Illicit Discharges

In Minnesota, our storm sewer systems carry water directly to our lakes, rivers, and wetlands. This water does not go to a treatment plant before entering our surface water. To maintain fishable, swimmable, and drinkable water and prevent pollution from entering our waterbodies, only stormwater should enter a storm sewer system.

Anything other than stormwater is an "illicit" discharge.

Illicit discharges enter stormwater through either direct connections (e.g., wastewater piping either mistakenly or deliberately connected to the storm drains) or indirect connections (e.g., infiltration into the MS4 from cracked sanitary systems, spills collected by drain outlets, or paint or used oil dumped directly into a drain). The result is untreated discharges that contribute high levels of pollutants, including heavy metals, toxics, oil and grease, solvents, nutrients, viruses, and bacteria to receiving waterbodies. Pollutant levels from these illicit discharges have been shown in EPA studies to be high enough to significantly degrade receiving water quality and threaten aquatic, wildlife, and human health. 


Both the Twin Cities (UMTC) and Duluth (UMD) campuses are designated as urban sites requiring a Municipal Stormwater permit. These permits require the University to identify and remove any illicit discharges from the stormwater system, and to prevent illicit discharges by education in the University community.

DEHS staff conduct staff training, and participate in public events to educate the University community about stormwater. View this Stormwater Video for an introduction to stormwater issues on campus.

Visit the Stormwater page for more information about University stormwater. Visit the Outreach and Current Projects page to see public participation opportunities.