Stopping Loss, Saving Funds
Leaky pipes and non-revenue water are forcing utilities to strike a balance between leak detection, pipe repair, and economics.
The city of O’Fallon, MO, was losing 83,000 gallons of water day because of leaks in its municipal water lines. Dan Scherer, director of water and sewer operations for the city, thought it’d be even worse. Still, 83,000 gallons multiplied by 365 days does equal a lot of lost water throughout a typical year. “You hope that leak testing doesn’t find anything,” says Scherer. “But you have to be realistic. A lot of our water system is relatively old: our water loss was creeping up from year to year. We want to curb that, and detecting the leaks is the first step.”
The city of O’Fallon isn’t alone. Many municipalities across the country are delivering water to their residents through old cast-iron pipes. These pipes are, unfortunately, susceptible to corrosion. And when corrosion occurs, so do leaks. These leaks lead to water loss, much of which disappears into the ground. This means that many municipalities have little idea exactly how much water they are losing each year.
Fortunately, a host of manufacturers offer leak detection and pipe-repair solutions. Using ultrasonic technologies and high-end water meters, these companies can help municipalities quickly discover leaks that in years past would have gone largely undetected.
These manufacturers say that while leak detection and repair programs aren’t cheap, municipalities who ignore leaking pipes run the risk of occurring even larger bills in the future. “There are so many reasons why leak detection is important to utilities,” says Craig Hannah, development manager for the municipal utility solutions team of Johnson Controls. “You have the financial reasons that come with reducing the amount of potable water loss in your system. You will also save money on the energy used to treat the potable water, as well as the chemicals that you purchase to treat the water. If you are purchasing water from another utility, you will save a tremendous amount of money, especially when you are paying retail or near-retail costs for that water.”
Hannah’s a realist. He knows municipalities today are struggling with tight budgets—the rough economy has made that a certainty. And when dollars are tight, municipalities are tempted to live with their existing water loss rather than spend the money it takes to detect and repair leaks. It’s an approach Hannah doesn’t recommend. Unfortunately, it’s one that’s common in today’s difficult times.
Worth the Cost in O’fallon
But don’t count O’Fallon as one of those municipalities that doesn’t understand the value of leak detection. The city hired ADS Environmental Services to test its water lines with acoustic leak detection and correlation equipment. The testing ended in August, and ADS determined that O’Fallon was losing about 83,000 gallons of water every day through leaks.
The good news is that the majority of leaks came from fire hydrants that were not closed down properly, Scherer says. And, in even better news, only a small number of the hydrants needed to be disassembled and rebuilt.
Those pinhole leaks that ADS detected have already been repaired, Scherer says. Doing this will save the municipality a significant amount of money each year.
“Personally, I thought they’d find even more leaks,” he says. “We’ll do this process once every three years now to make sure nothing else pops up along the way. You have to stay on top of these things to make sure that leaks don’t become an even more serious problem in your system.”
Not every municipality takes the same approach as O’Fallon. Doug McCall, director of marketing for Sensus—a company that manufactures water meters that detect potential leaks—says that some municipalities view leaks as a cost of doing business. They’d rather suffer yearly water loss than pay the money for new water meters or to hire a company to check their system for water loss.
McCall says that, in general, large municipalities that pump a significant amount of water each day are more aware of how costly system leaks can be. Smaller municipalities, with their corresponding smaller budgets, are more likely to put off leak detection and repair systems. Other municipalities that are located in parts of the country where the cost of water is inexpensive are often less inclined to vigilantly track down and repair leaks in their pipes, he adds.
And far too often, water utilities have no idea how much water they’re actually losing to leaks each year. “For the most part, water utilities don’t know what they don’t know when it comes to leaks,” says McCall. “There hasn’t been a real big drive for utilities to do any type of water loss in-depth empirical studies. And those studies that are done, are done in areas that are poster children for water loss. They focus on the utilities with the worst problems. Those are no-brainers: When you’re losing that much water, yes, you’ll detect and fix the leaks; but the real question comes up when you’re looking at utilities that are more typical: When should they be concerned with water loss?”
McCall says the typical water utility loses anywhere from 10% to 30% of its water a year due to various reasons. Pipe leaks are a major part of what is often called non-revenue water.
Three factors can change this mentality, he says. First, and most important, is cost. When water costs go up, utilities will recognize the financial importance of detecting and repairing leaks. Utilities’ customers will place more pressure on their municipalities if they see their water bills rising because of the cost of undetected leaks.
