The Minnesota Pollution Agency’s plan to release its recommendation for a scientific standard to protect wild rice from sulfates has been delayed. The agency was set to announce a preliminary findings today, but cancelled the plan abruptly.
In an email to reporters, MPCA Communications Director Dave Verhasselt wrote, “We thought we would be ready to release preliminary findings on the wild rice sulfate standard on Thursday, but we are not.” Verhasselt said the agency will provide updates as possible in the weeks ahead.
Sulfate is a key pollutant in discharges from mines and wastewater treatment facilities, and can cause stands of wild rice to die. While the state has had a legal standard for sulfate discharges into wild rice waters for decades, it only recently started to enforce the regulation. The enforcement move was followed by a lawsuit by the Minnesota Chamber of Commerce and efforts at the legislature to change the standard. Ultimately, the MPCA was directed to determine if the standard should be changed, and to conduct three years of research to inform the recommendation.
Before the MPCA cancelled its announcement, the Star Tribune reported that the results were pointing to a strict standard, “If scientific findings are the guide, which has been the one unifying principal among all the opposing interests, then hundreds of mines, wastewater treatment plants and other facilities may have to come up with new and expensive ways to reduce a pollutant that was long regarded as fairly benign.”
In a recent story in MinnPost, one of the lead researchers suggested the studies were not indicating the standard should be weakened, “We found there really is no threshold at which sulfide becomes toxic,” John Pastor, a biologist at the University of Minnesota Duluth, said. “As soon as you add any, you get a decline in growth rate.”
Another scientist contributing to the study said research into seasonal differences in wild rice’s susceptibility to sulfate damage does not suggest it’s safe to discharge waste in the winter, as some have suggested. Nathan Johnson, told MinnPost that sulfate in sediment converted to harmful sulfides even in winter.
The Minnesota Chamber of Commerce is reportedly contesting the findings of the research. Minnesota Public Radio News reports that it received an analysis from the Chamber suggesting that the studies actually show that no sulfate standard is needed, but, “if the MPCA determines one is needed, the Chamber said a standard of 1,600 milligrams/liter should be adopted for waters that produce wild rice.”