Better Flow Monitoring, Greater Transparency

water tower

Water Utilities Continue to Raise the Bar on How They Use Data

By Dan Pinney

Consumers are becoming more tech-savvy and, as a result, their expectations for the data and services utilities offer are more demanding than ever. They want to see data to support the charges outlined on their water bills and expect a response to issues in real-time. At a time when transparency is valued more than ever, better transparency can be an essential asset to utilities seeking to improve relationships with their customers.

One way utilities can gain greater accuracy in their billing and improve transparency for their customers is through flow measurement.

When examining flow measurement, it’s first important to define exactly what this entails. Flow measurement speaks to how the water meter monitors the volume of flowing water running through it in order to accurately detect usage. While utilities cannot control how fast water is flowing through their pipes, they can provide accurate data to measure it.

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In addition to providing accurate data for billing purposes, having a better understanding of the rate provides insights that can help assess potential damage when there is a water leak or monitor the risk associated with a broken pipe in terms of lost revenue.

The choice of meter is critical in helping to deliver better flow measurement. Static meters have emerged as a strong option in delivering long-term value and more comprehensive flow data for technicians, yet not all static meters are alike.

The Case for Static Meters

Static meters are solid-state meters with no moving parts to wear out, degrade or break. As a result, static meters can maintain the same level of accuracy long-term, especially at very low flows. Static meters also reduce maintenance requirements. They do not need meter testing programs. Nor do they have as high a frequency for repair and replacement as mechanical meters.

While the initial cost of a static meter may be higher, the meter’s long-life accuracy, low-flow measurement capability and reduced maintenance result in a lower life cycle cost than a mechanical meter. Types of residential static meters include ultrasonic and electromagnetic technologies.

Ultrasonic vs. Electromagnetic Technology

When it comes to flow measurement, ultrasonic meters measure the instantaneous speed of the water. They do this by measuring the difference in transit time of sound pulses with and against the direction of flow. The volumetric flow rate is determined by complex internal linearization and correction calculations within the meter.

Ultrasonic meters produce very accurate measurements and have worked well for providing flow measurement data to utilities. However, the data is provided in quick “snapshots” and doesn’t give a continuous view of the flow. Electromagnetic technology offers benefits that extend beyond these capabilities and should be considered when utilities are making decisions about infrastructure investments.

Electromagnetic meters measure flow based on the voltage generated when water passes through a magnetic field in a section of insulating pipe. This voltage is directly proportional to the flow rate and over a much wider range than any other flow metering technology. Magnetic metering technology is a long-established method of flow measurement for larger diameter pipes. When adapted to residential meters, it has several advantages over other static meter technologies. The technology is fundamentally immune to real-world flow disturbances.

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Temperature variation, vibration, particulates, air bubbles and flow disturbances have minimal effect on the meter’s accuracy. Electromagnetic meters have no impediments within the pipe to disturb the flow pattern. Also, no sensitive reflectors or other components are exposed to effects from the water. In a well-designed residential electromagnetic meter such as the Sensus iPERL meter, the flow measurement is inherently linear by design. Sensus ally meters have the additional feature of an internal 3-state ball valve that allows for remote service turn-on, shutoff or restricted use. Unlike ultrasonic meters, an electromagnetic meter can provide continuous measurement, rather than a series of snapshots. This means that real-world intermittent consumption of water is accurately captured.

Utilities need meters that have a high degree of accuracy. They also need meters with a certain degree of ruggedness, dependability and long life in the field. Simplicity of operation and installation is important too. As noted above, electromagnetic metering technology has several advantages over other meter types. Through careful design, electromagnetic meters can be extremely accurate at low-flow rates and can achieve long-term accuracy. Utilities that use electromagnetic water meters can expect the following benefits:

  • Long-term accuracy;
  • Ability to measure with great accuracy at very low flow;
  • Better high-flow durability;
  • No restrictions on installation orientation;
  • No effects from flow disturbances, low head loss;
  • Minimally affected by field disturbances — vibration, temperature, particulates, air bubbles;
  • Linear flow measurement by design—no complex internal linearization;
  • Continuous measurement for great accuracy with intermittent flow;
  • Reliable detection of empty pipe and backflow conditions; and
  • No components within the pipe to disturb the flow pattern or be exposed to damage.

