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Despite pressure to lower Minntac sulfate emissions, status quo could last awhile

A new permit would require Minntac to cut back on its sulfate emissions, but the MPCA recently decided to allow Minntac to continue operating under its expired permit for now.

View of U.S. Steel’s Minntac tailings basin, showing the rivers that receive wastewater from the taconite production process.
Courtesy of the Minnesota Pollution Control Agency

The U.S. Environmental Protection Agency is pressuring Minnesota to do more to reduce water pollution from Minnesota’s largest taconite plant.

For decades, U.S. Steel’s Minntac plant in Mountain Iron has been emitting sulfates at levels far higher than the law allows. Sulfates are harmful to wild rice, which grows in some of the affected waterways.

The Minntac plant has been operating on an expired permit for 23 years. The Minnesota Pollution Control Agency (MPCA) has been working with U.S. Steel for three years to try to come up with a permit both can agree to. A new permit would require Minntac to cut back on its sulfate emissions. But the agency recently decided not to make a draft permit public, and to allow Minntac to continue operating under its expired permit for now.

The agency’s director of metallic mining, Ann Foss, says that’s because the agency’s rules governing sulfates are about to change, and the Minnesota Legislature is considering bills dealing with sulfates.

Waiting for clarity, partly from lawmakers

“Until there’s more clarity on both of those issues,” the MPCA won’t release any draft permits for facilities located upstream of potential wild rice waters, Foss said.

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The decision could mean years of delay. The MPCA’s new sulfate standard is expected to go through a rule-making process, which typically takes two years. But Foss said there might be enough information to proceed on permits when the new wild rice/sulfate standard is officially proposed, which could be this fall.

Environmental groups are frustrated. Kathryn Hoffman, an attorney with the Minnesota Center for Environmental Advocacy, said developing a new standard is not a good reason not to apply the current one. “Simply because a law may change in the future isn’t a reason you don’t have to comply with it,” Hoffman said. “And let’s remember, the sulfate wild rice standard has been on the books since 1973.”

The EPA has also been critical of Minnesota’s failure to act. It recently said Minntac should be required to operate under an updated permit that should include “extensive and specific actions, and definitive timeframes for these actions.”

Hoffman said she thinks the MPCA simply “lacks the will” to enforce the law. She believes the agency has put off reissuing the permit because it is afraid it will be sued. She also said, “If it’s incredibly lax and doesn’t enforce the Clean Water Act, they’d face the wrath of EPA and environmental groups.”

But Hoffman also places blame on the Minnesota Department of Natural Resources (DNR).

“DNR has as much authority if not more (than MPCA) to regulate environmental impacts of mining,” she said. “The permit-to-mine statute is very broad: Absolutely DNR could come into a mining operation and require them to take steps to improve air and water quality. They could require active wastewater treatment plants. But DNR has never exercised any of that authority, and that doesn’t appear to be changing.”

DNR’s dual mission

Hoffman points to the dual mission of DNR: The agency is tasked with both promoting and regulating mining.

“It seems DNR sees their primary operating instructions to promote mining, with regulation only a secondary goal,” Hoffman said.

As for the state’s top official, Gov. Mark Dayton said in an interview with MPR, “U.S. Steel has made it very clear that they’re not going to agree to a permit that has a standard of ten” milligrams per liter of sulfates, the current legal standard for waters containing wild rice. Dayton said an “antiquated” standard should not “close down an industry.”

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MPCA has been studying the effects of sulfate on wild rice for three years, and in late March the agency announced that it wants to eliminate the current standard of 10 milligrams of sulfate per liter of water in wild rice waters, and begin to apply different standards to different waters based on their chemical makeup. Foss said the agency has not decided whether to apply the sulfate standard to any industries during the time it takes to develop the new plan and begin implementing it.

Many other mines, in addition to Minntac, are operating with expired permits. Most mines discharge wastewater with high sulfate levels, but as the largest taconite producer, Minntac discharges the most contaminants.

Minntac’s 8,500-acre tailings basin, where fine waste rock and water are stored, straddles the Laurentian Divide and drains on the west side into the Dark River, a trout stream. On the east side it drains into the Sand River, which flows into Lake Vermilion. Calculations show that at the property boundary, the sulfate concentration exceeds not only the wild rice standard of 10 mg/liter, but even the much looser standard of 250 mg/liter set for drinking water.

