AWWA ACE63094

This paper discusses a new concept in monitoring leakage throughout the distribution system by placing acoustic monitors on service lines. Coupled with the use of an automatic meter reading system, it has become possible to monitor nightly changes in vibration patterns on a daily basis. As part of the research, sections of Connellsville, Pennsylvania, water mains were exhumed and inspected to look more closely at the mechanism of main failure from the start of the leak to the surfacing main break. It is believed that many of the main breaks in Connellsville began as leaks from corroding pipe. If that proves correct, detecting leaks early may not reduce the quantity of and intensity of main breaks but lead to a better approach to making infrastructure improvements for the system. The project had the following major objectives: to evaluate the potential of a daily acoustic monitoring network system as a method to effectively manage an aging water distribution network; to identify differences in the pipes, and the subsurface environments between the onset of detectable subsurface flow and the time when the leaks actually surface; to learn how acoustic signatures as well as pipe failures and environmental characteristics might categorize leaks of varying types discovered at the onset of leaking; and, examine the structural characteristics of breaks captured near the time the leak starts to gain additional insights into the dynamics of failure. Leaks were divided into three categories: rapidly repaired leaks, those examined and repaired when first detected by the MLOGs; slowly repaired leaks, those that were repaired after specific periods of time after acoustic device detection; and, conventionally repaired leaks, those leaks repaired after detection by normal appearance (surfacing) of the leak. The field task routine was a cyclic process of leak confirmation, locating, timed response and data collection. The follow-up data analysis and reporting coincided with AwwaRF reporting requirements to assure a strong research response as the research progresses. Most tasks actually reflected a sequence in response to individual leaks identified over time. The task of reviewing acoustic information was performed several times per month. The leak repair/exhume/monitor responses was decided quickly for main breaks, service line repairs were accelerated. Includes 9 references.