Government regulations, too, can play an important role in forcing water utilities to pay more attention to leaks, McCall says. EPA tends to focus its energies on the quality of water being pumped into homes, but other state and local governmental agencies can inspire utilities to invest more energy into detecting leaks if they forbid them from losing more than a certain percentage of water every year.
Finally, the companies involved in the leak detection and repair businesses need to craft detailed case studies showing utilities just how much water, and money, they’re losing during an average year, McCall says. Utilities need more evidence to justify spending big dollars on detection and repair programs. “Too many utilities don’t know how much water they are losing in a specific period,” he adds. “They don’t know if the amount of water they are losing justifies the cost of investing in a leak detection system. They have to go out there and find the leaks, dig up the damaged pipes, and repair the leaks. At the end of the day, they don’t know if that leak was worth all that investment.”
For Hannah, the benefits of leak detection and repair far outweigh the costs associated with them. Not the least of which is the damage to their infrastructure that utilities can avoid if they detect and repair leaks quickly. “If leaks are repaired before much time passes, the amount of damage done by the leak itself will be greatly reduced,” he says. “Over time, leaks generally get bigger; they rarely stay the same. The damage to the pipe itself, as well as to the area surrounding it, is reduced if the leak is found and repaired quickly.”
Leaks can also damage the soil surrounding pipes, Hannah says. He points to a study done by the American Water Works Association (AWWA) at utilities across the US. AWWA asked utility officials to excavate a sample of the soil around any leaks or breaks in their lines and send that sample to a lab for analysis.
AWWA found that many soil samples contained a high concentration of chemicals. Hannah himself has seen human excrement in water meter vaults. If there is a leak in the vault, a negative-pressure incident can siphon that excrement back into the water lines. “There are so many reasons to fix leaks and breaks as quickly as possible,” he says.
Too many water utilities are in denial of this, Hannah states. “I hate to be negative, but a lot of water utilities don’t believe that they have a problem with leakage. They believe that if they have a leak, they’ll know about it—it will promptly surface. But I believe that gravity has worked every time it’s been tried. More often, a leak will work its way into the surrounding soil, and water utility officials will not see it. They will never know about it.”
Tom Walski, senior advisory product manager for water network engineering and management company Bentley Water, says water utilities not only have to be committed to finding leaks, they have to be equally interested in determining whether leaks are really at fault for the water loss they experience each year. This is because leaks aren’t the only cause of water loss, he says. Non-revenue for water can often be traced back to meters that aren’t registering properly or to theft of water. Often, residents will illegally open fire hydrants. Many municipalities don’t accurately track the amount of water that firefighters use in battling fires.
Those municipalities that don’t know the real reasons for their water loss run the risk of spending big dollars on problems that may or may not exist. For example, a municipality will lose money if it spends a significant amount of dollars on finding and repairing leaks only to find that the real reason for their annual water loss are meters not properly registering the amount of water the customers are using. If a municipality’s real problem is leakage, it won’t make any dent in its water loss by replacing the system’s meters.
“Water loss is not just leakage,” says Walski. “In the old days, people talked about unaccounted-for and accounted-for water. That’s all they knew. Today, it’s important for water utilities to know exactly why they are losing water. They need to realize that their water loss might not be the result of leaks.”
Walski would like to see more water utilities in North America follow the trend, in much of Europe, of breaking large water systems down into smaller subsystems. Many water utilities in the UK do this, breaking their large systems into District Metering Areas. With this approach, utilities in the UK can quickly identify anomalous water use in smaller neighborhoods.
Officials won’t know why the water use in a specific subsystem is spiking. But at least they’ll know where the strange pattern is taking place. Officials can then take steps to determine whether the water loss is the result of leaks, theft, or some other reason, Walski explains. Whether utilities take this or other steps to boost their leak detection abilities depends largely on each individual water district’s circumstances, he says.
For instance, a water utility in the middle of the desert in Arizona can’t afford to suffer a 25% rate of non-revenue water. However, a water utility that sits on the edge of one of the Great Lakes and serves a town with a small population probably wouldn’t be troubled by that same rate of non-revenue water, Walski says.
“The extent of whether you go after a loss depends upon the extent of how badly the losses are hurting you,” he adds.
