Car Washing

Chappaqua Central School District
66 Roaring Brook Road
Chappaqua, NY 10514


MS4PY8 Stormwater Program

Fact Sheet #1
July 2017


BMPs for Car Washing

For more information, contact your stormwater coordinator:
Joe Gramando at 914-238-7210 x1201 or at


  1. Adverse Environmental Impacts From Car Washing
    Car washing is a common a popular way for organizations, such as schools, scout troops and sports teams to raise funds. However, most of the time, cars are washed in driveways and parking lots which allow wash water/rinse water (dirty water) to find its way to the nearest storm drain, ultimately draining into our drinking reservoirs and nearby waterways.
  2. Car Washing Pollutants
    The wash water contains pollutants such as sediment, oils and grease, phosphates (from soap), road salts and other chemicals and heavy metals, all of which adversely affect our environment. The vehicle wash water can also carry sediments and contaminates into our nearby onsite drinking water wells. It has been reported by EPA that that contaminates in wash water can cause a variety of health effects such as kidney damage, circulatory system problems, increased cancer risk and delays in children's physical and mental development.
  3. Car Washing Cleaning Agents
    Using phosphate-free, biodegradable detergents for car washing will reduce the amount of contaminants entering the storm sewer and the groundwater. Cleaning agents containing solvents should not be used because they emulsify and can cause adverse impacts to our drinking reservoirs and nearby waterways.
  4. Commercial Car Wash Fundraisers
    Car wash fundraisers are a popular means for raising money for worthwhile causes such as school clubs and charities. The best action you can take for protecting our waterways as well protecting your onsite drinking water well is to take your car to a commercial car wash, especially if you plan to clean the engine or the bottom of the car. Most commercial car washes recycle the water several times before discharging the wash water for treatment at a wastewater treatment plant. Call your local car wash and ask them if they will sponsor your fundraising event. Most car washes will gladly sponsor such events.
  5. Non-Commercial Car Washes
    If you plan to wash your car at non-commercial car wash you should incorporate the following practices to reduce the overall environmental impact from wash water:
    • Selecting the Site: The best location is an area which includes gravel, grass or a permeable surface, so that the ground can filter the water naturally
    • Locate Well, Septic System and Storm Drain: Choose a site at least 75 feet from the nearest well, septic system and storm drain. Locate the site downstream from these systems
    • Divert Discharge Wash Water: If possible divert wash water to grass swales, rain gardens and nearby landscaped areas so that the wash water pollutants can be filtered and absorbed by soil and plants before being discharged offsite to a stream
    • Absorbent Pads: Absorbent pads, which can be purchased at automotive shops, should be placed in the curb or grass swale and around the car washing site, to catch oils and other chemicals
    • Contact Your Public Works Department: Contact your Town's Public Works Department so that you can review where to place your car washing site. They can also assist you in locating the nearest storm drain. If required, they can also install temporary catch basin filters or solid covers over the storm sewer inlets to catch oils and other chemicals that may enter the storm drain
    • Use Soap Sparingly: Try to use non-phosphate or biodegradable, non-toxic, and chlorine-free detergents. Do not use acid-based wheel cleaners or engine degreasers. The safest products for the environment are vegetable-based or citrus-based products. Phosphates are nutrients that can accelerate algae growth in nearby waterways
    • Use High Pressure, Low Volume Hose: Use a hose with a nozzle that automatically turns off when left unattended or one that has a pistol grip or trigger nozzle to save water. Wash one section of the car at a time and rinse it quickly
    • Cleaning Up: when you are done, empty your bucket of soapy water down the sink, not the street. Collect absorbent pads and dispose of them properly.