BMP #3 - Distribution System Audits, Leak Detection and Repair
Background
A distribution system audit, leak detection, and repair program can help facilities reduce water losses and make better use of limited water resources. If you are located at the average, circa 1940's, military facility it is possible that more than 10 percent of your total water production and purchases may be lost to system leaks or poor metering practices (e.g., meter under registration and meter reading errors due to malfunction, poor installation, or wear). Regular surveys of distribution systems should always be conducted prior to obtaining additional water supplies and can have substantial benefits including:
- Reduced water losses. Reducing water losses will help stretch the existing supplies to meet increasing demand. This could help defer the construction of new water facilities such as wells, reservoirs, or treatment plants.
- Reduced operating costs. Repairing leaks will save money by reducing power costs to deliver water, and reduce chemical costs to treat water.
- Increased knowledge of the distribution system. As personnel become more familiar with the system including knowing the location of mains and valves, they are able to respond more quickly to emergencies such as main breaks.
- Reduce property damage. Repairing system leaks can prevent damage to property and safeguards public health and safety.
- Improved justification for water management. By conducting routine water audits and verifying production and end point meters, better accounting will result and help validate the need to reduce water losses.
For more information on this and other FEMP Water Efficiency Best Management Practices, please see the resources section.
Operations and Maintenance
- Complete a prescreening system audit to determine the need for a full-scale system audit using one of the following methods. Recommend that every two years:
- Determine authorized uses
- Determine other system verifiable uses
- Determine total supply into the system
- Divide authorized uses plus other verifiable uses by total supply into the system. If this quantity is less than 0.9, a full-scale system audit is needed.
Or
- Once a system audit has been conducted, obtain and monitor minimum system flow. This is usually the flow rate at around 3 or 4 AM. Significant increases to this amount can be assumed to be leak-related and would indicate that a full-scale leak detection survey is necessary.
- When indicated, facilities shall complete full-scale water audits using the latest edition of the American Water Works Association Water Audit Software found at their web site
Retrofit and Replacement Options
- Repair leaks or replace pipes when leaks are found.
- For specifics on this technology, consult with experts in the field. Your first resource should be your local or higher headquarters engineers, but do not overlook or rule out the benefits of input from experienced contractors or other Governmental agencies (DOD, CERL, DOE, FEMP, etc.)
Distribution System Audits, Leak Detection and Repair Resources
Kunkel, G. et al, 2003. Water Loss Control Committee Report: Applying Worldwide Best Management Practices in Water Loss Control. Journal AWWA, 95:8:65.
US Army Corp of Engineers Construction Engineering Research Laboratory. Preventing Water Loss in Water Distribution Systems: Money Saving Leak Detection Programs, Technical Report Number N-86/05.
Water Audits and Loss Control Programs, American Water Works Association, Manual of Supply Practices. AWWA Number M36.