Page 279 - Water Loss Control

248 Cha pte r F i f tee n

Unauthorized consumption occurs to some extent in virtually every drinking water
utility. It typically occurs through the deliberate actions of customers or other persons
who take water from the system without paying for it. The nature and extent of unau-
thorized consumption occurring in a water utility usually depends upon a combination
of the following factors:
• The demographic scale of the community being served
• The economic health of the community being served
• The value the community accords to water as a resource, often as a function of
the relative abundance or scarcity of water in the region
• The strength and consistency of the enforcement policies and practices existing
in the water utility
• The political will of water utility management and public officials to enact and
enforce effective policies to thwart unauthorized consumption

The value that the community and water utility place upon water supply and the
management effectiveness of the water utility are often reflected by the amount of
unauthorized consumption occurring in a locale. Establishing features of a good
accountability and loss control program—water auditing being foremost—will inevita-
bly uncover situations where unauthorized consumption is occurring.
Of the major components of apparent loss, unauthorized consumption creates the
greatest impacts to ratepayer equity. When a portion of the customer population under-
pays or fails to pay for water service, the paying
portion of the customer population effectively pays
for the nonpaying portion, since rates are usually
Unauthorized consumption
set to recover all costs of service. When the need
occurs to some extent in virtually
arises to increase water rates, the paying population
every drinking water utility.
is forced to shoulder an even greater financial bur-
den while scofflaws remain unchecked. If a water
utility does not control unauthorized consumption, it does a disservice to its paying
customers and risks a public relations backlash should the knowledge of high unau-
thorized consumption reach the media or general public.

15.2 Quantifying the Volume of Unauthorized
Consumption in the Water Audit
Most instances of unauthorized consumption are attributed to customers who either can-
not or will not pay for the services they are rendered. All utility systems are susceptible to
the occurrence of unauthorized consumption, and this occurrence is substantial for some.
In large, urban systems, occurrences of unauthorized consumption are likely to be more
numerous than that of medium or small systems in suburban or rural settings. Yet, in
most cases and regardless of system size, the total annual volume of water lost to unau-
thorized consumption is likely to be a small portion of the water that a utility puts into
supply. The water audit should quantify the component of unauthorized consumption
occurring in the utility. For first-time water audits, or where unauthorized consumption
is not believed to be excessive, the auditor should use the default value of 0.25% of water
supplied (WS) as the volume of unauthorized consumption. This percentage has been