MINNEAPOLIS (CN) – Minnesota pollution regulators granted the final state permits Thursday for the operation of a contentious $1 billion copper-nickel mine and processing plant in the Superior National Forest.
The Minnesota Pollution Control Agency issued the final air and water quality permits for PolyMet Mining Corp.’s NorthMet project in the northeastern part of the state. The agency also issued a Clean Water Act Section 401 certification, which relates to wetland protections.
MPCA Commissioner John Linc Stine said in a statement that he is “confident the requirements in these permits will protect the environment and human health over the long term.”
“Issuing these permits comes after a years-long process that saw the most thorough environmental review any construction project has ever had in Minnesota,” he said.
The state permits bring PolyMet one step closer to building and operating an open-pit mine that is expected to yield about 1.2 billion pounds of copper, 170 million pounds of nickel, 6.2 million pounds of cobalt and 1.6 million troy ounces of precious metals over the course of 20 years, according to the company.
The only major hurdle left is securing a wetlands permit from the Army Corps of Engineers.
Jon Cherry, president and CEO of PolyMet, said that decision is expected soon.
“This represents the culmination of many years of hard work to allow the building of Minnesota’s first copper-nickel mine,” he said in a statement. “We look forward to the opportunity to responsibly develop the NorthMet mine and produce those metals that are critical for our society while creating value for our shareholders and the communities in which we operate.”
The controversial project has been a hot-button issue for environmental groups, including WaterLegacy, which sued the U.S. Department of Agriculture’s Forest Service in 2017 over its approval of a land-exchange deal for the development of the PolyMet mine.
The group opposed Minnesota’s issuance of the Clean Water Act certification, claiming it gives the Army Corps a “green light” to permit PolyMet to pollute waters and destroy wetlands by, for example, increasing mercury concentrations in water and fish.
WaterLegacy alleges the project would destroy or impair more than 1,000 acres of wetlands and result in significant appropriation of water from the St. Louis River headwaters.
However, MPCA Commissioner Stine says the permits have safeguards to assure they will fulfill their purpose.
The water permit requires the construction of advanced water treatment technology and the installation of a seepage capture system around the perimeter of an existing basin, as well as a monitoring system and annual performance evaluations.
The air permit includes specific emission limits, Stine said.
While Minnesota has one of the largest undeveloped copper and nickel deposits in the world, the state has a long history of mining iron. Seventy-five percent of the total U.S. iron ore production comes from Minnesota, according to the state’s Department of Natural Resources.