BUTTE - Montana Resources estimates they have another 30 years of copper mining in Butte. That also means they have another 30 years of dealing with all the waste, they keep it here in this tailings impoundment, but in order to keep mining, they need more space to store the waste.

“If you can’t do anything with your tailings, you can’t eat ore, so, no, it is key to sustaining operations here in Butte,” said Mark Thompson, Montana Resources’ Vice President of Environmental Affairs.

WATCH - Copper Mining in Butte: New Tailings Dam Plan Set to Extend Operations

The mining company submitted an application recently to the Department of Environmental Quality to increase the height of the dam of the Yankee Doodle Tailings Impoundment by another 100 feet. This is the 1,500-acre site where the mine sends a slurry of waste material after it has removed all the copper ore from it. Mine officials report it sends more than 44,000 tons of waste material a day to the impoundment, and it goes up about 5 feet each year.

“It’s 100 feet that will give us about 20 years of storage. With what we have now, that gives us a total of 30 years of future mining,” said Thompson.

An independent review panel has approved the design of the impoundment expansion, and the DEQ will conduct an environmental review later. Thompson is confident in the safety of the impoundment dam.

“The base, the rockfill at the base is over half a mile thick, so it’s just massive, and that’s what ensures the stability and the safety of this facility,” he said.

There will be public comments about this project once DEQ completes its environmental impact assessment by the end of this year. If all goes in favor of the mining company, the project will begin in about a year and a half.

When mining eventually ends 30 years from now, Montana Resources will cap the tailings impoundment.
“We take topsoil, put topsoil over the top, and we revegetate that soil and end land use as wildlife habitat,” said Thompson.