Wild rice waters contaminated with sulfate from industrial pollution have never been included on Minnesota's long list of officially polluted waters that require fixing.

But they will be now — 30 of them across the state — thanks to federal regulators who stepped in to say the Minnesota Pollution Control Agency (MPCA) was breaking federal law by not listing them as impaired.

The U.S. Environmental Protection Agency (EPA) this week sent the MPCA a list of 30 wild rice waters that don't meet the state's water quality standard for sulfate and said it plans to add them to Minnesota's roster of impaired waters. It could add more in the future, the EPA said.

The historic move caps decades of bitter struggle in Minnesota over protecting the aquatic grass, which is Minnesota's state grain. The MPCA said its hands were tied by a state law that prevented it from adding the waters to the list.

To Minnesota's American Indian tribes, the move is long overdue because listing the waters is the critical first step for protecting the dwindling wild rice stands sacred to their cultures.

"We are elated by the EPA's recent decision and it is reason to celebrate for the protections of clean water and revitalization of manoomin," said April McCormick, secretary-treasurer of the Grand Portage Band of Lake Superior Chippewa, using the Ojibwe word for wild rice.

It took the united strength of Minnesota tribes to move the EPA to action, McCormick said, and decades of work. Some expressed frustration with that.

"It's unfortunate that tribal leaders and staff have to spend thousands of hours of time to get the MPCA to follow their own regulations and get EPA to enforce the requirements of the Clean Water Act," said Darrell G. Seki Sr., chairman of the Red Lake Nation. "I am hopeful that this action by EPA will lead the MPCA in a more appropriate direction going forward."

Shelley Buck, president of the Prairie Island Indian Tribal Council, called it "a good first step."

"It's pretty crazy that MPCA couldn't do it themselves," Buck said. "It's crazy that they still say they are not lawfully able to list these wild rice waters."

None of the 30 wild rice waters at issue appear to be on reservation land. However, in exchange for ceding vast land tracts throughout Minnesota, the tribes were promised hunting, fishing and gathering rights on these ceded lands, rights that have been affirmed by the U.S. Supreme Court, McCormick said. In many cases tribes serve as co-regulators and co-managers of these off-reservation waters, where they exercise their legal rights to harvest wild rice, she said.

For many of Minnesota's Indigenous families, wild rice is often a baby's first solid food. It is part of ceremonies and served at community meals, and the harvesting and processing of wild rice is a deep community tradition. For the Ojibwe, manoomin is part of their migration stories.

"It's sacred and it's a part of who we are," said McCormick.

Sulfate is a chemical salt that occurs naturally but is also discharged into the environment by industrial operations: mining companies, power plants and municipal wastewater treatment plants, for example. It turns into sulfide when it settles to the mucky bottom of lakes and rivers and damages the roots of wild rice plants that thrive in shallow water.

High concentrations also speed the conversion of mercury to methylmercury, the most toxic form of mercury, that builds up in fish and other wildlife and winds up in humans who eat them. Mercury is a neurotoxin than can cause brain damage in babies.

Minnesota is leading on the issue, as it is the only state with a sulfate standard for wild rice, according to the MPCA. The standard — 10 milligrams per liter — has been the source of great controversy.

Tribes in Minnesota and elsewhere have also set sulfate standards.

As expected, many of the waters the EPA plans to add are on the Iron Range, where key culprits have been taconite mines and power plants. U.S. Steel Corp.'s Minntac plant in Mountain Iron is the state's top discharger, along with Minnesota Power's Boswell and Laskin power plants, according to MPCA data.

But it's not just an Iron Range problem. About one-third of the EPA's list are waters scattered elsewhere.

A long stretch of the Clearwater River in northwest Minnesota is marked. So are parts of the Long Prairie River near Motley, the Middle Fork of the Crow River in Kandiyohi County north of Willmar, Trott Brook in Anoka County and Rice Lake near St. Cloud.

Two stretches of the Mississippi River are also included along Wabasha, Winona and Houston counties.

Katrina Kessler, the MPCA's assistant commissioner for water, said it's possible that some of the waters are just naturally high in sulfate and were not contaminated by industry and others with permits to discharge.

"We haven't dug into where these locations are in proximity to permit holders," she said.

The MPCA says it's sandwiched between state and federal law and will likely get sued no matter how it moves.

Kessler said the agency didn't list the polluted wild rice waters because the Legislature passed a law in 2015 saying it could not — and could not enforce the 10 milligram per liter standard until rule-making was done. Its hands were tied, the MPCA said.

The EPA stepped in.

In a March 26 letter it told the MPCA that the federal Clean Water Act requires the MPCA to list the wild rice waters. The state's existing list has about 5,700 waters impaired for different things, including mercury in fish tissue.

The EPA's proposal starts a 30-day public comment period that runs through May 31. If the EPA alters the recommendations, another comment period starts.

Typically, the MPCA would start determining the source of the pollution and how much needs to be reduced to meet standards — a process that can take years.

"I don't know if we have that luxury under the Clean Water Act," Kessler said.

Kessler said the MPCA probably will have to consider the sulfate standard earlier as the water permits that dischargers hold come up for their five-year reissuance.

There will be trouble until the conflict between state law and the federal Clean Water Act is resolved, she said.

"We are going to face a legal challenge if we don't implement the standard or we do implement the standard."

Jennifer Bjorhus • 612-673-4683