Stream-friendly car wash information

Car washing is a pollution problem

Water that flows into storm drains goes to the closest body of water. When cars are washed in a parking lot or at home, wash water carries dirt, soap, heavy metals and oil down the nearest storm drain. This is a problem because soap and other pollutants are harmful to fish and the aquatic insects they eat. Soap contains surfactants which are chemicals designed to coat dirt and grime so they don’t stick to your car. In a stream surfactants and other pollutants coat fish gills and prevent fish and aquatic insects from getting the oxygen they need. Car wash water should not enter the storm drainage system.

Suds and dirt from your car end up in Puget Sound! Help keep our water clean and practice stream friendly car washing.

Prevent Pollution When Washing Your Car

The best place to wash your car is at a car wash. Commercial car washes have drains that are connected to the sewer system (which is separate from the storm drain system). Many commercial car washes also recycle their water. If you choose to wash your vehicle at home, the following simple tips help reduce pollution in local streams:

• Choose a non-toxic, phosphate-free car washing detergent. Avoid anything that has key words like “toxic, hazardous, corrosive, or flammable” on the warning label.
• Move your car to a gravel or grassy area where the soapy water can soak into the topsoil. Topsoil can act as a filter for soap and surfactants before water reaches a stream.
• Try using a waterless car washing product. The products are sprayed onto the car and coat the dirt particles. Then you can wipe the car with a soft cloth. The car is sparkling clean and the products will not scratch the paint!