An illicit discharge is any discharge into the storm sewer system that is not composed entirely of stormwater (rainwater or snow melt), except for discharges allowed under a National Pollutant Discharge Elimination System (NPDES) permit*. An illicit discharge or connection may result from:

• An illegal dumping practice i.e., improper disposal of hazardous waste, motor oil, paint, etc.
   
• A direct connection from the wastewater sewer to the storm sewer.
   
• An indirect / improper runoff from the surface that washes into the storm sewer i.e., hosing down a sidewalk, parking lot, or other outdoor impervious surface.

Industrial facilities, businesses, and residents are the first line of defense in protecting storm drains and waterways. Use Best Management Practices (BMPs) to stop pollution. Anything you put in a storm drain ends up in a creek, river, or body of water – where you swim and fish. Prevent Illicit Discharges in four areas:

1. Waste Management 
    
2. Facility and Grounds
    
3. Fleet Maintenance
    
4. Spill Prevention and Cleanup

Many industrial activities contribute to stormwater pollution (such as vehicle/equipment maintenance, improper disposal of hazardous waste, metal grinding and polishing, and more) during daily operations. Waste, residues, and byproducts from these activities enter storm drains and flow into creeks and rivers, harming aquatic life and impacting water quality.

OLWS implements programs to reduce non-stormwater discharges into area creeks and streams. Programs include:

• Outreach to businesses and residents
• Stormwater monitoring and sampling
• Permitting, inspection, compliance, and regulation of water discharge activities for industrial users