Conservation Groups Challenge Air Quality Permit for Stibnite Gold Mine over Threat to Public Health

Today, Advocates for the West filed suit in Idaho state court representing the Idaho Conservation League (ICL) and Save the South Fork Salmon against the Idaho Department of Environmental Quality (DEQ) for failing to protect public health in issuing an air quality permit to Perpetua Resources for the proposed Stibnite Gold Mine, an open-pit cyanide leach gold mine in Valley County.

Perpetua’s proposed mining activities would result in large quantities of dust and particulate matter being emitted into the air, which can cause serious health problems. The rocks, soils, and dust at Stibnite are known to be high in arsenic, a human carcinogen known to cause developmental effects, diabetes, pulmonary disease, and cardiovascular disease.

“We deserve clean air, not just on our public lands, but in our communities too,” said Bryan Hurlbutt, Staff Attorney at Advocates for the West. “The way DEQ bent the rules to permit the Stibnite Gold Mine sets a dangerous precedent that industry could use to emit larger quantities of toxic air pollution anywhere in Idaho.”

“Idaho DEQ’s misleading analysis of arsenic emission and cancer risks could expose anyone who works or recreates near the mine to dangerous levels of toxic and carcinogenic pollution,” said Will Tiedemann of ICL. “We should be able to trust that agencies such as DEQ will protect the public instead of misleading us about public health risks.”

“Idaho DEQ continues to cater to Perpetua Resources’ attempts to bend the rules and disregard the risks from its proposed mine,” said Judy Anderson of Save the South Fork Salmon. “Perpetua’s disregard is particularly brutal given that its workers will be living at the mine site, forced to breathe toxic air day after day. Time and again, DEQ has been given an opportunity to protect public health from toxic air pollution as the law requires, and time and again it has failed to do so.”

In today’s lawsuit, ICL and Save the South Fork Salmon, represented by Advocates for the West and Julia Thrower of Mountain Top Law, seek to revoke the air permit unless and until the mine can be permitted in a way that protects public health and complies with law.

At Issue

Controlling dust from Perpetua’s extensive mining operations is critical to protect public health, but the permit—intended to verify the project meets federal Clean Air Act and state air quality requirements to protect public health and the environment—fails to include adequate monitoring and other safeguards that ensure particulate pollution is kept to safe levels. The permit allows Perpetua to emit arsenic at levels that would exceed the yearly limit DEQ itself set to protect the public from this carcinogen. The permit also exempts the Stibnite Road—which the public will be allowed to use during mining—from having to comply with Idaho’s air pollution protections.

Background

The massive Stibnite Gold Mine is proposed mostly on public lands within the Boise and Payette National Forests. The proposed mine site is 45 air miles east of McCall, Idaho, adjacent to the Frank Church–River of No Return Wilderness Area, and is within the homelands of the Nez Perce Tribe.

Conservation groups and the Nez Perce Tribe raised repeated concerns during the permitting process about particulate and arsenic pollution that would result from the project, which DEQ failed to address when it issued the permit in June 2022. ICL, Save the South Fork Salmon, and the Nez Perce Tribe appealed the permit to the Idaho Board of Environmental Quality. The Board ruled in favor of the conservation groups and the tribe in 2024, faulting DEQ for manufacturing an exception to Idaho’s arsenic pollution standards to permit the mine. This May, however, the Board signed off on the permit, even though it still fails to ensure arsenic-laden dust is kept to safe levels.

While the U.S. Forest Service issued its approval of the mine earlier this year, that approval does not allow mining to commence until the Forest Service approves Perpetua’s final plan of operations and receives required cost estimates and financial assurances for reclamation, which have not yet occurred.

The air quality permit issued by DEQ is just one of several permits needed by Perpetua before the proposed mine could move forward. ICL, Save the South Fork Salmon, and their partners recently submitted public comments on DEQ’s draft water pollution discharge permit for the mine. DEQ is currently taking public comments on another water quality permit for the mine, which DEQ is modifying in response to a contested case filed last year by ICL, Save the South Fork Salmon, and other conservation groups.

Perpetua’s mine plan doubles the size of the existing disturbance at the site to 3,265 acres—the equivalent of nearly 2,500 football fields—and entails excavating three massive open pits. It would create 280 million tons of waste rock and include constructing a 475-foot tall, 120-million-ton tailings storage facility—more than 1.5 times taller than the Statue of Liberty.

Read the Petition