1. Driveway washing uses less water than a professional carwash.
Industry numbers indicate that a typical car washed by a consumer in a driveway takes as much as 120 gallons (450 litres), while the industry WaterSavers™ program target is 40 gallons (150 litres) per wash. Don’t take the industry’s word; the Lower Colorado River Authority (LCRA) in the U.S. did its own examination of this issue which ended up as a YouTube video:
Fact: Professional carwashes use on average about a third of the water used when washing a car at home.
2. Professional carwashes use too much water.
Based on the Water Footprint Calculator, an average bath uses 35-50 gallons (132-190 litres), while the average shower 25 gallons (94 litres) per minute for old style shower heads or 2.5 gallons (10 litres) for low-flow shower heads. The WaterSavers™ program target for a tunnel carwash is 40 gallons (150 litres) per wash, or about the same as an average bath or an eight minute shower with a standard shower head.
Fact: to save water take showers with a low-flow shower head and wash your car at a professional carwash instead of in your driveway.
3. Storm sewer water is treated.
Few people realize that there are two parallel sewer systems in most municipalities, the storm sewer hooked up to street grates that take water runoff from rain directly to lakes and rivers, and the sanitary sewer system which takes industrial and household waste water to a processing plant. The Leger Marketing survey showed that on average 51 per cent of the Canadian population believes that water from storm sewers goes to a treatment plant, or is absorbed by the land, or just don't really know what happens to it.
Fact: Letting any type of chemical or soap run into storm sewers can be environmentally harmful.
4. Using environmentally friendly soaps means you can wash your car in the driveway.
There is no such thing as environmentally benign soaps, even those labeled environmentally friendly leave a chemical footprint for aquatic life to deal with. Consumers should take care to avoid having any kind of soaps, chemicals or fertilizers run off of their property into storm sewers for this reason. In addition, according to the City of Toronto, "The dirt on cars can contain toxic chemicals, heavy metals, oil and grease. When you wash a car in your driveway or on the street, that dirty water runs into the storm sewers and straight into local waterways, contributing to water pollution and affecting Lake Ontario's water quality." Unless you're living in southern Ontario of course, it will be some another lake or river.
Fact: Professional carwashes are clearly the environmentally friendly alternative to driveway washing.