Leak detection equipment from Schonstedt Instrument Company helped the town of Lonaconing, MD, diagnose its water system and successfully locate five leaks.
Rex Bowman of the Maryland Environmental Service contacted Tim Moore and Mike Curtis of Schonstedt Instrument Company after reading the article "Leak Detection Equipment Manufacturer Helps Find Major Line Breaks" published in the January issue of WaterWorld Magazine. Maryland Environmental Service is an independent state agency that provides operational and technical advice to communities in Maryland.
Bowman contacted Schonstedt to explore ways to help Lonaconing. On Feb. 10, Bowman, Moore and Curtis met with John Winner, Lonaconing's town administrator, to assess the town's problems. The town's four connected water systems were experiencing fluctuating water tank levels and staff could not determine the cause, although water leakage was suspected.
By closing and opening valves, the Water Department isolated one leak to a length of 6-inch diameter ductile iron pipe that was almost a mile long. The pipe runs parallel to and in a railroad right of way for several hundred feet, and then it goes diagonally across open ground and alongside a major roadway and out to the west end of town.
Moore and Curtis used the company's Water Hound Leak Noise Correlator to check the site where the leak was estimated to be. One accelerometer sensor was placed on a gate valve and another on a hydrant approximately 2,000 feet apart. By using the instrument's quick check survey mode, they determined there was no leak in that stretch of pipe.
The sensor on the hydrant was left in place while the other was moved to another hydrant approximately 550 feet west near a pressure reduction valve in the water main.
Moore and Curtis discovered a strong leak indication at about two-thirds of the total distance, located immediately beneath a crossing tributary at 90 degrees to the water main. The leak was feeding a stream, which bisects the town.
No leak was evident to the human eye or ear. An amplified ground microphone often is used to confirm the exact leak noise location; however the streambed site was not appropriate for this approach. Instead, several good-sized stones removed from the stream bank disclosed a "push" in the edge of the stream. Reasonable skepticism was resolved by conducting a chlorine test, which showed positive.
The streambed was excavated and the main exposed. The team discovered a 7-gpm (420-gph) leak located on the site of a prior repair performed one year earlier.
Throughout the day, the correlator pinpointed another four leaks in the town's business and residential neighborhoods under normal business traffic conditions.