Page 181 - Water Loss Control

CHAPTER 11

Controlling Apparent

Losses—Capturing Missing

Revenue and Improving

Consumption Data Integrity

George Kunkel, P.E.
Julian Thornton
Reinhard Sturm

11.1 Introduction
Water losses in drinking water utilities occur as two distinct types: real losses are the
physical losses from distribution systems, mostly leakage but also water lost from tank
overflows. Apparent losses are the nonphysical losses that occur when water is success-
fully delivered to the customer but, for various reasons, is not measured or recorded
accurately, thereby inducing a degree of error in the amount of customer consumption.
When such errors occur systematically in an appreciable number of customer accounts,
the aggregate measure of water consumption can be greatly distorted and significant
billings can be missed.
This chapter explains the causes of apparent losses and describes the significant
impacts that they exert on consumption data integrity and revenue capture potential in
systems with metered customers. Chapters. 12 to 15 explain the major categories of
apparent loss and the means to control these losses to economic levels.
Apparent losses are defined as nonphysical losses, since no water is physically lost
from the water supply infrastructure. However, these inefficiencies in the accounting and
information-handling practices of the water utility can exert significant impacts. They are
caused by faulty, improperly sized or badly read meters, corruption of water consump-
tion data in billing systems, and water which is taken from the distribution system with-
out authorization. Apparent losses consist of three primary components:

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