The Necessity of Accurate Metering
Meters are the cash registers of a city’s water and sewer department
Water meters not only help municipalities collect the revenue they’re due; they also help pinpoint leaks, locate pressure problems along their waterways, and identify and study periods of peak and non-peak use among both residential and business consumers.
But meters can only perform these feats if they are accurate. Problem is, at too many municipal systems, water meters are far from accurate. Some may be outdated. Others may be in poor repair. Whatever the reason, they fail to accurately chart exactly how much water businesses and residences are consuming.
This is a serious problem if left untreated. Inaccurate water meters not only result in lost income for often cash-strapped utilities; they also prevent municipalities from realizing the potential for greater savings: Without accurate meters, water and sewer departments can’t completely participate in some of the newest experiments and techniques designed to foster increased water efficiency. In the long run, this may cause a utility to lose more dollars than will non-revenue water.
Don Kirkland, assistant director of the Wichita Water and Sewer Department, understands all this. That’s why he’s pleased that his utility more than three years ago began converting to automated meter reading, arming its employees with handheld devices that allow them, in many cases, to obtain readings without even leaving their vehicles.
Automated reading provides a host of benefits over manual. There’s accuracy, of course, with automatic meter reading eliminating the possibility that a meter reader will jot down a wrong number. Automated reading, though, also cuts down on labor costs, something that may result in even greater savings. Utility workers—especially in areas where meters are spaced far apart—can record their meter readings far quicker with automated systems that don’t require them to stop, write down a series of numbers, and then move on.
But the automated meters provide other benefits that may prove more significant over time. For instance, they provide real-time data on the amount of water passing through consumers’ meters. When consumers have leaks, it may take a utility six to eight weeks, or longer, to discover the problem by manually reading meters. With automated meter reading, underground and hard-to-detect leaks can be noticed far sooner. Real-time data allow utility workers to discover any unusual fluctuations in water flow.
Kirkland estimates that the utility is about halfway through the conversion. The utility serves about 14,000 customers, most of which have a single meter.
“This is an important project for us,” says Kirkland. “We know that by finding leaks earlier, we’ll save on adjustment costs. You save on manpower costs when doing the physical meter reading. That can equate into not only labor cost [savings], but capital cost savings on your trucks and equipment, too. Then there are some areas that are difficult to quantify financially. We’ll be able to respond to customers’ questions quicker. That’s hard to quantify from a financial standpoint, but it does make you a more responsive and customer-focused utility.”
Wichita is far from the only municipality that recognizes the importance of accurate meter reading. Utilities across the country are taking steps to guarantee that the amount of water recorded by their meters is actually the amount their consumers are using.
A Serious Problem
The US Geological Survey in 1995 released a study of water loss that contained some shocking numbers. According to the study, of 40 billion gallons of water withdrawn each day by US water utilities, a full 6 billion gallons per day are categorized as lost or non-recorded. This is more than enough, the survey says, to meet the water needs of the 10 largest US cities.
In more recent research, the 2001 American Water Works Association Research Foundation reported that 5 billion to 10 billion kilowatts of power generated in the US are expended each year on water that is either not paid for or leaked away.
Utilities have taken action. In Denver, for instance, Denver Water has converted more than 220,000 meters to automated meter reading. The utility predicts that it will convert the rest of its meters to the system by the end of 2006. In the spring of 2002, Washington DC’s DC Water and Sewer Authority began the process of converting all of its 125,000 water meters to automated meter reading.
Accurate Metering in Philadelphia
George Kunkel, assistant chief of the Water Conveyance Section of the Philadelphia Water Department, has worked for the utility during his entire career. He, along with the rest of the department, realized several years ago that Philadelphia, thanks in part to its old infrastructure, suffers from a large amount of what the utility once called unaccounted-for water and now refers to as non-revenue water.
This is the water, of course, that businesses and residences use but is not accurately recorded. The lost dollars from this non-revenue water? That’s impossible to tell, but over the years, Kunkel guesses, the figure must be significant.
