Wild rice at center of sulfate debate
Soudan resident Bob Tammen says he canoed in the St. Louis River south of Aurora and saw wild rice growing, but when he went downstream, the iron levels increased in the water from the mines and the wild rice had died off.
Defying what some might expect a former taconite mine worker to say, Tammen urged officials at the Minnesota Pollution Control Agency hearing to "get science right."
"Let's restore the wild rice and bring it back to the St. Louis River," Tammen told listeners.
Tammen was one of about 75 people who showed up at Fond du Lac Tribal and Community College last Thursday evening for a hearing regarding the state's proposed changes to sulfate water quality standards and how that could affect the growth of wild rice, the official state grain of Minnesota.
The biggest concern of all involved is the amount of sulfide and sulfate that is safe for wild rice to continue to grow and flourish in our Minnesota lakes.
For example, sulphate is released when mining byproducts enter the water, but sulphate itself is not harmful to the plants. Bacteria in the soil breathes in the sulphate and breathes out sulfide, which in large amounts is believed to contribute to the demise of wild rice plants over time.
In August, the MPCA announced the rollout of the new wild rice sulfate standard, developed over several years after an old standard was deemed too vague and too difficult for industry to meet. A law in place since 1973 limited sulfate pollution in all Minnesota waters that hold wild rice to 10 parts per million. But the MPCA said that rule was too broad — not all water can handle the same amount of sulfate.
The new rules would instead study the water chemistry of each wild rice lake and river to determine what sulfate level they could handle and still grow wild rice. The new rule, if enacted, will limit sulfides to 120 parts per billion, and calculate a lake-specific sulfate concentration based upon the amount of iron and carbon in the sediments.
That sulfate concentration in the water column would be low enough to ensure that the sulfide in the sediments, where it is toxic to plants, does not exceed 120 parts per billion.
There are about 1,300 lakes and rivers listed so far on the statewide list of wild rice waters. About 350 of those waters — downstream of industries or cities that discharge sulfate — are the most likely to be affected by the changes.
Critics say the new rule could cause increased regulation for taconite iron ore processing operations and some municipal sewage treatment plants. If the new rules are applied and enforced, critics say it could cost millions of dollars for the mining companies to comply, spurring mine shutdowns and layoffs.
John Arbogast, president of Local 1938 United Steelworkers Union, said Thursday that wild rice seems to be flourishing. Addressing the audience at the hearing, Arbogast claimed if sulfide levels went up to 2,400 parts per million (ppm), wild rice would still be fine. He said the "destructive little rodents" (beavers) who build dams and cause flooding is the real problem, not mining.
Some residents came simply to learn about the issue.
Others, like Nancy Schuldt — water projects coordinator for the Fond du Lac Band's Environmental Program — have been involved with water issues for many years. Wild rice is hugely important to the culture and diet of the Fond du Lac Band of Lake Superior Chippewa.
Schuldt said she has been researching the effects of sulfate on wild rice for 20 years. She was also part of a pilot experiment that added iron to see if it would protect the root of the rice plant from sulfide.
The pilot experiment showed that sulfide doesn't kill the wild rice right away. However, Schuldt said, it kills the plants over time by not allowing the plants to absorb nutrients, resulting in lower numbers of seeds, as well as smaller seeds.
In a follow-up interview with the Pine Journal, Schuldt said that at one point, the MPCA's approach to the new wild rice standard was based on the theory that adding iron to water would neutralize the sulfide. However, ongoing research appears to prove that false. Instead, the iron combined with the sulfide to prevent the roots from taking up nutrients by coating the roots with a plaque, Schuldt said.
Schuldt said the Embarrass River and Sandy and Little Sandy lakes are examples of what happens when sulfate is allowed to go unchecked in bodies of wild rice waters.
"They have been decimated," Schuldt said.
Sophia LaFond-Hudson wrote a thesis for the University of Minnesota about the pilot experiment.
According to her thesis, "Iron (hydr)oxides are thought to protect macrophytes from toxic reduced species, such as sulfide, by providing an oxidized barrier around the roots. However, wild rice grown under high sulfate loading develops a black iron sulfide precipitate on the root surface, and produces fewer and lighter seeds, leading to a decreased population long term."
While Schuldt credits the MPCA for providing public hearings so residents can have input, she doesn't support the proposed change.
"I would like to see them keep and enforce the existing standard of 10 ppm of sulfide," Schuldt said. She would also like to see the list of protected wild rice waters expand to include the nearly 900 more that are recognized by the tribes and the DNR.
At the end of her five-minute speech Thursday, Schuldt responded to Arbogast's comment that up to 2400 ppm of sulfide would not affect wild rice.
"If sulfide levels were allowed to be 1600-2400 ppm, it would be like the stuff you drink before a colonoscopy," Schuldt said. "That's the reason why we have a drinking water standard of 250 ppm."