Page 136 - Water Loss Control

118 Cha pte r Ni ne

• An optimised overall pressure management policy in which
• The presence of surges are identified and steps are taken to minimise their
adverse effects
• Projects are implemented to adopt basic simple reductions of excess
pressures
• Further projects are implemented in order of cost/benefit
• An optimised repair time policy for all bursts
• An economic intervention policy for awareness, location, and repair of
unreported (hidden) bursts which is
• Influenced by the level of investment in leakage management infrastructure,
that is, telemetry/SCADA, DMAs, advanced pressure management
• Influenced by the exit level (background and other leaks remaining after
interventions)
• An economic level of investment in mains and services renewals which takes
account of all regulatory factors
If each of these activities is pursued to a logical conclusion in terms of cost and ben-
efit, then the definition of the economic level of water loss can be summarised as:
“That level of water losses which results from a policy under which the marginal
cost of each individual activity for managing losses can be shown to be equal to the
marginal value of water in the supply zone.”

References
1. Wikipedia. Production theory basics. [Online]. Available: http://en.wikipedia.org/
wiki/Production_theory_basics. [Cited: 10 April 2008]
2. Parkin, M. Economics. 5th ed. Addison Wesley, 2005. ISBN 0201537621.
3. Lambert, A., S. Myers, and S. Trow. Managing Water Leakage: Economic and Technical
Issues. Financial Times Energy, 1998. ISBN 1 84083 011 5.
4. Lambert, A. and A. Lalonde. “Using Practical Predictions of Economic Intervention
Frequency to Calculate Short-Run Economic Leakage Level, with or without Pressure
Management.” IWA Leakage2005 Conference, Halifax, Canada: The world Book, IWA,
2005.
5. Rizzo, A. “Tactical planning for effective leakage control. Leakage Management.” A
Practical Approach Conference: IWA, Lemesos, Cyprus: IWA, 2002.
6. Dellow, D. and S. Trow. “Implementing a New Operational ELL Model.” Water U.K.
8th Annual Leakage Conference. WaterUK, Oct 2007.
7. Department for Environment, Food, and Rural affairs, Environment Agency, and
Office of Water Services. Future Approaches to Leakage Target Setting for Water
Companies in England. Ofwat, 2003. http://www.ofwat.gov.uk/aptrix/ofwat/publish.
nsf/Content/tripartitestudycontents
8. Lambert, A. and J. Morrison. “Recent Developments in Application of ‘Bursts and
Background Estimates’ Concepts of Leakage Management.” Journal of Chartered
Institute of Water and Environmental Management. 10 April 1996:100–104.
9. Water Research Centre. Managing Leakage. WRC, 1994. ISBN 1 898920 0 87.
10. Lambert A., T.G. Brown, M. Takizawa, et al. “A Review of Performance Indicators
for Real Losses from Water Supply Systems.” AQUA. 48(6), 1999:ISSN 0003−7214.