An Agate Original

Probably few Minnesotans have heard much about the state’s latest sulfide mine proposal. Talon Metals is planning to dig 800,000 short tons of nickel out of the ground (a short ton is 2,000 pounds) in northern Aitkin County, an area of forests, lakes and wetlands south of Grand Rapids. Some residents and environmental advocates are concerned about the plan, and one group is calling for an in-depth study of the possible impacts of sulfide mining in this area.

Talon is in partnership with Rio Tinto, the world’s second-largest metals and mining company, which four years ago generated outrage when it demolished a sacred cave with evidence of 46,000 years of continual human occupation in Australia. There have also been accusations of poor labor practices and environmental damage at Rio Tinto mines in Papua New Guinea and Indonesia.

Unlike other currently proposed mines, NewRange and Twin Metals, Talon plans to load the ore on rail cars and haul it for processing to Mercer County, in western North Dakota. The company says this is an example of its responsiveness to community resistance. “We understand there are concerns about mining and processing sulfide-based minerals in a water-rich environment,” says Todd Malan, Talon’s Chief External Affairs Officer & Head of Climate Strategy. “We plan to be open with the community; in fact, we’d like to do a community monitoring program, where we provide resources, and the community supervises monitoring.” Such a program exists at the Eagle mine near Marquette, Michigan.  

Talon says the mine is critical to the nation’s transition to renewable energy, especially for electric cars, which typically use batteries containing nickel and cobalt. It projects a shortfall in nickel supplies in the next three-to-seven years.

Malan says the mine would employ 300 workers for seven-to-ten years. An entrance tunnel would lead down to the ore body. It would be built with a tunnel boring machine, which can dig through saturated soils without needing to remove water from the surrounding soils. Once it reaches the ore body, 500 to 1,500 feet below the surface, the tunnel would turn and rise to the surface near the entrance tunnel.

Other structures to be built on the surface include an exhaust filtration building, an enclosed ore storage and railcar loadout building, and a water treatment plant.

Below the surface, the mine would spread across 224.9 acres; it is planned to work as most underground mines do. Drifts about 16 feet wide and up to 20 feet high are excavated into the ore body, advancing by repeated explosions detonated by ammonium nitrate and fuel oil. A front-end loader removes the blasted rock and loads it into trucks. This material is split into three classifications depending on its sulfur content and intended use. The highest-sulfur rock is shipped to North Dakota; the rest is used for backfilling. When the ore from a drift is gone, workers mix the blasted rock with commercial aggregate and backfill the drift. A train of between 40 and 100 cars leaves the site once or twice a week.

Waste rock would be stored underground or placed temporarily in a lined storage area above ground, built with a water collection system to gather runoff, which would undergo treatment.

Talon officially submitted its proposal to the Minnesota Department of Natural Resources in summer 2023. Since then, the company and the DNR have been exchanging questions and answers to arrive at a final Environmental Impact Statement (EIS), required by law for such a project.

In that back-and-forth process, Talon has informed the DNR that it does not plan to install a leakage detection system. “The tunnel lining includes dual waterproofing measures… these types of lining systems are regularly used for tunnels where routine maintenance is challenging without creating a major service disruption.” Since the tunnel will be in regular use, any problems would be noted immediately, Talon said. It also asserted that future stages of mining are not planned. “There is ongoing exploration activity in the vicinity of the project area but given the uncertainty of information that may be learned through exploration, no future development is currently planned.”

Meanwhile, the company is putting out news releases every few months trumpeting new discoveries in areas north of the planned mine, a section the company calls the Raptor Zone. The company’s chief exploration officer, Brian Goldner, is quoted as saying, “The more we drill, the more we discover.”

Many of the questions being posed by the DNR so far are answered with, “To be addressed in the EIS.” Thus, many questions remain.

Talon has received commitments of $114 million in federal support from the Department of Energy through the Bipartisan Infrastructure Law for its Battery Mineral Processing Facility in North Dakota, and $20 million from the Department of Defense for its exploration activities.  Both are grants to be matched by Talon.

Concerns 

The primary environmental concern about sulfide mining (defined as mining for valuable ores such as nickel, copper, and gold found in sulfur-rich ore bodies) is water pollution. When minerals bonded to sulfur are exposed to air and water, a chemical reaction occurs that generates sulfuric acid. This releases heavy metals present in the mines. Scientists are unable to point to such a mine that has not contributed harmful chemicals to surrounding waters, typically acidifying and often killing off life in nearby rivers. This is called acid mine drainage.

Back in the 1970s, the Minnesota Environmental Quality Board conducted a comprehensive study about possible effects of sulfide mining, examining geology, chemistry, hydrology, economics, and other topics in great detail. The state placed a moratorium on mining until the study was completed in 1979.

This work continues to inform state decision-making today. It provides detailed baseline information about the Duluth Complex. But it is 40 years old, and it did not consider tribal concerns; nor did it include the more recent detailed scientific research that has been done since the state began trying to enforce its limit on sulfate in wild rice waters. It was also geographically limited to the Superior National Forest near the Boundary Waters Canoe Area Wilderness.

Talon’s proposed mine in Aitkin County is outside that study area. The Tamarack Intrusive Complex was identified more recently as a potential mining district. It lies upstream from the Mississippi River, the Wild and Scenic St. Croix River, and the St. Louis River, which flows into Lake Superior. Now, a small group of researchers who were involved in the 1970s study are suggesting that the state should conduct a similarly wide-ranging and in-depth study of the Tamarack Complex.

