The Minnesota Pollution Control Agency (MPCA) recently proposed new permit modifications for the 249 Minnesota municipalities covered under its municipal stormwater general permit.

One new modification would require municipalities to address chloride pollution from de-icing salt. Some municipalities would be required to do outreach to educate businesses and institutions in their municipalities on appropriate salt use.

Salt applied to roads, parking lots and sidewalks to melt ice runs off into storm drains and is contributing to increased chloride in bodies of water around the state, which, at sufficient levels, is toxic to fish as well as other aquatic life. 

Another proposed permit modification tightens up standards on properties being redeveloped. For instance, project proposers may be required to install stormwater treatment systems on sites where an acre or more of pavement is being replaced.

The municipal stormwater general permit requires cities, townships, counties, hospitals and other public entities that own or operate stormwater systems to develop stormwater pollution prevention programs and adopt practices that keep pollutants out of their storm sewer systems.

The MPCA is seeking input on the proposed permit, which is open for public comment until 4:30 p.m. Jan. 10, 2020. Find out more at