MPCA to EPA: It's time to set mercury limits on the taconite industry

30 years is long enough to set mercury standards, state agency tells federal regulators.

FILE: Northshore Mining
Cleveland-Cliffs’ Northshore Mining in Silver Bay. (2020 file/News Tribune)

The Minnesota Pollution Control Agency has asked the U.S. Environmental Protection Agency to set mercury standards on the taconite industry, something the federal agency has avoided for 30 years.

In a petition filed late Monday with the Michigan Department of Environment Great Lakes and Energy in U.S. Circuit Court of Appeals in Washington D.C., the MPCA sought court-ordered mercury standards and urged the EPA to reconsider a recent rule that did not set standards for mercury emissions at taconite plants.

MPCA Commissioner Laura Bishop in a news release Tuesday said that "mercury pollution poses a significant threat to our waters, human health, and economy," and the agency cited a Minnesota Department of Health study that found 10% of tested Minnesota newborns in the Lake Superior Basin region had elevated mercury concentrations at birth. High mercury levels can harm the nervous system and brain development.

“The MPCA has been working with Minnesota’s taconite industry to make significant reductions in mercury emissions, but the EPA has reneged on its responsibilities to develop standards for taconite processing ... The EPA has had 30 years to address mercury emissions from taconite, and its inaction leaves us no other choice than to ask the court to intervene,” Bishop said.

Mercury, a potent neurotoxin that can harm human health even in small amounts, is found naturally in the earth's crust. While it is released into the environment from volcanic activity and weathering of rocks, its largest source is human activity, including burning coal and processing taconite iron ore, among other industries.


According to the MPCA, U.S. Congress in 1990 required the EPA to set mercury emission standards by 2000, but it did not meet that deadline. The EPA didn't set a mercury limit in its 2003 required hazardous air pollutant rule for taconite processing facilities. Then, in 2005, the Circuit Court of Appeals required the EPA to establish mercury emissions limits, the MPCA said.

However, by 2019 and 2020, when the EPA released its proposed and final National Emission Standards for Hazardous Air Pollutants: Taconite Iron Ore Processing Residual Risk and Technology Review , standards on mercury were again missing.

In comments made by the MPCA in November 2019 responding to the proposed rule, the agency said more than 10,500 pounds of mercury were released by the state's taconite industry since 2003 and showed the state's taconite plants released nearly a combined 800 pounds of mercury in 2018.

"EPA must withdraw this proposed rule amendment and re-propose a standard that complies with the Clean Air Act (CAA) by including a mercury emissions limit," Frank Kohlasch, manager of the MPCA's air assessment section, wrote in the cover letter of the comments. "The rule does not fulfill EPA's obligations under the CAA, and will not productively reduce mercury deposition to Minnesota's lakes and streams, so very important to Minnesota in addressing fish consumption advisories through Minnesota and beyond."

In separate November 2019 comments on the proposed rule, the Fond du Lac Band of Lake Superior Chippewa said "EPA’s technology review is incomplete because it fails to even discuss potential mercury controls."

The band said tribal nations were uniquely impacted by high levels of mercury in water because of the high amount of fish its members consume.

"Beyond threatening the physical and economic well-being of Tribal members, mercury deposition also threatens Tribal culture and spiritual well-being," the band said. "Many Tribal cultures are greatly intertwined with natural resources so when these resources are lost, so are the associated cultural practices."

Responding to the comments, the EPA wrote in its final rule that its reading of the Clean Air Act was different and that it didn't need to set standards for emissions that didn't already have them.


Addressing comments that argued the EPA should have included the MPCA's requirement of taconite plans to file mercury reduction plans to reduce emissions by 2025 in its sources of information, the EPA said, "We note that these (mercury reduction plans) are still under review by MPCA and that the technologies discussed therein have only been applied at the taconite processing facilities in pilot scale studies. That is, these control technologies remain unproven at commercial scale and the amount of mercury reduction achieved by them remain uncertain."

The EPA did not respond to the News Tribune's request for comment Tuesday afternoon.

ArcelorMittal — owner and operator of Minorca Mine in Virginia and the majority owner and operator of Hibbing Taconite — and Cleveland-Cliffs — owner and operator of United Taconite in Eveleth and Forbes, Northshore Mining in Silver Bay and Babbitt and Tilden Mine in Michigan — both did not respond to the News Tribune's request for comment Tuesday. Cliffs announced early Monday morning that it would be buying ArcelorMittal USA's assets — including Minorca and its share in Hibbing Taconite — by the end of 2020.

In an email to the News Tribune Tuesday, U.S. Steel spokesperson Meghan Cox said the company was aware of the petition but declined to comment further. U.S. Steel owns and operates Keetac and Minntac mines and pellet plants in Keewatin and Mountain Iron, respectively.

In a statement, the Minnesota Center for Environmental Advocacy said it supported the MPCA's lawsuit.

"We know that mercury is a pollutant that can be controlled, and that there is a huge upside for public health in doing so," MCEA CEO Kathryn Hoffman said. "A national air emission standard for mercury in the taconite industry would formalize needed limits, and protect the health of children, especially those in northern Minnesota."

Jimmy Lovrien covers energy, mining and the 8th Congressional District for the Duluth News Tribune. He can be reached at or 218-723-5332.
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