Geologist Fred Campbell’s first job after graduate school was to estimate the tonnage of copper and nickel in the Duluth Complex based on assays voluntarily submitted by exploration companies for that 1970s study. Now retired, Campbell says groundwater flow is “one of the most complex things you can possibly imagine. Water flows downhill, but when you have fractured material, glacial or bedrock, it’s hard to know exactly where the groundwater is going to flow.” And it inevitably affects surface water. “They’re always connected. If you contaminate surface water, it’s always going to get into groundwater.”

Campbell notes that the Tamarack Intrusion has more nickel than most deposits—ten times as high a concentration as in the Duluth Complex. Much of the area to be mined has two percent nickel, some zones as much as 15%. This ore-rich body is large, about 31,000 acres or 48 square miles. And Talon says it has secured rights to explore the entire area, from the state of Minnesota and private landowners.

Aside from acid pollution, a couple of things worry Campbell. One is the possibility that serpentine group minerals may be present in the rock. One of the minerals in this group is cummingtonite, an asbestiform mineral. “It shaves off into needle-shaped fibers that can be a health concern. If they get into the drinking water, they can get trapped in the digestive tract and cause cancer,” he says. When these “asbestos-like particles” were found in Duluth’s drinking water in 1973, the court forced Reserve Mining to stop depositing its waste rock into Lake Superior.   

The other concern for Campbell is how rigorous the Environmental Impact Statement will be. “They should have a lot more data and plans,” he says. “When I worked for the Minnesota Pollution Control  Agency (MPCA), we always looked for contingency plans. They’re almost non-existent for this project and others currently being proposed. They need a plan in case something goes wrong.”

During the 1970s copper-nickel study, Bruce Johnson was a field chemist on contract with the MPCA. Since he retired, he’s kept a close eye on both the MPCA and the DNR. He says it would be a lot easier to plan for individual mines in the Tamarack area if we had a basic understanding of the natural systems of the area. “What are the stream sizes? How big are the watersheds, the sub watersheds? How much volume of water is there, what is the chemistry? How much mercury is already in these waters? We need to know the terrestrial biology, the socio-economic data,” he says.

For the earlier study, scientists collected water samples for five years. There was plenty of data. Johnson worries the data collected for the Talon mine is insufficient for rigorous science. Plus, he’s suspicious of Talon’s long-term plans. “The known mineralization is 31,000 acres, and they’re saying, ‘We’re just going to go down with this little mine.’ Given the history of mining in Minnesota, we know they’ll want to do more.” And he predicts the plan to ship by rail to North Dakota is fine to start with, but when federal support dries up, they’ll want to have a tailings basin on site. “It doesn’t make sense to haul it to North Dakota. Once the camel’s nose is under the tent, they’ll have to have a tailings basin.” 

Johnson predicts liners will leak; he points to documented leaks in taconite storage areas; he worries about the water that will need to be pumped out of the mine after it’s been in contact with nickel. It will be so high in minerals that it will kill plant life, he predicts. And the pumping could disturb the groundwater flows.

The DNR is responsible for the Environmental Impact Statement, but the DNR is not responsible for water quality; that comes under the purview of the MPCA. Johnson asks how we can be sure the EIS will provide enough information about water quality.

The retired scientists and Paula Maccabee, Advocacy Director and Counsel at Water Legacy, sent a request for an in-depth study of the possible environmental effects of mining in the region to the Minnesota Environmental Quality Board and the Commissioners of DNR, MCPA, and the Minnesota Department of Health . Those offices say they are developing a response.  

Tribal concerns

Talon has kept the Mille Lacs Band of Ojibwe informed of its mining plans but has not engaged in formal tribal consultation efforts with Band leaders, according to the Mille Lacs Band of Ojibwe’s Commissioner of Natural Resources, Kelly Applegate.

“The federal government’s role is as a trustee to tribes,” Applegate says; “that means the federal government has the duty and the responsibility to protect our forever homelands, the little we have left, from threats like this.”  

But Applegate does find it ironic that in some respects the nation’s energy transition is being loaded on the backs of tribal people. A recent study found that resources for critical minerals are overwhelmingly located near reservations and lands sacred to indigenous people. The report says 97% of nickel, 89% of copper, 79% of lithium and 68% of cobalt reserves and resources in the U.S. are located within 35 miles of Native American reservations.

“That’s a huge environmental justice concern,” says Applegate. “That’s not fair to tribal nations, to put this type of industry right in their backyards when we rely on clean water and are interconnected with the land, and all the resources we depend on are all there. The threat of pollution in such a way that we may not be able to use it the same way again, it’s very alarming.”

Applegate points out that some car manufacturers are turning to other resources for batteries.  Lithium iron phosphate, called LFP, is commonly used in China, and it uses materials that are cheaper and easier to source than nickel and cobalt. Tesla now uses LFP batteries for its cheaper models.

Applegate is also convinced the mine will eventually expand. “They’ve applied for permits beyond that zone of exploration that they were originally looking at. So, it’s slowly becoming a massive project, it would be there forever, and who’s going to babysit it after closure?”

These are questions to ask about any mining project. Talon’s Todd Malan says his company is working in advance with tribal authorities; he says the company is gathering sufficient data to protect the groundwater and surface water systems in the area. And he emphasizes the importance of nickel for the energy transition now underway. “I hope people will come to grips with the mineral intensity of clean energy,” he says.

The DNR will probably work on the EIS for the rest of this year; then it will ask for public comment. To follow the process, check out the DNR’s web page.

NOTE: This story has been changed to correctly describe the relationship between the Mille Lacs Band and Talon.