Our comments on Minnesota's 2022 Impaired Waters List

by Trevor Russell

Many wild rice waters in Minnesota have damaging amounts of sulfate, but not all of them are on the state's Impaired Water List. (Photo: Lorie Shaull, CC BY 2.0)

On January 7, FMR was one of eight environmental organizations (led by the Minnesota Center for Environmental Advocacy) that provided comments to the State of Minnesota on the state's 2022 Impaired Waters List.

This Impaired Waters List, which serves as Minnesota's comprehensive inventory of all waters that fail to meet state and federal standards, is prepared every two years for review and approval by the U.S. Environmental Protection Agency.

Our letter, which was prepared with input from a retired state water research scientist, focused on three key pollutants of concern and proposed actions:

1. Sulfate pollution to wild rice waters: Continue working with representatives of Tribal Nations and organizations concerned about water quality to identify additional sulfate-impaired waters to the Impaired Waters List.

2. "Forever chemicals": Ramp up state testing efforts to better identify sites contaminated with PFAS and continue to add polluted waters to the Impaired Waters List.

3. Nitrate: Implement long overdue nitrate standards for the protection of aquatic life in lakes and streams, and add waters that do not meet this standard to the Impaired Waters List.  

Read the full letter below.

RE: Minnesota Environmental Partnership's Comments on 2022 Impaired Waters List

Thank you for the opportunity to provide comments on Minnesota's 2022 Impaired Waters List (the "2022 List").

Minnesota Environmental Partnership ("MEP"), a statewide coalition of environmental and conservation non-profits, applauds the Minnesota Pollution Control Agency ("MPCA") for following the science and adding 305 impaired waters to the 2022 List. In particular, we are pleased to see the addition of wild rice waters impaired for sulfate and other waters impaired for PFOS. However, MEP believes MPCA has more work to do to protect Minnesota's waters, including (1) adding more wild rice waters impaired for sulfate, (2) adding more waters impaired for PFOS, and (3) establishing standards for nitrate in Class 2 waters, and adding waters that do not meet those standards to the list.

A. MPCA Must Add More Wild Rice Waters Impaired For Sulfate To The Impaired Waters List.

MEP strongly supports MPCA's decision to add three wild rice waters impaired for sulfate to the 2022 List, in addition to those added to the 2020 Impaired Waters List (the "2020 List") at the behest of the Environmental Protection Agency ("EPA"). Wild rice is critical to Minnesota, culturally, ecologically, and economically. It provides food and habitat for fish, waterfowl, and other wildlife; it cleans water of excess nitrogen and phosphorus; and it provides important economic benefits for communities where it is grown and harvested. (1) Most importantly, wild rice is a central part of the history and culture of local Tribal Nations, many of which retain rights to harvest natural wild rice on reservation and ceded lands.(2) For the Ojibwe people, wild rice (or manoomin) has special spiritual, cultural, and nutritional significance. (3) Wild rice also is deeply embedded in Dakota culture, as shown by its use in ceremonies, gifts, and traditions passed down for generations. (4)

But wild rice is under threat from many sources in Minnesota—particularly sulfate pollution. (5) Sulfate interacts with bacteria in the water to create sulfide, which is devastating to the growth of wild rice.(6) For decades, MPCA has failed to adequately respond to the growing danger sulfate pollution poses to wild rice waters. In 1973, recognizing the critical status of wild rice for the state, MPCA adopted a 10 mg/L water quality standard for sulfate in waters used for the production of wild rice, which was approved by the EPA pursuant to the Clean Water Act. (7) In the following decades, however, MPCA's enforcement of this standard has been virtually nonexistent due to opposition from mining interests and other industrial polluters. Finally, in 2021, EPA disapproved part of the 2020 List, asserting that MPCA must list 32 waters that fail to meet the sulfate standard to protect wild rice. (8) For the 2022 List, MPCA has included those waters and added three more.(9) While the addition of these waters is a laudable step, further work is required to protect Minnesota's wild rice waters.

MEP asks MPCA to continue working with representatives of Tribal Nations and organizations concerned about water quality to identify additional sulfate-impaired waters for inclusion on Minnesota's Impaired Waters List. The Joint Tribal Comments to the EPA on the additions to the 2020 List identify numerous other wild rice waters that are currently impaired for sulfate and others that are likely impaired but require further study. These waters should be evaluated for future inclusion on the Impaired Waters List. In addition, MPCA's rationale for the adding three particular waters to the 2022 List while declining to include other identified waters is unclear. MEP asks that MPCA clarify its reasoning, so that advocates understand how to focus their efforts and advocacy in the future to ensure Minnesota's wild rice waters are protected.

