The Minnesota Pollution Control Agency (“MPCA”) opened public comment on a draft water pollution (“NPDES/SDS”) permit for the U.S. Steel Corp. Minntac tailings basin site. Please tell the MPCA to require U.S. Steel to stop irresponsible pollution and clean up its Minntac contamination NOW!

Minntac is the largest taconite plant in the United States. Its tailings basin is huge (13.6 square miles). Since its construction, in the 1960s, the Minntac tailings basin has leaked and discharged hundreds of thousands of tons of sulfate.

Minntac sulfate pollution through surface water and groundwater has killed hundreds of acres of wild rice in the Sandy and Little Twin Lakes and the Dark River.

Minntac mine and tailings basin water pollution also poisons wild rice and increases mercury contamination of fish in the St. Louis River, which flows to Lake Superior; in the Little Fork River and Rainy River flowing north to Lake of the Woods; and in the Pike River, Lake Vermilion, Vermilion River and Crane Lake, affecting the Boundary Waters Canoe Area Wilderness.

NEW DEADLINE for Comment to MPCA on U.S. Steel Minntac Tailings Basin Permit: Monday, October 26, 2026 at 11:59 pm

What is in the MPCA’s Proposed Minntac Permit?

The Good News:

1. For the first time ever, MPCA has proposed that the Minntac tailings basin permit will include an effluent limit based on Minnesota’s 10 mg/L wild rice sulfate standard.
2. U.S. Steel would need to build a wastewater treatment plant within 6 years after the final Minntac permit is reissued. Although the permit isn’t specific in the permit, this would be a modern ultrafiltration and nanofiltration plant.
3. For the first time ever, MPCA admits that tailings basin drainage through groundwater to surface water (where most of the sulfate pollution killing wild rice and poisoning fish comes from) is the “functional equivalent” of a direct discharge and must be controlled to protect wild rice, fish, human health, and Tribal exercise of treaty-reserved rights.
4. The MPCA and U.S. Steel have proposed building a “cutoff wall” and pumping polluted seepage from the east (Twin Lakes) side of the tailing basin to reduce existing pollution in groundwater and downstream impaired wild rice waters.

The Bad News:

1. U.S. Steel wouldn’t have to comply with Minnesota’s groundwater sulfate standard until as much as 45 years after the new Minntac permit is issued. MPCA is allowing this delay even though MPCA’s prior 2018 Minntac permit, which the Minnesota Supreme Court upheld on this point in 2021, required U.S. Steel to comply with groundwater standard by December 31, 2025.
2. U.S. Steel wouldn’t have to comply with Minnesota’s wild rice sulfate standard until 45 years after the new Minntac permit is issued. This “compliance” date is three-quarters of a century after MPCA told U.S. Steel in 2000 that it would enforce the wild rice sulfate standard.
3. Neither MPCA’s draft Minntac water pollution permit nor any existing permit to mine for the Minntac mine or tailings basin require U.S. Steel to post financial assurance to build or maintain water pollution treatment, cutoff walls, or extraction wells. Minntac could close down (its current life of mine would end in 2044) long before contamination is cleaned up.

Why is it important that you comment?

• MPCA has tried and failed to control sulfate pollution at the Minntac mine and tailings basin since at least 1987. In 2000, the MPCA sent a warning letter to U.S. Steel’s predecessor saying: “Sulfate has been identified as a pollutant of concern at the tailings basin since at least 1987.” This warning said that Minntac discharge violated the 10 mg/L wild rice sulfate standard.

• For more than a quarter of a century, U.S. Steel has dragged out the process with one failed “compliance plan” after the other. In a court case won by WaterLegacy and the Fond du Lac Band of Lake Superior Chippewa in 2021, the Minnesota Supreme Court admonished that, since 2000, U.S. Steel and the MPCA entered into a “series of compliance schedules,” but “sulfate levels have continued to increase since then.”

• Sulfate levels in downstream Little Sandy Twin Lakes are 250 mg/L; which is 25 times the wild rice sulfate standard. The 1854 Treaty Authority and Lake Superior Basin Anishinaabe communities have rated the cultural and ecological functionality of these formerly-abundant wild rice waters as shown below:

