On March 26, the U.S. Environmental Protection Agency (EPA) made its approval decision on the 2020 303(d) impaired waters list released by the Minnesota Pollution Control Agency (MPCA). While the EPA approved the waters listed by the MPCA, it did not approve the decision to exclude water quality limited segments (WQLSs) for sulfate impairment. The MPCA had concluded that Minnesota state law bars the agency from assessing or listing waters against Minnesota’s federally approved standard for “waters used for production of wild rice during periods when the rice may be susceptible to damage by high sulfate levels.”
The EPA disapproved of Minnesota’s decision to not identify certain WQLSs for sulfate impairment because the existing and readily available data for those WQLSs indicate impairments for sulfate. According to the EPA, the decision to exclude these waters is inconsistent with Section 303(d) of the Clean Water Act and the implementing regulations.
The EPA’s next step will be to identify the specific WQLSs still requiring total maximum daily loads (TMDLs) to be included on the impaired waters list under Section 303(d). Future TMDLs may result in facilities discharging to the WQLSs being required to reduce their pollutant loading.
The EPA’s list will be published in a separate document within 30 days of the decision (around April 25). The EPA will then issue a notice for a 30-day public comment period and may make revisions based on any comments received before sending its final list of sulfate-impaired waters to the MPCA.
For more information about this issue and what it means for your facility, please contact Keith Hanson at 218-590-2790.