Changing this has been a long-term goal of Kunkel’s. Not only does he study ways to improve how his utility can more accurately measure water use; he is an active member of both the American Water Works Association and the International Water Association, where he works alongside other industry veterans to generate ideas to help identify and control losses in the water industry.
The way Kunkel sees it, municipalities have rarely placed enough importance on controlling such losses.
“In the world of drinking water, at least in this part of the world and in the United States in particular, we are pretty heavily regulated when it comes to water quality. The quality of water is tested for numerous parameters, rules, and regulations. There is a lot of auditing and enforcement,” Kunkel says. “On the quantity side of the equation, though, it’s pretty much always been the exact opposite. There is far less of a structure in place to really make sure that water utilities are accurately tracking their volumes of water, that they can account for where the water is going.”
The American Water Works Association has released policy statements and written guidelines recommending that utilities accurately meter their customers, Kunkel says. Problem is, these guidelines don’t specifically spell out the best way for utilities to do that.
For example, to accurately count water usage, utilities should be metering not only at each of their customers’ locations but also at several different locations along the water-delivery process. The Philadelphia Water Department meters water at its source, when it leaves water treatment plants, and when it goes to the utility’s customers.
The department isn’t stopping there, either. Kunkel and his fellow department officials are studying newer techniques that, essentially, add another metering step between the treatment plant and the customer. It’s all about district-metered areas.
The Science of DMAs
Better known as DMAs, district-metered areas are especially useful in helping water departments identify leaks in a system. The areas work by creating small zones in larger systems to help pinpoint problems.
It’s not easy to track water when it’s traveling through hundreds of miles of pipeline, as it does in Philadelphia’s water system. But if officials can instead break the system down into smaller zones and then study them, it’s far easier to track how customers are using water and if there are any problems in the system.
The Philadelphia Water Department is midway through a research project conducted by the American Water Works Association that is designed to study the effectiveness of DMAs. In Philadelphia, water department officials create their small study areas by closing some of the valves in the pipeline in specific locations. By doing this in a connect-the-dots fashion, they create a boundary of closed valves that makes an island of the zone, a zone that usually includes from 1,000 to 3,000 customer connections.
Department officials leave two water mains open to supply the area with water and install temporary portable water meters on each of the mains. This way, department officials can study the usage profile of an area.
How important is this? Kunkel gives an example:
The portable meters provide the department with real-time data of the flow of water coursing through a DMA. In areas that don’t have a large industry, the department’s researchers will generally discover a trend with such water flows. If the DMA is mainly residential in nature, water flow will drop significantly in the evening, when customers are sleeping. In the morning, everyone gets up and the water flow surges. It then goes down again in the middle of the day as customers leave their homes and go to work. There’s another smaller peak toward the end of the day, and then the flow heads back down again later in the evening.
In a residential DMA, then, department officials know that the legitimate amount of water usage is at its lowest in the middle of the night. Department officials also know that there is always a certain amount of leakage in their system. That leakage is the greatest percentage of total flow in residential DMAs during the evening. If department officials can get an estimate of who is using water for legitimate reasons, they can then subtract that from the total night flow and get a good estimate of the amount of leakage in the DMA.
“This helps us get a much better measure of leakage,” Kunkel says. “We can then identify problem areas quicker and take care of them in appropriate ways.”
DMAs may prove to be a far better way of finding and controlling a system’s leaks. Usually, utilities find leaks by canvassing an area with sounding equipment, placing sensors on valves and fire hydrants, and listening for the sounds leaks create in pipelines. That’s a fairly accurate way to find leaks, but it does have limitations. The biggest is that canvassing never tells water departments how large a leak is. It may not make economic sense to dig into an area where a leak has been detected only to find that the leak itself is a tiny one.
“It all involves taking a more proactive approach to looking at what’s going on in a distribution system,” Kunkel says. “It does entail metering at different points of the system so that we can better dissect where the water is going. It’s an evolution of change. It’s not suddenly overnight going to correct all the losses in our system. But we think it will be a pretty effective system.”
Philadelphia’s water department began participating in the research project in 2004 and expects to create a final report on its results sometime in 2007. The DMA the utility has created covers just about 5 miles of pipeline, a small area considering that the entire Philadelphia water system covers some 3,000 miles.
