The Environmental Protection Agency defines illicit discharges in general as any discharge into a storm drain system that is not composed entirely of storm water. The exceptions include water from fire fighting activities, discharges from dechlorinated waterlines, fire hydrant flushing and discharges from facilities already under an NPDES (National Pollutant Discharge Elimination System) Permit.
Illicit discharges are a problem because unlike wastewater, which flows to a wastewater treatment plant, storm water generally flows to waterways without any additional treatment. Illicit discharges often include pathogens, nutrients, surfactants, and various toxic pollutants.
Examples of Illicit Discharges
- Motor vehicle fluid spills or illegal disposal into a storm drain
- Improper disposal of household or other hazardous materials, including paints and stains
- Vehicle wash water from loading areas in the vicinity of storm drain inlets
- Improper storage of oil, pesticides, dirt, or fertilizers
- Leaking dumpsters
- Improper pet waste disposal
- Erosion of dirt or landscaping materials being swept into a storm drain or water body (including from construction sites)
- Damaged sanitary sewer lines or sewer cross connections to storm water systems
- Septic system failure
- Examples of What You Might See That Result From Illicit Discharges
- Oily/greasy sheen in the stream water
- Foamy/soapy water in the waterway
- Muddied water from sediment and dirt
- Discoloration of water
- Overflowing manholes
To Report an Illicit Discharge
For emergency situations that include hazardous waste spills, spills of raw sewage, gasoline, or other hazardous materials, dial 911.