Your clean car can mean dirty water

May. 24, 2014 @ 12:01 PM

The weather is nice, the pollen and bugs are out and it is car washing season in Durham.

You see clues that a car is being washed even before you see it happening -- soapy water flowing down the street. This water, along with the soap and grime it carries, is most likely running into a nearby storm drain. Many people do not realize that this water flows straight into our rivers and creeks. It does not get cleaned first!

Washing your car removes pollutants that rainwater does not. You can see this in the grime that comes off: grease, oil, and toxic chemicals from paint, exhaust and brake pads. Even the soap is harmful to fish and other aquatic animals. Biodegradable products are less harmful, but they still remove oxygen from water during breakdown. The waste water from washing your car needs to stay out of the storm drain. Washing your car is not the problem. It is just how and where you do it that matters.

The easiest way to clean your car in an environmentally friendly way is to take it to a commercial car wash. They are better for the environment because their waste water is cleaned (ask about this at your favorite car wash). They also use high-pressure nozzles and pumps that conserve water. Car washes use about 60 percent less water to wash a car than washing it at home with a hose. Look for a car wash that recycles its waste water to be even more environmentally mindful.

If you go to a mobile car washer, ask how they contain and dispose of their wash water. They should have a visible system to block dirty water from going to the nearest storm drain or ditch.

If you wash your car at home, use the following tips to protect our rivers and streams.

Tips for “Greener” car washing

-- Wash your car where the water will drain to a landscaped or grassy area. Avoid letting soapy water flow into the street.

-- Try using waterless car wash products.

-- Don’t let water flow the whole time you are washing. Use nozzles on your hoses that automatically turn off the water when you are not using it.

-- Use a biodegradable soap. Look for labels that say “phosphate free,” “non-toxic” or “biodegradable.” Avoid products with: petroleum-distillates, kerosene, silicone or mineral spirits. Citrus or vegetable based soaps are best for the environment.

-- Use the smallest amount of soap possible. Muscle power and water can take care of most grime on a car. Using less soap not only helps the environment, it also saves you money!

-- Use a bucket of soapy water to wet your sponge. Wring your sponge back into the bucket to keep dirty water out of the storm drain. The water in these buckets should be dumped into the sanitary sewer. This can be done by using an inside drain such as a sink or toilet.

-- Avoid the use of acid-based wheel cleaners.

Keeping our creeks and lakes clean is a job for everyone. You can do your part by preventing dirty car wash water from entering storm drains. To report water pollution, call the stormwater hotline at (919) 560-SWIM.

Laura Webb Smith is public education coordinator for the City of Durham’s

Public Works Department, Stormwater and GIS Service, which is guided by the city’s strategic plan goals of stewardship of the City’s physical assets and well-managed city. Activities include storm drainage design and plans review; inspecting and maintaining city-owned drainage systems; enforcing stormwater ordinances and regulations; education and outreach; stream monitoring, restoration, and watershed master planning; maintaining multiple layers of the city’s geographic information system; and stormwater billing. To learn more, visit and, “like” on Facebook at and follow on Twitter @DurhamStormH2O.