In Sandy and Little Sandy Lakes about a mile and a half east of the basin, average sulfate concentrations in recent years have been approximately 20 times the limit for wild rice waters. Tribal groups say these lakes were once rich with wild rice. U.S. Steel is cooperating with the tribes to see if wild rice can be restored there.

Progress on improving water quality

Both U.S. Steel and the MPCA say the company has already done much to improve water quality in these receiving waters. It installed a system on the east side of the basin that collects water seeping through the dikes, and pumps it back to the basin. The MPCA’s Ann Foss said this system has reduced the sulfate load in receiving waters by about 50 percent, though it is still too high to meet current wild rice protection limits.

U.S. Steel plans a similar system on the west side of the basin.

Minntac also recently switched to a new source of water used in the taconite production process. Previously it was using water from the Mountain Iron pit, which was high in sulfate. Now it’s also using water pumped from the current mine pit, with lower sulfate concentrations.

The MPCA also required the company to install monitoring wells, which provide information about how far contaminated water is spreading. The agency expects the company to conduct a site investigation to identify exactly where water flows out of the basin in order to determine where further mitigation should be done. And the DNR is studying the complex interaction of water and chemicals in the basin, to better understand what happens to pollutants there.

“So there’s been a lot of progress, and it is a very complicated site,” said Foss.

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U.S. Steel is considering building a system to filter the water leaving the basin. It’s at least the fourth idea for dealing with water pollution that the company has floated since the permit expired 23 years ago.

U.S. Steel’s general manager of environmental affairs, Tishie Woodwell, said in an interview that the huge flows and heavy mineral concentration in the wastewater mean “some technologies just simply don’t work.” For example, back in 2009 the company proposed building an expensive reverse osmosis water treatment system, hired a consultant to study the idea, and dropped it because the consultant said it would create huge quantities of a briny waste product which there is currently no way to treat.

Evaluating new technologies, as yet unproven

“These days there’s so many people coming out with technologies that they think might be feasible, so we’re open to evaluating those,” Woodwell said. “The problem is that most aren’t proven yet so you have to go through a lot of pilot studies.”

Woodwell would not speculate on how long it will take the company to figure out whether the current idea of filtering the water will work.

And she said it’s been a challenge for U.S. Steel to solve the problem because “the problem keeps changing.” Until recently, the company had only been trying to reach the drinking water standard of 250 mg/liter, because the MPCA had not tried to enforce the higher standard for wild rice. Now the company needs to get the water far cleaner, if it is to meet the 10 mg/L wild rice limit.

For at least three years, the MPCA has been sending signals that it intends to start enforcing the wild rice protection standard. But Woodwell said the company only received official notice that it was expected to meet the limit in December.

“I don’t think the technologies are quite up to the ability to meet the new standard,” Woodwell said, referring to the 1973 wild rice standard. Asked if the company will eventually be able to reach that limit, Woodwell said she doesn’t know.

“We don’t have any technologies that we’re aware of that would get us into compliance,” she said, suggesting it could take at least five years to find a way. “The issues are complicated; there’s not a one-size-fits-all or a silver bullet,” Woodwell said. “We will continue working and continue making improvements to the environment, but it’s not simple.”

Company says enforcement would be premature

The company also says it’s premature for the MPCA to apply the 10 mg/liter standard to the Minntac plant because the limit only applies to waters that are used for the production of wild rice.

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“MPCA needs to establish the criteria that will be used to determine whether a body of water is used for the production of wild rice, and then go through the process of designating each water body,” Woodwell said. “So our position is they have to go through the proper process before the (sulfate limit of) 10 can be applied.”

The MPCA has published a preliminary list of wild rice waters, and it includes the Sand/Pike/Vermillion system on the east side of the Minntac basin. The agency plans to conduct a rulemaking process to create the system it will use to designate individual lakes and rivers as wild rice waters. That will likely take more than two years, beginning with public hearings this fall. 

Seventeen other mining facilities are operating with expired permits that have been extended without being updated. In 2012 MPCA promised EPA that it would hire more staff and prioritize the oldest and biggest-polluting facilities for permit renewals, with the goal of eliminating the backlog within five years. The agency has added staff, and Foss said “we’ve made tremendous progress,” but she said there is currently no schedule for eliminating the backlog.