Ground Penetrating Radar Systems (GPRS) was called in for a system wide leak detection in the borough of Greenwich, located in New YorkCity, NY. Based upon the flow times in the main pump house and the amount of water flowing into the system, the client was aware a leak must be present.Without GPRS help, the client had acoustically tested their own hydrants with their equipment and found no indications of a leak. No water was surfacing in the town but the rate of loss was near 100,000 gallons per day and draining their water tanks.
Upon arrival on site, GPRS water loss specialist Nick Starr obtained the borough’s available mapping of the water system, asked all the necessary questions, and began an independent investigation. An independent system wide investigation consists of acoustically locating all hydrants and where needed, main line valves and service valves. Each hydrant can be acoustically tested in mere seconds to determine if a pipeline leak is nearby and if further investigation in a particular area is warranted. Of the areas sounded, a few suspect spots were located. A major concern in leak detection is the possibility of false leak signal, which candidate from multiple different sources and can sound like a real leak is present. One area was on the town limits where main line valves were producing a particularly large amount of leak signal. Being so close to the borough limits raises a certain question; is there a master meter pit nearby?Exploration of the area near the valves produced a large meter pit which housed pressure reducing valves, back flow preventers, and other excessive noise producing equipment. The meter pit on the borough limits is used to transfer water between neighboring municipalities in the event of major water loss or other high demand. Being so close to the meter pit meant that all noise nearby was false leak signal and the investigation moved on to other spots. A second location was on a city street where minimal noise was located on two hydrants. Correlations between the hydrants were run, however no definitive results were produced. Upon sounding the hydrants once again, the noise had completely disappeared which indicated general water usage and no leak present.
Over the course of the day, all the locations suspected of having a pipe leak were ruled out and Nick was no closer to finding the missing100,000 gallons a day. The client advised Nick that the high school in the upper north of the town was also on their water system and that the lines within the school property were not private. The high school was not indicated on the provided mapping. Sounding of two hydrants on the school property yielded heavy leak signal, indicating a suspected main break. Correlations between the hydrants generated a leak location and acoustic ground testing was used to further pinpoint the leak spot. A main break was discovered in the school parking lot and upon repairing it, the water tanks recovered, and the area was back at normal operating levels.
GPRS can be contacted to provide an array of specialized services such as leak detection and utility location. To schedule any of your utility or leak detection needs in the New York City area, call 303-945-5415 or visit gprsinc.com.
GPRS also provides leak detection services in the following surrounding areas: Brooklyn NY, Long Island NY, and Queens, NY.