Audit Methodology
Chapter 4: Water Reduction Measures
4.1 Introduction
The areas of water reduction will mainly be associated with physical
changes, but user habit change will also be an ingredient in a successful
water efficiency program. Implementing water reduction measures will have
no effect on human comfort.
Many water reduction measure alternatives will become obvious during
the water audit and will aid in the development of a water efficiency
strategy. Demand management methods that involve reducing the demand for
water at the user end of the distribution system include
- system optimization
- water-saving systems (retrofitting and replacement)
- reuse/recycle systems
- process changes
- alternative water sources
- user habit changes
- metering
General supply management approaches, such as leak detection and repair
as well as pressure reduction, are effective in reducing the water used by
controlling the supply and distribution system.
4.2 System optimization
Because the system optimization measures are specific to the water use
operation, opportunities for water reduction cannot be identified until
the water audit has been completed. However, based on the audit, several
systems can be considered for optimization, including
- regular calibration of all water flow meters
- implementation of a preventative maintenance program including leak
detection for water-using operations such as toilets and faucets
- optimization of the individual processes and equipment in major
water-using areas
4.3 Water-saving systems
Selecting water-saving devices that reduce the harm an activity would
otherwise cause to the environment could be considered a good
environmental choice. The Environment Choice Board was created to help
users find products that ease the burden on the environment. As the range
of products identified by EcoLogo, the Board's symbol of certification,
grows, it will become easier to decide on environmentally sensitive
purchases.
4.3.1 Retrofitting systems
Standard retrofitting devices are common for domestic water use
components such as toilets, showerheads, faucets, and outdoor hoses.
Components that may be considered for retrofitting include
- toilets – if the toilets at the facility are
valve-operated and use 19-25 L per flush. A toilet retrofitted with
flow control valve would use less than 15 L.
- urinals – Standard urinals use 7-9 L/flush;
water-saving flush valves reduce this to the 3 L range. Moreover,
using infrared sensing equipment further saves water by "flushing when
required," thus eliminating double or stack flushing common with manual
valves.
- showers – Standard showerheads, using an estimated
100 L per use, could be retrofitted with flow restrictors.
- faucets – Sink faucets could be fitted with flow
restrictors or aerators. For washroom sinks, timed on/off valves may
prove to be water efficient.
- drinking fountains – Drinking fountains could be fitted
with flow restrictors or timed on/off valves.
- sprinklers – Water sprinklers could be fitted with
timers so that they could be operated and shut off automatically during
the night, when water lost to evaporation is at a minimum.
4.3.2 Replacement systems
Water efficient toilets, showerheads, faucets, and appliances (e.g.,
dishwashers and washing machines) are being developed for conventional
water uses.
Replacement of water-using devices with new, low water-using fixtures
should be considered facilitywide for toilets, taps, showers, hoses, and
drinking fountains. Current sprinklers could be replaced with more
water-efficient systems.
4.4 Reuse/recycle systems
Reuse and recycle systems are those that use water that has previously
been used in another operation; however, treatment may be required before
the second use.
The pilot audit identified the following opportunities in this regard.
Water used in various air-handling equipment should be reused for
humidification. Well-timed and well-maintained recycling fountains can
reduce water use without affecting business.
Both reuse and recycle systems should be considered to reduce water use
if large volumes of uncontaminated water are to be discharged to municipal
sewers.
4.5 Process change
Process change describes the replacement of water-using practices with
those that perform the same function in a different manner. Process change
can also refer to the complete elimination of a water-using practice.
Basic approaches that appear to save significant quantities of water
include regular equipment maintenance, conversion to chemical or dry
processes, and elimination of once-through air conditioning units.
Consideration should be given to convert all water-cooled equipment to
chilled water or closed-loop glycol cooling systems. This list is for
illustration purposes and is not exhaustive since process change steps are
regarded as site-specific in nature.
4.6 Alternative water sources
If the water required for the operation does not need to be municipal
grade, then there may be a large cost savings associated with using an
alternative supply. Alternative water sources could include direct surface
water supply, groundwater supply, and stormwater.
4.7 User habit changes
Changes in people's water-use habits could include
- organizing work to minimize water loss
- ensuring that taps are completely turned off and not left running
unnecessarily
- reporting leaking faucets, toilets, urinals, and water fountains to
appropriate maintenance personnel
- insulating hot water pipes serving faucets or showers to reduce the
time water must run to become hot
- adjusting lawn watering schedules to low evaporation periods of the
day
4.8 Metering
Metering water use is a good way for the facility to gain the support
of users involved in the water reduction program, as they will see the
results of their efforts. Placing and monitoring a flow meter on a supply
line allows both management and employees of a facility to immediately
recognize how much water has been used and whether that use falls within
the normal range.
Based on the information gathered in the water audit survey, it might
be possible to obtain enough flow monitoring data
- to assess the progress of a water efficiency program
- to ensure that the reductions are maintained and not allowed to be
eroded
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