It’s a question Margaret Doss and her colleagues at Columbia County’s Water Utility are working diligently to answer – all in the name of conservation.
“Technically, it’s called ‘non-revenue water’,” said Doss, the department’s environmental compliance manager. “You look at what you make, and what you bill for, and the difference is what nobody paid for.”
Columbia County is one of about 250 larger water producers that must perform detailed audits to comply with the Georgia Water Stewardship Act, a new law designed to reduce the need for more water by promoting more efficient use of what is already available.
“We’re not required to do the audit until next year, but we did it this year as a proactive run,” said Doss, whose staff traced the 5.294 billion gallons of treated water pumped into the system during 2010.
The amount for which revenue was received was just 4.742 billion gallons.
“So the losses are 552 million gallons a year,” Doss said. “That is 9.9 percent.”
In Augusta, which has a larger and older system, the volume of unmetered water in 2010 was about 15 percent, or 2.1 billion gallons, Utilities Director Tom Wiedmeier said. The city’s two treatment plants produced 14 billion gallons, of which 11.9 billion were metered.
The amounts might sound high, but the volumes of lost water in both Columbia County and Augusta are well below the industry average.
Larger systems typically cannot account for 20 to 30 percent of the water that leaves their treatment plants, said Lebone Moeti, an environmental engineer with the Georgia Environmental Protection Division’s drinking water program. “That is just an educated guess.”
Auditing water use and defining the amount of water that is treated and sent out, but never paid for, is expected to improve efficiency and save money. “When your operations improve, you have less need for additional water, so there is conservation,” he said.
The new rule, which requires some utilities to complete formal audits by next April, applies only to water systems that serve more than 3,300 people.
“It is just 10 percent of the systems, but these systems provide 80 percent of the potable water for the entire state,” Moeti said. “So their activities will have a significant impact.”
Where does lost water go? Finding the answers sometimes takes detective work.
Leaky pipes and faulty meters are always prime suspects.
“Sometimes, if water is used to fight fires somewhere, that water may not be metered, but it can be estimated,” Doss said.
In Columbia County, high-tech devices are used to find leaks and clandestine connections or identify meters that may not function properly.
The LD-12 water leak detector, for example, includes headphones, probes and sensors – all packed neatly into a carrying case.
“It’s kind of like a doctor’s stethoscope,” Doss said. “It’s a high-powered listening device.”
The telltale, underground hiss of escaping water grows louder as the operator gets closer to the source.
In Augusta, with more than 63,000 accounts, the Water Stewardship Act audit will be a challenge but could also help make the department more efficient, Wiedmeier said.
“There’s a lot we don’t count right now,” he said. “The irrigation along medians on Greene Street and Broad Street are unmetered, for the most part,” he said. “But in recent years we’ve tried to take steps to meter everything that’s being used, even if we don’t charge for it.”
Good detective work – and an occasional lucky break – can sometimes find large leaks that create huge water losses, he said.
“We had a big one out Walton Way Extension near Best Buy and we spent a lot of time looking for it,” he said.
The break came when a landowner planning to develop vacant property tested a small stream whose presence might have triggered regulatory rules.
“Their sampling found the water to be very clean,” Wiedmeier said. “It even had some fluoride in it.”
The stream, it turned out, wasn’t a natural stream at all. It was treated drinking water flowing from a pipe that was thought to have been capped when a nearby line was re-routed for a road project. It has since been fixed.