Enhancing Minnesota’s water resources and wild rice are common goals shared between environmental advocates, community members, Minnesota tribal nations, legislative leaders and industry alike – but the issues are not simple. In fact, understanding the environmental and human influences that impact a natural resource like wild rice, and how to address them, is multifaceted and has led to diverging viewpoints among the various groups.

Natural Allies is concerned that the current sulfate water quality conversations fail to consider important environmental and human influences that potentially exert more control on the wild rice habitat than the current sulfate water quality standard. This maintains a regulatory approach in law that does not reflect current, best available and ongoing scientific research.

Our coalition is advocating for amending the existing water quality standard and investigating wild rice management programs that consider the physical, hydrological and biological factors that impact wild rice habitat.

  • Wild Rice Task Force

    In 2018, Governor Mark Dayton established Executive Orders 18-08 and 18-09, creating the Wild Rice Task Force. The Wild Rice Task Force was charged with preparing a report to the Governor identifying wild rice waters and addressing issues related to best management practices for restoration and enhancement of wild rice, water quality standards and funding for wild rice protection activities.

    The task force included representatives from Tribal Nations, industry, environmental advocacy groups, scientists, state government agencies and other stakeholders. The task force reviewed existing peer-reviewed scientific literature and other information to better understand the ecological and chemical impacts on healthy habitats for wild rice.

    Over the course of several meetings in 2018, the task force discussed topics like wild rice habitat preservation and restoration, sulfate treatment and the MPCA’s variance process. At the end of 2018, the Wild Rice Task Force’s recommendation was to create a stewardship council to look at a holistic approach to wild rice habitats.

  • Minnesota Legislature

    Wild Rice has always been an important grain in Minnesota. In the past 15 years, several key events at the Minnesota Legislature have influenced the regulatory status of wild rice.


    • The Minnesota Legislature passed a law requiring the Commissioner of Natural Resources to prepare a study for natural wild rice that includes location of natural stands, potential threats to natural stands and recommendation on projecting wild rice.



    • Minnesota Department of Natural Resources (DNR) completed Natural Wild Rice in Minnesota; A Wild Rice Study, which includes a list of wild rice waters.



    • The DNR’s interagency wild rice management workgroup begins to identify important wild rice waters.
    • As part of its triennial review, the MPCA recognized the need to further understand and clarify the sulfate standard.



    • The Minnesota Legislature provided funding to the MPCA to research the effects of sulfate and other substances on wild rice.
    • Wild Rice Advisory Committee began advising the MPCA on research and rulemaking.



    • The MPCA began research on the impacts of sulfate on wild rice.



    • The MPCA released Wild Rice Sulfate Standard Preliminary Analysis (March).
    • The MPCA drafted the Analysis of the Wild Rice Sulfate Standard Study for scientific peer review (June).
    • The MPCA received peer review feedback (September).
    • Fort et al. published findings.



    • The MPCA worked on the development of rule revisions for the sulfate water quality standard.
    • Tribal members only required to have Tribal ID to harvest/gather wild rice on ceded territory, no need of additional state permit (2016).



    • The MPCA underwent rulemaking process, proposing an equation-based standard and initial list of approximately 1,300 waters to be designated as wild rice waters.
    • MPCA withdrew the rule in 2018.
    • Governor Dayton issued Executive Order 18-08 establishing the Governor’s Task Force on Wild Rice.
    • Fond du Lac published notice of their revised water quality standards for public comment under their federal Clean Water Act authority. The Band proposed maintaining their 10mg/L sulfate standard and are adding protective narrative standards for wild rice waters (2018).
    • Ultimately, the MPCA rulemaking process was halted when two Administrative Law Judges ordered that the new equation was too vague and required significant changes in order to pass the “reasonable person” test. See the Judges’ rulings here and here. The Chief Administrative Law Judge requested that the legislature propose a new law or give better direction to the MPCA. As a result, the existing but outdated sulfate water quality standard of 10 mg/L remains on the books.
  • Wild Rice and Sulfate Overview

    Minnesota’s current sulfate standard of 10 parts per million (10mg/L) was enacted in the 1970s with the goal of protecting wild rice. Since then, the standard has been both challenged and defended. Today, we have emerging research that questions the validity of the science that created the original sulfate standard.

