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What you need to know about the Twin Metals mine plan

Twin Metals submitted a plan to regulators Wednesday for a copper-nickel mine on the doorstep of the Boundary Waters Canoe Area Wilderness, formally kicking off what is likely to be a multi-year environmental review process.

Twin Metals offices in Ely.
Twin Metals offices in Ely. The company hopes to build an underground mine primarily for copper and nickel, but also to collect cobalt, palladium and platinum.
Courtesy of Twin Metals Minnesota

Twin Metals Minnesota submitted a plan to state and federal regulators Wednesday for a copper-nickel mine on the doorstep of the Boundary Waters Canoe Area Wilderness, formally kicking off what is likely to be a multi-year environmental review process.

The company, which is owned by Chilean mining giant Antofagasta, has been working for roughly a decade to reach this moment, researching its deposit and prepping a blueprint for operations at an underground mine near Ely.

It almost didn’t happen. In the final days of Barack Obama’s administration, the federal government rejected two mineral leases owned by Twin Metals and began a study that could have led to a 20-year ban on mining within the Rainy River watershed. After Donald Trump was elected, however, he reversed the federal decisions, shelving the study and renewing the leases.

Now the company is starting the review process needed for state and federal permits. Here’s what we know about the project based on the proposal documents and more:

What’s the scope of the project?

Twin Metals hopes to build an underground mine primarily for copper and nickel, but also to collect cobalt, palladium, platinum, gold and silver. The project is located in Superior National Forest, roughly nine miles southeast of Ely and about five miles outside the Boundary Waters Canoe Area Wilderness. It would take between two and three years to build and would sit within the Rainy River watershed, which drains into the BWCA. The mine would produce about 180 million tons of ore over 25 years.

Why here? Why now?

The deposit owned by Twin Metals is within the Duluth Complex, one of the world’s largest undeveloped reserves of copper and nickel. While the complex was discovered more than 60 years ago, nobody has mined it for copper or other metals.

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Demand is expected to grow in the coming decades for copper, nickel and other metals because they’re used in critical technology, such as windmills, solar panels, electric cars and cellphones.

Rock samples taken by Twin Metals at their warehouse in Ely for research into the minerals the company hopes to mine.
MinnPost photo by Walker Orenstein
Rock samples taken by Twin Metals at their warehouse in Ely for research into the minerals the company hopes to mine.
Antofagasta has massive copper mines in Chile, but the quality of its ore has decreased, driving interest in the Minnesota project. The mine is also in part of Superior National Forest the U.S. Forest Service has designated for mining to provide the country with needed resources.

What would a mine mean for the economy of northeast Minnesota?

Twin Metals plans to directly employ 700 full-time workers at the mine and estimates it would create another 1,400 spinoff jobs in the region. By comparison, PolyMet says it will create 360 direct jobs and more than 600 indirect jobs.

While the northeast Minnesota has thousands of open jobs, few have as high of wages as typical mining positions. The average weekly wage in the industry was $1,904 in 2018, compared to $323 for hospitality and food service jobs.

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Overall, the mining industry employed about 5,700 people in 2017, and makes up nearly 4 percent of jobs in northeast Minnesota. That’s roughly equivalent to the impact Target’s downtown headquarters has on Minneapolis. Twin Metals says it plans to hire local workers wherever possible, although some specialized jobs may come from elsewhere.

It’s too soon to know if, or how many, of those positions will be union jobs. Julie Padilla, chief regulatory officer for Twin Metals, said only the workers themselves can decide to be part of a union or not, but she said the company would not oppose it. About 80 percent of Antofagasta workers are unionized, and earlier this year, Twin Metals agreed to use union workers to build its mine.

For all that, some have argued Twin Metals could actually hurt the region’s economy. One Harvard University study says any initial benefits would evaporate after mining is over while harming the long-term viability of an economy built on wilderness tourism.

What are the environmental risks of the mine?

The question at the heart of debate over Twin Metals is whether it will create pollution that drains into the BWCA. But the answer to that question is unknown, at least for now.

