Montana DEQ issues draft EIS for Black Butte Copper Project

Hydrologists from Hydrometrics taking water samples at Black Butte

HELENA – The Montana Department of Environmental Quality has issued a draft EIS for the proposed Black Butte Copper Project. DEQ will take public comment on the draft through May 10 and hold four public meetings, with public hearings, in April and May.  

The EIS is an extensive environmental review that discloses the potential impacts of the project and includes opportunities for public review and involvement.

“We are looking for feedback on our analysis – this is a very important part of the process,” said DEQ Director Shaun McGrath.

The draft EIS identifies the Agency Modified Alternative as the preferred alternative. This alternative includes all elements from the Proposed Action, with one additional component: backfilling additional underground mine workings. In the AMA, DEQ proposes to backfill certain mine voids, like access openings, at the end of operations with a material consisting of cemented paste tailings generated from mill processing of the stockpiled ore and/or waste rock. This backfill material has low hydraulic conductivity and would return these bedrock zones to conditions similar to the pre-mining state, eliminating the potential development of new groundwater flow paths. The AMA also minimizes the exposure of reactive mineral surfaces that could potentially impact water quality within the mine workings at closure.

DEQ held scoping meetings and accepted public comments in 2017. These comments helped identify key issues for DEQ to examine and address in the EIS.

“One of the main issues we heard during scoping were concerns of impacts to the Smith River. Because of that, we looked at what potential impacts could be, for all resources, to the Smith River,” said McGrath. DEQ’s analysis has not found any potential impacts to the Smith River including water quality, air quality, or aquatic life.

The draft EIS is posted to the DEQ’s website at:

Public Meetings:

April 29, 2019, 6 – 9 pm, Park High School (102 View Vista Drive, Livingston MT)

April 30, 2019, 6 – 9 pm, White Sulphur Springs High School (405 S Central Ave, White Sulphur Springs, MT)

May 1, 2019 and May 2, 2019 webinars, 6 – 9 pm, signup instructions to follow at a later date.