Leak-testing Laboratory

Henry County puts leak detection systems to the test and makes big strides in reducing water loss.
Leak-testing Laboratory
The Henry County Water Authority team includes, from left, GIS field technicians Gary May, Connie Nutt and David Berkowitz, lead GIS field technician Brock Biles, and GIS field technicians Lee Mooney and Brad Rowland.

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When the water utility serving Henry County, Ga., was ready to replace its leak detection equipment a few years ago, the agency didn’t just rely on word of mouth, a hunch, or a persuasive sales pitch from the vendor.

Instead, Brock Biles of the Henry County Water Authority road-tested three competing systems over a three-month period. The system that came out on top got the nod.

That sort of attention to detail exemplifies how the utility goes about its everyday business. By paying close attention to reducing leaks throughout the system, Henry County officials report they’ve saved more than a million dollars in lost revenue.

Leak detection has been the utility’s most valuable tool in holding down costs, says Allen Rape, the GIS manager for the Henry County Water Authority. When the state imposed tough new water conservation measures a few years ago in the face of a drought, “we were already doing this,” Rape says, referring to the leak detection program. “Every leak we find reduces our non-revenue water loss.”

Growing concern

Located in north-central Georgia, Henry County is a mix of rural and suburban communities. The county seat, McDonough, is located in the center of the county about 35 miles south of Atlanta.

The water authority mainly serves county residents who don’t live in incorporated municipalities. The 55,000 water service customers are connected by 1,400 miles of water line, about 60 percent of it ductile iron, 35 percent PVC, and the remaining 5 percent a mix of other materials. They’re served by two treatment plants and five reservoirs.

Henry County set up its leak-detection unit in 2007. With the age of some of the pipes, water loss from leaks had become a growing concern.

In 2010, Biles, who had been an inspector for the utility, moved over to run the leak-detection program. He made the move just as the authority was getting ready to replace its existing leak-detection equipment.

“We had to purchase all new equipment,” Biles says. He decided to choose the new supplier scientifically.

Systematic testing

Biles contacted several vendors. Three sent sample products, including the maker of the system the county was getting ready to replace.

To try them out, Biles took over an empty subdivision. It had been prepared for new homes, and the authority had already extended water and sewer service there. But with the national real estate bust, nothing had been built and the utilities had gone unused.

It was a perfect opportunity. “I made my own test site,” he says.

A leaking stretch of service line that was designated to be replaced elsewhere in the system came in handy. “We took it out of the field and installed it in the subdivision so we could use it for testing,” Biles explains.

Then, day after day, they ran leak-detection tests, comparing the three systems as they ran side by side.

They used other pieces of pipe as well, exploring the results with various materials. “I even put a PVC line in,” Biles says.

Being able to use “real” leaks that had developed through the natural course of operation of the system was important. Holes made deliberately in clean pipe just to test for leaks didn’t sound the same as a true hole, he says.

Altogether the testing team used six different leaks and sent three different volumes of water through each leaky test pipe for each system being tested. “The higher the volume, the louder the leak noise is,” Biles explains.

Strengths and weaknesses

The tested systems were all variations on logger-based systems in which sensors were deployed across the system to record leak data at designated times, usually overnight. “We put them a maximum of 500 feet apart,” Biles says, because when they were farther apart, sensors would sometimes miss the leak they were supposed to detect.

“I was really able to see how to get the optimal performance from each logger,” Biles says. The experiment also allowed the team to put each product through the paces on all the different types of pipe used on the Henry County system to analyze the strengths and weaknesses of each.

When the testing was finished, Biles says, the authority selected the Permalog Plus system from Fluid Conservation Systems Inc., based in Milford, Ohio. Coincidentally, the system was replacing a previous FCS product.

Daily checks

The authority’s procedure for leak testing has stayed pretty much the same since the program began in 2007. Two employees go out daily and deploy 120 loggers in a prescribed segment of the water line system.

The loggers are programmed to turn on at 2 a.m., when there’s unlikely to be much actual use of the system, which could confound the readings.

If the loggers detect a leak, they turn back on an hour later to verify it; otherwise they’ll shut back off and stay shut off. The next day, the workers retrieve the loggers, shifting them to the next segment of the line.

It takes about a year and a half to get through the entire system this way.

“We’ve swept the county three times already since 2007,” says Biles. “We’re in our fourth cycle now.”

The loggers are used strictly for ductile iron pipe. Three other employees use ground microphones to systematically work their way through the system’s PVC lines as well as checking every joint, fixture and fire hydrant and the small amount of pipe made of other materials.

That part of the procedure is new. When Biles was first conducting tests on the three alternative systems he realized that PVC lines weren’t getting the same attention. “This cycle [of inspections] is the first time we are actually doing that,” he says.

For those and related tasks, the agency relies on a mix of equipment, including the Xmic, from Fluid Conservation Systems, as well as the TriCorr and Soundsens i correlators.

Staying connected

From the very beginning of the inspection routine six years ago, with every logger deployment, the utility mapped every stretch of pipe inspected and recorded the data on its condition and any repairs that have been made. “We can pull up at any time information about what the results were,” Biles says. In addition, the information that the logger collects when it is in use  —  including when it was deployed and when it was retrieved, can help the authority track the workflow process.

The maps are updated by handheld readers that logger crew members carry.

“When you pick the logger out of the ground, you swipe it to the handheld devices,” Biles explains. The data is uploaded wirelessly to the reader. “Every afternoon the crew comes in, they dock the handheld, it uploads to the server and it updates our maps and records.”

When a leak is detected, the inspectors, who carry laptops in their trucks, enter information in the laptop’s database regarding the location and the severity of the problem. They measure how much water is coming out from the leaky pipe, take pictures of each leak and attach them in the database.

If repairs are urgently needed, the detection team contacts the authority’s operations manager, who in turn sends a repair crew to the scene.

And as the inspection program over time has helped in the targeting of repairs to damaged pipe, the number of leaks has begun to decrease. “The lower the number of leaks you have, you don’t have to say, ‘We have to go expand our treatment plant,’” Biles says.

The empty subdivision remains handy now, only instead of a testing lab it’s a teaching environment: “When new employees come in, I use it to train them on how to use the equipment,” he says.

Now that the housing market has begun to improve, he’s not sure how long the unoccupied neighborhood will be available.

“One day I’m going to lose it,” Biles says, “because they’re going to build houses on it.”



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