The Minnesota Pollution Control Agency (MPCA), on February 1, 2016, placed on public notice proposed amendments to Minnesota’s water quality standards governing nondegradation/antidegradation. The proposed rules would repeal Minnesota’s current “nondegradation” rules in Minn. R. 7050.0185 and 7050.0180 and replace them with a more extensive set of “antidegradation” rules designed to be consistent with federal antidegradation policy set forth in 40 C.F.R. § 131.12. Federal antidegradation policy requires states to adopt policies and implementation procedures to ensure that existing uses of waters will be maintained, that lowering of water quality in high quality waters will be allowed only in limited circumstances, and that certain outstanding water resources will be protected.

The Rainy River Headwaters Watershed (Source:

The Rainy River Headwaters Watershed (Source: Antidegradation is a key component of state water quality standards. It stems from the Clean Water Act’s goal to “restore and maintain the chemical, physical and biological integrity of the Nation’s waters.” 33 U.S.C. 1251(a).

Whereas Minnesota’s existing nondegradation rules apply to “new or expanded discharges” to waters of the state, the proposed requirements would be triggered upon the issuance of new, reissued, or modified individual NPDES wastewater, industrial stormwater and construction stormwater permits which are reasonably anticipated to result in net increases in loading or other causes of degradation to surface waters. The proposed rules remove a de minimis provision in the current rules that exempts discharges that are not “significant” from certain of the rule’s requirements. The proposed rules also include specific antidegradation procedures and standards relating to 401 certifications, particularly with regard to certification of section 404 permits. Notably, MPCA’s proposed rules do not include any substantial changes to nondegradation requirements set forth in chapter 7052 (Lake Superior Basin) or 7060 (groundwater). MPCA will hold public hearings on the proposed rules on March 31, 2016.