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Sulfate level recommendations for wild rice waters to be issued

John Myers

This week the Minnesota Pollution Control Agency is expected to make its first recommendation on how much sulfate pollution is too much for wild rice.

The agency will announce whether the current sulfate limit for wild rice waters, 10 parts per million, is too high, too low or just right.

Beyond what the sulfate limit should be, PCA officials say they also will work toward an administrative rule change to better clarify exactly where the rule should be enforced — which lakes and rivers are official wild rice waters.

“This is going to be our preliminary recommendation based on the science we have so far; an announcement of where we are and where we plan on going with this,’’ said Shannon Lotthammer, director of the PCA’s environmental analysis division. “There will be room for change from this point on, but this is an effort to tell everyone where we are right now.”

Lotthammer said the recommendation will be preliminary until a scientific panel can review the field and laboratory data collected during the past two years on which the PCA is basing its decision. That could happen later this summer, she said, and an administrative rulemaking process could begin later this year.

The sulfate rule, if enforced, has huge implications for the state’s iron mining industry, with some taconite processing plants apparently releasing sulfate at levels above the current standard.

It could affect the state’s fledgling copper mining industry as well as wastewater treatment plants in areas where wild rice grows, or did grow in the past.

The proposed PolyMet copper mine, for example, can meet the existing sulfate standard, an environmental review concludes, but only by treating water that leaves the site for decades, possibly centuries to come.

The current sulfate rule was enacted in the 1970s based on work from the 1940s by a state biologist who found that wild rice didn’t grow in water with high sulfate levels.

But business interests say that standard is too strict and that it’s not based on sound science. They say that if the old rule is enforced it could force businesses to upgrade wastewater treatment with no proven environmental benefit.

“We’ve always said that wild rice must be protected, but that any rule be based on real science, not on hunches, before (the state) mandates millions of dollars of investment,’’ said Frank Ongaro, executive director of Mining Minnesota, the state’s copper mining trade group.

Environmental groups and tribal natural resource agencies counter that the current rule is based on an obvious impact and that sulfate pollution may be one reason many wild rice waters have seen wild rice crops greatly diminished in recent years. Long stretches of the St. Louis River, for example, are now void of the famous wild food source that’s considered a sacred gift by many Ojibwe people.

The PCA recommendation will be based on the results of two years of field and laboratory work. The data was collected by studying wild rice in outdoor tubs and indoor labs at the University of Minnesota Duluth and by University of Minnesota, Twin Cities, campus scientists studying wild rice in rivers and lakes statewide.

The $1.5 million effort appears to show that sulfate at certain levels does indeed affect wild rice, as suspected. But it’s not a direct, toxic effect, said John Pastor, the lead UMD scientist on the project. Only when the sulfate is converted to sulfide does it have an adverse impact on wild rice.

That conversion happens in the sediment as the plant tries to pick up nutrients, Pastor said, effectively starving the plant. Where sulfate wasn’t converted to sulfide, wild rice generally wasn’t damaged, he said.

The laboratory work corroborated the field work, Pastor noted, as well as the observations made in the 1940s.

But the research did not determine what, if any limit should be placed on sulfate pollution. That will be up to the PCA.

If the PCA decides the 10-part-per-million rule should be changed, it would begin a months-long rulemaking process that would include public input, testimony and hearings headed by an administrative law judge, all under the watchful eye of the federal Environmental Protection Agency.

Even if no change is recommended in the actual sulfate limit, Lotthammer said, the PCA definitely will move forward to better define what a wild rice water is, setting parameters to define lakes and rivers where the standard will apply. The PCA also will better define when the standard applies: all year or only during the growing season?

Sulfates are ions 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. Environment and tribal groups want to keep the old standard, saying higher sulfate standards could decimate wild rice beds and may cause other harmful environmental effects.

Minnesota lawmakers tried, on their own, to relax the state sulfate rule in 2011 in an effort to help industry. But the EPA said they could not change a law tied to the Clean Water Act without scientific backing. So the Legislature also approved money for what became the state’s largest study of wild rice.

The current standard of 10 parts per million was upheld in December 2012 by a state court of appeals ruling.