Wash Your Car the Safe Way

The Facts About Car Washing

If car washing is done incorrectly, a clean vehicle could lead to dirty waterways.

Water entering storm drains, unlike water that enters sanitary sewers, does not undergo treatment before it is discharged into our waterways. When cars are washed on streets and driveways, that dirty, soapy water eventually flows into our rivers, streams, creeks and lakes.

Washing one car may not seem like a problem, but collectively, car washing activity adds up to big problems for our local lakes, creeks and streams.

What’s the problem?

Washing your car is only a problem if you don’t know where or how to do it correctly. Did you know that the average homeowner uses 116 gallons of water to wash a car? Most commercial car washes are far more efficient, using 60 percent less water for the entire process than a homeowner uses just to rinse the car.

Water quality experts say that car washing is a serious contributor to water pollution. Water that runs off a car when it is washed in a driveway, street, or parking lot can contain substances that pollute the environment. Dirty water containing soap, detergents, residue from exhaust fumes, gasoline, heavy metals from rust, and motor oils can wash off cars and flow directly to storm drains and into the nearest creek or stream where it can harm water quality and wildlife.

The phosphates from soap can cause excess algae to grow. Excessive algae smell bad, look bad, and harm water quality. As algae decay, the process uses up oxygen in the water that fish need.

Car wash fundraisers can be a significant source of this kind of pollution. These events are usually held in heavily paved areas where there is little runoff control or grass to filter out harmful substances before they reach our waterways.

What Can You Do?

The best way to minimize the effect washing your car has on the environment is to use a commercial car wash. Most locations reuse wash water several times before sending it to a treatment plant.

However, if you choose to wash your car at home or on the street, these are some things that you can do to minimize the water quality impact:

  • Use biodegradable, phosphate-free, water-based cleaners only.
  • Minimize water usage by using a spray gun with flow restriction to minimize water volume and runoff.
  • Wash on an area that absorbs water, such as gravel or grass. This can filter water before it enters groundwater, storm drains, or creeks.
  • Avoid washing cars on concrete or asphalt pavement unless it drains into a vegetated area; however, only let wash water soak into the ground if you are using biodegradable, phosphate-free cleaners.
  • Always empty wash buckets into sinks or toilets.
  • When planning a car wash fundraiser, try developing a partnership with a commercial car wash facility, or use a location that limits water runoff.