An Overview of Leak Detection and Monitoring Techniques

摘要

High unaccounted-for water is often related to leaks in the water distribution system. Other factors responsible for the un-accounted-for-water include under-metering or malfunctioning of meters, water loss due to main breaks, water used for fire fighting, system flushing, tank overflows, and unauthorized use of water. It is estimated that the value of water that is "unaccounted-for" in the United States may be as high as $1 billion. Leaks in water distribution systems may occur at fire hydrants, valves, joints, or pinholes caused by corrosion activity. Every water system is expected to lose some water through leaks and breaks. Even newly constructed water lines are allowed a certain minimum leakage rate depending on system pressure, pipe size, number and kind of joints, and type of pipe. The leakage rate from water distribution systems in many aging urban areas of the United States is expected to increase if effective leak detection and pipe rehabilitation plans are not implemented. An effective leak detection and repair program can significantly reduce the level of unaccounted-for-water. It should be understood that it may not be economical to repair all sources of leakage. The leakage sources which are not economical to repair are referred to as "unavoidable leakage." On the other hand, those sources of leakage which can be economically repaired are referred to as "recoverable leakage."