AWWA ACE60003

The Halifax Regional Water Commission was created in 1996 as a result of a Provincialamalgamation of three former water utilities in the Halifax metropolitan area. Each ofthe former water utilities had reported water losses quite differently. The new HalifaxRegional Water Commission reviewed the water loss reporting information and foundthat significant inconsistencies were present in the reporting procedures.The utility undertook a comprehensive industry assessment of the available strategiesfor assessing and reducing system water losses. The International Water Association(IWA) Standard Water Balance and corresponding strategies were adopted by theCommission in 2000. The international approach to water loss reduction was applied inHalifax, and significant loss reduction results were achieved using internationalstandards and strategies.The IWA approach quickly identified that standard terminology used in the utility, andthroughout North America, is not the same as the terms applied internationally. Theutility adopted many of the standard terminologies used internationally such as systeminput (production or system input feeds), active leak control, the adoption of "reported"and "unreported" leaks in its administrative process, district metered areas, andpressure management areas in describing the zones throughout the system. Severalnew concepts were adopted including the fixed and variable area discharge pathsknown as FAVAD, and component analysis of burst and background leakage estimates,or BABE, in calculating unavoidable losses from small undetectable background lossesand unavoidable burst run times.The Infrastructure Leakage Index (ILI) was adopted as the leakage measurement andsystem condition indicator. The ILI is a ratio of the calculated annual unavoidable realloss (background losses and unavoidable losses) to the calculated annual real losses,derived from the standard water balance. The utility adopted this index for a morecomprehensive assessment of the system leakage condition, described as a ratio ofreal losses over the lowest technical achievable loss level. The ILI can also be used asa utility comparison to assess the system condition and leakage performance on anational and international basis. The strength of this leakage performancemeasurement, and the comprehensiveness of the international approach to water lossassessment and strategies, were overriding factors in the Commission adopting theinternational approach to water loss assessment and management. Includes 15 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/17/2004

Number of Pages:

6

File Size:

1 file , 900 KB