Stories from DEP is a collection of feature articles
published in DEP's internal newsletter, Weekly Pipeline.
This article was originally published October 26, 2010.
Sleuth Crews Use Clues to Seek Leaks
Using sound as its principal weapon, DEP’s Leak Detection Unit systematically searches for leaks throughout New York City’s water distribution system to prevent water loss and property damage. Created in the late 1970s, the program’s crews are equipped with sophisticated sound monitoring equipment to check water mains for leaks by listening to the flow of water in them. Leaks can usually be identified by the distinctive noise created as the water escapes the pipe, and are repaired before they can develop into larger water main breaks.
As part of the Bureau of Water and Sewer Operations, District Supervisor Richie Mazzella leads a team of 15 people. Not only does the crew respond to leak complaints that DEP receives through 311, the “bread and butter” of the team’s activity is conducting daily surveys where leaks are not even visible. These “detectives” are able to identify leaks without seeing them, or needing to dig up streets unnecessarily.
Last year, more than 4,000 miles of water mains were investigated and 389 leaks were located.
By successfully detecting and repairing those leaks, DEP conserved over 60 million gallons a day of water.
Just like in the past, sound is still the best way to pick up leaks. The main device used is the Digital Correlator, which has two sounding devices — similar to microphones — that are used on either side of a suspected leak. Each device is affixed to an access point in the distribution system, which are located at every intersection and fire hydrant. These sounding devices transmit signals to the Digital Correlator base station, and together with other data, DEP calculates and pinpoints suspected problems in the system.
Special features in the equipment also filter out subway and other disruptive noise. This is important because water flowing through an unbroken pipe is “silent,” but with a leak sound is produced by the disturbance in the flow.
With this data in hand, DEP crews are able to proactively fix leaks before they become a big issue. To all the leaks out there — you can “run,” but you cannot hide!