Three environmental groups that sued the state of Minnesota for allowing U.S. Steel's Minntac taconite plant to operate a waste pit with a long-expired pollution permit are now dropping the lawsuit.

The Minnesota Pollution Control Agency (MPCA) released a new draft permit last month, with stricter controls for Minntac's giant waste pit at Mountain Iron — a step that met the suit's primary goal, said Hudson Kingston, a lawyer with the Minnesota Center for Environmental Advocacy (MCEA). Kingston's group filed the lawsuit on behalf of itself, the Save Lake Superior Association and Save Our Sky Blue Waters.

The dismissal, filed in Ramsey County District Court Tuesday, includes a stipulation requiring state regulators to complete the new permit within nine months and meet all standards set forth in the federal Clean Water Act.

The agency must also include the environmental groups in any mediation it enters with Pittsburgh-based U.S. Steel regarding the permit.

If the conditions aren't met, the groups have the right to restart the lawsuit, said Kingston, whose group has also monitored state regulation for a new wave of mining operations that would produce copper on Minnesota's Iron Range.

"This lawsuit shined a light on the fact that PCA has failed to regulate the mining industry in Minnesota," Kingston said. "Until PCA can issue legal permits for the mines we have, it should not be attempting to issue permits for new mining that is proposed in our state."

MPCA spokesman Dave Verhasselt said his agency rejects that notion.

"The ... Minntac draft permit is one example of ongoing work," Verhasselt said. "We share the same interests in protecting water quality as MCEA. We may not agree on the best strategies to accomplish that protection."

At least 15 taconite operations operate in Minnesota with expired permits that haven't been updated to comply with tougher standards for protecting water, wildlife and wild rice. But none has gone as long as Minntac, whose permit expired in 1992. The water permits are normally issued every five years.

The state agency first released the draft of the new Minntac permit in November, less than a week after the environmental groups filed suit. Kingston said the "timing speaks for itself."

MPCA Assistant Commissioner Rebecca Flood said Wednesday that the draft permit was well underway before the legal action. "The timing of it is entirely coincidental," she said.

Flood said permitting for very large facilities is complex, but she agreed that 24 years "is a long time for a permit to be expired."

The new permit will regulate the concentration of sulfates and other pollutants in Minntac's tailings pool.

The public has until Dec. 16 to comment on the draft permit: www.pca.state.mn.us/sites/default/files/Draft%20Permit%20-%20MN0057207%20-%202016.pdf

Trout stream threatened

According to the lawsuit, Minntac's 10-mile long tailings basin has been fouling nearby lakes and streams for years, leaking water tainted with at least five pollutants including sulfates and salts. The basin threatens a trout stream called Dark River, destroyed wild rice stands in Little Sandy Lake and Sandy Lake, and left nearby groundwater unsafe for drinking.

The concentration of sulfates in the waste pit is higher than at any of the other taconite tailings basins on the Iron Range, Flood acknowledged.

Erik Smith, an MPCA hydrologist, said the permit's main focus is limiting sulfate concentrations in the basin's water to new, lower standards. It also requires the company to notify the agency when it complies with standards for the other pollutants, he said. The permitting program is based on self-monitoring.

Smith said that because the permit is in a public comment period, he couldn't address the allegations in the lawsuit. A U.S. Steel spokeswoman also declined to comment on the lawsuit being dropped, saying U.S. Steel wasn't a party to it.

"U.S. Steel is reviewing the permit, like other interested stakeholders, and any comments we have on it will be submitted in accordance with MPCA's guidelines and deadlines," U.S. Steel spokeswoman Erin DiPietro said.