WATER CONSERVATION:
REDUCING WASTE SAFELY
after the
passage of the Energy Policy Act
(EPAct) of 1992, water conservation
has re-emerged as a top national
priority. Drought and a growing
population continue to put stress
on water supplies. According to
the U.S. Environmental Protection
Agency, the U.S. population has
grown 90% in the last 50 years, but
public demand for water has risen
209%. A recent survey showed at least 36 states foresee local,
regional or statewide water shortages by 2013.
ese growing concerns are the basis for the renewal of
the plumbing industry’s commitment to water e ciency, the
impetus for new and enhanced plumbing technologies, and
the International Association of Plumbing and Mechanical
O cials (IAPMO) e ort to ensure these products and systems are safe, reliable and achieve anticipated savings.
Replacing a PRSV that uses up to 3 gpm with a high-
e ciency unit can save 60–180 gallons of hot water daily.
FAUCETS, AERATORS AND SHOWERHEADS
In residential applications, high-e ciency faucets and aerators are available with ow rates of 1. 5 gpm or less. e EPA
has developed a performance specification that helps to
ensure that products perform well throughout a specified
pressure range. On the commercial side, plumbing codes
and faucets standards already mandate that public lavatories
be limited to 0.5 gpm or 0.25 gallons per metering cycle.
Many higher-efficiency showerheads are available with
ow rates of 2.0 gpm or less. ese products use 20% or less
water than required by EPAct and represent a big opportunity to save water. Although there are a number of excellent
products on the market, questions will remain without adequate standards addressing thermal shock and scalding. e
EPA WaterSense programs and North American standards
developers have planned testing and research.
TOILETS, FLUSHING DEVICES AND URINALS
ere are two types of high-e ciency gravity- ushing toilets
– single- and dual- ush. A high-e ciency, gravity, single-
ush toilet uses no more than 1. 28 gallons of water per ush.
Dual- ush toilets use 1. 6 gpf for a full ush and 0. 8–1. 1 gpf
for a short ush. Several studies conducted by water utilities
have concluded the average flush volume for a dual-flush
toilet is 20% or less than conventional 1. 6 gpf toilets.
Toilets that feature pressure-assist technology and ush-
ometer valves are also available in high-e ciency versions.
Single- and dual-flush, high-efficiency flushometer valves
have similar use levels as high-e ciency, gravity- ush toilets. Toilets equipped with high-efficiency pressure-assist
technology are available at volumes of 1. 28 gpf and 1.0 gpf.
Manufacturers have re ned existing urinal technologies
and developed new ones that use 0.5 gpf or less. High-e -
ciency urinals can save thousands of gallons of water.
With the advent of high-e ciency toilets and urinals, an
evaluation must be made to ensure that no problems will
occur in drain lines due to the reduction in water previously
available to carry and remove waste.
PRE-RINSE SPRAY VALVES
Pre-rinse spray valves (PRSV) are used at dishwasher pre-rinse stations in commercial kitchens. In 2005, a revision
to EPAct limited PRSV ow rates to 1. 6 gallons per minute
(gpm). As a result, PRSVs are available with flow rates of
1. 1–1. 6 gpm.
ALTERNATE WATER SOURCES
Employing systems that utilize alternate water sources, such
as gray water, harvested rainwater and reclaimed water, has
the potential to save billions of gallons of fresh, treated water.
More jurisdictions are revising regulations to allow these
systems. However, the potential health and safety risks are
significant without proper assurances of adequate water
quality, system maintenance and cross-connection control.
e increased awareness of the importance of conserving
water has led to a number of e orts to establish water-e -
ciency requirements and incentives within green building
programs and standards. These efforts lack the input and
expertise of plumbing and mechanical professionals.
In order to make certain that this happens, IAPMO
has brought together industry experts of diverse interests.
rough its Committee for the Awareness and Understanding of a Sustainable Environment (CAUSE) and the Green
Technical Committee, IAPMO is updating the Uniform
Codes and developing a Green Plumbing and Mechanical Supplement that will include a comprehensive set of
provisions addressing the important performance, design,
installation and maintenance of water-efficient products
and systems.
Dave Viola is director of special services for the International
Association of Plumbing and Mechanical O cials. He can be
reached at 708/995-3004 or at dave.viola@iapmo.org.
