What’s the problem with car washing?

When you're washing your car in your driveway, you're not just washing your car in your driveway.
There's no problem with washing your car. It's just how and where you do it. Most soap contains phosphates and other Washington Waters Ours to Protectchemicals that harm fish and pollute the lake where families swim and play.

If you live in the city and you wash your car in the driveway, the soap, together with the dirt and oil washed from your car, flows into nearby storm drains that run directly into the lake. The phosphates from the soap can cause excess algae to grow. Algae look bad, smell bad, and harm water quality. As algae decay, the process uses up oxygen in the water that fish need.

Car washing doesn't have to be a problem. What will you do to help?

At home:

  • Use a commercial car wash, either self-serve or machine wash.
  • Wash on lawns or other surfaces where water can seep into the ground.
  • Divert water away from the storm drain.

Get more info! (PDF)

Charity car washes:

  • Sell commercial car wash coupons instead.
  • Locate the wash to divert wash water into vegetated areas, not the storm drain.
  • Rent a 'Bay for a Day' at a self-serve car wash that is hooked up to sanitary sewer.
  • Contact the Stormwater Department to see if your location drains to the lake.

Don't feed soap to the storm drain. Wash your car right. Keep your waters clean.

Car in Car Wash


Soapy water is caught in commercial system and piped to municipal sewer treatment system.

Soapy water


Soapy runoff travels quickly across flat surfaces and into gutters... which take it - untreated - directly into surface waters