Page 180 - WaterSense at Work

October 2012
because the cloth brushes or curtains collect water and detergent from previous
washes and require less re-wetting.
Conveyor vehicle wash facilities are good candidates for installing reclamation sys-
tems because the tunnel length allows for wash wastewater to be easily separated
from rinse water of higher quality. Without reclamation, conveyor vehicle washing
can use 65.8 gallons per vehicle (gpv) of fresh water during friction washing and
gpv of fresh water during frictionless washing. A reclamation system can reduce
freshwater consumption to as low as 7.8 gpv during friction washing and 16.8 gpv
during frictionless washing.
In-Bay Systems
In-bay vehicle washes can be found at many gas stations or similar facilities where
vehicle washing is a secondary service option. For in-bay vehicle washing, the vehicle
remains stationary while the washing process occurs. Like conveyor vehicle washing,
a series of nozzles and/or brushes is used to complete either a friction or frictionless
wash process. One set of nozzles is typically used to perform all wash cycles.
In-bay vehicle washing facilities can also benefit from the use of a water reclamation
system. However, because there is typically only one wastewater collection pit, an in-
bay water reclamation system must be properly designed to separate contaminated
water from cleaner water. A water reclamation system can reduce average in-bay
water use from 60.0 gpv to as low as 8.0 gpv.
Self-Service Car Washes
Self-service car washes allow customers to wash vehicles themselves, using a hand-
held nozzle to perform all washing processes. In some cases, there could be a brush
available for the wash cycle. The pricing structure for a self-service car wash is typi-
cally set up so that the customer pays for a base amount of time of water use and can
make additional payments for each additional time increment.
Of the three types of vehicle washing, self-service vehicle washing tends to use the
least amount of water—15.0 gpv, on average.
While self-service vehicle washing
typically uses the smallest amount of water per vehicle, water reclamation systems
are often not feasible for use with a self-service washing facility, because it is diffi-
cult to collect and separate the wastewater. Coupled with the fact that water use in
these facilities is driven by user behavior, self-service vehicle washing offers the least
potential for water savings through retrofit or replacement.
East Bay Municipal Utility District. 2008.
WaterSmart Guidebook—A Water-Use Efficiency Plan Review Guide for New Businesses
Pages 37-39, WASH1-6.
Brown, Chris,
op. cit.
Page 16.
Vehicle Washing