Is washing of cars good for the environment?

A recent event in London, Ontario promoting the environmental benefit of commercial car washes got GallonDaily thinking about an issue that had not recently come to our attention. The Canadian Car Wash Association, an association of car wash operators, is claiming that automatic and coin-operated car washes are more environmentally responsible than washing your car on your driveway.

Their claim is based on:

  • To save water, wash cars at a professional carwash instead of in the driveway. Professional carwashes use on average about a third of the water used when washing a car at home.
  • Letting any type of chemical or soap run into storm sewers can be environmentally harmful.
  •  The dirt on cars can contain toxic chemicals, heavy metals, oil and grease. Commercial car washes send the wash water to the sewage treatment plant rather than allowing it to flow down storm sewers into rivers, lakes, and the ocean.

These are interesting claims but GallonDaily is not totally convinced. It is certainly true that wash water from car washing should not be allowed to flow into street drains because these are not connected to the sewage treatment plant. So far, one for the industry. Some, but not all, automatic car washes recycle the wash water. That is certainly a good thing for the environment when compared to not recycling the wash water and another plus for the operators of that type of car wash. Others advertise fresh waster for every wash. That is wasteful.

But is car washing actually a good thing to do at all. We suspect that the industry would claim that washing your car prevents all that dirt from being washed on to the road and into the storm drains. The problem with the claim is where that dirt came from in the first place. Most of it came from the road surface and from droppings of oil, grease, rubber, and other materials from the underside of the car. If your car was not on the road, all the dirt would be washed into the storm drain. By being on the road, your car is picking up some of the dirt but is also adding to the dirt. Our guess is that most cars add more to the dirt than they pick up and that however you wash the car you are not really helping the environment.

We will give the car wash industry the benefit of the doubt and indicate that washing your car at a commercial wash may be better than washing it on your driveway if your driveway drains into the storm drain on your street. But we are still worried about the amount of water and energy that a car wash uses. Maybe the best thing to do is not to wash your car at all, and for sure the even better thing to do is to not use your car at all, or at least to dramatically reduce the amount of car driving you do.

We thank the Canadian Car Wash Association for drawing this matter to our attention and we look forward to more research on all kinds of car wash options. More information about the Canadian Car Wash Association’s environmental position can be found at  and

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