The Halifax Regional Water Commission was created in 1996 as a result of a Provincial
amalgamation of three former water utilities in the Halifax metropolitan area. Each of
the former water utilities had reported water losses quite differently. The new Halifax
Regional Water Commission reviewed the water loss reporting information and found
that significant inconsistencies were present in the reporting procedures.
The utility undertook a comprehensive industry assessment of the available strategies
for assessing and reducing system water losses. The International Water Association
(IWA) Standard Water Balance and corresponding strategies were adopted by the
Commission in 2000. The international approach to water loss reduction was applied in
Halifax, and significant loss reduction results were achieved using international
standards and strategies.
The IWA approach quickly identified that standard terminology used in the utility, and
throughout North America, is not the same as the terms applied internationally. The
utility adopted many of the standard terminologies used internationally such as system
input (production or system input feeds), active leak control, the adoption of "reported"
and "unreported" leaks in its administrative process, district metered areas, and
pressure management areas in describing the zones throughout the system. Several
new concepts were adopted including the fixed and variable area discharge paths
known as FAVAD, and component analysis of burst and background leakage estimates,
or BABE, in calculating unavoidable losses from small undetectable background losses
and unavoidable burst run times.
The Infrastructure Leakage Index (ILI) was adopted as the leakage measurement and
system condition indicator. The ILI is a ratio of the calculated annual unavoidable real
loss (background losses and unavoidable losses) to the calculated annual real losses,
derived from the standard water balance. The utility adopted this index for a more
comprehensive assessment of the system leakage condition, described as a ratio of
real losses over the lowest technical achievable loss level. The ILI can also be used as
a utility comparison to assess the system condition and leakage performance on a
national and international basis. The strength of this leakage performance
measurement, and the comprehensiveness of the international approach to water loss
assessment and strategies, were overriding factors in the Commission adopting the
international approach to water loss assessment and management. Includes 15 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 900 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 6 |
| Published : | 06/17/2004 |
