Illicit Discharge Hotline

Illicit discharges are generally any discharges into a storm drain system that are not composed entirely of stormwater. Illicit discharges are a problem because, unlike wastewater which flows to a wastewater treatment plant, stormwater generally flows to waterways without any additional treatment. Illicit discharges often include pathogens, nutrients, and various toxic pollutants.

Illicit discharges enter the system through either direct connections (i.e. wastewater piping either mistakenly or deliberately connected to the storm drain) or indirect connections (i.e. infiltration into the MS4 from cracked sanitary systems, spills collected by drain outlets, or paint or used oil dumped directly into a drain). Pollutant levels from 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."

Sources of Illicit Discharges:

• Sanitary wastewater
• Effluent from septic tanks
• Improper oil disposal
• Radiator flushing disposal
• Laundry wastewaters
• Spills from roadway accidents
• Improper disposal of auto and Household toxics

Not all non-storm water discharges are considered illicit discharges. Examples of discharges not subject to enforcement actions include:

• Fire fighting activities and water line flushing
• Landscape irrigation and lawn watering
• Diverted stream flows
• Rising ground waters
• Uncontaminated ground water (infiltration or pumped)
• Discharges from potable water sources
• Foundation and footing drains
• Air conditioning condensation
• Water from crawl space pumps
• Individual residential car washing
• Flows from riparian habitats and wetlands
• Dechlorinated swimming pool discharges
• Street wash water.