Restoring Minnesota’s Impaired Waters
What are “impaired waters”?

What’s the current status of Minnesota’s impaired waters?
Political pressure from mining companies has been a significant obstacle to listing any wild rice waters as impaired as a result of excessive sulfate. MPCA has listed many mercury impaired waters, including some waters downstream of existing and proposed mines. The biggest challenge in relationship to mercury has been the MPCA’s failure to conduct a TMDL analysis to determine the pollutants contributing to elevated mercury in the water column and mercury contamination of fish.
Wild Rice Waters
WaterLegacy has repeatedly commented to MPCA and to EPA that MPCA must list waters that are impaired due to sulfate pollution that harms wild rice. This listing is critical to the process of analyzing and cleaning up these waters. MPCA’s failure to list wild rice impaired waters was one of many regulatory failures challenged in WaterLegacy’s petition to withdraw MPCA’s authority to issue Clean Water Act water pollution permits.
In 2011, the Minnesota Legislature passed a session law prohibiting the MPCA from listing wild rice impaired waters until rulemaking to change the sulfate standard was completed. The final deadline for completing rulemaking set by the Legislature was January 15, 2019. The rulemaking process was completed in 2018, and WaterLegacy and our allies successfully defended the wild rice sulfate standard.

Yet, as of summer 2020, MPCA has not listed a single wild rice water as impaired.
Mercury Impaired Waters
Embarrass River: Embarrass Lake to Esquagama Lake (mercury in fish)
Embarrass River: Esquagama Lake to St. Louis River (mercury in water, mercury in fish)
Partridge River: Headwaters to St. Louis River (mercury in water, mercury in fish)
Sabin Lake (mercury in water)
St. Louis River: Embarrass River to East Two River (mercury in water)
Wynne Lake (mercury in water)
St. Louis River Mercury TMDL
The St. Louis River is the largest United States tributary to Lake Superior. It runs through the Fond du Lac Reservation and the City of Duluth, and has a huge ecologically important estuary where it meets Lake Superior. The St. Louis River is affected by sulfate discharge from mining and impaired for mercury in water and in fish tissue along much of its length. MPCA data has shown that the level of mercury contamination in fish tissue in lower reaches of the St. Louis River is higher than it is in upstream waters.

In 2011, EPA provided Minnesota with $1 million to conduct a St. Louis River TMDL study. MPCA was a key agency for this process, which also included EPA, the Fond du Lac Band of Lake Superior Chippewa, and the state of Wisconsin. The TMDL study and the plan approved by all of the TMDL participants – including MPCA – explicitly included effects of sulfate loading to the river, as well as mercury discharge.
In early 2013, MPCA abruptly pulled out of the St. Louis River mercury TMDL, claiming that the model chosen by EPA was inadequate. WaterLegacy believes that MPCA’s claims about the model are a pretext, not only because MPCA staff had previously approved the TMDL work plan, but because the plan included a suite of models that could have been adjusted or elaborated to meet any scientific concerns. In addition, records secured by WaterLegacy indicate that MPCA derailed the St. Louis River mercury TMDL after a meeting with mining staff of the Minnesota Department of Natural Resources (DNR) to discuss how the TMDL could conflict with DNR studies being done in coordination with the mining industry.
Although MPCA has since gathered information on mercury and the effects of ditched and drained peatlands on the St. Louis River, investigation of the impacts of sulfate on mercury impairments is conspicuously absent from MPCA’s updated research list.
EPA has not provided new TMDL funds. However, in 2016, with support from community members engaged by WaterLegacy, EPA enacted a rule allowing tribes that already have “treatment as a state” under the Clean Water Act to set reservation water quality standards (like the Fond du Lac Band) to also seek authority to conduct their own TMDL studies.
MPCA left a million dollars of EPA funding on the table when it cancelled the St. Louis River mercury TMDL study. Since then, MPCA has failed to research what limits should be placed on sulfate to reduce mercury contamination of fish and has not set limits on sulfate pollution of the St. Louis River. These deficits reflect the conflict between human health and mining interests.
Comments Seeking Listing of Impaired Waters
Failure to Conduct St. Louis River Mercury TMDL
Oct. 19, 2006
April 9, 2010
Oct. 7, 2011
The accompanying plan states that DNR has $900,000 in research money, of which $400,000 is from Environmental and Iron Ore Research programs and $500,000 is directly from mining companies. The plan proposes that DNR, MPCA, and mining company experts will direct the research and that MPCA should obtain EPA funding to coordinate with this DNR/mining industry study.
Feb. 10, 2012
Jan. 7, 2013
Jan. 14, 2013
March 12, 2013
April 11, 2013
Alie Muneer, the Chicago EPA official leading the project, said Minnesota officials had never before expressed its concerns and that she was surprised and puzzled by the suddenness and “the magnitude” of the decision . . .
She also pointed out that mercury assessments have been successfully completed on rivers in other states — some with less information than would be used in the St. Louis River assessment. As designed, it “would have produced a scientifically defensible TMDL,” she said.