Priority Detection: Accounting for water resources and applying efficient leak detection tops water utility “to-do” lists.
by Dan Rafter
Editor’s Note: We’ re reprinting this important article in its entirety because it underlines one of the most obvious but soundly ignored facts about water management–the fact that leaks are a significant contributor to water shortages. –Hardly Waite.
Reinhard Sturm knows that water utilities across the country are losing water through leaks in their system. And he knows that many are losing a significant amount of water.Sturm is vice president of operations with Water Systems Optimization Inc. (WSO), an international engineering group with US offices in San Francisco, CA, and Nashville, TN. His company specializes in helping utilities determine how much water they are losing and identify the steps they can take to reduce this loss.
WSO engineers do this partly through water audits and leak detection. The results are often surprising, with some utilities losing 20% or more of the treated water they pump through their systems.
Sturm knows, too, that not every water utility will invest in the money it takes to either detect leaks or repair them. That’s because of a simple fact: For some utilities, leak detections and water audits simply aren’t cost-effective. “Look at a city like Philadelphia. There, water is quite cheap; it is plentiful,” he says. “Even though the amount of water losses can be high for utilities in the Philadelphia area, they are not high enough to justify making expensive repairs. That might be different on the West Coast where water is not as plentiful or cheap. But at a utility where that is not the case? They have no
justification to go further than identifying their water loss and making sure that it doesn’t get to be too high.”
That sums up the attitude today of water utilities, according to the companies that provide water audits and leak detection technology. Many are embracing new technology that lets them better monitor the amount of water that they pump into the ground, what is known as non-revenue water.
But others, in areas where water is plentiful and cheap, are not. They live with the water loss in their system until it no longer makes economic sense to do so.
The motivator for utilities? Money. Those who won’t suffer financially from water loss will invest little in leak detection and audits. Those who will suffer will do the opposite.“Those utilities who are interested in getting their hands around the amount of water they are losing are doing it because of financial reasons. The primary drive is the savings that they will see,” says Cliff Wilson, president of Buffalo Grove, IL-based Wachs Water Services, a provider of asset-management services for water-distribution systems. “The goal is to make sure that utilities are getting paid for this valuable resource that they are processing, to insure that utilities are getting paid for this product that they are delivering to their customers.”
Count Chris Leauber, executive director of the Water & Wastewater Authority of Wilson County in Lebanon, TN, as one of those water officials who is an advocate of water audits and leak detection.
The Wilson County utility runs its own water-loss control program in-house. This isn’t surprising—Leauber for about 20 years worked in the water loss consultancy side of the business before he came to the utility side. “We put a tremendous amount of emphasis on controlling our water loss,” says Leauber. “We purchase 100% of our water. Identifying and fixing leaks, then, is very valuable to us. When you produce your own water, the dollars you save in identifying and fixing leaks come in the form of the power you use to produce it and the chemicals you use to treat it. When you purchase your water, though, the savings are far greater.”
The Wilson County water system is divided into 16 district metered areas, or DMAs. The utility meters all the water that flows into these areas. System officials are able to compare the water coming into an area with the water that is actually billed to customers.
Using leak detection technology, the utility is able to isolate areas where leaks might be occurring. This is important: Nearly 100% of the pipe distributing potable water to customers in the Wilson County system is PVC. It can be hard to listen for leaks with this kind of pipe.
But by isolating specific areas, crews can target sections of pipe that might be losing water. It’s far easier to hear the sounds of leaking when utility crews already know where to look, Leauber says. “If you didn’t go through the district metered process, you’d have to go through the whole distribution system looking for leaks,” he says. “You can spend hours looking for leaks where there aren’t any if you take that approach. This breaks the leaks down to a specific area. We can now find our leaks 100% of the time. They are then repaired, saving us money in the long run.”
Discovering the Leaks
Mark Patience, product manager for water loss management line at Itron, says that he’s seeing a growing number—though not all—of municipalities investing more dollars into detecting leaks in their water delivery systems.
Patience says that many municipalities are even asking for leak detection capabilities to be included in the automatic meter reading/advanced metering infrastructure systems to which they are now upgrading.
This varies by state, though, with municipalities in some states particularly aggressive in tracking down and eliminating what the American Water Works Association refers to as non-revenue water.
Patience points to Tennessee, a state that he cites as enforcing especially stringent rules on how utilities can report non-revenue water numbers. “If officials in Tennessee see something that doesn’t make sense, they’ll perform an audit themselves,” he says. “That is kind of historic.”
Much of the increased attention to leaks and water management can be traced to the hot weather that has blanketed sizable portions of the United States in recent years. Many states in the southern portion of the country are struggling with drought conditions, Patience says. Some states, such as California, are trucking in water to their municipalities because they don’t have enough.
