Judge halts mine project that could affect iconic Smith River

DEQ, Tintina plan to appeal decision

By: - April 12, 2022 5:58 pm

Boaters on the Smith River in Meagher County (Photo by Montana Fish, Wildlife and Parks).

A district court judge has halted a proposed mine near the headwaters of the iconic Smith River after saying the Montana Department of Environmental Quality’s actions were “arbitrary, capricious and unlawful.”

The future of the Black Butte Copper Mine, owned by Tintina Resources, will be halted until satisfactory plans are presented, or until a higher court hears the case.

In a statement, the Montana DEQ said that it planned on appealing the decision of Judge Katherine M. Bidegaray of Sidney.

“We care about protecting water quality, the iconic Smith River and upholding the laws of Montana—that’s why our team of experts thoroughly analyzed the permit application and required stringent measures to protect Montana. Before, and after, becoming director I have been involved in this mine permitting process and know it is one of the most protective permits DEQ has ever issued. DEQ plans to appeal Judge Bidegaray’s decision on this sound and defensible permit,” said DEQ Director Chris Dorrington.

Montana Trout Unlimited, Montana Environmental Information Center, Trout Unlimited, Earthworks and American Rivers were all plaintiffs in the case that took on the Montana DEQ, Tintina Montana and Meagher and Broadwater counties.

Bidegaray’s decision focused on two aspects of the case – the way Tintina proposed to deal with the mine waste and the water quality of the surrounding tributary, Sheep Creek, which provides spawning habitat for rainbow trout and other coldwater fish and winds its way to the Smith River.

“The mine would generate millions of tons of toxic tailings and require the discharge of nitrogen-laden wastewater into Sheep Creek,” the judge said.

The Black Butte Mine would be located adjacent to Sheep Creek, within the Smith River watershed, about 20 miles away from the river. Sheep Creek provides approximately 30 percent of the flow of the Smith River during the late summer, according to the court documents. The mine itself is estimated to be active for 13 years, and extract about 14.5 million tons of copper ore from the “Johnny Lee Deposit.” That translates to 440 tons of copper per day, and 18 trucks per day would carry the concentrate to rail terminals in Livingston or Townsend. The court documents say that the mine would generate 12.9 million tons of tailings that have the potential to produce acid-mine pollution.

“Rock waste generated by Tintina’s excavation activities would contain high levels of acid-generating minerals and toxic metals, including nickel, thallium, strontium, copper, lead, arsenic and uranium,” the documents in the decision said.

About half of the tailings would be used to backfill underground areas of the mine with the combination of cement. The rest would be stored above ground in a 72-acre tailings facility, which the court documents note, is the size of more than 54 football fields on the side of a hill overlooking Sheep Creek.

Tailings facility

In her ruling, Bidegaray cited concerns about the type of tailings storage system engineers and the DEQ had approved. The tailings – or the waste from the mining and concentration process – would be mixed with a cement to essentially lock the toxic waste into place, making it resistant to leaching toxic, acid-laden water.

Bidegaray said that the DEQ violated the law by exempting the tailings facility from more detailed and rigorous procedural requirements that would have ensured its safety, calling the analysis “unlawful.”

In addition to not following the “plain language” of Montana law, Bidegaray said the measure also violates Montanan’s constitutional rights to a clean and healthful environment because the department failed to evaluate or meaningfully respond to evidence that Tintina’s tailings facility does not ensure the structure will remain “safe and stable.”

Bidegaray said that DEQ and Tintina failed to demonstrate that a mixture of 0.5 percent cement and other binders would form and maintain a “solid, non-flowable mass.”

The judge said that neither organization proved that seismic activity, mine blasting or even slope instability – as is found on the side of the hill – would protect the “slumping” material to stay out of the watershed.

Bidegaray said that the DEQ and Tintina failed to prove that tailings, when mixed with as little as 0.5 percent binder materials, would harden into a mass, that any of the tailings would not mix with water and oxygen, thereby becoming acid-mine drainage, and that the mass would remain stable in the event of mine blasting or an earthquake.

“DEQ’s inadequate or irrational analysis with respect to any one of these assurances alone is enough to render DEQ’s decision to permit the Black Butte Copper Mine arbitrary, capricious and unlawful – yet DEQ failed to support all three assurances with adequate testing and analysis,” Bidegaray said.

Instead, the judge said the testing they provided was a cement-binder material that contained four times the amount of binder material, at 2 percent.

“Because Tintina expects new layers of 2 percent cement-paste tailing to take 28 days to set fully at the facility, new tailing layers would frequently be added before the previous layer had set even with the highest binders content authorized by DEQ,” Bidegaray wrote. “Moreover, DEQ acknowledges that, most often, the binders content of the tailings will be much closer to 0.5 percent than 2 percent. The administrative record shows that reducing the binders content of tailings significantly increase their drying time … Yet DEQ did not evaluate whether the tailings will form a stable, non-flowable mass when fresh layers are consistently layered atop lower layers that have not fully set.”

Oxidation and acid

Bidegaray also questioned whether the oxidation could “undermine the stability of the tailings facility.” Acid-mine drainage from mining can become a never-ending problem for mines because once rock and minerals are exposed, any mixture of oxygen or water can cause acid leaching. For example, acid-mine draining is and continues to be a decades’-long concern in the Zortman-Landusky site.

“While the record raises concerns about oxygen and water entering the tailings mass, DEQ did not meaningfully consider the resulting impact on the stability of the impoundment,” Bidegaray said. “The record indicates that Tintina proposes to allow the tailings to weather in the facility for up to 30 days before being covered, leaving ample time for oxidation before fresh tailings are layered on top.”

Moreover, tailings research presented to the court shows that a laboratory study of cemented tailings may develop oxidation paths and persistent cracking, allowing oxygen to mix with the tailings.

“DEQ’s conclusion that acid generation would not be possible was therefore arbitrary,” Bidegaray wrote.

Independent review

Bidegaray’s ruling also points out that the mine design must be submitted to an independent review panel to prove the engineering is “sound.”

“DEQ acknowledged in the record that Tintina had not produced a design document satisfying the (law’s) requirements,” Bidegaray said.

Tintina pointed to a letter by an independent panel submitted in 2017, but Bidegaray dismissed it, saying “it lacked basic information that was both statutorily required and essential to understanding the safety and stability of the proposed facility.”

Moreover, even DEQ noted that the mining company had referenced, but not supplied a “construction management plan,” and Bidegaray identified “myriad other required elements missing from the design document, including descriptions of the chemical and physical properties of materials and process solutions to be stored in the tailings facility.”

Water treatment plant

Tintina also proposed transporting most of the groundwater from the mine portal to a water treatment plan where it would undergo reverse osmosis and reduce the pollutants, including “aluminum, arsenic and thallium.”

Bidegaray found that even the treated water would still mean that the water would exceed the nitrogen load by almost double the allowable concentration. The nitrogen limit is intended to “reduce the growth of nuisance algae” which could kill fish by depleting the oxygen content in the water.

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Darrell Ehrlick
Darrell Ehrlick

Darrell Ehrlick is the editor-in-chief of the Daily Montanan, after leading his native state’s largest paper, The Billings Gazette. He is an award-winning journalist, author, historian and teacher, whose career has taken him to North Dakota, Minnesota, Wisconsin, Utah, and Wyoming. With Darrell at the helm, the Gazette staff took Montana’s top newspaper award six times in seven years. Darrell's books include writing the historical chapters of “Billings Memories” Volumes I-III, and “It Happened in Minnesota.” He has taught journalism at Winona State University and Montana State University-Billings, and has served on the student publications board of the University of Wyoming.