Page 237 - Water Loss Control

210 Cha pte r T h i r tee n

When a meter reading attempt is unsuccessful in obtaining an actual meter reading,
most water utilities bill customers using an estimated volume that is calculated based
upon a standard estimating protocol or the customer’s recent consumption history.
While these are reasonable approaches, multiple cycles of meter readings without an
actual reading greatly increase the prospect of inaccurate estimates. Over periods of
time, buildings are sold and new owners with vastly different water consumption hab-
its may become the permanent occupants. An estimate generated for a household of
two may be fine until the house is sold to a family of seven. Water consumption could
triple, but understated billings based upon the outdated estimate could continue for
some time. When an actual meter reading is eventually obtained, a large billing adjust-
ment will confront the new property owner, a scenario that commonly creates customer’s
ill will toward the water utility. Clearly, obtaining routine, accurate meter readings is
critical in maintaining sound oversight of customer consumption patterns and stable
billing and revenue collection functions.
Recognizing that some level of meter reading and data transfer error occurs to a
degree in virtually all water utilities, managers should designate staff time to periodi-
cally analyze meter reading and billed consumption data in order to detect trends of
irregular consumption stemming from data transfer error. A billing analyst should look
for trends such as successive cycles of “zero consumption” or other suspicious con-
sumption patterns. Accounts that register zero consumption for several successive
meter reading cycles should be sampled and investigated to determine if the zero con-
sumption is valid (which could occur if a building becomes unoccupied) or whether
AMR failure or tampering has occurred. The analyst should monitor the meter reading
success rate for both residential and industrial/commercial categories of accounts. The
number of estimates assigned should also be tracked and an approximation of the error
due to poor estimation should be attempted. Estimating protocols should be reassessed
if they have long been in use. Other sources of systematic data transfer error can exist
in any given water utility. Depending on available resources, investigations can be con-
ducted to assess any occurrences of data transfer error that are unique to the utility.
The auditor should attempt to quantify the major components of apparent loss due
to data transfer error and include them in the water audit. By investigating and analyz-
ing a manageable number of suspect accounts, the auditor should be able to identify
apparent loss volumes for a valid sample of the customer accounts in the water distri-
bution system. By extrapolating this value of apparent loss volume per account to the
entire customer population, the auditor can determine reasonable volumes for various
types of data transfer error. One type of potential apparent loss occurrence typical in
water utilities are accounts that have not been read for many billing cycles due to access
difficulties that prevent the meter reader from obtaining a manual reading. Special
efforts will likely be needed to gain access to these meters; perhaps written notices to
customers to arrange specific appointment times to allow for a meter read, or a request
to remove household items blocking access to the meter. If the local water regulations
allow—and the situation warrants it—the utility may need to send to the customer a
notice of violation that states that they must provide access to the water meter, or penal-
ties could be enacted, including, if permitted, shutting off water service to the customer.
Figure 13.10 gives an example of the calculations used to quantify volumes of apparent
loss due to data transfer error in the fictitious County Water Company.
Depending upon the size of the customer population, mode of meter reading, water
regulations or policies, and other circumstances unique to each water utility, the num-
ber of apparent loss subcategories due to data transfer error could range from as few as