SAN ANTONIO – With constantly aging pipes, it's a big task to keep water from leaking from the San Antonio Water System.
KSAT 12 News reported last week San Antonio loses 10.5 billion gallons each year. While that is a lot, in comparison to other big cities, San Antonio has a proactive water leak detection system. What many don't know is that system is run mainly by sound detection.
A SAWS leak detector isn't an electronic piece of equipment. It's a person.
"That's what it's supposed to sound like," said expert Herman Martinez, holding his hands to his headphones, describing the sound of water flowing through pipes in the ground.
Martinez is one of many leak detectors with a trained ear.
"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," said SAWS Construction and Maintenance Director Alissa Lockett.
"Newer subdivisions, there's mostly PVC in the ground, it'd be a different sound. The sharper the noise, the bigger the leak," Martinez explained.
Martinez compared the sound of water running through that first pipe to another one nearby, which he explained had a leak.
"That's going to be a service leak, that's not going to be on the main itself," he quickly assessed. "With a distinctive sound, it's a metallic main. It's an 8 inch."
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 leak Martinez found Monday was just outside of Julie Shank's front yard, so she won't be footing the bill.
"Very good news!" Shank said.
She's glad to see SAWS being proactive in detecting leaks before they turn into much bigger headaches.
"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."
Lockett says it's all about speed.
"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," she said.
She said SAWS is also looking for more technology to help in the process.
"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.
This year SAWS also started a four-year study that will help determine how often leaks reoccur all over the city, so crews can target problem areas with higher leak detection.