B. MPCA Must Continue To Identify Waters Impaired For PFOS And Add Them To The Impaired Waters List.

MEP also applauds MPCA's work in identifying additional surface waters impaired for PFOS. Listing these 15 waterbodies is a critical step towards protecting public health and highlighting the growing spread of these toxic chemicals throughout Minnesota. As MPCA and other state regulators discover more waterbodies impaired with PFOS—and other PFAS chemicals —the agencies must quickly act to alert the public with fish advisories and other information to prevent Minnesotans from ingesting these chemicals through fish tissue consumption.

Recent studies continue to underscore the health risks associated with consuming PFOS. In addition to a battery of health complications such as thyroid disease, (10) kidney cancer,(11) and more, (12) we now know that ingesting elevated levels of PFOS materially impacts learning and memory, (13) and heart development. (14) We also know that exposure to these chemicals is irreversible and ingesting even trace amounts of PFOS over time increases the concentration of the chemical in the body and elevates the risk of adverse health outcomes. Certain populations—pregnant mothers, newborns, and immigrant populations (15) - are especially at risk.

The acute toxicity of PFOS—and many other PFAS chemicals—is doubly frightening considering MPCA and other agencies lack essential information about how these chemicals enter the environment. According to conversations with the Minnesota Department of Health, testing surface and groundwater for PFOS remains a reactive assignment, limited to areas surrounding known contamination sites. But as explained throughout MPCA's Draft PFAS Monitoring Plan, (16) the agencies lack a fulsome understanding of how all PFAS enters the environment. Without a more robust understanding of this key information, our world of "known" contamination sites is incomplete. Testing for PFOS and other PFAS chemicals only at "known" contamination sites, therefore, fails to sufficiently inventory waters in Minnesota impaired for PFOS.

MPCA must ensure that surface water monitoring and the Fish Contaminant Monitoring Program include, at a minimum, PFOS as a regularly tested contaminant. As we continue to discover how widespread PFAS contamination is throughout Minnesota, MPCA must ramp up its testing efforts to better identify sites contaminated with PFOS and continue to add polluted waters to its Impaired Waters List.

C. MPCA Must Complete Numeric Standards For Nitrate To Protect Aquatic Life And Add Nitrate-Impaired Waters To The Impaired Waters List.  

While the Impaired Waters List includes waters impaired for nitrate that are designated for drinking water, it does not include any such waters that are designated for use by aquatic life—even as MPCA recognizes nitrate is toxic to the State's fish and other aquatic life. (17) MPCA should implement a nitrate standard for the protection of aquatic life in lakes and streams designated as Class 2 waters of the state and add waters that do not meet this standard to the Impaired Waters List.

Nitrate-nitrogen—which largely enters the water as runoff from agricultural fields (18) - can adversely affect freshwater invertebrates, fish, and amphibians, even at levels considered safe for drinking water. (19) The state's first effort to establish numeric standards for nitrate-nitrogen in surface waters (Class 2a & 2b) launched in earnest in 2010 at the behest of the Minnesota legislature. (20) The 2010 legislative directive referenced existing draft nitrate-nitrogen water quality standards to address aquatic life toxicity in Minnesota's waters. Those draft standards were based on the scientific references included in the MPCA's own draft technical support document. (21) The document outlined appropriate draft nitrate-nitrogen standards for Class 2 waters as follows:

"The draft acute value (maximum standard) calculated is 41 mg/L nitrate-N for a 1-day duration, and the draft chronic value is 4.9 mg/L nitrate-N for a 4-day duration. In addition, a draft chronic value of 3.1 mg/L nitrate-N (4-day duration) was determined for protection of class 2A surface waters." (22)

Given the breadth of research included in the 2010 references and the absence of any countervailing scientific conclusions in the interim, the ongoing absence of a nitrate-nitrogen standards for Class 2 waters represents a failure to apply science-based standards to our states waters as required under the Clean Water Act. We urge the MPCA to begin updating the 2010 technical support document and prepare to complete development of these long-overdue water quality standards.

Again, we thank you for the opportunity to comment on the 2022 list.