“Many utilities are not able to meet the demand of their users,” says Patience. “These utilities have to put more effort into preventing water from escaping from their systems.”
Other municipalities want to prevent the future, often more costly, problems that can result when leaks are not identified and repaired, says Wilson.
Leaks can be devastating if left untreated, he says. They could steadily increase the amount of water that flows into a municipality’s wastewater treatment plant, eventually overwhelming the facility. They could push chlorinated water into a nearby creek. They could even undermine the stability of an entire street, leading to a costly cave-in.
“Leaks can cause a whole dimension of collateral damage if they are not repaired,” says Wilson. “We’ve all seen pictures of fire trucks falling into holes in the street. We’ve all seen giant sinkholes in busy intersections. Often that was caused by leakage. And it’s not often caused by a big break, but by leakage over time. It builds up.”
The cost of the collateral damage, then, is often much higher than losses utilities experience from non-revenue water, Wilson says. “These are the losses that utilities need to consider when they wonder whether to fix a leak or to invest in leak detection,” he says. “The actual financial losses from water loss might not seem so bad. But when you consider the long-term damage that leaks can cause, that changes the financial situation.”
Even with collateral damage factored in, though, not all municipalities are as careful as others when it comes to detecting leaks and performing water audits.
Again, Patience points to outside factors for an explanation.
While many parts of the country are fighting through drought conditions, many other municipalities sit in parts of the United States where water is not only plentiful but cheap, too. If water is cheap enough, it’s not cost-effective for these utilities to invest in leak detection. Simply put, the technology is too expensive and the cost of water too cheap to make advanced leak detection a worthwhile investment for such utilities.
Today, many utilities are strapped for both cash and manpower. State budgets remain squeezed throughout the country. And municipalities facing budget hurdles aren’t likely to hire the staffers necessary to conduct water audits and monitor leak detection if the cost of water isn’t high enough to justify the extra expenditures, Patience says.
“Some utilities barely have enough staffers to go out and read the meters,” he adds. “They’ll outsource that work to third-party contractors. These utilities aren’t likely to hire the manpower needed to accurately track non-revenue water.”
Utilities face another hurdle when it comes to water audits and leak detection: the knowledge gap.
Doug McCall, director of marketing for Sensus, says that many utility managers have no real idea of how much water that’s escaping from their treatment and delivery systems each month.
Such utilities don’t have the technology they need to tell them how much water they’re pumping into the ground, McCall says. “A lot of utilities will tell you that they think they’re losing about 10% of their water in leaks,” he adds. “That’s actually pretty low. Best-in-class standards are 7%. But when you dig into the utilities’ data, you’ll find that they are just estimating how much water they are losing. There are political and other reasons why utilities want to keep that number low. If you do a real system test, you’ll find that most utilities are losing from 15 to 25% of their water. That is the range that we usually find.”
And once utilities are armed with this knowledge? They’re generally more likely to take steps to address their high percentage of non-revenue water.
The good news is that leak detection technology has improved over the years. Today, it can far more accurately tell utilities exactly how much of their water isn’t being delivered to their customers.
Sensus provides a good example. Sensus engineers can study the entire water infrastructure of a utility to determine how much water a utility is pumping into its distribution network and how much actually comes out of it.
It sounds like simple math. But it’s more complicated. By measuring water flow at meters located throughout the distribution system, and subtracting out the flow through utilities’ service connections, Sensus can calculate how much water these utilities are pumping into the ground instead of delivering to their customers.
There are complications, though. For instance, some utilities don’t meter parks or other public services, McCall says. Still, a macro approach can give utilities a solid feel for how much non-revenue water they are generating.
Sensus also works with partners that provide acoustic technology that lets engineers listen to pipes to find the biggest leaks in a system. Sensus will often deploy these partners after performing a macro analysis of a utility’s water distribution system.
Once Sensus identifies the zones that are plagued by the most leaks, the company’s partners will analyze these sections with acoustic technology to pinpoint specific leaks. Armed with this knowledge, utilities can then dispatch crews to exact locations to fix these potentially costly leaks. “If you own a water utility with a dozen zones, we can do an analysis on each zone,” says McCall. “We can tell you which are the top zones that are leaking the most water on a macro level. This is helpful information. We can then take acoustic technology to find the biggest leaks. This is a powerful combination of two different technologies that can help utilities cut down on their leaks.”
Sensus offers technology that directly benefits property owners, too. The company, for instance, offers meters that can identify continuous flows of water to residences or commercial properties. If the meters detect a continuous flow for more than 24 hours, the utility is notified of a possible leak. Utility crews can then investigate and, hopefully, repair a leak before too much water is lost.
Improved technology, though, hasn’t converted all utilities to fans of water audits and leak detection . . . yet.
