Story by James Szczybor
Photos by Emily Cikanek
The one good thing about leaky kitchen faucets is that they’re easy to see and hear. Underground leaks in water mains and distribution pipes are a whole different matter. Buried beneath streets and soil, the Chicago region has tens of thousands of miles of pipe, and as a result of such factors as age, corrosion, and the freeze-and-thaw cycles of our brutal winters, a lot of those pipes leak. Many leaks start as mere trickles, creating a steady stream of wasted water; but they can increase in size and given the right (or wrong) conditions, lead to catastrophic main breaks that damage roads, other utility systems, and private property. Avoiding those costly problems sounds relatively straightforward – find leaks and fix them – but it requires a good … artist?
For more than 20 years, Skip Semetulskis has been detecting and fixing leaks in municipal water pipes for Illinois American Water (IAW), a investor-owned water utility that serves 120 communities throughout Illinois, and 35 in the greater Chicago region, including Orland Hills, Homer Glen, and St. Charles. “Leak detection is a mix between science and art,” says Semetulskis, and to prove it, this modern day da Vinci demonstrated how he uses his “paintbrush” to identify possible leaks in the 327 miles of pipe IAW manages in Bolingbrook – and the 715 in total across their metro Chicago service area.
That paintbrush is the x-mic sounding device that Semetulskis runs through the underground service area to listen for consistent sounds. Standing on the sidewalk on a hot summer day, he can hear the water flowing through pipes, a squirrel running across a neighbor’s lawn, and a car driving through the intersection 150 yards away. These extremely sensitive tools are the leak specialist’s “paintbrush,” used to paint a picture of the underground pipe system. Knowing what’s what is where the art comes in. What Semetulskis hears depends on the pipe’s material. Whether it’s copper, plastic, concrete or steel, the sound of a leak can be deduced from the steady drum of the water. A leak in a copper pipe, for instance, sounds like a high pitch screech – and sure enough is a sign all is not well.
Once Semetulskis suspects a leak he turns to science. He uses a line detection device to determine the exact location of the pipe below ground, then locates valves at opposite ends of that section of pipe. The movement of water through a pipe creates a certain pressure wave with a known frequency; a leak alters that pressure. By analyzing the discrepancy between the intended frequency and the actual frequency, the location of the leak between two valve points can be pinpointed quite accurately, in a process called “correlation.” The technology and expertise to identify leaks this way is relatively new. In the past, workers were forced to dig up large tracts of land or concrete to manually find leaks in pipes. Now, a hydroexcavator is used to dig very precisely, dramatically reducing the cost and time of fixing leaks.
Leaky pipes can waste a lot of water. In the Chicago region, it’s not uncommon for a public water system to “lose” 10 to 18 percent of its water during transmission, before it even reaches a home or business for consumption, in systems without a proactive approach. Not all of that “unaccounted-for-flow” is due to leaks (some is due to theft or faulty meters), but they’re a primary culprit. A modestly sized community might pump about 5 million gallons of water a day; at 10 percent loss, that’s 500,000 gallons of water lost every day.
Every drop that is procured, treated, distributed, and subsequently leaked into the ground is non-revenue water. The more non-revenue water a utility pumps, the harder it is to fund the system, and the greater the need to increase the price of the water that makes it through the system to a customer. Moreover, lost water isn’t just lost water. Leaks waste energy and treatment chemicals, cause cracks and sinkholes in roads, erode soil and ruin landscaping, and lead to flooding that damages property.
Historically, leak detection and repair has been a reactive task – and sometimes it still is, especially during the cold winter months when pipes are more vulnerable to breaking. But new technology and savvy experts like Semetulskis are making proactive management more and more common. A lot like getting regular oil changes for a car to avoid engine failure, a steady stream of preventative maintenance is more cost effective than allowing systems to degrade to the point of breaks. Regular leak detection is a cost of reliable service, and IAW, as an investor-owned utility, is required by the Illinois Commerce Commission to account for that in its rates. Many municipal utilities do the same, and so derive the same sort of benefits as communities served by IAW. However, it’s still the case that in many communities, regular leak detection is discontinued when there is insufficient revenue to cover that cost. Ironically, that can be the result of leaky pipes and an abundance of non-revenue water, creating a vicious cycle of inefficiency.
“Water is worth the cost of reliable service,” says Semetulskis, before slipping his headphones back on to listen for the high-pitch whine that will let him know a leak is at hand. “No leak is too small to fix. Even a tiny hole can cause big problems.” Somewhere mixed in with science and art, the work Semetulskis and other leak detectors do is part common sense too.
WOWW factors
48,000 gallons/year
The amount of water – enough for a year of daily showers – that a pinhole-sized leak can let out of a home’s water system.
$190.08/year
The money that same household loses from the pinhole-sized leak, at $3.96 per thousand gallons (NE Illinois’ average uniform volume rate as of 2010).
500,000 gallons/day
A conservative estimate for the amount of water a modestly sized utility could lose daily, assuming 10 percent loss.
$722,700/year
At $3.96 per thousand gallons, the amount of lost revenue that utility would experience at that rate of loss.
Conservation tips
Look for leaks at home, Part 1: IAW offers a home leak detection kit to its customers, and some municipal water utilities do as well. Check with yours.
Look for leaks at home, Part 2: Even without a kit, you can still look for leaks. Check your water meter, then refrain from all water use for two hours. Check the meter again. If the reading changed, you’ve got leaks.
Look for leaks everywhere else: If you see standing water on the street during dry weather, or if there’s a puddle that doesn’t seem to go away, or any other water that doesn’t seem like it should be there… there may be an underground leak. Report it to your utility or public works department.
Resources
Water Loss Control – What Can Be Done?, Alliance for Water Efficiency
Water 2050 (Chapter 4, page 100), Northeastern Illinois Regional Water Supply/Demand Plan
Learn how to find and fix leaks with this short instructional video:
