PATAGONIA, Ariz.— Health and environmental groups are calling on the U.S. Environmental Protection Agency to overturn the state of Arizona’s approval of an air pollution permit for the Hermosa heavy metals mine in the Patagonia Mountains south of Tucson.

“This is about standing up to the Arizona Department of Environmental Quality’s blatant attempt to give the mining industry a free pass to pollute,” said Jeremy Nichols, senior advocate at the Center for Biological Diversity. “Clean air is essential for people, the environment and all living creatures. If Arizona’s environmental agency is unwilling to do its job, the EPA should intervene to protect air quality in this important sky island ecosystem.”

In a legal petition filed Sept. 12, the coalition requested the EPA to reject an Arizona Department of Environmental Quality permit allowing multinational mining company, South32, to construct and operate the Hermosa heavy metals mine. The mine would be dug into the Patagonia Mountains, a biodiversity hotspot and a drinking water source for Santa Cruz County. It would be located 5 miles from the town of Patagonia, a community sustained by local businesses and ecotourism.

“Industrial exploitation of the Patagonia Mountains threatens the prosperity of this region and the very survival of the Patagonia community,” said Carolyn Shafer with the Patagonia Area Resource Alliance. “South32’s Hermosa mine should never have been issued an air pollution permit. The EPA is our last chance for reversing this disastrous decision and protecting the health and wellbeing of all creatures that live in and near the Patagonias.”

Despite widespread opposition, the state approved Hermosa mine’s air pollution permit in August. The permit authorized the release of hundreds of tons of toxic air pollution annually, including particulate matter, lead, manganese and smog-forming nitrogen oxides.

“More air pollution means more risks to our health and environment,” said Sandy Bahr, director of Sierra Club’s Grand Canyon (Arizona) Chapter. “We’re disappointed the Arizona Department of Environmental Quality didn’t live up to its duty to hold polluters accountable by requiring a strong permit that is protective of public health.”

Under the federal Clean Air Act, the air pollution permit is subject to EPA review. The groups’ petition calls on the agency to reject the permit because it violates clean air laws and regulations. The EPA must respond within 60 days.

The petition lists several deficiencies with the permit, including that the state failed to establish enforceable limits on particulate matter pollution, require adequate pollution monitoring and assure compliance using the best available pollution controls.

If the EPA grants the petition, the department will have 90 days to fix the permit or the EPA will be required to take over and potentially deny it.

This latest legal challenge follows a 2023 lawsuit over the U.S. Forest Service’s approval of South32’s mining exploration in the Hermosa mine area.

The groups petitioning are the Center for Biological Diversity, Patagonia Area Resource Alliance, Sierra Club — Grand Canyon Chapter, Arizona Mining Reform Coalition, Calabasas Alliance and Friends of the Santa Cruz River.