Illicit Discharge Detection and Elimination

The City of St. Helens’ Illicit Discharge Detection and Elimination (IDDE) Program is a key component of the City’s Department of Environmental Quality (DEQ)-mandated Mercury Total Maximum Daily Load (TMDL) Implementation Plan. Its purpose is to identify, eliminate, and prevent pollutants from entering the storm drain system—which ultimately flows into our local waterways.

The IDDE Program protects both public health and water quality by addressing illicit discharges—any flow into the stormwater system that isn't composed entirely of stormwater. These discharges can include anything from motor oil and household chemicals to wastewater from illegal connections.

Program efforts include:

• Mapping the storm sewer system
• Inspecting storm drain inlets
• Educating the public and City staff
• Enforcing regulations to stop discharges from businesses, construction sites, and illegal connections (e.g., cross-connected sanitary sewers)

What is Stormwater? 

Stormwater is rainwater that flows over rooftops, streets, driveways, and yards, eventually entering storm drains, gutters, ditches, and pipes. In St. Helens, stormwater flows through a separate system from our sanitary sewer (wastewater) system.

Unlike wastewater, stormwater does not receive treatment before entering local creeks, rivers, and bays. Because we rely on these waterways for recreation, natural beauty, and ecological health, it’s vital to keep stormwater clean.

Why Is It Important to Prevent Pollution in Stormwater?

It is important to keep pollutants and toxic chemicals out of stormwater because stormwater flows through the City’s stormwater conveyance system, which consists of a network of more than 2,600 structures and 50 miles of storm drains, culverts, and ditches which flows directly into our rivers and streams. 

Even small amounts of pollutants like:

• Fertilizers and pesticides
• Motor oil and antifreeze
• Paint or cleaning chemicals
• Pet waste

can harm aquatic life and degrade water quality. These harmful substances can enter the stormwater system through illicit discharges as unauthorized or accidental flows which carry pollutants directly into our waters.

More Examples of illicit discharges include:

• Improper Waste Oil Disposal / Auto Fluids Flushing
• Laundry Wastewater / Detergent
• Home Improvement Waste (e.g. concrete, paint)
• Pesticides and Fertilizers
• Improper Disposal of Commercial and Industrial Hazardous Waste
• Cooking Grease / Household Waste
• Spills on roadways and other accidents

How You Can Help

Everyone has a role to play in protecting our water resources. If you see suspicious discharges—such as unusual smells, oily sheens, or colored water flowing into storm drains—please report it. By staying informed and taking action, we can all help preserve the health of our waterways for future generations.

Spills can happen, but intentional dumping is illegal (Municipal Code Section 13.20.070 through Section 13.20.110) and harmful to our streams and rivers. If you see activities that threaten the health of the local waterways, report it to the City of St. Helens via our Pollution Prevention email, online Pollution Prevention Incident form, or in person at City Hall. City staff understands the need for confidentiality, so reports can be anonymous. If possible, collect as much information as you can about the spill/incident, including date and time, a description of what you observed, including the approximate quantity dumped, and a few photos, this will help City staff identify the problem and determine the most appropriate plan of action.

Most Common Illicit Discharges,

• Motor oil, antifreeze, gas, etc. entering or being poured into or allowed to drain into a storm drain
• Water coming from outfalls that looks oily, frothy, or discolored
• Off-colored discharge, stains, or unusual odors in gutters and storm drains
• Sediment from an unknown source entering a waterway
• Spills on roadways and other accidents
• Untreated sewage or illegal RV waste dumping

You Can Help

• Don’t dump or wash anything down storm drain inlets that you don’t want in your drinking water. That means no paint, leftover automotive fluids, pressure-washing runoff, concrete wash out water, cleanout from RV waste systems, used cooking grease, water from hot tubs, or trash like leftover medications, cigarette butts, and coffee cups.
• Use pesticides and fertilizers sparingly and dispose of excess safely. 
• Wash your car on the grass or at a car wash
• Don’t sweep leaves and yard waste into storm drains

Report Spills, Illegal Dumping, or Illicit Discharges

If you see a suspicious spill, illegal dumping of chemicals or other substances, or notice an illicit discharge occurring, Click on the Button Below to Report it and a City of St. Helens staff member will investigate the report after it is received.