MPCA issues PolyMet air and water permits

Contact: Dave Verhasselt, 651-757-2278

The Minnesota Pollution Control Agency (MPCA) today issued the final air and water permits for PolyMet’s proposed NorthMet project in northeastern Minnesota.

“Issuing these permits comes after a years-long process that saw the most thorough environmental review any construction project has ever had in Minnesota,” MPCA Commissioner John Linc Stine said. “We are confident the requirements in these permits will protect the environment and human health over the long term.”

The MPCA developed draft permits and released them for public comment on Jan. 31, 2018. During the time the draft permits were open for public comments (through Mar. 16, 2018), the MPCA received more than 700 comments. After carefully evaluating the comments and revising the permits based on those comments, the revised draft permits were sent to the U.S. Environmental Protection Agency, which has federal oversight on the air and water permits. The EPA had no comments during the period allotted, and MPCA Commissioner John Linc Stine signed the final permits effective Dec. 20, 2018.

The permits MPCA issued include the combined federal/state permits for water discharge and air emissions. The water permit is the key mechanism for protecting water quality. The agency also issued the Clean Water Act Section 401 certification, which focuses on wetland protections.

Stine said the permits contain numerous safeguards to assure they will fulfill their purpose. For example, the water permit requires the construction of advanced water treatment technology to meet permit limits, the installation of a seepage capture system around the perimeter of the existing tailings basin, and a robust monitoring system and annual performance evaluations. The air permit includes specific emission limits — addressing both ore processing and transport from the mine site to the processing plant — and rigorous daily, weekly, and monthly monitoring and recordkeeping requirements.

The permits can be found on the agency's PolyMet’s NorthMet mining project webpage.