How A Utility Deploys Human Hearing Against Water Loss

Despite developments in data analytics and technology to help water utilities detect leaks, the best resource may be low-tech.

“A San Antonio Water System (SAWS) leak detector isn't an electronic piece of equipment. It's a person,” KSAT 12 reported.

Listening to pipes through a pair of earphones, Herman Martinez, of the system’s leak detectors, said per the report: "That's what it's supposed to sound like. Newer subdivisions, there's mostly PVC in the ground, it'd be a different sound. The sharper the noise, the bigger the leak," Martinez said.

SAWS Construction and Maintenance Director Alissa Lockett said: "They have the listening device that they put up to the metal pieces in our system like a meter is metal, a valve is metal. They're able to hear leaks even on PVC pipes.”

Here’s how the job works, per the report:

Most of the leaks are in the meter boxes or valves near the top of the system. They are rarely in the pipes themselves. There is a certain device that will then help experts like Martinez find where the leak is, plus or minus about three feet. They determine whether it is in a SAWS pipe or a pipe from a private property.

The utility says speed is a top priority in leak detection.

"Try to identify them faster so we can stop the water loss sooner. When they find a leak like that they file a work order that day," Lockett said.

For customers like Julie Shank, leak detection by the utility helps avoid surprises on the bill.

"You just hate if there's a drought in the summer or something, to see all this water running down the street. Because once it erupts, I'm sure it takes them much longer to fix it than it would take with this detection system," Shank said. "We had a huge eruption of water in the school yard over here some time ago, and it took all day to get it stopped and to get it fixed and for all of us to have water back."

Despite the effectiveness of its current practices, the utility continues to look at technology that can help it detect and address leaks.

"Most of the leaks in our system have always been detected through acoustics because it's very expensive to put anything in the pressurized pipe. So we haven't been doing anything in the pipe but we're looking at new technologies that are available to put in our larger pipes. Because it's more difficult in our larger areas like the medical center or downtown to go with a microphone and actually hear what's going on inside the pipe," Lockett said.

Leaks and water main breaks are a frequent problem in San Antonio. The utility recorded 2,556 water main breaks between June 1, 2015, and July 14, 2016, KSAT 12 reported.  About 4,000 acre feet of water was lost, the utility estimated.

SAWS is hardly alone in the fight against leaks and other problems linked to non-revenue water.

"The total cost to water utilities caused by non-revenue water worldwide can be conservatively estimated at $141 billion per year, with a third of it occurring in the developing world. In developing countries, about 45 million cubic meters are lost daily through water leakage in the distribution networks — enough to serve nearly 200 million people," according to a report by the World Bank.

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