Residents of Federal Way, Wash., who wash their cars on impervious surfaces without properly disposing wastewater can significantly pollute surrounding waterways and the Puget Sound, according to a local study released in July by the city’s Surface Water Management Division.
Officials measured the pollutants created by five weekend charity carwash events held in 2007 and 2008 and then estimated the annual amount of residential carwashing that occurs in Federal Way, according to a report by the Federal Way Mirror.
The Residential Car Washwater Monitoring Study concluded that the cumulative effect of charity and home carwashing contributes significantly to the city’s storm water pollution. Oil, phosphorous, ammonia, surfactants and solid wastes were all measured during the study.
Federal Way officials estimate that 190 gallons of gasoline, diesel and motor oil; 400 pounds of phosphorous and nitrogen; 60 pounds of ammonia; 2,200 pounds of surfactants and nearly 34,000 pounds of dissolved and suspended solid wastes are deposited annually into the city's storm water drainage system as a direct result from residential carwashing.
These pollutants can find their way into local waterways and eventually into the Puget Sound, endangering aquatic life and the balance of the ecosystem. The Federal Way results echo those found in a 2007 fish toxicity report commissioned by Car Wash Enterprises, which operates the Washington-based Brown Bear Car Wash chain. The 2007 report demonstrated the dangers untreated runoff from residential carwashes can have on wildlife.
In that study, fish toxicity tests were performed in Seattle using a water runoff sample collected from a charity carwash event held in a parking lot and compared against a simulated runoff sample that was potable. The carwash runoff sample caused 100 percent mortality of fish in all dilution steps tested, while all the fish survived in the potable water sample.
Federal Way officials are urging residents who do not use commercial carwashes to wash their vehicles on grass or gravel to reduce the amount of pollutants that make their way into storm drains. The city also supplies free carwash kits for organizations to use during charity carwash events. The kits help catch pollutants and prevent runoff from entering the storm drainage system.
Source:
Federal Way Mirror: Car wash pollution and the numbers to prove it