Changes to a proposed wastewater permit for the Montanore mining project near Troy have prompted the Montana Department of Environmental Quality to repeat its public comment process.
“We identified some new metals that needed to have limits in the permit, as well as other parameters that needed to be evaluated,” DEQ water discharge program bureau chief John Kenning said Monday. “For example, we found antimony in the water, and there needs to be a limit for that.”
Spokane-based Mines Management Inc. has an existing 500-gallon-per-minute effluent discharge permit for its planned copper and silver mine. DEQ launched its initial public comment review last October for a five-year renewal of the permit. The additional comment period lasts through May 18.
The permit would cover discharge of treated water coming from three existing mine adit outfalls as well as four new storm-drain outfalls. It would also require Mines Management to develop and maintain a storm-water pollution prevention plan, and to monitor and report pollution discharges and upstream conditions of Libby Creek.
The proposed mine would support about 350 jobs when in full operation, extracting 20,000 tons of ore a day. Opponents have argued that it would also de-water streams in the Cabinet Mountains Wilderness, threatening spawning streams for federally protected bull trout. A coalition of environmental and conservation groups has already sued the U.S. Forest Service for issuing a permit allowing the mine to go forward.
That Forest Service permit is contingent on state examinations. In February, DEQ approved the mine’s reclamation, air quality and siting plans for exploration-level work.
A draft wastewater discharge permit, fact sheet, and the department’s tentative determination are available on the DEQ website at: deq.mt.gov/Public/notices/WQnotices and at the DEQ's Metcalf Building in Helena.
DEQ will accept public comments until the close of business on May 18. Comments should be sent to DEQ Water Protection Bureau, P.O. Box 200901, Helena, MT 59620 or by email to DEQWPBPublicComments@mt.gov.
DEQ’s Record of Decision, the Joint Final Environmental Impact Statement, and other documents for the Montanore Project are available at: deq.mt.gov/Land/hardrock/Montonore-Mine-Project.