When cars are washed on streets and driveways, the dirty water eventually winds up in streams, rivers, and lakes. 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 into storm drains. Pollution associated with car washing degrades water quality while also finding its way into sediments, impacting aquatic habitats.
Washing one car may not seem to be a problem, but collectively car washing activities add up to big problems for our local waterbodies. 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.
Here are some tips for reducing your impact to the environment:
- Go to a commercial car wash when your car needs cleaning. Commercial car washes recycle water and send wastewater to treatment systems where it is treated before being discharged into a waterway.
- If you must wash your car at home, use the following tips to reduce stormwater pollution:
- Use a bucket and special biodegradable soap. Use as little soap and water as possible. Look for products that do not contain phosphates (which contribute to algal blooms and low oxygen levels in waterways) or nonylphenol surfactants (that act as endocrine disrupters and can lead to sex changes in fish).
- Use a pressure washer or spray nozzle to control water flow from the hose and reduce water use.
- Wash the car on a grassy area or other porous surface where soil microbes and vegetation can filter and break down pollutants and keep wash water out of the street and storm drains.