Geneva on the hunt for water leaks

Geneva officials want to know: Where is all the water disappearing to?

Equipment at the water treatment plant, opened in 2008, is able to measure the amount of water being pumped into the system.

Comparing that to the amount billed to utility customers, they've discovered a 20 percent loss, which the water department superintendent deems "unacceptable." It estimates it was losing close to 1 million gallons a month.

And since there aren't geysers of obvious leaks spouting up, the only way to find the leaks is check 75 miles of water mains suspected as the likely culprits for "hidden" losses.

The city council is likely to approve Monday a request to spend $7,500 to hire Westrum Leak Detection Services. Work would begin this year.

Leaks can happen in mains, service lines, valves and hydrants. Other unaccounted water is that used when hydrants are flushed, or to fight fires.

The city has already determined the mismatch is not due to unread meters.

"That's all energy that is being wasted," said Alderman Charles Brown, noting the power used to pump, treat and store the water.

The last time the city surveyed for leaks was 1999, and most were found in the oldest sections of town. That's where they will look first this time.

The other half of the city's lines - an additional 75 miles - will be surveyed in fiscal year 2010-11.

Usually when a water main leaks, water comes up to the surface. People notice and call public works. But sometimes, water leaks into a nearby storm sewer, or in a recent case on South River Lane, right through bedrock to the Fox River.

Westrum will use transducers and amplifiers to listen for leaks at accessible valves and hydrants. If leaks are suspected, a device called a correlator will be used to pinpoint the leak. Special microphones will be placed on two adjacent hydrants. Noise from a leak under pressure travels along the pipe's walls, the contents and the surrounding ground. The correlator measures how long it takes the sound to reach each of the microphones, and calculates the distance to the leak.

Leaks found on the public mains will be repaired by city crews. If a leak is suspected in a private service line, the city will notify the landowner, but it would be up to the owner to decide whether to fix it or not.