In a novel attempt to enforce a longstanding Minnesota rule protecting wild rice, the Environmental Protection Agency is investigating U.S. Steel's taconite mine, Keetac, for repeatedly releasing a rice-killing pollutant into surface waters.

The mine and tailings site in Keewatin broke sulfate limits set in two wastewater permits 299 times between 2019 and 2022, the EPA alleged in a May notice that only recently was publicly revealed. The agency could eventually impose fines, but the notice of violation it sent to U.S. Steel is not a final decision.

Sulfate, a mineral salt, does not occur naturally in high levels in water in northeast Minnesota. It comes from multiple sources, such as sewage plants, some power stations and mines that process rock containing sulfide. In the mucky bottoms of lakes, it's been shown to smother the roots of growing wild rice plants, gradually snuffing out the plant that re-grows annually from fallen seeds.

U.S. Steel said in a statement that although it has tested several technologies, there is no workable way to stop the sulfate releases. Simultaneously, the company argues it's not violating any water-pollution rules because of changes in state law.

The EPA is accusing the company of breaking a standard that limits sulfate to 10 parts per million (ppm) in streams, rivers and lakes where rice has historically grown. The rule has been on the books in Minnesota for more than half a century, but not enforced until recently. In 2011, 2015 and 2016, lawmakers limited the rule or directed regulators to rewrite it.

"The permit states that the sulfate effluent limits in the interim are for monitoring purposes and are effective limits when U.S. Steel is notified by MPCA that limits are considered final. That has not occurred," Andrew Fulton, a spokesman for U.S. Steel, wrote in an email.

The Minnesota Pollution Control Agency noted in a 2017 inspection report that it could not enforce the standard on the company, according to documents obtained in a Freedom of Information Act request by the environmental group CURE.

But the state has started to enforce the sulfate rule in recent years because the EPA directed it to do so in 2022. That same year, the federal agency started looking closely at Keetac. Federal inspectors visited the mine in October 2022, the first time the EPA noted that the site was releasing more sulfate than the limits in its permits.

"MPCA had two totally contrary orders, one to follow federal law, and one from the Legislature to not follow federal law, and they got caught in that trap," said Hudson Kingston, the legal director of CURE. "Luckily, the EPA is not bound by state law."

The documents Kingston received from the case end in August. It's unclear what has happened in EPA's enforcement case since then.

EPA Region 5 spokeswoman Macy Pressley said the case was still active, but did not answer a list of detailed questions.

Seeking an exception

Separately, U.S. Steel is arguing in court that it should receive a legal exception to the rule it's accused of violating.

The company asked for a "site specific standard" for Hay Lake, the small body of water downstream of the facility in Keewatin, that would raise the sulfate limit there from 10 ppm to 79 ppm.

The standard is allowed in law, but the company has to prove the change won't harm the rice. In April, MPCA said U.S. Steel had not met that bar and denied the request. The company appealed.

In court, U.S. Steel has argued that EPA can't preempt laws passed in Minnesota that limited the rule.

There is evidence that rice in Hay Lake has suffered. The group WaterLegacy, arguing in court in support of MPCA's decision, peppered its brief with pictures of flattened rice beds and rotting stalks collected in field surveys by the Minnesota Department of Natural Resources.

Paula Maccabee, an attorney for WaterLegacy, said that if U.S. Steel were to prevail in its request for a different standard, it would effectively end EPA's enforcement case.

The MPCA is in the process of updating Keetac's permits now, said agency spokeswoman Becky Lentz. If the company prevails in court, a looser sulfate standard would also likely change those new permits.

A second company, Cleveland Cliffs, has also asked for a looser sulfate standard near its United Taconite mine in Eveleth. Lentz said the agency is not considering that request now, because it is not in the process of re-issuing Cliffs' water permit.

EPA likely to change under Trump

Kingston said that as President-elect Donald Trump enters office in January, EPA might be directed away from enforcement cases like the one at Keetac. Trump has repeatedly expressed support for mining in northeast Minnesota.

Additionally, Project 2025, the Heritage Foundation blueprint for a second Trump term, stresses that the EPA should "encourage compliance over enforcement" and eliminate its enforcement office.

Asked whether U.S. Steel has discussed the Keetac investigation with any elected officials or the incoming Trump administration, Fulton responded that "no discussions have occurred."

"We look forward to working constructively with EPA to strike a balance between the needs of the environment and the needs of industry," he added.

Not everyone is so concerned about the potential of EPA backing off the case, however. Maccabee said companies will still be accountable to state law, and lawsuits from the public.

"It's really important for people to realize there will be recourse and there are ways to protect the environment," Maccabee said.