HELENA, Mont. (AP) — Officials said Monday that a copper mine proposed along a tributary of one of Montana's most popular recreational rivers would cause the river no harm, a conclusion that conservationists question and say will reinvigorate opposition to the plan.
The state Department of Environmental Quality released its draft environmental impact statement of the Black Butte Copper Project for public comment, a significant step forward for the proposed mine more than three years after developers applied for a permit.
The proposed underground mine is on private land and would extract 15.3 million tons (13.8 million metric tons) of copper-laden rock and waste over 15 years — roughly 440 tons (400 million metric tons) of copper-rich concentrate a day. It is located in central Montana near Sheep Creek, a waterway that feeds into the Smith River some 19 miles (31 kilometers) away.
The Smith River, a blue-ribbon trout fishery that passes through stunning limestone canyons as it flows to the Missouri River, is so popular with boaters that it is the only river where a permit is required for a three- or four-day float. Permits are in such high demand that a lottery is held annually to distribute them.
Conservation groups have strongly opposed the mine since Tintina Resources filed its application in December 2015, saying mining pollution would threaten the river system and could lower water flows so much the trout fishery would be harmed. Tintina, which was later bought owned by Australian mining company Sandfire Resources, says water resources will be protected and that more than a mile will separate Sheep Creek from the facility that will process mine waste.
The environmental review looked closely at the potential effects to the Smith River because of the immense public interest in the project, said Kristi Ponozzo, DEQ's public policy director.
Everything in Sandfire Resource's proposal complies with state law, she said. In addition, tunnels and access openings would be filled with mine waste that has been thickened with cement into a paste, which would cut off any new potential paths for groundwater to flow.
"That's something we think adds water quality protections above and beyond what we think is required to comply with state water quality laws," Ponozzo said.
Mining operations would use groundwater and reduce water flows by 70 percent to nearby Coon Creek, but that effect would be countered by pumping water into the creek from a planned reservoir, according to the analysis. Less than 1 percent of the Sheep Creek watershed area would be affected.
Sandfire Resources America CEO and Vice President of Project Development Rob Scargill said in a statement that the analysis is a key step toward the completing the project "which will set new standards for mine developments globally."
Derf Johnson, the Montana Environmental Information Center's clean water program director, said he has not yet reviewed the newly released analysis, but he questioned any finding that the mine won't affect the Smith River.
The waterways that feed the Smith River are all part of a very interconnected system, and Sheep Creek in particular is important for the Smith River's water quality, water quantity and fishery, he said.
"This is the wrong mine in the wrong basin at the wrong time," he said. "It's just an incredible risk for the DEQ to even consider permitting. It's shocking."
Johnson's organization is part of the Save Our Smith coalition that formed in opposition to the mine. He said he believes the conclusions in the environmental analysis will breathe new life to that opposition.
"I think that this is really going to cause a lot of people to get involved," he said.
Public meetings on the environmental impact statement are planned for April 29 in Livingston and April 30 in White Sulphur Springs. DEQ officials plan to hold two additional online public meetings, and they will eventually issue a final environmental analysis before deciding whether to issue the project permits for mining, water discharge and air quality.