EPA slams lax air quality permit for gold mine

The Environmental Protection Agency slammed an air quality permit for a proposed central Idaho gold mine issued by the Idaho Department of Environmental Quality, saying it is so lax that it may violate the federal Clean Air Act.

In an Aug. 10 letter and accompanying 19-page background document sent to IDEQ Director Jess Byrne, EPA Region 10 Administrator Casey Sixkiller said the permit awarded to Perpetua Resources Idaho does not sufficiently limit the release of dust, known as large particulate matter, and arsenic. He is seeking a meeting with Byrne and would like the agency to revise the permit.

“The Agency has reviewed the final Permit, statement of basis and the Department’s response to comments and continues to be concerned that construction and operation of the Stibnite Gold Project under the terms set out in the Department’s Permit would not comply with the Clean Air Act,” Sixkiller wrote.

Perpetua Resources wants to reopen and expand a long-dormant open pit gold and antimony mine neary Yellow Pine and along the East Fork of the South Fork Salmon River east of McCall. The company is seeking dozens of necessary state and federal permits to do so. But the controversial mine adjacent to the Frank Church River of No Return Wilderness Area is bitterly opposed by the Nez Perce Tribe and the conservation groups Save the South Fork Salmon and the Idaho Conservation League who contend it will damage critical spawning habitat for threatened spring chinook, steelhead and bull trout and lead to other environmental degradations. Perpetua Resources says it will use some of the profits from mining to clean up past waste at the mine site.

Last year, DEQ issued the company an air quality permit to construct that outlines the expected release of toxic pollutants from mining activity and measures to mitigate those releases in order to keep them below the federally set National Ambient Air Quality Standard. The emissions are largely related to fugitive dust resulting from mining traffic along haul roads as well as drilling and blasting at the mine.

The EPA contends DEQ applied improper background standards when modeling the mine’s potentia air emissions. As a result, the federal agency said the calculated emissions qualify the mine as a “minor source” of pollutants instead of a “major source” requiring a higher degree of permitting and oversight. The federal agency questions the permit’s determination that Perpetual Resources will be able to control 93.3% of the fugitive dust by application of magnesium chloride and water to haul roads. The EPA is also taking issue with DEQ’s contention that the general public won’t be exposed to air pollutants in the large mining area which includes 2,372 acres of the Boise and Payette national forests.

The letter comes just weeks before a scheduled contested case hearing regarding the permit. The tribe and conservation groups are petitioning the Idaho Board of Environmental Quality to reconsider the permit. Many of their arguments with the permit mirror the deficiencies highlighted by Sixkiller.

“We completely agree with what the EPA is saying. We feel IDEQ has really dropped the ball in this process,” said Julie Thrower, an attorney representing Save the South Fork Salmon. “In the process they have deferred to Perpetua’s analysis to the detriment to the air quality and public health of Idahoans and the people who are going to use the area.”

She said it is unusual for the federal agency to so vigorously protest a state-issued permit. Under the Clean Air Act, the EPA sets national ambient air quality standards and states have the responsibility to ensure those standards are met.

“For EPA to get involved, they really have to think this is a serious issue because at this point it is supposed to be a state process,” Thrower said.

Byrne, the director of IDEQ, defended the permit and said the letter contains information that EPA had previously communicated to the department during its development.

“DEQ is confident in the permit we issued and intends to continue defending it in the administrative proceedings and otherwise,” he said. “It is unfortunate that EPA chose to issue this letter while an administrative appeal is pending, and we do not want to prejudice the ongoing administrative proceedings involving this permit by commenting further.”

Perpetua Resources declined to comment on the letter, saying it is an administrative issue between the state and federal agency. In an email to the Tribune, Perpetua spokesperson Mckinsey Lyon said the “permit imposes more robust air quality compliance obligations on our mining project than imposed previously on other mining projects in Idaho.”

A hearing on the permit challenge will be held Sept. 21.

The Payette National Forest is in the process of reviewing comments to a supplemental draft environmental impact statement regarding the mine and is expected to issue a final EIS and decision on the mine late this year or early next year.

Barker may be contacted at ebarker@lmtribune.com or at (208) 848-2273. Follow him on Twitter @ezebarker.