Page 206 - Water Loss Control

180 Cha pte r T w e l v e

season and heavily utilized during the peak season. Care needs to be taken when gath-
ering consumption data so that consumption profile(s) are obtained to reflect the varia-
tions in demand that the customer property will incur. In many communities water
consumption is notably higher during the warm or hot months of the year. Much of this
increased water consumption goes to outdoor irrigation, but additional showers and
bathing also occur during this time of year. Peak period consumption patterns can have
a big impact on any potential meter sizing decision. When looking at consumption pro-
files in vacation or resort areas, obvious care has to be taken with the season. When
considering the consumption profile of a large apartment block during winter and sum-
mer, the occupancy rate could change from 10 to 100%. Again the volume used will
change dramatically, however most of the use will be at peak times, as people prepare
for the day or evening ahead.
Large meters (1-in diameter and larger) are typically installed in multiunit residen-
tial buildings as well as commercial, industrial, or agricultural settings. Water demand
profiles can vary widely among the different types of building uses and/or manufactur-
ing processes that occur in some of these properties. Normally the largest variations are
seen in commercial or industrial properties between weekday use and weekend use
with minimal weekend consumption since business
is closed during this period. Seasonal consumption
Seasonal use variations of variations depend upon the type of manufacturing
or business process. Certain manufacturing pro-
customer properties should be
cesses may incur steady water consumption through-
carefully checked when sizing
out the day, and maintain this pattern continuously.
meters.
Other processes may utilize large quantities of water
in batches, with high volume flows alternating with
periods of minimal use. Some factories shut down processes during nights and week-
ends or may close for several weeks during holiday periods. The water utility manager
should inquire about the water usage patterns of a particular facility before determining
which periods of time to analyze using customer water consumption profiles.
The economics of meter right-sizing must also be taken into account. The water rate
or tariff structure of most North American water utilities includes several component
charges. A water charge is typically based upon consumption, with variations for class
of customer as well as for volumes of consumption; typically increasing block charges,
declining block charges or other billing structures. A separate waste water charge, or
even storm water charge, may be included for water utilities that provide these addi-
tional services. Most water utilities also assess a fixed service charge to cover the admin-
istration expenses of metering, billing, and other overhead functions. Many water
utilities base the service charge on the size of the customer meter, with the charge increas-
ing dramatically with meter size. In downsizing from a larger meter of poor accuracy to
a smaller meter of high accuracy, the water utility can more reliably capture the volume
of water consumption and increase revenue from the usage charge. However, in reduc-
ing the size of the meter, the water utility could lose some revenue due to a smaller ser-
vice charge. The net change in revenue to the utility, therefore, depends upon the amount
of recovered revenue due to improved accuracy, offset by reduced service charges. Each
customer account being considered for downsizing should, therefore, be carefully
reviewed to determine the exact economic impact to the water utility. The Greater Cin-
cinnati Water Works reported on the success of a structured large meter downsizing
effort, but noted the dilemma of downsizing certain large meters when anticipating a net
loss of revenue due to a significantly lower service charge. 6