WATER CONSERVATION
IN CARWASH SYSTEMS
As more AreAs of the country get serious about water
conservation, efforts to save water have spread to nearly
every industry and usage type. An example is the professional
carwash industry, which has embraced water conservation
and, in the process, become part of the water waste solution.
Provisions regarding water conservation in carwashes even
appear in the section on automatic and self-serve systems in
the new Public Version 1.0 of the International Green Construction Code (IGCC).
According to the International Carwash Association
(ICA), professional carwash systems use an average of 12 to
16 gallons of water per car for self-serve, and 24 to 72 gallons
for automatic wash systems. The water used by individuals
washing cars in their driveways or charity carwashes can
vary widely. But, with the average open hose dispensing
about 8-gpm, it doesn’t take long to use far more than most
carwashes. These kinds of savings have resulted in local ordinances that require the use of professional carwashes during
times of drought. Consumers are responding and, according
to ICA, the number of consumers washing their cars at home
has declined 13% in the last 12 years. 3, 4
There are three primary types of carwash systems: conveyor
automatic, in-bay automatic and self-service. In conveyor
systems, the car is moved through the system and cleaned by
means of brushes or high-pressure nozzles. In-bay automatic
systems work the opposite way by holding the vehicle stationary and moving the nozzles or brushes. self-service systems
require the user to manually wash the car with a wash and
rinse nozzle, and sometimes a brush. 2
VIRTUALLY ALL CARWASHES CONSERVE WATER
Carwash operators have worked to reduce their total water
consumption by using a range of technologies, as shown in
the table above. eric Wulf, ICA executive director, states,
“Water conservation products have been used in carwashes
for years, but thanks to advances in technology, declines in
equipment costs, the increasing cost of water and consumer
preferences, water conservation is now ubiquitous in pro-
fessional car washing. Today, almost all new construction
incorporates water conservation technologies.”
The IGCC, for example, calls for all automated systems
to reclaim and reuse a minimum of 50% of the water used
for the rinsing phase. It also requires that towel and chamois
washing machines have a high-level water cut-off feature.
self-service spray wands are limited to no more than 3-gpm.
For all systems, wastewater from reverse osmosis water
treatment systems is required to be discharged to wash water-
holding tanks. reverse osmosis is used in the systems to treat
rinse waters to a high level of purity to achieve a spot-free
finish, but can be highly inefficient, discharging 70 to 90% of
the source water as waste. This discharge water is still fairly
clean, and appropriate for use in water used for washing
operations.
RECLAIMING WASTEWATER
As long as water is used to wash vehicles, the problem of
wastewater processing will always remain. A well-designed
carwash system incorporates a water reclamation system to
capture a large percentage of the water used for reuse. Not
only does this reduce the total volume of water consumed, it
reduces the quantity of water released to the sanitary sewer
and the resulting fees. reclaim systems can even be retrofitted
to existing facilities to improve their environmental footprint.
The gasoline residue, oil, dirt, contaminants and sediments
washed from the vehicles are disposed of in the sewer, for
proper containment and treatment. Wash-bay designs have
been improved to reduce or eliminate the runoff of soap and
contaminant-laden water into the parking lot drive lanes. 1
During driveway washes, this wastewater almost always
escapes as runoff, polluting groundwater or local waterways.
CONSERVING MORE THAN JUST WATER
sustainability is more than water conservation, of course, and
many carwashes are pushing the envelope in other areas as
well. some have integrated photovoltaic solar cells into their
roof design, producing energy to operate the facility and
feedback into the grid. others have used solar thermal water
heating systems to reduce the quantity of energy consumed
heating water, which can be used in nearly any climate. A
range of detergents, drying agents and presoaks have also
been developed that release fewer VoCs; they also are more
environmentally friendly.
Plumbing engineer Shawn Martin is the International Code
Council’s PMG Group director of industry relations. Additional information is available at pmgresourcecenter@iccsafe.
org or at www.iccsafe.org.
1 “The Next Generation of ‘Green’ Car Washes.” Aaron Vorhees,
America’s Car Care Business, May, 2009, p. 80.
2 “Water Conservation in the Professional Car
Wash Industry,” Chris Brown
3 “Water Conservation in the Professional Car Wash
Industry,” International Carwash Association, 2000
4 “Water Use in the Professional Car Wash Industry,”
International Carwash Association, 1999
