What is an Illicit Discharge?

Illicit discharge is any discharge into the storm sewer that is not comprised entirely of stormwater. Illicit discharges may be a result of industrial activity, deposits of oil on parking lots, excess lawn fertilizer and yard clippings, and a variety of other sources which pollute water with turbidity, excess nutrients, and bacteria. Illicit discharges can also be from failing septic systems or improperly connected sewer lines. Dumping liquids or refuse into storm drain inlets is also considered an illicit discharge and eliminating these discharges is an important step in protecting the City of Bismarck’s waterways.

The City of Bismarck Department of Public Works is developing an illicit discharge detection and elimination program (IDDE) which is mandated by the Municipal Separate Storm Sewer System (MS4) Permit. Under the MS4 permit, the City of Bismarck is required to adopt an illicit discharge prohibition ordinance, sample discharge from storm sewers, and map the storm sewer system.

Resources

View City of Bismarck Stormwater Management Ordinance

Illicit Discharge	Allowed Discharge
Septic tank effluent	Lawn-watering/irrigation
Improper oil disposal	Street washing/sweeping
Grass clippings/Leaves left in street	Water line flushing
Commercial car wash wastewater	Residential car washing
Sanitary wastewater	Any activity with NPDES permit

What can I do to prevent illicit discharges?

The best ways to keep illicit discharge from occurring is to follow good housekeeping practices. This includes recycling or properly disposing of waste, keeping waste receptacle lids secured on windy days, and cleaning up spills or litter immediately. It is also important to keep grass clipping and leaves off of the street and keep your neighborhood storm drains clean of debris and litter.