Liberty Carwash

Sewer vs. storm drain - how washing you car by hand is bad for the environment.

Water used to wash your car at home or at a charity wash drains directly into and poisons the environment. At Liberty Car Wash, the water we use flows to the sewer for treatment and processing before being released into the environment. Even if you use a environmentally friendly soap like we do, your wastewater may carry trace amount of metals (copper from brake dust and zinc from tire wear) along with small amounts of gasoline and diesel fuel, oil, grease and antifreeze. When combined with the fact that a professional car wash uses only a fraction of the water used to wash a car by hand, it’s no wonder that The Nature Conservancy and other organizations recommend washing at a professional car wash as the more environmentally friendly choice.





What We're Doing
The water we use flows to the sewer for treatment and processing before being released into the environment.
Computer controls minimize the waste of any water so you can get a clean shiny car knowing it used only a fraction of the water used when washing by hand.
Our soap and energy efficient practices reduce the environmental impact of getting a clean car.


It's true! The Nature Conservancy recommends using commercial car washes as a more environmentally friendly alternative to washing at home or using charity car washes that let waste water drain into the environment. If you do wash at home please visit the Nature Conservancy website for easy ways to reduce your negative impact on the environment.

If you’re planning a charity car wash, please contact us. We can help you meet your fund raising goals in a more environmentally responsible way!


Study: Fish Toxicity and Mortality Related to Home and Charity Car Washing



Read this complete study and learn about other efforts professional car washes are taking to protect the environment while protecting the appearance of your car!



Visit the International Carwash Association at



Executive Summary

Water from residential driveway or fundraising car wash events is usually allowed to run down the street or across a parking lot and into the nearest storm drain, and empties, untreated, into the nearest stream, river or lake. This wastewater may carry detergents, trace amount of metals (copper from brake dust and zinc from tire wear) along with small amounts of gasoline and diesel fuel, oil, grease and antifreeze.



Environmental Partners, Inc., Issaquah, Washington conducted two tests in 2006 to measure the effects of untreated car wash affluent from domestic and charity-type car wash events on juvenile rainbow trout. The independent study was commissioned by Seattle-based Brown Bear Car Wash.



In the first test, runoff water from a fundraising car wash event was collected. The event was held in the parking lot of an automotive service facility on a sunny, summer afternoon. No direction was provided as to how to mix the retail car wash detergent concentrate with water or how much rinse water to use. The wastewater ran across about 30 feet of asphalt parking lot before being collected from a plastic tub inserted into the storm drain. This was the car wash runoff sample.



For the second test, the same detergent concentrate that was used for the car wash event was used by the test laboratory to prepare a stock solution for testing. This solution was mixed according to instructions on the detergent container and was further diluted to simulate addition of rinse water. All water used in the second test sample preparation was potable. This was the simulated runoff sample.



These samples were then used to conduct a 96-hour acute effluent toxicity bioassay test using juvenile Rainbow Trout as test specimens exposed to different dilution rates of the samples. For each test fish were exposed to successive dilutions of the submitted water samples. For the car wash runoff sample a series of five dilutions of the sample were tested (100%, 50%, 25%, and of the original sample). For the simulated runoff sample a series of six dilutions were tested (10%, 1%, , , , and of the original sample).



These tests are termed “practical” fish toxicity tests because the water for both was collected or prepared such that each represented actual runoff water that would be expected to enter into storm water drains and, eventually, the streams and rivers of Puget Sound.



The car wash runoff sample caused 100 percent mortality of fish in all dilution steps tested and 0% percent mortality was observed in potable water. All mortality occurred within 24 hours. The concentration of sample water that caused 50 percent mortality in the trout was calculated to be



For the simulated runoff sample 100 percent mortality of fish was observed in the 10% dilution and percent mortality was observed in the 1% dilution. All fish survived in the remaining dilutions. The concentration of sample water that caused 50 percent mortality in the trout was calculated to be



Because the solution for the simulated runoff sample was prepared in the laboratory, it is reasonable to assume that the fish mortality was due solely to the effect of the chemicals in the car wash concentrate. The most likely chemical could be found in such a product is a surfactant or mix or surfactants.



As a part of the study, calculations were performed for a hypothetical urban or suburban Puget Sound setting in which a small stream is subjected to car wash effluent via storm drains. Approximately 100,000 people were assumed to live in the watershed area. With only 1% of the cars washed in driveways on a typical summer weekend, the results showed that toxicity levels could easily meet or exceed the situations tested in the lab resulting in potential fish kills of 50% of a juvenile species. The 75 gallons of car wash effluent per car would contain an estimated 53 parts per million (ppm) of detergent.