On November 13, 2012, the Minnesota Court of Appeals affirmed the MPCA’s Clean Water Act section 401 certification of the EPA’s proposed general National Pollutant Discharge Eliminations System (NPDES) permit for vessel ballast water discharges. In re 401 Water Quality Certification, No. A12–1661, slip op. (Minn. Ct. App. Nov. 13, 2012). Section 401 provides that EPA may not issue a permit allowing discharges of pollutants into navigable waters unless the states affected by the permit have certified that the permitted activity will comply with state water quality standards. The proposed ballast-water permit would allow shipping vessels in Lake Superior to discharge ballast water potentially containing non-native aquatic species.  Relators, environmental groups, first argued that MPCA applied an improper standard by certifying that there was a “reasonable assurance” that issuance of the permit would not cause violations of state water quality standards. This language, which is taken from EPA and MPCA regulations, is slightly different than section 401 itself, under which states must simply “assure” no violations of state water quality standards. The court sidestepped any issue regarding inconsistency between the statute and the rules by finding that MPCA’s certification satisfied both standards.  Relators also argued that MPCA erred by not imposing numeric water-quality limitations as part of its certification of the ballast-discharge permit, relying instead on narrative standards. However, the court deferred to MPCA’s determination that effective numeric WQBELs for non-native aquatic species are technologically infeasible and legally indefensible at this time.