mine, situated south of the Grand Canyon. The mine operator, Energy Fuels Inc., had requested higher arsenic levels, citing data collected over 4½ years, including enhanced monthly monitoring since January 2025.
The Havasupai Tribe has expressed grave concerns, warning that the proposed changes could imperil Havasu Creek, the tribe's only permanent water source and central to their culture and identity. Tribe Chairwoman Melinda Yaiva criticized ADEQ for lowering pollution standards and weakening environmental protections.
ADEQ stated its decision followed a thorough review of Energy Fuels' data, concluding that naturally occurring arsenic from the surrounding geology is moving towards perimeter wells due to a hydraulic sink created by the mineshaft. The agency asserts that the company is not adding arsenic to the groundwater.
However, the Havasupai Tribe, along with groups like the Center for Biological Diversity and independent scientists, questioned the adequacy of the investigation. They argued that Energy Fuels has not sufficiently demonstrated that the elevated arsenic levels are exclusively naturally occurring or that mining operations are not contributing to the increase.
