Public Works & Utilities

Illicit Discharge Detection and Elimination

What is an Illicit Discharge?

The City’s storm sewer system is designed to transport stormwater (rain and melting snow) to the nearest lake, stream, or wetland. Any waste or pollution that enters the storm sewer system will flow directly to the nearest waterbody without treatment and may cause serious environmental damage. Any discharge into a storm sewer system, ditch, river, stream, or waterbody that is not composed entirely of stormwater is called an illicit discharge.

Examples of Illicit Discharges

  • Fertilizer, grass, leaves, pesticides, pet/human waste.
  • Gas, oil, paints and cleaners.
  • Concrete washout and sediment from construction sites.
  • Restaurant cooking oil.
  • Carwash wastewater.
  • Laundry washwaters.
  • Industrial wastewaters.
  • Effluent from septic tanks.
  • Spills from roadways.
  • Sanitary wastewater illegally connected to the storm drain system.
  • Anything that is not rain or snow melt down the drain is a potential illicit discharge.

City of Duluth’s Role

The City of Duluth has an Ordinance in place prohibiting illicit discharges to the storm water system. The Ordinance can be found here: Chapter 43A – Illicit Discharges to the City Storm Sewer. The City is authorized to regulate, investigate and enforce illicit discharge entering the City’s storm drainage system by any user. City Public Works & Utilities crews inspect on a regular basis for illicit discharges and other issues.  

How You Can Help

  • Report any suspicious discharges. To report an illicit discharge please contact 218-730-4130 or submit online.
  • Clean up hazardous spills immediately.
  • Pick up litter and trash near storm drains. You can adopt a storm drain at
  • Clean up pet waste and dispose in trash.
  • Vegetate bare areas to reduce soil erosion.
  • Do not blow leaves, grass clippings and mulch into the street. Sweep them up if they do land there.
  • Recycle oil, antifreeze and batteries.
  • Bring household products, including paint, paint thinners, and solvents to a hazardous waste dump site. See the following link to the WLSSD Disposal Guide.

Report an Illicit Discharge

Prompt reporting of a suspected illicit discharge is encouraged and helps protect local water quality. To report an illicit discharge please contact 218-730-4130 or submit online