Stormwater pollution
What is stormwater runoff? How does stormwater become polluted? And what can be done to prevent it?
Stormwater runoff is developed from rain events and melting of ice and snow that then flows over surfaces such as grass, woods, crops, paved streets, parking lots, and building rooftops. The less pervious a surface is, the more runoff volume is generally created. As stormwater flows and makes it way to a storm sewer system or body of water, it collects pollutants like trash, oils, chemicals, debris, dirt, and sediment that can harm streams, rivers, lakes, and coastal waters. Communities, municipalities, businesses, and others can implement best management practices to prevent pollution by controlling it at its sources.
Here are some main ways to prevent pollutants from entering our water resources:
- Dispose of pesticides, fertilizers, and herbicides properly and limit use to prevent excess runoff.
- Wash your car on the grass to filter and prevent runoff into the storm sewer.
- Report any discharges from storm water outfalls during times of dry weather with a lingering odor or color.
- Pick up after pets and dispose of their waste properly. Storm water runoff can carry pet waste into streams.
- If materials have to be stored outdoors, use containers that do not rust or leak. Use proper containment.
The benefits of effective stormwater management can include flood control, protection of public health, preservation of wetlands and ecosystems, and improved quality of waterbodies.
NPDES Stormwater Program
The National Pollutant Discharge Elimination System (NPDES) stormwater program regulates stormwater discharges from three potential sources: municipal separate storm sewer systems (MS4s), construction activities, and industrial activities. This program is a mechanism designed to prevent stormwater runoff from washing harmful pollutants into local surface waters.
For municipalities, the NPDES stormwater program has established requirements that municipalities must meet to discharge stormwater from MS4s to surface waters. The regulations require that the management program address six strategies: Education and Outreach, Participation/Involvement, Illicit Discharge Detection And Elimination, Construction Site Runoff Control, Post-Construction Runoff Control, and Good Housekeeping. When implemented, these strategies are expected to result in water quality and environmental benefits.
Stormwater Outreach
Stormwater Management Program brochures and other educational material are available at this website.
Stormwater Documents
Stormwater Resources
For more information, check out the following links:
Or, read more about stormwater and how the community can help reduce pollutants entering rivers, lakes, and streams:
Disposal & Cleanup
Bellevue’s bi-annual Clean Up Days are held on the 2nd Saturday in May and October.
Household hazardous waste collection information can be found at http://underthesink.org or call 444-SINK (444-7465).
Recycling information for other items can be found at https://www.greenbellevue.org.
Illicit Discharge
An illicit discharge is any discharge that does not originate from stormwater, such as sanitary wastewater, effluent from septic tanks, car wash wastewaters, oil disposal, radiator flushing disposal, laundry wastewaters, and auto and household chemicals and toxics. Illicit discharges to the municipal storm sewer system are prohibited unless the illicit discharge is an approved source as defined in the City of Bellevue Municipal Code § 27.5-21. Illicit discharges are a concern since, unlike wastewater, which flows to a treatment plant, stormwater generally flows to waterways without any additional treatment. Illicit discharges can contain pathogens, surfactants, nutrients, and various other pollutants.
When a storm drain has measurable flow during dry weather containing pollutants and/or pathogens, submit a reporting form found in Report a Concern below.