While Spokane city officials have ratcheted up efforts to “slow the flow” and conserve more water, the city is having trouble keeping its own supply from leaking away.
The Spokane Water Department has lost about a fifth of its water supply – 12 billion gallons – during distribution of 63 billion gallons during the past three years, according to the city’s annual water quality report released Thursday. Last year, 3.79 billion of the 21.2 billion gallons the city pumped or purchased were not delivered to customers and were “assumed lost to the ground,” the report said.
The report showed the city met or exceeded all tests of water quality. But the amount of leakage is more than two and a half times the state average and almost double the standard adopted by the state when it reformed municipal water laws in 2003.
“There’s a lot of complexity to that number, but certainly it’s a concern,” city spokeswoman Marlene Feist said.
The city acknowledges it hasn’t met the state’s leakage standard of 10 percent, Feist said, and officials are currently reviewing how it measures consumption and loss through updating and checking the accuracy of consumer meters.
Not all calculated losses are from leaks, Feist said. Any unmeasured or estimated water uses – such as a fire hydrant – could be measured as a loss for the water system. And faulty meters can register less than the amount of water received, she added, which also counts as a loss.
But the problem lies largely with the century-old pipes, which can rupture and lead to small leaks that are difficult to detect and account for the greatest water loss, said Dan Kegley, the city’s water services supervisor.
“There’s a portion of our system that is at or beyond its expected life,” Kegley said. “The joints on those pipes are such that for freeze-and-thaw cycles … we may experience a little bit of movement” that could cause a break.
Unfortunately, leaks that don’t reach the surface often go unnoticed. Kegley said monitors regularly listen for leaks using a geophone, a stethoscope-like device that can detect leaks by sound. City departments also continue to replace old pipes during repaving projects – a coordination between departments that wasn’t always there.
But until water consumption can be accurately accounted for, the leaking will continue.
“Then we’ll start throwing darts at a dartboard instead of throwing darts at a wall,” Kegley said.
The report revealed Spokane achieved its total consumption goals last year, coming in at 6 percent under the goal despite the leaks.
But with water loss, the city inherently loses money, Kegley said, equal to the energy costs associated with pumping the water to the point of leakage. Without knowing exactly where leaks are, however, it is difficult to assess a dollar amount, he said.
Consumers don’t see water losses reflected in their bill because rate increases are guided by inflation, Feist said. Still, a water loss is something the department has to budget, she said.
Will Jernigan, a water loss expert with the American Water Works Association, said water leakage is a major problem facing communities nationwide. It drives up the operational cost of systems.
“Any time water is pulled from a source and treated and then pumped and delivered into the system, there is an investment made into that water,” Jernigan said. “If that water is lost, the cost of delivering that water is lost.”
Data obtained from the Washington Department of Health on more than 700 Washington water suppliers showed an average 2013 leak rate of 8.2 percent. Reports from 17 water suppliers in Spokane County showed a 9.9 percent average leak rate, with wide variations among municipalities. The city of Deer Park, for example, reported a 4.8 percent leak rate, while in the town of Rockford, more than half of its water supply was lost.
The city of Airway Heights reported a 9.4 percent figure, while the city of Millwood reported 26.7 percent.
Jernigan called the state’s 10 percent cap on water loss “inherently challenging” for Spokane because some systems simply operate at a higher leak rate. The key, he said, is first to understand how much of the total loss is actual leaking.
“The trick is the right tool has to be applied to the right part of the problem,” he said.