Page 191 - Water Loss Control

Contr olling Appar ent Losses—Capturing Missing Revenue and Data Integrity 165

1. Conduct bottom-up audits to confirm extent of losss

2. Identify relative impacts to revenue and data integrity

3. Identify corrective actions to address prority impacts

4. Confirm cost-benefit ratios of corrective actions

5. Set an action plan for apparent loss control interventions

FIGURE 11.6 Establishing an apparent loss control strategy. (Source: Ref. 6.)

as few as 50 meter tests per year, with 25 randomly selected meters and 25 meters
that have registered high cumulative consumption. Data from this testing will give
a preliminary representation of the accuracy status of the current meter population,
and the yearly trend will ultimately reveal the points at which meters lose accuracy
significantly due to cumulative volumes passed through the meter.

The above first steps are manageable in terms of effort and expense and can provide
good data and possible recoveries that can get apparent loss control efforts started pro-
ductively. Once water auditing has been performed for several years, additional bottom-
up data from field investigations should become available and a more robust assessment
of existing apparent losses can be undertaken.
Figure 11.6 identifies a sequence of steps to take to develop and implement the
apparent loss control strategy after the initial top-down water audit has been compiled.
These steps, starting with the bottom-up auditing activity, should be followed in
sequence in order to assure that intervention actions are economically justified and well
planned. Bottom-up activities for apparent loss control include detailed investigations
of metering, accounting, and billing functions. Flowcharting the billing system process
is an important bottom-up activity described in Chap. 14 as the recommended first-step
action. Meter accuracy testing also falls under the heading of bottom-up activities.
These activities also include field investigations of customer properties to inspect con-
nections for possible meter tampering, illegal connections, or other forms of unauthor-
ized consumption. Many other similar activities could be conducted to track down
apparent losses. Any activity that delves into the specific conditions of suspected appar-
ent losses can be considered bottom-up activities. Bottom-up activities require more
work to conduct than top-down activities but they specifically identify individual
losses, allowing intervention actions to be strategically targeted to known losses and
more reliable data to be generated for the water audit.

11.8 Developing a Revenue Protection Program
to Control Apparent Losses
The most significant impact of apparent losses for water utility managers is uncaptured
revenue. The label revenue protection program is used to identify the collective activities
used to protect the utility’s revenue base by controlling apparent losses. As noted above,