ELR Citation: 53 ELR 20122
No(s). A19-0112, A19-0118, A19-0124, A20-1271, A20-1380, and A20-1385 (Minn. Aug 2, 2023)

The Minnesota Supreme Court affirmed in part and reversed in part an appellate court ruling in a challenge to the Minnesota Pollution Control Agency's (MPCA's) decision to issue an NPDES permit for a proposed mine and processing plant to extract copper, nickel, and precious metals in northeastern Minnesota. Environmental groups and a tribal band argued the permitting process was procedurally improper, that the MPCA erred by issuing a permit that did not include water quality-based effluent limitations, and that the permit did not comply with a Minnesota rule addressing discharges to groundwater. The appellate court had concluded it was not necessary to determine whether the permitting process was unlawful or arbitrary or capricious because the procedures did not prejudice the substantive rights of the group or the band; deferred to the MPCA's application of federal and state law in concluding the permit adequately protected state and tribal water quality; and concluded the agency reasonably interpreted its groundwater rule and did not err in issuing the permit. The high court found "danger signals" suggesting that the agency did not take a "hard look" at whether the permit complied with the CWA and that it did not engage in reasoned decisionmaking in addressing concerns raised by EPA; it concluded the MPCA's issuance of the permit was arbitrary and capricious and remanded to the agency. It further concluded the groundwater rules prohibited pollution of groundwater in the "unsaturated zone" within a containment system, and remanded to the agency to consider whether a variance is available to allow the planned discharge to the unsaturated zone within the containment system.