Page 330 - Water Loss Control

Contr olling Real Losses—Speed and Quality of Leak Repair 299

essential for water utilities to provide excellent service, particularly for large water util-
ities that encounter thousands of complaints and work requests every year. The average
time to repair leaks can be increased if poor work order tracking results in a delay in
forwarding leakage information from the leak detection crew to the designated repair
crew. For utilities that employ paper work order tracking, it is not uncommon for paper-
work to be lost, resulting in a failure to respond to suspected leaks that have been iden-
tified during leak detection surveys. Water utility managers should review the structure
and effectiveness of their work order tracking process in order to ensure that unneces-
sary delays are not injected into the leak repair process due to poor work order informa-
tion management.
Component analysis of real losses, as discussed in Chap. 10, is a powerful tool to
analyze the impact various repair time policies have on the overall real loss volume of
a water utility. Again, leak repair policies and leak repair time targets should be based
on sound benefit to cost analysis.

17.3 Quality of Leak Repair
The quality of leak repair work plays a significant role in the overall leakage manage-
ment effort. Quality of materials and quality of workmanship are two main factors
influencing the overall quality of leak repairs. If the quality of leak repair is poor, then
there is a good chance that leaks will recur at the location of a previous leak repair. In
the worst case poor repair quality might even result in the creation of new leaks.

17.4 Summary
Leaks must be repaired in timely and effective fashion to ensure that loss volumes are
kept to a minimum. Surprisingly, many utilities do not always repair known leaks! This
may in some cases be due to an economic decision or one based on distribution logis-
tics, but in some cases it is just a lack of awareness of the impact on annual loss volumes.
Chapter 10 discusses in detail some of the methods available to model annual losses
and the impact of various interventions on those losses. The impact of an improved
repair program can be easily modeled. Not only must leakage be repaired, it must be
done in a manner which will ensure that this particular leak will not recur in the short
term. Unfortunately, quality of repair is an area which is sometimes overlooked. The
time until leak repair is carried out will almost always have a large effect on the annual
volume of real losses, whether it is leak repair from surfacing reported leaks or unre-
ported leakage which is located during a routine leak survey. Many small leak volumes
soon add up to one large leak volume!

Reference

1. IWA Water Loss Task Force. “Leak Location and Repair Guidance Notes,” 2007.