Department officials chose the 5-mile area for specific reasons: It’s a densely populated area, as is most of the city of Philadelphia. It is residential in nature, so it is not an area where a large factory or bottling works will be consuming large amounts of water 24 hours a day, a variable the department did not want in its study.
The utility also selected an area with high operating pressures—an average of about 100 pounds per square inch compared to an average throughout the city of 55 pounds per square inch—so that department officials could experiment with yet another method of saving water that also relies on accurate metering: pressure management.
Applying the Pressure
Fundamentally, pressure management involves controlling the level of water pressure throughout a distribution system to also control the amount of leakage leaving through it. It works like this: If a pipeline has a pinhole leak, the amount of leakage would be higher if the pressure in that pipeline was higher. The leakage would be less if the pressure was lower.
Problem is, water departments have traditionally only worried about meeting the minimum pressure levels they need to fight fires, supply households with water, and keep business customers happy.
Because of this mindset, utilities have rarely considered lowering the amount of water pressure in certain sectors of their system to also reduce the amount of water leaking in these sections.
“Rarely has there been any focus on pressure maximums, other than looking at the limitations of the materials themselves. The thought among water departments is that as long as you can meet the minimum pressures, anything above that is fine. There’s also a perception that the higher the pressure, the more water their customers will use, which means more revenue for them,” Kunkel says. “The reality is, if you have pressure higher than what you need, you are probably stressing the system more than you need to. You can be leaking more than you need.”
Accurate metering plays a large role in pressure management, too. Before utilities can use pressure management to slow down their leaks, they must first find out where leaks are occurring. For instance, late at night, when residential customers are sleeping, meters can tell utilities about how large a leak is in a DMA. This is because leakage is at its highest percentage of total flow late at night, when fewer customers are washing dishes or taking showers.
With pressure management, utilities use pressure-reducing valves to regulate the water pressure at different times of day. They can reduce the amount of pressure late in the evening, when its customers don’t need it. By doing this, they are reducing the amount of leakage during these hours, because the water pressure is not pushing as much water out of any pinhole leaks.
This has been an effective way to cut a specific type of leakage known as background leakage, the little leaks and seeps in joints that crews never see from above ground.
“There are probably scattered background leakages in dozens if not hundreds of locations in most systems,” Kunkel says, “each one of which is very tiny. It’s never cost-effective to dig up all these little leaks and seeps to fix them. But you can have one pressure-reducing valve, one of these pipelines that feed these DMAs, to reduce pressure at nighttime and reduce the leakage from dozens or hundreds of leaks and seeps, just by regulating the pressure. It’s very effective and very cost-effective.”
Going Automated in Wichita
Meanwhile, in Wichita, Kirkland is looking forward to the day when his utility converts completely to automated meter reading.
“We think over a period of time, we will recoup the money we are spending on this project,” Kirkland says. “It will make us a more efficient water system. We won’t have as much inaccuracy in our readings.”
In Wichita’s new system, meter readers will be able to drive down the street holding wireless handheld units. These units pick up the meter readings with the employees never having to leave their vehicles. Not only does this save time, and labor costs; it eliminates some of the human error that accounts for inaccurate readings.
The long-term goal in Wichita is to have the handheld devices electronically transmit meter information directly into a central location. That hasn’t happened yet, but simply by using the handheld automated units, the utility is boosting the accuracy of its metering, Kirkland says.
“We truly are interested not only in saving money but in becoming a utility that provides even better service to our customers,” Kirkland says. “That’s what this is really all about.”
In Philadelphia, the move to use metering to create DMAs is one part of a water-accountability program that the utility launched in 1993. Kunkel, who is chairman of that committee, says that the utility, since forming it, has cut its non-revenue water by one-third.
That’s a significant figure considering that Philadelphia’s water department supplies hundreds of millions of gallons of water every day to its customers.
“You’re never going to completely eliminate your non-revenue water,” Kunkel says. “That’s not possible. But you can take measures to reduce it as much as possible.”
