ST. PAUL—Minnesota would measure how much wild-rice-killing sulfide is in the water of specific wild-rice lakes and rivers when setting pollution regulations, and not just the sulfate that spurs sulfide production, under a proposal that could impact the state's mining industry.
On Aug. 21, the Minnesota Pollution Control Agency announced a new rule that will, if made final, apply to any industry that discharges sulfate pollution to waters that hold wild rice.
Instead of the current statewide sulfate limit for all wild-rice lakes and rivers of 10 parts per million, the state is now proposing to use a 120 parts per billion sulfide as the benchmark for wild rice to thrive.
Based on the chemical nature of each wild-rice water, namely how much iron and carbon it has, the PCA says it will develop a separate sulfate pollution discharge limit for each lake and river downstream of industries with sulfate discharge. The aim is to keep harmful sulfides below 120 parts per billion.
Scientists decades ago found that wild rice usually doesn't grow well in waters with high sulfate content. In recent years scientists, including John Pastor at the University of Minnesota Duluth, found that sulfates are converted to toxic sulfides in some waters and that it's actually the sulfides that inhibit wild rice.
But that conversion into sulfides can vary from lake to lake. Higher levels of iron in the sediment can lead to less sulfide — higher levels of organic carbon can lead to more sulfide.
"We believe the changes we're proposing are an innovative and precise approach to protecting wild rice," said John Linc Stine, PCA commissioner, in announcing the proposed rules. "The proposal also allows for flexibility in permitting for facilities that discharge to wild-rice waters."
Also Aug. 21, the PCA also released its list of 1,300 lakes and rivers considered officially wild-rice waters, and the only places the state regulation would apply. The lakes and rivers currently have wild rice or had it anytime since 1975. The PCA also unveiled a process to add or subtract lakes and rivers from that list in the future.
About 350 of those wild-rice waters are downstream of industries that discharge sulfate and the most likely to be affected by the changes.
The proposed changes could make it easier for some Iron Range mining operations to meet their water pollution discharge regulations, but it will depend on the chemical nature of the lake or river that they release pollution into.
"For some facilities that discharge sulfate, it could be that they don't have to make any changes in their discharge" because the waters they discharge into are not as sensitive to creating sulfides, said Shannon Lotthammer, who directs the environmental analysis and outcomes division at the PCA.
Facilities upstream of more sensitive wild-rice waters with high sulfides may be required to reduce their sulfate discharge, Lotthammer said.
The PCA published the proposed changes in the State Register Aug. 21. The proposed rule will be the subject of public hearings overseen by an administrative law judge held in October with public comments accepted into November.
The announcement comes after years of scientific review, political debate and court actions spurred by complaints from Minnesota's mining industry that the 10 parts per million sulfate limit was unnecessary and overly burdensome. The rule had been on the state's books since the 1970s but had rarely been enforced until environmental groups began challenging proposed water pollution permits for Iron Range taconite iron ore processing centers.
As efforts to enforce the sulfate limit increased, critics said it could stifle or even shut down some businesses. Some taconite and sewage plant discharges are much higher than 10 parts per million. In 2010, the Minnesota Chamber of Commerce, on behalf of five taconite plants, sued the state, saying the 10 parts per million sulfate standard was arbitrary and illegal. But the state court of appeals in 2012 upheld the current rule and kept it in place pending the latest PCA review.
Sulfates are ions or salts that can come from decaying plants and animals as well as some mineral deposits and industrial processes such as mine discharges; mine stockpiles and waste piles; tanneries; steel mills; pulp mills; sewage-treatment plants; and textile plants. When sulfate levels are high in the water around the roots of wild-rice plants, they can spur the production of hydrogen sulfide, which can starve the plant of nutrients. Wild rice generally suffers when sulfide levels hit 150-350 parts per billion. Those levels begin to occur when the surrounding water has sulfate starting at 4-16 parts per million.
The PCA proposal gained critics on both sides of the issue Monday.
Kelsey Johnson, president of the Iron Mining Association of Minnesota coalition of iron ore producers, said early estimates are that the new regulation "could have devastating economic implications for communities in Northeast Minnesota that discharge into wild rice waters — including municipal wastewater treatment facilities and the iron mines."
Johnson and other critics said Monday the PCA should have waited for an economic impact study on the new regulation before settling on a course of action.
Environmental groups say the state should simply enforce the current 10 parts per million rule on sulfate, which scientists agree would protect all waters and is more easily enforced.
"WaterLegacy is strongly opposed to the MPCA's proposal to eliminate Minnesota's existing 10 parts per million limit on sulfate pollution and replace it with an unenforceable and unprotective equation," said Paula Maccabee, attorney for the group. "Protection of wild rice requires that Minnesota regulators have the backbone to enforce existing water quality rules, rather than finding a way to circumvent or weaken the rules whenever a powerful industry objects to controlling its pollution."
Written comments on the plan will be accepted through Nov. 2 to minnesotaoah.granicusideas.com/discussions or mail to: Office of Administrative Hearings, P.O. Box 64620, St. Paul, MN 55164-0620 (Docket 80-90030-34519.)
Hearings are scheduled for Oct. 23 in St. Paul; Oct. 24 in Virginia; Oct. 25 in Bemidji; and Oct. 30 in Brainerd. For more information go to pca.state.mn.us/water/protecting-wild-rice-waters.