Minnesota Supreme Court deals blow to Minntac iron mine

February 10, 2021 GMT

ST. PAUL, Minn. (AP) — Regulators can apply strict drinking water standards to limit groundwater pollution from North America’s top-producing iron mine, the state Supreme Court ruled Wednesday.

The Minnesota Pollution Control Agency properly concluded that pollution seeping into groundwater from the Minntac mine has harmed waters covered by federal standards meant to protect drinking water, Justice Paul C. Thissen wrote for the court.

The Star Tribune reported that the decision threw out a lower court ruling that said the MPCA couldn’t use those stricter standards when it issued a permit to Minntac’s mine in Mountain Iron, which is owned by U.S. Steel Corp.


The ruling was a victory for state regulators and environmental groups, which argued that the state is allowed to limit sulfate pollution into groundwater — not just surface water — under the federal Clean Water Act.

“In U.S. Steel’s zeal to prevent any regulation of its own pollution, the company had put all of Minnesota’s regulation of groundwater at risk,” said Paula Maccabee, lawyer for the environmental group WaterLegacy, which appealed the case to the state Supreme Court along with the MPCA and the Fond du Lac Band of Lake Superior Chippewa.

U.S. Steel representatives did not respond to the newspaper’s request for comment. The company had sought a variance from the strict groundwater quality standards.

The MPCA is still reworking Minntac’s water quality permit. The mine has a 13-square-mile waste basin. Pollutants — primarily sulfates — have long been leaking into local groundwater. U.S. Steel estimated in court documents that roughly 2,000 gallons of wastewater seeps every minute from the basin directly into the groundwater.