November-December 2006
The Necessity of Accurate Metering
Meters are the cash registers of a city’s water and sewer department
Water meters not only help municipalities collect the revenue they’re due; they also help pinpoint leaks, locate pressure problems along their waterways, and identify and study periods of peak and non-peak use among both residential and business consumers.
But meters can only perform these feats if they are accurate. Problem is, at too many municipal systems, water meters are far from accurate. Some may be outdated. Others may be in poor repair. Whatever the reason, they fail to accurately chart exactly how much water businesses and residences are consuming.
This is a serious problem if left untreated. Inaccurate water meters not only result in lost income for often cash-strapped utilities; they also prevent municipalities from realizing the potential for greater savings: Without accurate meters, water and sewer departments can’t completely participate in some of the newest experiments and techniques designed to foster increased water efficiency. In the long run, this may cause a utility to lose more dollars than will non-revenue water.
Don Kirkland, assistant director of the Wichita Water and Sewer Department, understands all this. That’s why he’s pleased that his utility more than three years ago began converting to automated meter reading, arming its employees with handheld devices that allow them, in many cases, to obtain readings without even leaving their vehicles.
Automated reading provides a host of benefits over manual. There’s accuracy, of course, with automatic meter reading eliminating the possibility that a meter reader will jot down a wrong number. Automated reading, though, also cuts down on labor costs, something that may result in even greater savings. Utility workers—especially in areas where meters are spaced far apart—can record their meter readings far quicker with automated systems that don’t require them to stop, write down a series of numbers, and then move on.
But the automated meters provide other benefits that may prove more significant over time. For instance, they provide real-time data on the amount of water passing through consumers’ meters. When consumers have leaks, it may take a utility six to eight weeks, or longer, to discover the problem by manually reading meters. With automated meter reading, underground and hard-to-detect leaks can be noticed far sooner. Real-time data allow utility workers to discover any unusual fluctuations in water flow.
Kirkland estimates that the utility is about halfway through the conversion. The utility serves about 14,000 customers, most of which have a single meter.
“This is an important project for us,” says Kirkland. “We know that by finding leaks earlier, we’ll save on adjustment costs. You save on manpower costs when doing the physical meter reading. That can equate into not only labor cost [savings], but capital cost savings on your trucks and equipment, too. Then there are some areas that are difficult to quantify financially. We’ll be able to respond to customers’ questions quicker. That’s hard to quantify from a financial standpoint, but it does make you a more responsive and customer-focused utility.”
Wichita is far from the only municipality that recognizes the importance of accurate meter reading. Utilities across the country are taking steps to guarantee that the amount of water recorded by their meters is actually the amount their consumers are using.
A Serious Problem
The US Geological Survey in 1995 released a study of water loss that contained some shocking numbers. According to the study, of 40 billion gallons of water withdrawn each day by US water utilities, a full 6 billion gallons per day are categorized as lost or non-recorded. This is more than enough, the survey says, to meet the water needs of the 10 largest US cities.
In more recent research, the 2001 American Water Works Association Research Foundation reported that 5 billion to 10 billion kilowatts of power generated in the US are expended each year on water that is either not paid for or leaked away.
Utilities have taken action. In Denver, for instance, Denver Water has converted more than 220,000 meters to automated meter reading. The utility predicts that it will convert the rest of its meters to the system by the end of 2006. In the spring of 2002, Washington DC’s DC Water and Sewer Authority began the process of converting all of its 125,000 water meters to automated meter reading.
Accurate Metering in Philadelphia
George Kunkel, assistant chief of the Water Conveyance Section of the Philadelphia Water Department, has worked for the utility during his entire career. He, along with the rest of the department, realized several years ago that Philadelphia, thanks in part to its old infrastructure, suffers from a large amount of what the utility once called unaccounted-for water and now refers to as non-revenue water.
This is the water, of course, that businesses and residences use but is not accurately recorded. The lost dollars from this non-revenue water? That’s impossible to tell, but over the years, Kunkel guesses, the figure must be significant.