    In 1975, the administrative hearings on the discharge permit for the Minnesota Power Clay Boswell power generation plant near Cohasset, Minnesota focused on the potential application of the 10 mg/L sulfate standard. Dr. John Moyle recommended that a sulfate limit of 20 mg/L would be appropriate. Another expert testified that a standard of 200 mg/L was appropriate. The Minnesota Pollution Control Agency (MPCA) issued a permit with a variance applying the 20 mg/L suggested standard and later amended the permit to remove references to the discharge limit and the variance.

    In the late 1990s, the MPCA revised its water quality rules with a new provision to ensure “harvest and use of grains from this plant as a food source for wildlife and humans” and designated 24 water bodies as subject to that provision.

    In 2011, the Minnesota Legislature provided funding to the MPCA to research the effects of sulfate and other substances on wild rice and directed the MPCA, upon completion of the research, to address water quality standards for waters containing wild rice, designate waters to which a standard applies and define the times of year when the standards should apply. The law limited the MPCA’s authority to require that permittees expend funds for design and implementation of sulfate treatment technologies until the standard was updated.

    This body of research on sulfate and wild rice began in 2012, when the MPCA used legislatively appropriated funds to commission studies conducted by the University of Minnesota to understand the specific mechanism by which sulfate could impact wild rice. For more on this study, visit the MPCA’s Wild Rice Sulfate Standard Study webpage.

    The MPCA found that sulfate in and of itself does not impact wild rice. This finding was consistent with a study that was conducted by the environmental toxicology firm Fort Environmental Laboratories (Fort Labs). This study can be found here.

    Key Finding 
    The University of Minnesota and Fort Labs found that sulfate in the water does not have an impact on wild rice at levels of at least 5,000 mg/L.
  • Wild Rice and Sulfide Overview

    After determining that sulfate is not harmful to wild rice, the MPCA hypothesized that sulfate could impact wild rice seedlings if it turned into sulfide in low-oxygen conditions in the sediment where wild rice grows. The MPCA used this hypothesis as the basis for determining that the wild rice sulfate standard needed to be revised and proposed new rulemaking in fall 2017.   

    In the proposed rulemaking, the MPCA shifted its approach from regulating sulfate through a single numeric limit, and instead proposed an equation that accounted for specific conditions in each water body. The equation proposed by the MPCA determined how much sulfate can be in the water based on how easily it would turn into sulfide given the amount of iron and carbon present. The MPCA stated that more iron in the water reduces the amount of sulfate that turns into sulfide, while more carbon means more sulfide.

    While the MPCA expanded their approach to recognize site-specific factors and acknowledged that sulfate is not itself harmful to wild rice, the MPCA failed to consider many other natural factors at play. That is, sulfate may not be inhibiting wild rice growth. Instead, physical, hydrological and biological influences like water levels and the presence of other species may exert as much or more control on wild rice presence. In that case, enacting a sulfate standard may not improve wild rice growth.  

    Additionally, the proposed equation failed to consider important research conducted by Fort Labs which found that sulfide did not impact wild rice at much higher levels than predicted by the MPCA. However, Fort Labs agreed with the MPCA that iron had a mitigating effect on sulfide toxicity.

    Key Finding
    There are contradicting results from experiments conducted to determine the safe level of sulfide for wild rice:  
    Fort Labs protective level of sulfide
    John Pastor protective level of sulfide
    Key Finding
    Sulfate may not be the sole or dominating control on wild rice growth. Instead, physical, hydrological and biological factors like water levels and the presence of other species may exert as much or more control on wild rice presence.
    Key Finding
    Fort Labs’ work represents best available science because it attempted to replicate the study conducted by Pastor and concluded that the methodology used was flawed. Best available science requires the experiment to be replicated with similar results.
    Key Finding
    Public and independent research both show that iron has a mitigating effect on the toxicity of sulfide.

    Across the state, many wild rice water bodies have been thoroughly tested for sulfide levels. The graph below was included in the ALJ report and shows where sulfide may affect the ability of wild rice to grow. The graph suggests that the “no effect” endpoints represent quite a wide range, indicating that sulfide has no effect on wild rice water bodies. The various points depict instances in which wild rice is growing in lakes that have sulfate levels above the Proposed MPCA Protective Level offered in the wild rice sulfate rule.


    There are multiple lines of evidence demonstrating no effect levels of sulfide concentrations on wild rice significantly higher than the protective threshold the Minnesota Pollution Control Agency proposed in 2018.

    Sulfide Chart

  • Tribal Wild Rice Task Force

    The Tribal Wild Rice Task Force reviewed existing literature, including literature and information based on tradition, culture and science, that is available to inform readers of the impacts of sulfate and other sulfur compounds on habitat conditions on wild rice.