Craig Hannah, development manager with Johnson Controls, says that the majority of utilities across the country still don’t view leak detection and water audits as anything close to a priority.
But he also says that this is slowly changing.
Part of the reason? The cost of water.
The cost of water has been relatively inexpensive for decades, Hannah says. But as municipalities look to the future, they realize that this will likely change. Water prices won’t decrease, but they might very well rise, Hannah says.
And because of this, utilities will be encouraged to take more steps to monitor exactly where their water is going. This will include both leak detection and a greater number of utilities ordering regular water audits, he says.
“Attitudes are slowly changing. For the longest time, people have viewed water distribution as a service, just like police and fire protection,” says Hannah. “No one questions the need to provide police and fire protection, just like no one questions the need to provide clean drinking water. But as long as municipalities treat water as a service, and not as a business, they won’t worry as much about the water they are losing from their system.”
McCall from Sensus agrees. “The primary goal in life of a utility is to make sure that clean, potable water comes out of the taps when customers turn them on,” he says. “If utilities pump some of that into the ground, even if it’s 15%, 20%, or 25%, as long as the utility is delivering clean water, no one’s that worried.”
This is changing, though. Many state legislatures—Texas and Tennessee among them—have mandated that utilities must conduct regular water audits as a way to prevent large water losses. Such requirements have become more frequent as water becomes both scarcer and, at least slightly, more expensive.
“The factors are lining up for some changes in the way utilities treat non-revenue water,” says Hannah. “The cost of water has been so low for so long, I really can’t imagine that cost decreasing any time in the future. If anything, it will rise. At the same time, the technology for monitoring water is improving. That’s a combination that is making an impact.”
In addition to price and legislation, another factor is motivating utilities to focus more heavily on leak detection and water monitoring: customer service.
Utilities that want to provide the best customer service need to invest in leak detection. Customers will appreciate it when their utility proactively takes step to stop leaks at their homes and businesses before they develop into more costly problems.
Sensus software, for instance, can alert utilities to potential leaks in the system. Sensus also provides software that notifies the end users of water that there is a potential problem. These notices can come in a number of different ways, including e-mail messages and text alerts.
“We can send a sudden-flow alert,” says McCall. “We can tell end users that something is broken.”
Other utilities are relying on out-of-town notification systems to provide better service to their customers. Such systems allow homeowners or business owners to notify their utilities by e-mail that they will be out of town for a certain number of days. If the utility sees water use at these properties, it can alert their owners that there might be a potential leak. If the water use meets or exceeds certain thresholds, the utility can send crews to investigate.
Detecting Leaks in Clayton County
The Clayton County Water Authority in Morrow, GA, provides water to more than 75,000 customers. The authority has five raw water reservoirs and can produce up to 42 million gallons each day of potable water.
Staffers here also maintain about 1,500 miles of water distribution pipes, 1,400 miles of sewer conveyance pipes, and 500 miles of stormwater infrastructure.
The water authority is also committed to reducing its non-revenue water.
In 2000, the authority began working with Itron to detect its leaks. This decision came after Clayton County at the start of that year found that its non-revenue water losses were nearing an unsustainable 20%.
Like other counties in the south, Clayton County faced a situation in which water supply was limited. County officials knew that Clayton County couldn’t afford to pump so much water into the ground.
The county’s leak detection program has since saved Clayton County a significant amount of money. According to Itron, the county’s non-revenue water losses fell to 12.5% in 2008.
The county relied on a suite of products from Itron to find its leaks. The first, a digital correlator, uses acoustics to localize pipeline leaks. Engineers can analyze the pressure waves caused by leak turbulence inside pressurized pipes to locate sources of leaks.
The county also used digital correlating loggers provided by Itron. These devices pinpoint the exact locations of the county’s leaks in just one overnight surveillance session. Clark County placed the loggers 400 to 4,000 feet apart to investigate several miles of water pipeline.
Clark County today relies on a network of leak-detecting sensors provided by Itron. This technology alerts Clark County officials of possible leaks in their system, allowing them to take action quickly before the leaks increase in size. The county also created a leak detection crew made up of its water utility employees. These employees work with a repair crew that is dedicated to mending the leaks that the leak detection team discovers.
Patience, from Itron, says that the combination of improved leak detection technology along with a growing water shortage in much of the country is making water audits and leak detection more important.
“Will water utilities invest more in leak detection in the future? I think they’ll have to,” says Patience. “In the United States, we generally have a good water source. But more people are living here. That source of water won’t be there forever. We are already seeing in Texas, California, and some other states that there are water shortages. Globally, it’s an even bigger issue. So, yes, we will see leak detection move up the priority list in the future; I can’t see how it couldn’t.”