Page 190 - Water Loss Control

164 Cha pte r Ele v e n

why these errors are occurring. It is then possible to consider various solutions to reduce
these losses. Possible solutions might range from improved auditing, new reports to
identify these errors, or better training as low-cost endeavors to replacement of the
entire customer meter population or a new customer billing system at the opposite end
of the cost spectrum. Solutions to reducing apparent losses due to meter reading errors
may range from better training for meter readers, improved auditing of meter readings,
and improved software on handheld meter-reading equipment to the implementation
of a complete AMR system as a long-term solution. The cost of each of these alternative
solutions should be compared to the projected revenue recovery from the reduction in
apparent loss, and the solutions ranked in terms of cost/benefit. Only those solutions
with a sufficiently attractive cost/benefit ratio or payback period should be included in
the apparent loss control plan. Clearly the scale and the shape of the cost curve for solu-
tions to the various components of apparent loss could be very different and will vary
from utility to utility. Also, comprehensive solutions, such as an AMR system, offer
many additional benefits in addition to apparent loss control. Until further research has
been undertaken, it is up to each water utility to develop appropriate utility-specific
costs and cost curves for the various apparent loss components that they perceive to be
significant.
The above approach illustrates two limitations in the current status of apparent loss
target setting. Firstly, in applying the method using cost curves, considerable data must
be generated. This can be a complex and time-consuming undertaking. Secondly, sepa-
rate cost curves must be developed for each of the components (and subcomponents) of
apparent losses that are deemed significant; one for customer meter inaccuracy, one for
meter tampering, one for unauthorized use of fire hydrants, and so on. Unfortunately,
there is no single, composite ELAL for a water utility. There will be an ELAL for each
apparent loss control solution considered and the overall ELAL for the utility will be the
sum of each solution to the different components of apparent losses selected. Therefore
the present means of rigorously developing the ELAL is a demanding task that cannot
be executed without considerable data. At this time, work is underway by the IWA
Water Loss Task Force to develop a simpler and more straightforward method of obtain-
ing the ELAL.
Clearly, the current approach to identify the overall ELAL is resource intensive and
time consuming. While work is undertaken to develop a simpler method to calculate the
ELAL, water utilities can still undertake a cursory analysis of their apparent losses and
identify approximate levels of desired apparent loss reduction. If a water utility is only
beginning to audit their water supply then it is very likely that considerable apparent (and
real) losses exist and it will be economic to recover a cost-effective volume of both real and
apparent losses. In lieu of a complex apparent loss analysis, the following recommenda-
tions are offered as standard starting points for water utilities in apparent loss control.

• Flowchart the customer meter reading and billing process—understanding this
process and identifying any lapses or loopholes that allow apparent losses to
occur are fundamental to the management of all apparent loss components.
Additionally, this exercise can be conducted largely in a table-top manner with
limited resources and costs, and may identify a number of loss components that
are quickly and inexpensively corrected by policy, procedural, or computer
programming changes. See Chap. 14 for details on flowcharting.
• Unless the customer meter population is very young and well documented,
perform annual meter accuracy tests on a sample of customer meters. This can be