What is a Pollutant (Illicit Discharge)?

Pollutant Definition



The City of Des Moines Municipal Code (DMMC 11.20) defines a Pollutant or Illicit Discharge as “any direct or indirect non-storm water discharge to the municipal storm water system, surface waters, ground waters, or Puget Sound.” The City has separated these illicit discharges into three different types prohibited, conditional, and allowable. A full list of these illicit discharges can be found in the Municipal Code Section referenced above.

Some activities that may result in illicit discharges include:
  • Lawn watering with potable water
  • Dust control with potable water
  • Automobile and boat washing
  • Pavement and building washing
  • Swimming pool and hot tub maintenance
  • Auto repair and maintenance
  • Landscape maintenance (pesticides, herbicides, and fertilizers)

Resource Links


Report Spills and Other Water Quality Issues


Spills and other water quality issues can be reported to the Surface Water Management Department by calling 206-870-6869 during business hours, Monday-Friday, 8:00a.m. to 5:00p.m., or 206-878-3301 after hours, weekend, or holidays and/or the Washington Department of Ecology at 1-800-645-7911.

In order to protect water quality, the public is encouraged to report spills and improper disposal, including suspected illicit connections or discharges into the City’s municipal stormwater system or any body of water in Des Moines.