Experts Review State's efforts on Wild Rice and Sulfates

Stephanie Hemphill, reporting for MinnPost:

Eli Sagor, Flickr

Eli Sagor, Flickr

For two days, the experts picked through three years’ worth of data from Minnesota Pollution Control Agency’s lab and field studies, dispensing both praise and criticism for the agency.

The reason for the MPCA studies: The Minnesota Chamber of Commerce, representing mining and other industries, is challenging the state’s current limit of 10 milligrams per liter of sulfate in wild rice waters. Wastewater flowing from taconite mines and wastewater treatment plants boosts the level of sulfate in some rivers and lakes far higher than the limit, especially in northeastern Minnesota, and the Legislature has charged the Minnesota Pollution Control Agency with figuring out whether the standard needs to be changed.

MPCA’s efforts included laboratory experiments and field surveys, all of which the agency presented to the independent scientists for review, a standard practice in scientific endeavors....

Shannon Lotthammer, the MPCA staffer in charge of shepherding the process, said she was pleased with the guidance from the reviewers. Agency staffers knew the analysis was not complete, but wanted to get input from the independent scientists before they got further along in the process. A recommendation on whether the standard should be changed is expected by the end of the year.

In a dark place we find ourselves related to mining, and a little more knowledge lights our way. Difficult to see the long-term consequences of our exploitation of minerals. Always in motion is the future.

MPCA issues early analysis of study on sulfates and wild rice

Stephanie Hemphill, reporting for MinnPost:

Minnesota’s current standard to protect the iconic grain is ten milligrams of sulfate per liter. But industry has attacked that standard as unscientific. Mines, wastewater treatment plants, and other industries dispose of sulfate in rivers, and native groups have long complained the stands they rely on have been declining.

The research shows that bacteria convert sulfate into sulfide in the sediments in which wild rice typically grows. Researchers found strong correlations between the amount of sulfide in the porewater (water that flows in and around the sediments) and the amount of sulfate in surface water.

The agency concluded that the range at which sulfide limits the plants’ ability to grow corresponds to a range of sulfate in the surface water of 4 to 16 milligrams per liter – neatly bracketing the current standard.