Locating leaks with acoustic technology

Many water distribution systems in this country are almost 100 years old. A bout 26 percent of piping in these systems is made of unlined cast iron or steel and is in poor condition. Many methods that locate leaks in these pip es are time-consuming, costly disruptive to operations, and unreliable at f inding small leaks. This article presents the results of research conducted at the US Environmental Protection Agency's Urban Watershed Research Facil ity in Edison, N.J. The project sought ways to use acoustic technology to p inpoint leaks as small as 0.1 gph (0.1 mL/s) in petroleum pipelines, a regu latory requirement for those lines. Because all experiments were conducted using water and on pipelines of size and material similar to those found in many water distribution systems, results also apply to these pipelines. Al though leaks of 0.1 gph (0.1 mL/s) are unusually small to search for in wat er distribution systems, researchers were able to locate small leaks within 1 ft (0.3 m), which is comparable to the best practice of commercially ava ilable leak-pinpointing technology for water distribution systems.