Minnesota's planning to overhaul the water pollution rules it uses to protect the lakes and rivers where wild rice grows.
The proposal announced Monday by the Minnesota Pollution Control Agency (MPCA) after years of research would basically change the protections from apples to oranges. So it's hard to make a direct comparison between today's pollution standard and the one being proposed.
The new plan is opposed by some environmental groups, who say it would allow more pollution than the current rule.
But business groups have been saying for years the existing rule is way too strict and could put some of the state's taconite mines out of business if it were enforced.
A comment period on the MPCA's new plan is now open and public hearings are set around the state for October and early November.
Today's rule is rarely enforced
Wild rice is a plant with spiritual importance to Minnesota's American Indian tribes, whose rights to harvest it are protected by treaties. The plants are also a food source for birds, fish, and people.
Scientists figured out decades ago that rice won't grow in lakes or rivers with a lot of sulfate. So in 1973 Minnesota set a sulfate pollution standard – saying no project dumping more than a certain amount of sulfate into wild rice waters would get a permit.
That certain amount (10 milligrams per liter) was pretty low. As the Duluth News Tribune notes, it was rarely enforced over the years but lately clean water advocates have argued the standard should be used to deny permits to mines.
The Minnesota Chamber of Commerce worried the pollution rule would be used not just to block new mining projects, but to shut down existing taconite mines that don't meet the standard. They filed a lawsuit, claiming the wild rice pollution standard on the books is arbitrary and illegal. The courts did not agree but by the time an appeals ruling came out the state was already working on a new rule.
Finally, after about six years of research and debate, the new standard was proposed Monday.
What's so different about it?
One of the things the years of research clarified is that sulfate – which is released by mines, sewage treatment plants, and other industries – doesn't actually kill wild rice plants.
The research (read about it here) found that sulfates can generate sulfide and that's what's toxic to wild rice. So the new standard measures sulfide instead of sulfates. But there's more.
Each river and lake has its own chemistry, which determines how much sulfide gets generated. So the MPCA wants to measure pollution on a lake-by-lake and river-by-river basis.
The agency has set up a formula scientists can plug in to each of the state's 1,300 wild rice waters to determine how much sulfate that particular water can tolerate before it gets too polluted for rice to flourish.
The group WaterLegacy has already launched a petition drive in hopes of stopping the MPCA's proposal. They're critical of the new formula and want the state to stick with the existing pollution standard.