This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
A car may look sparkling clean after a wash, but the grime, oil and suds hosed onto the pavement don’t do much for the cleanliness of the environment.
"The soaps are just as toxic as some of the chemicals we regulate in the industrial [sector]. They kill fish," Sandy Howard, a spokesperson for the Washington State Department of Ecology, told the AP today. The department has singled out surface water runoff, including the car wash stream that flows down driveways, as the leading source of pollution in the Puget Sound.
Of course, officials aren’t suggesting everyone drive around in cars coated with enough dirt that a finger-written “Clean Me” is visible. Rather, a visit to the local car wash where the Clean Water Act regulates recycling and disposing of the used water could significantly limit the pollutants sent down the storm drain and straight into local waterways. For the die-hard do-it-yourselfer, parking the car on some grass or gravel before turning on the hose limits the contaminated runoff by catching and partially filtering the water. Even using a bucket to catch the dirtied water and then releasing it over a naturally permeable surface for filtration can help.
For those inclined to go extra green, waterless car wash products are available. In addition to reducing runoff, this approach saves the nearly 140 gallons of water the International Carwash Association estimates is used for an average at-home car wash.
Seattle is just one of many cities promoting natural ways to reduce runoff into rivers, streams and lakes. Santa Monica, Calif., is fining residents $500 if runoff leaves their property, reported the AP. An eco-conscious car washing certification program is now offered in San Antonio, Tex. And Cairns, Australia, may soon go as far as barring all home washings on roads or paved driveways, even public car washes, despite outcry from local sports teams and charities.
Of all the ways to clean your car, a wildlife park outside of Eugene, Ore., may have the most creative, if not necessarily the greenest, alternative yet. There, trained elephants do the job. “The car wash consists of two of the elephants sucking water into their long, slender trunks before showering it upon waiting vehicles,” reports the Oregon Daily Emerald. “After the initial rinse, the elephants grip a small sponge in their snouts and scrub the windows.”
The show is performed over permeable earth—“savannah-like land,” according to the report. This $20 "wash" may be more entertaining than cleansing, however.
Photo of iconic Seattle car wash by ricardo.martins via Flickr.