The Large Pipe Dynamic
Michael Higgins, vice president with Pure Technologies, knows that some leaks are worse than others. The way he sees it, leaks in large-diameter pipes are far more dangerous to water utilities than leaks in smaller pipes. Higgins’ company specializes in helping municipalities detect leaks in these larger-diameter pipes. “With bigger leaks, the leaks are generally occurring for a longer period of time before they are noticed,” he says. “The volume of water loss is higher. Another equally important benefit is that you also get a condition assessment of the pipe when you embark on a large-diameter pipe leak-detection program. The job of a pipe is to transmit water from point A to point B without leaking. If the pipe is leaking, it is not performing its job adequately.”
This is important because, as with most leaks, those in large-diameter pipes tend to grow over time. A pipe that is just beginning to fail will have a small leak. That leak will then accelerate the damage to the pipe. Once this happens, the small leak becomes a larger leak. It grows with the problems that the pipe is experiencing. As the pipe begins to suffer an ever-larger failure, the water utility’s ability to deliver water to its customers is placed in jeopardy.
Unfortunately, most water utilities are still focused on small-diameter leak detection, Higgins says. “We still think there is too much of a concern on small-diameter pipes. There is not enough focus on large-diameter pipes, which is unfortunate. They leak a lot more water than do small-diameter pipes. If you fix one leak in a large pipe, you fix the equivalent of many leaks in a small-diameter pipe. By fixing a large-diameter pipe, water utilities are using their resources in a more prudent manner. We are seeing an increase out there in water loss control. We’re just not seeing it being focused on larger-diameter pipes.”
Hannah says that all leaks, both in large-diameter and small-diameter pipes, are important to correct. One of the issues that municipalities face today is that they are often low on manpower. Budget cuts have forced them to do more with fewer employees. “Utilities understand that leaks are costing them money,” he says. “They simply don’t have enough people to go out there to find and repair the leaks. We’ll hear utility directors say, ‘Even if we knew where the leaks are, we don’t have the manpower to go out and repair them.’”
Hannah offers a simple response: “You may feel tired and sluggish. If the doctor says you have internal bleeding, most people don’t say, ‘I understand, but I’m very busy at work. I can’t afford to take time off for surgery.’ Many utilities don’t see it this way.”
Finding leaks is one thing—repairing them is another. Water utilities have to decide whether to repair damaged pipe or replace it. Bruce Hollands, executive director of the Uni-Bell PVC Pipe Association in Dallas, TX, recommends that utility officials, when they need to replace pipe, choose the PVC variety.
There’s a reason for this: PVC pipe does not corrode. “Most leaking in pipe connections comes from corrosion,” says Hollands. “The economy is weak, and more municipalities are feeling a financial pinch. PVC pipe is still the more cost-effective material. In tougher economic times, municipalities are looking at PVC pipe, because it is the best buy for the dollar.”
Not all municipalities work with PVC pipe. Many water utilities have older systems that already have cast-iron pipe in place. They’re reluctant to make the switch to PVC. “It is a very conservative business that we’re in,” says Hollands. “You have engineers who have worked with cast-iron for a long time. They are sometimes averse to looking at new materials, even though PVC has been used for water systems for 60 years.”
Mark Montgomery, area sales manager for Texas, Oklahoma, Arkansas, and Louisiana for JM Eagle, says that too many cities mistakenly believe that cast-iron pipes are tougher, thicker, and stronger than PVC pipe. “That’s simply not always the case. What we’ve found in the last 15 years of studying water systems is that corrosion can eat metal pipe.”
This means that municipalities could have several metal pipes that are on the verge of failing at any one time. “It’s like a ticking time bomb,” he adds. “And when it does fail, it inevitably fails at 2:30 in the morning. That’s the real problem: the nightmare of shutting businesses down.”
Leaks will continue to be a fact of life for municipal water systems. Walski says that the smallest of leaks simply can’t be detected today. And even if they were, it probably wouldn’t make financial sense for utilities to attempt to repair them.
But McCall does see the day when water utilities are more committed to addressing water loss, whatever the causes of that loss may be. To him, it’s all part of the still largely undefined push for a smart grid for water. One of the keys of any water smart grid would be a massive reduction in the amount of water loss that water utilities across the country experience.
The key is also to convince utilities that water loss is a serious issue, McCall says. He believes that will take a massive push from the companies that make up the water industry. “I wish the AWWA would step in and do this,” he says. “We need someone to fund some really well done and controlled tests and pilots of the water leak situation. We need to determine what the acceptable benchmarks for water loss are. That way other utilities could use these benchmarks to justify the costs of detecting and repairing leaks. If they can’t justify these costs to themselves, they certainly can’t sell it to their town councils.”
Author's Bio: Dan Rafter is a technical writer and frequent contributor.