Water discharge permit for Montanore Mine renewed

The Montana Department of Environmental Quality has renewed the Montana Pollutant Discharge Elimination Permit for the Montanore Mine, a proposed copper and silver underground mine located about 18 miles south of Libby near the Cabinet Mountains of northwestern Montana. The MPDES permit is designed to protect water quality and aquatic life in the Libby Creek watershed.

According to the final permit document, the permit will be effective March 1, 2017 and will expire on Feb. 28, 2022.

This is not the last permit that the Montanore Mine will need to receive, but from the DEQ’s perspective, Montanore is ready to move forward with the evaluation phase after many years, Kristi Ponozzo with the DEQ said.

The final permit contains, among other requirements, numeric effluent limits for sediment, a variety of metals, and pH. In addition, the renewed permit includes nutrient limits and a requirement to optimize nutrient reduction. It also adds four stormwater outfalls, requires the submission of a Stormwater Pollution Prevention Plan, and requires the implementation of Best Management Practices. The permit also requires monitoring for water quality parameters before water is discharged to surface water and requires specific stormwater monitoring.

The press release said, “DEQ received substantial comments on the draft permit during the first public comment period in August through October of 2015 and, as a result, DEQ reopened a comment period in April 2016. In response to comments DEQ made changes to the permit specific to effluent limits, monitoring requirements, permit conditions and improved readability.”

The Kootenai National Forest and DEQ issued a Draft EIS for the Montanore Project on Feb. 27, 2009, for public comment. In response to public comment, the agencies revised the mine alternatives and transmission line alignments and issued a Supplemental draft EIS on Oct. 7, 2011. On April 1, 2015, the KNF issued a final EIS and a draft record of decision to provide for a pre-decisional objection process in compliance with 36 CFR 218.

In February of last year, DEQ issued a Record of Decision approving the Evaluation Phase of the Montanore Mine Project.