The Minnesota Pollution Control Agency on Friday said it issued a new water pollution discharge permit for the U.S. Steel's massive Minntac taconite iron ore processing center in Mountain Iron, the first unexpired permit for the facility since 1992.

The permit will take effect Dec. 1 and sets long-range goals for U.S. Steel to meet to reduce pollutants - including sulfate - that are leaking out of the plant's 8,000-acre tailings basin and into nearby surface and groundwater.

The PCA says the new permit allows the plant to keep operating while setting firm deadlines for the facility to meet state and federal regulations already in the books.

Shannon Lotthammer, assistant PCA commissioner for water policy, said the agency is "confident that the technology exists for them to reach compliance. What specific technology they chose is up to them and what fits best for their process."

The last time a water pollutant discharge permit was issued for the facility was in in 1987, Lotthammer noted, and it's been up for re-issuance since 1992.

"It's been administratively extended since then," Lotthammer said, adding that the PCA was glad to be bringing the half-century old facility up to modern environmental standards, eventually.

"This facility was built really before there were modern environmental regulations,'' she noted.

Environmental groups have pushed for faster enforcement of existing laws, noting the PCA's own documents show Minntac operations have been violating sulfate and other standards since at least 2000.

In issuing the permit Friday PCA Commissioner John Linc Stine also issued a decision refusing a contested case hearing on the permit details and refusing to adopt a variance requested by U.,S. Steel for some pollution limits. Those decisions, and the permit itself, can still be appealed through the Minnesota Court of Appeals.

The new permit is good for five years but allows the company to take 10 years before meeting certain standards. The new permit's compliance schedule calls for Minntac to reduce sulfate within its tailings basin to 800 milligrams per liter within five years and to 357 milligrams per liter within 10 years in the expectation that groundwater below the basin and streams outside the basin will see a corresponding reduction. Past testing showed Minntac emitting sulfate levels as high as 1,320 milligrams per liter, with an average of 954 milligrams per liter.

The permit requires groundwater sulfate levels under the basin to drop to 250 mg/L, state drinking water standards, by the end of 2025.

The 12-square-mile tailings basin is the dammed-up holding pond for the wet slurry of mine waste leftover after taconite pellets are processed.

High levels of sulfate are known to spur sulfides, which are harmful to wild rice in many waters. But the state says human health is also a concern - levels of sulfate and dissolved solids are now above safe drinking water standards in groundwater under the Minntac tailings basin, the giant impoundment that receives all the taconite processing waste.

Minntac is the largest taconite iron ore mining and processing operation in the U.S. with production up to 16 million tons per year and 1,500 employees. The facility came online in 1967 and was expanded in 1974. The PCA said sulfate was a known issue at Minntac as early as 1987.

In a statement, U.S. Steel lauded the PCA for issuing the permit.

"U. S. Steel is pleased that MPCA acted to reissue the administratively extended Minntac Tailings Basin NPDES permit. We are currently reviewing the permit and evaluating the conditions," Spokeswoman Meghan Cox wrote in an email.

Paula Maccabee, attorney for the group Water Legacy, said the permit still won't force Mintac to bring down sulfate levels in nearby streams.

"Minntac tailings basin sulfate pollution has been decimating wild rice in nearby northern Minnesota lakes and streams for a quarter of a century. Today's permit for Minntac still doesn't limit sulfate pollution to protect wild rice and avoid increasing toxic mercury contamination of fish in waters directly impacted by tailings pollution,'' Maccabee said. "Minnesotans have long feared that state regulators lack the spine to stand up to the mining industry. What is new today is that the U.S. Environmental Protection Agency has completely abdicated its responsibility under the Clean Water Act to object to slipshod permits and protect Minnesota waters. Minnesota's clean water, our fish, our wild rice, our health and our quality of life depend on the EPA doing its job. Under this EPA Administration, it seems that the burglars are minding the store."

At one point there were two lawsuits filed on the expired permit, one by environmental groups demanding the PCA force Minntac to meet state and federal regulations, and one by U.S. Steel alleging PCA was stalling on issuing the permit.

In early 2017 the PCA filed a 33-page response to company's lawsuit, saying the company had regularly violated agreements with the state to reduce pollutants even as nearby waters showed ever-higher levels of problem substances. The state response blamed the Minntac operations and pollution seeping out of its tailings basin for pollution of nearby waters.

"Since the tailings basin was permitted, concentration of sulfate and other dissolved elements have increased in the groundwater around the tailings basin," the PCA said in the court document, also noting that the Dark River, Sandy River, Sandy Lake and Little Sandy Lake then exceeded some standards for sulfate, bicarbonate, hardness and total dissolved solids "because of polluted groundwater from the tailings basin is entering those surface waters."

Current state regulations require sulfate discharges be limited to just 10 milligrams per liter of water. Under criticism from the state's mining industry that the sulfate rule was too strict, the PCA in 2017 announced a new sulfate standard for wild rice with different rules for each waterway that holds wild rice, depending on the lake or river's chemistry. Those rules still are being hammered out as the state tries to define and list all wild rice waters and then measure the chemical nature of those waters.

Taconite industry supporters have argued for years that sulfate pollution is not impairing local waterways and that forcing taconite plants to further treat discharge would cost millions of dollars and would make Iron Range plants noncompetitive in an increasingly global iron and steel market.