3M is asking the state to change fish consumption advisories and remove the designation of "impaired" for the Mississippi River.
The request is based on a water and fish tissue study 3M did over the summer. 3M Vice President Jean Sweeney said the study included almost 400 fish in the length of the river between the Ford and Hastings dams, and the results were confirmed by an independent lab.
"We've done a number of things to try to make sure that it is a good scientific study. It has a statistically significant number of samples," Sweeney said. "It is a very robust and comprehensive study."
3M found that levels of suspected carcinogen PFOS had declined. Two years ago, PFOS in freshwater drum triggered a Health Department advisory of no more than one fish per month. But now, 3M's data suggests they can be eaten once a week.
State officials say they will evaluate the study. Shannon Lotthammer, a manager for water assessment and environmental information section for the MPCA, said the agency is compiling a draft list of impaired waters to present to the federal government by April 1.
"I would expect that we'll still be reviewing the information, and it could the the case that additional data is needed as well," Lotthammer said. "But certainly that would be subject to public comment and we would consider those comments and then respond to them as part of this overall process."
The MPCA has received a lot of public comment on a water discharge permit currently under review.