Location and Leak Detection

Location and Leak Detection
Internal leak detection system pinpoints waterline leak

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Advanced metering infrastructure helps track usage, find leaks

Problem: After five punishing years, drought conditions have reached critical mass in California and much of the western United States, with Golden State utilities scrambling to meet government mandates for 25 percent reductions in water usage. The San Francisco Public Utilities Commission (SFPUC) needed a system to control water use and find leaks.

Solution: The commission installed the STAR network from Aclara for reading meters hourly. The data collected from the city’s 180,000 meters by Aclara’s two-way fixed network powers the utility’s system for letting customers track usage online. Aclara also generates a report that allows the utility to identify customers who may have leaks inside their homes. “The Aclara report tells us which accounts have exhibited continuous usage every hour over a three-day reporting period each week,” says Heather Pohl, automated water meter program manager for SFPUC. “We filter that report for single-family homes and analyze it to identify the minimum usage for each account. This process allows us to gauge the severity of the suspected leak.” The utility reaches out to those who show up on the report by sending weekly postcards notifying them of a possible leak. It monitors the reports and notes which accounts have come off the list, assuming that they have responded to the utility’s notice and fixed the leak.

Result: The leak detection system provides critical information with only minimal operator involvement. Since the units were installed, operators monitor the system and analyze results at the utility office. 800/297-2728; www.aclara.com.


Leak detection system helps reduce nonrevenue water

Problem: Ha’Gihon, the Jerusalem region water and wastewater utility serving a population of 1 million residents, was looking to reduce nonrevenue water and save on maintenance costs. The project began in September 2013 and is currently operating over 1,500 sensors covering 400 miles of pipeline.

Solution: The AQS-SYS fixed solution from Aquarius Spectrum provides up-to-date graphical information of history and statistics of every point of failure, finding underground leaks from the earliest stages of their development. This enables the utility to take steps and repair the leaks before significant amounts of water are lost. Each night, at the synchronized time, all sensors take a noise sample and send the information to Aquarius Spectrum’s cloud servers. All signals are processed and correlation algorithms for detection and alerts are issued.

Result: By July 2015, the system had found 104 hidden leaks in Jerusalem, of which 73 were on the public network and 31 on private property. Fixing the leaks resulted in potential savings of over 264 million gallons of water. An additional 188 cases of non-leak faults were found, including faulty water meters, valves and other equipment under the responsibility of the water company. Of those, 116 were fixed and another 72 were determined to be emanating from external causes or not requiring repair. www.aquarius-spectrum.com.


Internal leak detection system pinpoints waterline leak

Problem: Vollers Excavating & Construction was working at an industrial property in New Jersey to verify the location of a leak on a 12-inch steel chilled waterline that was buried 10 feet in the ground. The piping network at the suspected leak location connected to a 90-degree offset straight down, then dropped approximately 20 feet vertically before connecting to another 90-degree offset, allowing the chilled waterline to enter the building’s mechanical room horizontally at a depth of over 30 feet below grade. The excavation cost to construct an engineer-designed safe hole with trench boxes and shoring was more than $100,000. Vollers wanted to verify the leak was on the 20-foot vertical portion of the pipe, justifying replacement at a shallower depth in order to avoid increased excavation costs and more extreme working conditions.

Solution: The company contracted NYLD Infrastructure, a.k.a. New York Leak Detection Inc., to assist in locating the leak. Acoustic listening and leak correlation methods could not be utilized for the process, as the leak was large enough that the pipe could not be fully pressurized. Vollers installed a 2-inch tap on the 12-inch steel waterline for NYLD to use the Investigator from JD7 to do a live insertion for internal condition assessment and leak detection.

Result: The Investigator helped pinpoint the leak nearly 12 feet below the 90-degree elbow on the 20-foot vertical portion of the line. NYLD also determined the internal condition of the pipe was good with no corrosion, pitting or tuberculation, and there was no reason for future concerns. 858/242-1640; www.jd7usa.com.


Contractor uses locator to battle underground ‘spaghetti’

Problem: The trend was clear to R.B. Hinkle Construction, based in Sterling, Virginia, on the outskirts of Washington, D.C. The underground infrastructure was getting so crowded that crews had taken to calling it spaghetti. Utilities were increasing their fees for line hits, and the company was paying more in those fees despite its heavy emphasis on safety.

Solution: They found McLaughlin and its Verifier G2 utility locator. To use a G2, a crew member points the hand-held device at the ground and is given information on the receiver’s LCD window to find the direction of an object line and its position. When the top of the line is found, the receiver beeps.

Result: A job site demo helped persuade the contractor that the G2 was the right choice. The crew deployed the G2 to confirm the marks and find potentially unmarked utilities. During the demo, an unmarked feeder cable was found that was directly in the excavation path. Using the G2, the crew followed the feeder cable to a pedestal where it terminated. If not for the G2, the crew “would have most likely hit this feeder cable and knocked out service to at least six townhomes,” says Todd Gieseman, director of business development. 800/435-9661; www.mclaughlinunderground.com.



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