• MPCA stressed in its 2000 warning letter that Minntac “tailings basin wastewaters constitute the headwaters for both the Dark and the Sand Rivers, both of which flow to sensitive, highly valued waters, including Lake Vermilion. The quality of the tailings basin seepage in large part determines the water quality of the downstream wetlands, and streams and lakes.”
• Minntac sulfate pollution not only kills wild rice; it extirpates sensitive fish and benthic macroinvertebrates (bugs and slugs) and increases contamination of the food web with toxic mercury.
• Minnesota Department of Health (“MDH”) testing of walleye in the Pike River Flowage Lake to Lake Vermilion showed that every fish tested had more mercury than the Minnesota limit (0.2 mg/kg) and fish longer than 18 inches had average mercury above the 0.95 ppm “DO NOT EAT” cutoff.
• The MDH found that 1 out of 10 newborns (more than 1,400 tested) in Minnesota’s Lake Superior region had high enough mercury in their blood to exceed the threshold where IQ is reduced.
• Mercury contaminated fish in the Rainy River/Boundary Waters and the St. Louis River/Lake Superior watersheds affected by the Minntac mine and tailings basin threaten developing brains of fetuses, infants, and children, particularly in families and communities that rely on fish for sustenance, culture, and exercise of treaty-reserved rights.
• MPCA needs to hear from members of the public that “responsible mining” means compliance with Minnesota law, not expecting our children and taxpayers to pay U.S. Steel’s and Nippon Steel’s costs.

What is the best way to Comment?

• Draft your comments and upload them using the MPCA Comment Page.
• We suggest you begin your comments with a personal statement of your concern regarding the potential damage this mine may cause and make specific suggestions for what MPCA should include in the permit. Feel free to draw from the template comment below.
• We recommend that you use the comment to attach a comment that you draft and edit in Word or another program and then upload your comment letter. You can use the attached Word document as a starting point.

Template for Comment on the MPCA Draft Permit for the U.S. Steel Minntac Tailings Basin

Courtney Sullivan
Minnesota Pollution Control Agency
7678 College Road
Baxter, MN 56425

RE: Comments on U.S. Steel Minntac Tailings Basin Wastewater Permit (MN0057207)

Dear Ms. Sullivan, MPCA Managers, and MPCA Staff:

I am commenting on the U.S. Steel Minntac Tailings Basin Wastewater Permit because I care about the quality of Minnesota water; the abundance of wild rice that sustains fish, wildlife, and rural and tribal communities; the health of people who eat Minnesota fish; the vitality of Minnesota’s recreation and tourism economies; and the basic principle that most of us learned in kindergarten: Clean up your mess.

Minnesota agencies and politicians talk a lot about “responsible mining,” but they do the opposite. For three-quarters of a century, MPCA and other agencies have allowed taconite mining to poison Minnesota waters, wild rice, fish, and the brains of our babies and children rather than use a portion of their profits to collect, recycle, and treat their water so that it meets legal standards. This must change.

U.S. Steel Minntac is the biggest taconite plant in the United States, with mine facilities and a tailings basin that have leaked hundreds of thousands of tons of sulfate for decades. It has polluted the air with massive quantities of mercury as well, killing wild rice and contaminating fish in both the Rainy River and Lake Superior watersheds. MPCA must, at long last, set enforceable requirements with specific deadlines.

Here are my specific requests for the MPCA Minntac tailings basin wastewater permit:

• Require that U.S. Steel build a modern wastewater treatment plant with the capacity to treat all wastewater not recycled back to the Minntac plant and any polluted seepage water pumped from near the tailings basin.
• Require that all discharge from the wastewater treatment plant comply with Minnesota’s 10 parts per million wild rice sulfate standard and all other Minnesota and downstream water quality standards.
• Require that U.S. Steel complete and operate the Minntac wastewater treatment plant no later than December 31, 2031.
• Require that U.S. Steel begin pumping and treating polluted seepage water from wells on the Twin Lakes side of the Minntac tailings basin within 90 days of permit issuance, along with researching effects on pollution reduction and potential use of treated water to maintain water levels.
• Require that U.S. Steel submit by April 15, 2032 a plan to achieve compliance with Minnesota surface water and groundwater standards by December 31, 2037.
• Require financial assurance and/or coordinate with the Minnesota DNR to require that U.S. Steel/Nippon Steel provide up front financial assurance to build, maintain, and operate a Minntac wastewater treatment plan, wells, pumps, and cutoff wall features to achieve and maintain compliance with all water quality standards for at least 100 years.

For as long as I can remember, the mining industry has told us that Minnesota is a good place for mining because we have such tough standards. Those standards are meaningless unless you enforce them. Please protect clean water, our health, our neighbors, our natural resources, and future generations.

Thank you for considering my comment.

Sincerely,
YOUR NAME
ADDRESS
EMAIL

ADDITIONAL READING AND RESOURCES

COMMENTARY in Minnesota Star Tribune, September 29, 2026: “Minntac needs to clean up mining pollution now — not in 2071” by Chairman Robert Deschampe of the Grand Portage Band of Lake Superior Chippewa