The City of Dallas, Ga., replaced approximately 320 meters in one subdivision and chose Sensus iPERL residential water meters for the project.

Ability to Measure Previously Untapped Data

The City of Dallas, Ga., provides a great example around the accuracy of electromagnetic meters. Just 30 miles northwest of Atlanta, the water infrastructure at the City of Dallas includes 3,700 water connections across 38 miles of water lines. After analyzing annual water loss audits for the city, billing clerk Amber Whisner and her team discovered significant issues around non-revenue water. In 2014, real and apparent water loss accounted for 31.3 million gallons — nearly 20 percent of the city’s total water supplied for the year — which meant lost revenue for the city.

“We discovered that a large percentage of our water was simply being lost, so it was a problem we couldn’t ignore,” said Whisner. “When you’re a paid utility that purchases its water from the county, every drop counts.”

The audit results spurred Whisner and her team to create a robust water loss and control program. As part of the program, the city decided to replace its existing water meters with a system that could more efficiently identify issues to help minimize non-revenue water.

The city replaced approximately 320 meters in one subdivision — and chose Sensus iPERL residential water meters for the project. “The iPERL water meter picked up flow data we never had before,” said Whisner. “The meters could register the smallest bit of water usage for activities like flushing toilets or washing hands.”

The results of the city’s initial deployment were immediate and quickly translated into real savings. In just four months, the city billed for an additional 600,000 gallons of water in the subdivision thanks to the new meters.

Loudoun Water implemented a Sensus AMI solution consisting of iPERL residential and OMNI water meters, connected by the FlexNet Communication Network.

Protecting Precious Resources

With magnetic metering and AMI technology, Loudoun Water, located in Ashburn, Virginia, was able to strengthen conservation efforts.

“We saw lots of issues with leaks that went undetected and mainly relied on our customers to call it in,” said Loudoun Water’s Customer Relations Report Technician Michael Rowe. “For example, we had water running down the road due to a problem with an irrigation system. After a call, our technician showed up to read the meter and discovered a significant leak of more than 100 gallons an hour.”

Loudoun Water’s team wanted to increase efficiency to conserve precious water resources. They decided their aging system needed a technology upgrade. After an extensive evaluation process, Loudoun Water ultimately determined that the Sensus Advanced Metering Infrastructure (AMI) solution, consisting of Sensus iPERL residential and OMNI water meters, all connected by the FlexNet Communication Network, would best fit their needs.

Click here for more on Loudoun Water’s AMI solution

Now the utility remotely collects usage data from its 79,000 water meters, empowering customers with insights to become more mindful about their usage.

“You can see our main values; integrity, innovation, leadership and stewardship, reflected in the decision to implement the AMI solution,” said Rowe.

Not only does AMI provide accurate flow data measurement to inform decisions about water usage, it has the capability to help Loudoun Water scale its operations as the region continues to flourish.

“Ultimately, it comes down to customer service,” said Rowe. “If we can help the customer use water efficiently, they are conserving water, saving money and protecting Earth’s most precious resource.”

Key Takeaways

Accurate and dependable water metering is more important than ever for today’s water utilities. For residential metering specifically, accuracy at low and intermittent flow is essential and meters must be able to measure accurately despite the imperfect conditions in the field.

Electromagnetic technology addresses these needs and prepares utilities for the future by equipping technicians with the data needed to keep up with the demand for excellent customer service and conservation efforts. Innovations in flow measurement allow utilities to provide more accurate usage data, in turn, giving customers more transparency into their usage to proactively identify and resolve leaks.

Dan Pinney is global director of water marketing at Sensus, a Xylem brand, based in Raleigh, N.C. Pinney has more than 27 years of experience in the global water industry with leadership roles in operations and development at Sensus. He attended the University of Florida, majoring in electrical engineering.

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