Sign In
Maryland State Government Maryland Department of the Environment

Water Conservation and Washing Vehicles

Water conservation begins at home.  Taking a few, simple steps when washing your boat or vehicle (including automobiles, trucks, motorcycles, and trailers) can help to conserve water and protect the quality of nearby water bodies.

Wash vehicles on grass, not on pavement. Wash your vehicle over an unpaved area, such as an area covered with grass or gravel.  Washing over an unpaved surface will allow the soapy water to soak into the ground, be filtered, and eventually recharge the groundwater.  If you have your own well, you should wash your vehicle at least 100 feet from the well head.  If you wash the vehicle on a paved surface, the runoff flows into a storm drain, and the water and contaminants are discharged to the nearest lake or stream.

Wash vehicles using a bucket with soapy water.  Soap and water usually work well.  If you need a special cleaning product for vehicles, read the label carefully and be sure to use a non-toxic, biodegradable detergent.  Do not use a product that says Poison, Harmful, or Danger.  Be sure to turn the running water off while you are washing a vehicle.

Rinse vehicles with a hose equipped with an automatic shutoff nozzle.  A standard garden hose uses about 10 gallons per minute.  This means you use 100 gallons of water with only a 10-minute car wash.  When you use an automatic shutoff nozzle on your hose, water does not flow continuously while you wash your vehicle, saving as much as 70 gallons per wash. 

Using a power washer can conserve even more water; power washers use, on average, about 2 to 5 gallons per minute, with a potential savings of up to 80 gallons over using a standard house without an auomatic shutoff nozzle.

Consider going to a commercial car wash.   If you cannot wash your vehicle in an area that drains to the lawn or a gravel area, take it to a commercial spray booth or car wash.  A properly designed car wash is connected to a sanitary sewer that carries the dirty water to a wastewater treatment plant.

There are three types of commercial car washes: self-serve car washes, in-bay automatic car washes, and conveyor car washes. The following table provides water use information by car wash type. The data represents the total water used, and does not take into account whether or not a car wash recycles its water.

Average Water Consumption (gallons per vehicle)
by Car Wash Type

Car Washing Type

International Car Wash Association1

Mid-Atlantic Carwash Association2

WaterWiser3

Home wash (with automatic shut-off nozzle)

--

--

30

Home wash4 (without automatic shutoff nozzle)

--

--

100

Self Serve

15

15

--

In-Bay

50-60

35

65-100

Conveyor

66-85

60

30-50

1 Brown, Chris.  2002.  "Water Use in the Professional Car Wash Industry& Car Wash Association."   p.   47.
2 Mid-Atlantic Carwash Association, Inc.  Information provided to the Maryland Water Conservation Advisory Committee.  June 2000.
3 WaterWiser [http://www.waterwiser.org/watch/wiser_watch.cfm?ArticleID=96]. February 2003.
4 Assumes a 15 minute car wash with flow of 10 gpm.

Many newer conveyor car washes and some newer in-bay car washes clean and recycle water in their car wash bays. Car washes that recycle their water use much less water than standard car washes. The quantity of water recycled varies from 10 percent to 80 percent of the water used. Check to ensure that the car wash you choose recycles its water.

Related Topics

Drought Home
Drought Coordinators