Jonathan Ambarian

HELENA (KPAX) — The Montana Supreme Court heard oral arguments Wednesday, as they consider whether to uphold a lower court ruling that said the state improperly issued a permit for a planned copper mine near White Sulphur Springs.

In 2020, environmental groups – including Montana Trout Unlimited, Montana Environmental Information Center, Earthworks and American Rivers – filed a legal challenge against the operating permit for the Black Butte Copper Project. They argued the Montana Department of Environmental Quality hadn’t done enough analysis on the possible impacts of the mine before issuing the permit.

Opponents of the mine have particularly raised concerns about how mining by-products could affect downstream water quality – especially on nearby Sheep Creek, a tributary of the Smith River.

Last year, District Court Judge Katherine Bidegaray ruled in the plaintiffs’ favor, saying DEQ had “dismissed without adequate analysis” potential changes to the planned operation that could have addressed some of the environmental concerns raised.

DEQ appealed Bidegaray’s decision, along with the mine’s operator, Tintina Montana – owned by Sandfire Resources America. Meagher County – where the mine would be located – and neighboring Broadwater County also intervened in support of the permit.

Dale Schowengerdt, an attorney representing Tintina, said the company had gone “above and beyond” in planning safety precautions for the project. He said DEQ had analyzed the plans for years, and it was unreasonable to say their choice to award the permit was “capricious or arbitrary.”

“Everybody agrees that the Smith River is a treasure, and that's precisely why Tintina sought to design the safest mine in Montana ever,” he said. “That's why DEQ gave this project the most exhaustive review of any mine in Montana ever.”

Schowengerdt argued the job of the district court – and the Supreme Court – was to determine whether DEQ’s process was appropriate, not to make their own decisions about the scientific analysis.

“Not to argue that the agency is right and the plaintiffs are wrong – that's never the function of a reviewing court in a case like this,” he said. “The only question is, did the agency take a hard look at the project and apply its professional judgment to every issue? It did here, on every issue.”

Much of the discussion Wednesday focused on Tintina’s planned tailings facility, where they would combine tons of waste products with cement in order to solidify them and make it less likely that they would end up in the environment in case of a catastrophic event. The company says the tailings would also be protected with an impermeable plastic layer, a rock embankment or dam, and pump systems to remove water that could seep through the tailings.

Tintina plans to include between 0.5% and 2% of cement and other binders in these tailings, saying they chose that amount for various reasons, including the need to pump the tailings into the facility in thin layers over time. The company performed tests on tailings with 0%, 2% and 4% of binder, and they did “humidity cell tests” to see if cemented tailings could oxidize – producing acidic runoff.

The plaintiffs argued that the testing wasn’t done specifically for the procedure Tintina will be using – with the lower percentage of binder and the multiple small layers of tailings. Jenny Harbine, an attorney representing the environmental groups, said that could have a significant impact on the time it takes for the cemented tailings to set and on the chances for oxidation.

“It’s really important that Tintina balance these tensions and get this timing right,” she said. “On this record, DEQ can’t tell us what that correct balancing is. But more troubling is DEQ can't tell us whether that balance is achievable at this facility with these issues.”

Justice Dirk Sandefur asked Harbine what the chances were of the embankment failing and allowing the tailings to escape the facility. Harbine said, while the probability might be low, the risks from such an event would be severe. Plaintiffs argued that the Black Butte project should undergo particular scrutiny because of the scale of those risks.

“DEQ’s failure to insist on compliance shouldn't be allowed to set the bar for future mine reviews, and it was unlawful,” said Harbine.

The court took no immediate action Wednesday. Chief Justice Mike McGrath said they will release an order in due course.

Nancy Schlepp, vice president of communications for Sandfire Resources America, told MTN that they are waiting on any underground work on the Black Butte project while the legal action continues. However, she said they are able to move forward with Phase 1 of the project: building facilities on the surface and an access road. Schlepp said Phase 1 work could be completed within the next year.