Minnesota Center for Environmental Advocacy

Clean Water Action Minnesota

CURE (Clean Up the River Environment)

Friends of the Mississippi River

Land Stewardship Project

League of Women Voters Upper Mississippi River Region

Minnesota Well Owners Organization

Minnesota Environmental Partnership

Howard Markus, Ph,D., P.E. [retired] MPCA Water Research Scientist



(1) Minn. Dep't of Nat. Res., Natural Wild Rice in Minnesota 1, 9-11 (2008), available at https://files.dnr.state.mn.us/fish_wildlife/wildlife/wildrice/natural-wi....
(2) Id. at 7, 17.
(3) Id. at 1, 7; Minn. Tribal Wild Rice Task Force, 2018 Tribal Wild Rice Task Force Report 12-13 (2018), available at https://mnchippewatribe.org/pdf/TWRTF.Report.2018.pdf.
(4) Minn. Tribal Wild Rice Task Force, supra note 3, at 12-13.
(5) Id. at 23-25.
(6) Id. at 23-27.
(7) Minn. R. 7050.0224, subp. 2.
(8 )Minn. Pollution Control Agency, Sulfate Impairments, https://www.pca.state.mn.us/water/sulfate-impairments (last visited Dec. 22, 2021).
(9) Id.
(10) Bevin E. Blake et al., Associations Between Longitudinal Serum Perfluoroalkyl Substance (PFAS) Levels and Measures of Thyroid Hormone, Kidney Function, and Body Mass Index in the Fernald Community Cohort, 242(A) Envtl. Pollution 894-904 (2018), available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6309414/.
(11) Environmental Pollutant, PFOA, Associated with Increased Risk of Kidney Cancer, National Cancer Institute, Division of Cancer Epidemiology & Genetics (Sept. 24, 2020), https://dceg.cancer.gov/news-events/news/2020/pfoa-kidney.
(12) Probable Link Evaluation for heart disease, C8 Sci. Panel (Oct. 29, 2012), http://www.c8sciencepanel.org/pdfs/Probable_Link_C8_Heart_Disease_29Oct2... Toxicological Profile for Perfluoroalkyls: Draft for Public Comment Chapter 2 at 5, U.S. Agency for Toxic Substances and Disease Registry (2009), available at https://www.atsdr.cdc.gov/toxprofiles/tp200-c2.pdf.
(13) Abdallah Mshaty et al., Neurotoxic Effects of Lactational Exposure to Perfluorooctane Sulfonate on Learning and Memory in Adult Male Mouse, 145 Food & Chem. Toxicology (2020), available at https://www.sciencedirect.com/science/article/abs/pii/S0278691520306001.
(14) Ren Zhou et al., Combined Effects of BPA and PFOS on Fetal Cardiac Development: In Vitro and In Vivo Experiments, 80 Envtl. Toxicology & Pharmacology (2020), available at https://www.sciencedirect.com/ science/article/pii/S1382668920301101.
(15) See Liza Gross, These Everyday Toxins May Be Hurting Pregnant Women and Their Babies, New York Times (Sept. 23, 2020), available at https://www.nytimes.com/2020/09/23/parenting/pregnancy/pfas-toxins-chemi... Daniel Endreson, Minimizing Methylmercury Exposure in the Hmong Community from Sport-Caught Fish Consumption in Minnesota, 12 (June 2, 2008), https://conservancy.umn.edu/bitstream/handle/11299/44311/ Endreson%20Daniel%20Plan%20B.pdf.This?sequence=1 (noting that Hmong culture includes eating fish).
(16) Minn. Pollution Control Agency, Draft PFAS Monitoring Plan (2020), https://www.pca.state.mn.us/sites/default/files/p-gen1-22b.pdf.
(17) Minn. Pollution Control Agency, Nitrogen, https://www.pca.state.mn.us/water/nitrogen (last visited Dec. 22, 2021).
(18) Id.
(19) Julio A. Camargo et al., Nitrate Toxicity to Aquatic Animals: a Review with New Data for Freshwater Invertebrates, Chemosphere (2005), available at https://pubmed.ncbi.nlm.nih.gov/15667845/
(20) Act of May 17, 2010, 2010 Minn. Laws, ch. 361, § 4, subd. 1.
(21) Aquatic Life Water Quality Standards, Technical Support Document for Nitrate, Minn. Pollution Control Agency, (2010), available at https://www.pca.state.mn.us/sites/default/files/wq-s6-13.pdf.
(22) Id. at 9.


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