Ron Sheffield | 6/13/2009 1:29:09 AM
Water loss from a water distribution system is a significant factor affecting water delivery to customers. Water loss can be either: (a) the apparent losses because of meter inaccuracies or unauthorized consumption or (b) real losses because of leakage at water service lines, breaks or leakage on mains and hydrants/laterals or at storage facilities. By using loss prevention methods such as the new International Water Association (IWA) Performance Indicator Methods, or other standard methods, Louisiana communities will be able to promote a more thorough assessment of water loss among water utilities.
BASIC DATA AND INFRASTRUCTURE REQUIREMENTS
Awareness that water loss is occurring in a water system is the first step in identifying leaks and making repairs. Once water loss has been documented and identified, a water system operator can then determine whether the water loss is a real loss or an unavoidable loss. The first step in accounting for water used and lost in a water distribution system is appropriate data collection, especially from water meters.
Important data needed to assess water use and loss in a system include:
A) Information relating to the water system infrastructure:
B) The quantity of potable water supplied to the water distribution system including water imported and existing system sources, such as:
C) The quantity of water metered or consumed and nonrevenue water lost within the distribution system
D) Operations and maintenance activities within the water distribution system, such as:
ACTIVITIES TO REDUCE WATER LOSSES
Most water loss can be prevented by effective and proactive infrastructure management. The following infrastructure management activities will help reduce real water losses:
The following activities will help reduce apparent water losses:
Deterrence of theft or illegal usage by maintaining a visible presence, aggressively prosecuting those who are caught and soliciting public involvement in reporting such crimes. Accounting and record keeping practices to improve reliability and accuracy of the water balance more easily pinpoint areas with water losses.
MANAGEMENT STRATEGIES TO REDUCE WATER LOSS
There are numerous ways to reduce the loss of water. Deciding which program to use will depend on the condition of the local water infrastructure and the areas where water loss is occurring. Municipalities should consider one or all of the following programs to help in the reduction of water loss in their distribution system:
A municipality applying these strategies and activities will benefit through reduced water loss and reduced costs to the utility. The importance of prioritizing active leak-control practices and procedures in the identification of water loss and the corresponding strategies to reduce leakage cannot be understated.
The municipality will not only increase revenues but also benefit through the extension of sustainable water supplies, reduced operating costs, improved system hydraulics and utility efficiency and improved environmental stewardship.
Many additional resources on water loss control programs are available online or from the organizations and researchers listed below.
Thorton, Julian, 2002, Water Loss Control Manual. First edition. McGraw-Hill. New York, NY.
Waldron T. (2005) Managing and reducing losses from water distribution systems. Manual 10, Executive Summary. ISBN 0 7242 9498 8
AWWA, 1999, American Water Works Association Manual M36 , “Water Audits and Leak Detection,” The Manual of Water Supply Practices, AWWA, Denver.
AWWA, 2003, Applying Worldwide BMP’s in Water Loss Control , AWWA Water Loss Control Committee.