I just recently started working at Auto Bell Car Wash detailing cars. This got me interested in ways that you could wash your car in a more eco-friendly way. All commercial washers are required to recycle their water, Auto Bell recycles about 80% of its water, which is pretty high when you consider how much water is used at a place like that. Another benifit of using a commercial washer is that they harness the power of air pressure along with the water. This allows for about 60% less water to be used that if you washed your car at your house. Using this air pressure also helps the water get all the soil and grime off of your car making it shine!
A study recently conducted by the International Carwash Association reported that less than 50% of Americans wash their car at home, but if you are one of those people there are many things you can do to decrease the amount of waste and pollution you produce. Washing your car on the lawn as opposed to the driveway is very benefical. As we have learned the soil acts as a filter, removing all the soap, oil, and other grime from the water used to wash your car. This helps to eliminate run-off of these nasty toxins into local streams and storm drains that pollute the water supply. This is a good idea in principle, but now the toxins are in the soil, maybe not so good. There are also many different types of soap that are considered eco friendly. The soap that runs-off into our local streams and ponds can kill the fish by removing the mucus lining around the fish that protects them from disease. Also adding soap to the water greatly reduces the surface tension of the water allowing fish to absorb the chemicals in the water, like pesticides. You should avoid using any soap that contains phosphates as well.
I saw a statistic that said the average home wash uses about 116 gallons of water to wash one car, a pretty rediculous amount. There are many things that one could do to reduce the amount of water used. You could also use a hose nozzle that regulates the flow from your hose. This greatly cuts down on the amount of water being used. Also using a bucket with a water-soap mixture has the same effect. Setting up a rainwater collection system would also be beneficial. Rainwater can be used to wash cars or many other things like irrigation or flushing your toilets.
Really the most eco-friendly way to wash your car at home is to wash it with just water, no soaps or chemicals. This really does not get your car that clean. That might be a price you are willing to pay to reduce you foot-print on the world.