High levels of sulfates released from Minnesota's mining industry are suspected of diminishing Minnesota's native wild rice beds. The state is reconsidering its current standard for sulfate in wild rice waters, but until recently it hasn't been enforcing the existing standard.
The issue is particularly important now, because a half-dozen companies are exploring for copper and nickel in northeastern Minnesota and could build mines to extract the minerals. The mines would likely release elevated levels of sulfate, a form of sulfur that comes off the rock when it's dug up and exposed to air.
The rivers and lakes of northeastern Minnesota used to be full of wild rice. The Ojibwe call it mahnomen, and it's not only a staple of their traditional diet; it's regarded as a special gift of the creator.
There are still wild rice beds in the region, but Ojibwe elders say they're not nearly as rich and plentiful as they used to be.
Grow the Future of Public Media
MPR News is supported by Members. Gifts from individuals power everything you find here. Make a gift of any amount today to become a Member!
A lot of factors have contributed to the decline -- changing water levels, clearing shorelines for beaches, acid rain. But in one area, attention is focused on pollution from iron mines.
Len Anderson is a retired science teacher who has paddled and harvested wild rice in the area for years. He points to research the DNR has done that shows a spike in sulfates in the St. Louis River as it winds its way south of the mines, collecting water from tributaries, like the Partridge River.
"Above the Partridge River, the river's choked with wild rice, and of course flocks of ducks that go with it. When you get to the Partridge River -- the end of wild rice," said Anderson. "That's when the first mining-impacted water hits the St. Louis River. It's the Partridge River."
Anderson says sulfate interferes with root development and the wild rice doesn't grow well. The sulfate comes from sulfide in rocks exposed to air during mining operations.
Existing taconite mines have been sending extra sulfate into the water for fifty years.
But now, half a dozen companies are exploring and planning to build a new kind of mine that's expected to produce much more sulfate. They've found copper and nickel in rock that contains more sulfide than most iron ore formations.
Minnesota has had a standard in place since the 1970s, to protect wild rice beds from sulfate pollution. But the Minnesota Pollution Control Agency only started trying to enforce the standard this year.
"Apparently they suddenly discovered their rule," said Mike Robertson, an environmental consultant with the Minnesota Chamber of Commerce.
Robertson says the MPCA only began enforcing the rule this year, when two mines applied for permits to expand. The permit work is moving ahead, but no one knows if the companies will be able to meet the standard of 10 parts-per-million of sulfate in water.
"The permits have quite lengthy timelines in them for compliance. That's one of the issues going forward -- to determine the technology, the cost, and the feasibility of meeting that standard," said Robertson.
With the volumes of waste rock and water from mining operations, there's no doubt it will be very expensive.
The Chamber argues the standard is arbitrary, and is not based on recent scientific research.
The group also says the rule was originally written to protect paddy-grown rice, not native wild rice, and should not be used as a standard in waters where wild rice grows.
Robertson also argues the rule could be applied to many types of facilities, including wastewater treatment systems, not just mines.
The PCA says until recently it had very little information about sulfates, and about which waters have wild rice growing in them. The agency says it made case-by-case permitting decisions.
The agency also says it was focusing on other concerns, such as excess nutrients, mercury, and other issues related to aquatic life and human health.
In an e-mail, MPCA spokesman Ralph Pribble says the agency has begun a review of the wild rice rule. He says over the next couple of years "we are looking to clarify the definition of water used for production of wild rice," and in the future the agency may update the numeric limit.
It's part of a periodic review of state water standards, which is required by the federal government.
Shannon Lotthammer, who is supervising the process at the MPCA, says the agency is hoping to get some answers from research going on now at the University of Minnesota Duluth.
"What we need is those toxicity studies, to show how different concentrations of sulfate affect wild rice health and viability and growth," said Lotthammer.
The PCA also wants to make a list of which bodies of water have wild rice growing in them and therefore need protection. But that could be a controversial process, since tribal groups say the mines and other sources of pollution have already wiped out so many of the stands that once sustained them.
Meetings Monday and Tuesday at MPCA offices all over the state will provide a chance for the public to learn more.