The Minnesota Pollution Control Agency has proposed to change the Class 3 and Class 4 water quality standards, which are intended to protect water used by industry, agriculture, livestock and wildlife.
The MPCA said the old standards were based on outdated science, without much evidence to support pollution limits. But water advocates fear the changed rules could lead to more salt pollutants in Minnesota’s lakes and rivers.
Melissa Lorentz, staff attorney at the Minnesota Center for Environmental Advocacy, one of the groups opposed to the changes, said they were “disappointed” with the EPA’s approval and were considering options, including a possible appeal.
“We are concerned because these regulations actually remove the standards that were in place to protect our waters from salt pollution,” Lorentz said. “And it’s pretty unusual under the Clean Water Act to remove the standards that are in place.”
Under the Federal Clean Water Act, the state sets standards based on how the water in that lake, stream, or river can be used, for example, for drinking, fishing, and swimming, or to support aquatic life.
A body of water can have more than one of these beneficial uses. Most of Minnesota’s lakes and rivers are protected for aquatic life, industrial and agricultural use.
State regulators use the standards to determine how much of a particular pollutant a lake or river can handle when they issue permits to anyone who discharges a large amount of wastewater into that body of water, such as industries, mines or sewage treatment plants.
The changes to the MPCA, which had been underway for nearly a decade, removed some numerical limits on certain pollutants, including those affecting salinity, and replaced them with narrative statements describing what the quality of the water should be. ‘water.
When proposing the changes, state regulators said there was not much scientific evidence to support some of the existing numerical limits.
“What we were really trying to do was build in some flexibility to look at specific conditions in Minnesota and make sure we had water quality standards that really suited the conditions we have in Minnesota.” Catherine Neuschler, who manages the MPCA’s water assessment work, said in March.
But water advocates argue that narrative standards will be more difficult to enforce. They are particularly concerned that the changes could lead to more chloride, bicarbonates and other salts being released into lakes and rivers, where they can harm aquatic life.
“Research shows that our lakes are getting saltier in Minnesota and the impacts of this pollution are really long term. Lorentz said. “So this is something we have to stop before it starts. It is not something that we can cleanse from our water.
Several tribal nations in Minnesota have also opposed the changes, arguing they will result in degraded water quality in lakes and rivers that are home to fish and wild rice.
The EPA issued a letter Oct. 8 approving the amended rules, saying it has determined they meet the requirements of the Clean Water Act and will protect aquatic life.