Best Management Practices: Washing Cars

At Home Commercial Car Wash Fleet Vehicles

Washing Cars at Home

Customers are encouraged to take their cars to a commercial car wash. Commercial car washes are usually more water efficient than washing your car at home. In addition, commercial car washes direct the wastewater to the sanitary sewer, which keeps detergents and other pollutants out of streams and rivers. Polluted water that flows directly to rivers and streams without being cleaned is a problem. An even bigger problem is that the sources of this pollution are extremely difficult to find so the problem can be corrected. Usually there are many different sources of this pollution, so the problem has become known as non-point source pollution. See the following web site for more information regarding non-point source pollution issues associated with home car washing. http://www.riversides.org/riversafe If you must wash you car at home, use a bucket for soap and water. Use a low phosphate soap. Use a shut-off nozzle on the hose for the final rinse. When possible, direct the runoff to a pervious area, like a lawn or a gravel area.

Commercial Car Washes

Commercial Car Washes can implement the following industry practices to maximize water use efficiency.

Self-Service Car Washes

• Reduce nozzle size and/or reduce pressure - (3.0 gpm maximum flow-rate)
• Check for and repair water leaks as they occur
• Replace brass or plastic nozzles with stainless steel nozzles that don't wear away to make a bigger nozzle size.
• Turn off spot-free rinse or recycle reject water
• Discontinue bay/lot wash down
• Install a temperature controlled weep management system (adjusted to 32°ree; F)

In-Bay Automatic Car Washes

• Install a water reclamation system
• Regularly check alignment of nozzles
• Check for and repair water leaks as they occur
• Cut out soap pass if there are more than one pass
• Reduce nozzle size
• Replace plastic or brass nozzles with stainless steel nozzles
• Eliminate spot-free rinse or recycle reject water
• Increase speed of cycle times
• Discontinue bay/lot wash down
• Install a temperature controlled weep management system (adjusted to 32°ree; F)

Conveyer Car Washes

• Install a water reclamation system
• Regularly check alignment of nozzles
• Check for and repair leaks as they occur
• Reduce nozzle size
• Replace plastic or brass nozzles with stainless steel nozzles
• Eliminate spot-free rinse
• Speed up the conveyer - reduce the rinse cycles to no more than 40 seconds per car.
• Turn off one or more arches
• Reduce prepping, turn off prep guns
• Re-arrange nozzles on the top and sides of arches: bigger nozzles on top and smaller nozzles on the bottom.
• Reduce the amount of water used in towel washing
• Reduce tip size and pressure in detail prep guns
• Eliminate part of the rinse or reduce rinse nozzle size to save at least 25% of rinse water
• Ensure that arches are properly timed to start and end as car passes under them
• Increase the dwell time in the final rinse cycle to catch and reclaim more water
• Install a temperature controlled weep management system (adjusted to 32° F)

 

Fleet Vehicle Washing

Companies with fleet vehicles should follow the appropriate Best Management Practices, corresponding to the Commercial Car Wash BMPs. In addition, companies should consider washing vehicles less frequently to save water.