The state of Montana released its draft environmental assessment for a waste disposal facility expansion at a hardrock mine in south central Montana and now seeks public comment.
The Montana Department of Environmental Quality analyzed the expansion of a tailings storage facility south of Big Timber at the East Boulder Mine, where the Sibanye-Stillwater Mining Company extracts platinum and palladium
DEQ hard rock mining bureau chief Dan Walsh says the company shows it can maintain water quality standards at the East Boulder River, control sediment and mitigate nitrate levels at the site.
“The structural integrity is protective of the stream itself and ultimately aquatic life in that stream,” Walsh says.
According to the draft environmental assessment, Sibanye would add 50 acres to its tailings storage facility, bringing it to roughly 287 acres within its permit area. The extra storage would extend mining operations from 2027 to 2033.
DEQ also analyzed the environmental impacts of not allowing the expansion.
The agency reviewed the assessment with the Custer Gallatin National Forest, part of the U.S. Forest Service.
The public can submit comments online through June 15.