MIL-HDBK-1133
4.1.4
Maintenance and Losses. The following factors
significantly contribute to water consumption and are listed for
informational purposes only. Due to the number of variables
involved, an accurate estimation of water consumption due to
losses cannot be made. Therefore, if metered values are not
available, consumption due to these factors should be reconciled
with the final billing statement (maintenance and distribution
losses generally apply to all tenants at an activity). This
process will be described in the next section.
a) Boiler Feedwater Usage: Boiler feedwater reflects
the average daily water usage by each industrial boiler for
makeup and other uses. When condensate return systems have been
abandoned, the boiler is a "once through" system that requires
more water to operate.
b) Street Cleaning: Street cleaning consists of the
average monthly water usage for cleaning paved streets and
parking lots. The average water usage for street cleaning is
one-half gallon per square yard, although quantity of water will
fluctuate based on pump pressure and size of nozzle. Street
cleaning is commonly eliminated in areas where water is expensive
or drought conditions exist.
c) Fire Hydrant Flushing: The average water discharge
is generated from testing hydrant pressure and from clearing
distribution lines of stagnant water. Fire hydrant flushing
usage is expressed as an average of 1,200 gallons per minute
(gpm) although it can range from 800 to 1,600 gpm depending on
system pressure.
d) Firefighting and Training:
Usage varies by
incidents and training schedules.
e) System Losses: System losses are dependent on
system age, maintenance practices, system design, and weather
conditions. Unusual weather conditions may cause excessive
losses.
4.2
Water Consumption Data Reconciliation. Reconciliation
of all estimated and metered water consumption data with the
total actual consumption is similar to the process performed for
energy in Section 3.
NOTE
This process can be done manually or with any
spreadsheet or database software. Using a spreadsheet
or database is strongly recommended and will provide
faster and easier calculation.
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