Changing this has been a long-term goal of Kunkel’s. Not only does he study ways to improve how his utility can more accurately measure water use; he is an active member of both the American Water Works Association and the International Water Association, where he works alongside other industry veterans to generate ideas to help identify and control losses in the water industry.
The way Kunkel sees it, municipalities have rarely placed enough importance on controlling such losses.
“In the world of drinking water, at least in this part of the world and in the United States in particular, we are pretty heavily regulated when it comes to water quality. The quality of water is tested for numerous parameters, rules, and regulations. There is a lot of auditing and enforcement,” Kunkel says. “On the quantity side of the equation, though, it’s pretty much always been the exact opposite. There is far less of a structure in place to really make sure that water utilities are accurately tracking their volumes of water, that they can account for where the water is going.”
The American Water Works Association has released policy statements and written guidelines recommending that utilities accurately meter their customers, Kunkel says. Problem is, these guidelines don’t specifically spell out the best way for utilities to do that.
For example, to accurately count water usage, utilities should be metering not only at each of their customers’ locations but also at several different locations along the water-delivery process. The Philadelphia Water Department meters water at its source, when it leaves water treatment plants, and when it goes to the utility’s customers.
The department isn’t stopping there, either. Kunkel and his fellow department officials are studying newer techniques that, essentially, add another metering step between the treatment plant and the customer. It’s all about district-metered areas.
The Science of DMAs
Better known as DMAs, district-metered areas are especially useful in helping water departments identify leaks in a system. The areas work by creating small zones in larger systems to help pinpoint problems.
It’s not easy to track water when it’s traveling through hundreds of miles of pipeline, as it does in Philadelphia’s water system. But if officials can instead break the system down into smaller zones and then study them, it’s far easier to track how customers are using water and if there are any problems in the system.
The Philadelphia Water Department is midway through a research project conducted by the American Water Works Association that is designed to study the effectiveness of DMAs. In Philadelphia, water department officials create their small study areas by closing some of the valves in the pipeline in specific locations. By doing this in a connect-the-dots fashion, they create a boundary of closed valves that makes an island of the zone, a zone that usually includes from 1,000 to 3,000 customer connections.
Department officials leave two water mains open to supply the area with water and install temporary portable water meters on each of the mains. This way, department officials can study the usage profile of an area.
How important is this? Kunkel gives an example:
The portable meters provide the department with real-time data of the flow of water coursing through a DMA. In areas that don’t have a large industry, the department’s researchers will generally discover a trend with such water flows. If the DMA is mainly residential in nature, water flow will drop significantly in the evening, when customers are sleeping. In the morning, everyone gets up and the water flow surges. It then goes down again in the middle of the day as customers leave their homes and go to work. There’s another smaller peak toward the end of the day, and then the flow heads back down again later in the evening.
In a residential DMA, then, department officials know that the legitimate amount of water usage is at its lowest in the middle of the night. Department officials also know that there is always a certain amount of leakage in their system. That leakage is the greatest percentage of total flow in residential DMAs during the evening. If department officials can get an estimate of who is using water for legitimate reasons, they can then subtract that from the total night flow and get a good estimate of the amount of leakage in the DMA.
“This helps us get a much better measure of leakage,” Kunkel says. “We can then identify problem areas quicker and take care of them in appropriate ways.”
DMAs may prove to be a far better way of finding and controlling a system’s leaks. Usually, utilities find leaks by canvassing an area with sounding equipment, placing sensors on valves and fire hydrants, and listening for the sounds leaks create in pipelines. That’s a fairly accurate way to find leaks, but it does have limitations. The biggest is that canvassing never tells water departments how large a leak is. It may not make economic sense to dig into an area where a leak has been detected only to find that the leak itself is a tiny one.
“It all involves taking a more proactive approach to looking at what’s going on in a distribution system,” Kunkel says. “It does entail metering at different points of the system so that we can better dissect where the water is going. It’s an evolution of change. It’s not suddenly overnight going to correct all the losses in our system. But we think it will be a pretty effective system.”
Philadelphia’s water department began participating in the research project in 2004 and expects to create a final report on its results sometime in 2007. The DMA the utility has created covers just about 5 miles of pipeline, a small area considering that the entire Philadelphia water system covers some 3,000 miles.
