Page 44 - Water Loss Control

26 Cha pte r T h ree

volume of actual water used. Customer meters also allow the user to monitor his or her
own water usage and provide the customer the option to exercise restraint against
excessive use and identify waste. Outwardly, this approach seems to follow the norms
of typical free market commodities, payment is
based upon the volume of product or service deliv-
ered. Yet, the use of customer meters and usage-
The guiding institution on
based billing is far from universal in the water
water supply in the United
industry in the United States or the world at large.
States, the American Water For a large portion of public water supply custom-
Works Association (AWWA), rec- ers, service is provided without any measurement
ommends that every water util- of their actual water usage and billings are based
ity meter all water taken into its upon flat rate charges assigned by customer user
system and all water distributed type. In the United States, perhaps only one-half of
from its system at its custom- all users have water meters, with sentiments regard-
er’s point of service. Customers ing metering sharply divided in certain areas of the
country. In England and Wales, traditionally only
reselling utility water—such as
the industrial, commercial, and institutional (ICI)
apartment complexes, whole-
customers were metered. Environmentalists and
salers, agencies, associations,
regulators support the establishment of universal
or businesses—should be
residential customer metering, and a slow transi-
guided by principles that tion is occurring with meters being installed in new
encourage accurate meter- construction and upon customer request. Approxi-
ing, consumer protection, and mately 25% of all residential properties were
financial equity. 5 metered in England and Wales as of the close of the
year 2006.

Why Do Apparent Losses Occur
Apparent losses occur in three primary ways:
1. Customer meter inaccuracies
2. Errors in water accounting
3. Unauthorized consumption
In comparison to real losses, apparent losses have a much greater negative effect on
the utilities revenue generation since they directly impact the utility’s cash register.
Apparent losses should always be valued at the retail value of the water sold. Another
important factor regarding apparent losses is that an understatement of the apparent
loss volume results in real losses being overstated in the water audit. This can poten-
tially misguide water loss control planning by placing inappropriate emphasis on leak-
age while highly potential revenue recovery goes unattended.

How Customer Meter Inaccuracies Occur
Errors in measurement can occur in several ways. First, water meters reading can be in
error due to a variety of mechanical or applications reasons. Due to widely varying
water consumption patterns among customer populations, a number of different meter
sizes, and sometimes types, can be found in any single water utility. Standard displace-
ment or velocity meters provide accurate flow measurement for residential users while