Copper-nickel and other sulfide mining has a long legacy of water pollution across the U.S. Unlike iron ore mining, copper-nickel mining has the potential to create an acidic runoff that can leach heavy metals into water. The phenomenon, known as “acid mine drainage,” happens when sulfides bound in rock are exposed to air and water through the mining process.

In a 2016 letter denying Twin Metals’ mineral leases, then-Forest Service Chief Thomas Tidwell wrote acid mine drainage could cause “serious and irreplaceable harm” to the BWCA.

Acid drainage can be created in all phases of mining, Tidwell said, from construction to storing waste rock and tailings. Twin Metals’ proposed mine site is next to Birch Lake and the Kawishiwi River, which empty into the BWCA.

Location of proposed Twin Metals mine and Boundary Waters wilderness
Twin Metals mine location indicated by the orange circle; Boundary Waters Canoe Area Wilderness is outlined in blue.

Such toxic waste could harm water quality, hurt wildlife and damage BWCA tourism. There are examples of acid mine drainage in the area, too. A now-closed taconite mine that dug through a layer of sulfide-bearing rock has produced acid drainage at a site known as the Dunka Pit.

PolyMet, another company hoping to build a copper-nickel mine, has planned an extensive water collection and treatment system, in part to avoid acid mine drainage at its project near Hoyt lakes. That mine would be in Lake Superior’s watershed and is closer to construction after 15 years of environmental review.

Nevertheless, Twin Metals maintains the geology of its deposit, along with modern mining technology can prevent toxic waste and harm to the wilderness. For one, the mine and its crushing operation would be underground, and the company says it won’t have any permanent waste rock piles above ground — a common source of acid drainage.

Julie Padilla
Twin Metals Minnesota
Julie Padilla
Padilla said the company’s deposit is unusual in that there is little unusable sulfide they won’t be able to sell. What little “rejectable” sulfide is left won’t be enough to generate acid once its compressed and stored in a tailings pile on the surface, Padilla said.

That tailings pile is another key part of Twin Metals’ strategy. Rather than store the mining byproducts in a pond held back by a dam, the company will squeeze water from it to form a mixture similar in consistency to sandcastle sand and stash it on a liner above ground.

It carries its own risks — such as dust being swept away by wind and into waterways. But it eliminates the possibility of a catastrophic dam failure that environmental groups have warned of elsewhere.

Ultimately, Padilla said the mine will have to meet or exceed state standards to operate and state agencies will determine risk to surrounding waters. But Twin Metals is not saying they won’t have any impact on water. Padilla also noted the company expects to work with the state to craft a financial assurance package to ensure the company will pay if clean up is needed.

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“It’s a box that I think the mining opponents would like to put projects in is that there should be no impacts, but that’s unrealistic for any type of project, whether it be residential, commercial, or industrial or recreational,” Padilla said.

Aside from questions of water pollution, documents submitted to the state also say the mine would produce an estimated 58,072 tons of greenhouse gas emissions per year. While not insignificant, transportation alone in Minnesota produced more than 40 million tons of greenhouse gas emissions in 2016.

Twin Metals says it will work to minimize dust, noise, vibrations and light pollution that come with a major industrial facility — and try and blend into surroundings. About 160 acres of wetlands would be impacted by the project, the company’s documents say.

What happens next?

Twin Metals’ proposal will need permits from the state and federal government, which includes an Environmental Impact Statement required by the Minnesota Environmental Policy Act and the National Environmental Policy Act.

In Minnesota, the Department of Natural Resources is the main state agency in charge of permitting the mine. The DNR will start by deciding the scope of its environmental review before launching its formal study.

The DNR will work to vet Twin Metals’ research and data and will ask for the results of the controversial federal study on a 20-year mining ban in the Rainy River watershed that was ended by the Trump administration.

The federal government will also complete its own Environmental Impact Statement. DNR often writes a joint EIS with the feds, but chose to go it alone on Twin Metals. “The credibility and transparency of this EIS process for the proposed Twin Metals project is critical to Minnesota,” DNR Commissioner Sarah Strommen told reporters last month.

Padilla estimated Twin Metals is between five and seven years away from finishing environmental review and permitting.