Department officials chose the 5-mile area for specific reasons: It’s a densely populated area, as is most of the city of Philadelphia. It is residential in nature, so it is not an area where a large factory or bottling works will be consuming large amounts of water 24 hours a day, a variable the department did not want in its study.
The utility also selected an area with high operating pressures—an average of about 100 pounds per square inch compared to an average throughout the city of 55 pounds per square inch—so that department officials could experiment with yet another method of saving water that also relies on accurate metering: pressure management.
Applying the Pressure
Fundamentally, pressure management involves controlling the level of water pressure throughout a distribution system to also control the amount of leakage leaving through it. It works like this: If a pipeline has a pinhole leak, the amount of leakage would be higher if the pressure in that pipeline was higher. The leakage would be less if the pressure was lower.
Problem is, water departments have traditionally only worried about meeting the minimum pressure levels they need to fight fires, supply households with water, and keep business customers happy.
Because of this mindset, utilities have rarely considered lowering the amount of water pressure in certain sectors of their system to also reduce the amount of water leaking in these sections.
“Rarely has there been any focus on pressure maximums, other than looking at the limitations of the materials themselves. The thought among water departments is that as long as you can meet the minimum pressures, anything above that is fine. There’s also a perception that the higher the pressure, the more water their customers will use, which means more revenue for them,” Kunkel says. “The reality is, if you have pressure higher than what you need, you are probably stressing the system more than you need to. You can be leaking more than you need.”
Accurate metering plays a large role in pressure management, too. Before utilities can use pressure management to slow down their leaks, they must first find out where leaks are occurring. For instance, late at night, when residential customers are sleeping, meters can tell utilities about how large a leak is in a DMA. This is because leakage is at its highest percentage of total flow late at night, when fewer customers are washing dishes or taking showers.
With pressure management, utilities use pressure-reducing valves to regulate the water pressure at different times of day. They can reduce the amount of pressure late in the evening, when its customers don’t need it. By doing this, they are reducing the amount of leakage during these hours, because the water pressure is not pushing as much water out of any pinhole leaks.
This has been an effective way to cut a specific type of leakage known as background leakage, the little leaks and seeps in joints that crews never see from above ground.
“There are probably scattered background leakages in dozens if not hundreds of locations in most systems,” Kunkel says, “each one of which is very tiny. It’s never cost-effective to dig up all these little leaks and seeps to fix them. But you can have one pressure-reducing valve, one of these pipelines that feed these DMAs, to reduce pressure at nighttime and reduce the leakage from dozens or hundreds of leaks and seeps, just by regulating the pressure. It’s very effective and very cost-effective.”
Going Automated in Wichita
Meanwhile, in Wichita, Kirkland is looking forward to the day when his utility converts completely to automated meter reading.
“We think over a period of time, we will recoup the money we are spending on this project,” Kirkland says. “It will make us a more efficient water system. We won’t have as much inaccuracy in our readings.”
In Wichita’s new system, meter readers will be able to drive down the street holding wireless handheld units. These units pick up the meter readings with the employees never having to leave their vehicles. Not only does this save time, and labor costs; it eliminates some of the human error that accounts for inaccurate readings.
The long-term goal in Wichita is to have the handheld devices electronically transmit meter information directly into a central location. That hasn’t happened yet, but simply by using the handheld automated units, the utility is boosting the accuracy of its metering, Kirkland says.
“We truly are interested not only in saving money but in becoming a utility that provides even better service to our customers,” Kirkland says. “That’s what this is really all about.”
In Philadelphia, the move to use metering to create DMAs is one part of a water-accountability program that the utility launched in 1993. Kunkel, who is chairman of that committee, says that the utility, since forming it, has cut its non-revenue water by one-third.
That’s a significant figure considering that Philadelphia’s water department supplies hundreds of millions of gallons of water every day to its customers.
“You’re never going to completely eliminate your non-revenue water,” Kunkel says. “That’s not possible. But you can take measures to reduce it as much as possible.”