Locating Leaks

April 18, 2019
Leveraging data to find leaks

From the agricultural fields of South Dakota to the coastal urban environment of North Miami Beach, FL, to the ancient city of Jerusalem, water utilities are seeking ways to address leaks in a precise and cost-effective manner.

“In the water industry, it’s not if you get a leak, it’s when you get a leak,” points out Aaron Beasley, vice president of sales for WaterSignal. “The EPA says you can’t manage what you can’t monitor. We’ve seen water rates rise all over the country and we’re starting to see it in a dramatic fashion from California to New York. Companies like ours are trying to get people to pay attention to water conservation.”

Henrique Costa, business development director, Itron, notes that on average, 30% of water that is treated and pumped is lost due to leaks or theft.

“This non-revenue water can be reduced through innovative leak detection technologies,” he points out. “The latest technologies that geographically locate leaks include artificial intelligence algorithms using real-time data from devices, satellite images, and signal sound recordings via acoustic devices.”

Leveraging a smart water network and artificial intelligence algorithms using real-time data from devices is very efficient and can be conducted continuously, he adds.

“Using satellite images to detect leaks in groundwater appears to be very innovative,” says Costa. “On the other hand, it gives a snapshot result. Signal sound recordings via acoustic devices are dependent on workforce in the field.”

Itron has implemented successful non-revenue water projects using a flexible architecture encompassing devices, analytics software and services, and a business model focused on the water utility’s greatest needs, says Costa.

“In most cases, Itron has delivered outcomes integrating information from the customer, including SCADA, telemetry systems, and analytics engines,” he adds.

Finding and fixing leaks is much more cost-effective than repairing a main break, Costa points out.

“With a smart water network or Advanced Metering Infrastructure (AMI) already in place, it can be easy to add leak sensors to the network to acoustically detect leaks,” he adds.

With artificial intelligence algorithms using real-time data from devices, a medium level of precision is involved in detecting a small area at a medium cost level, says Costa.

Satellite images also offer medium precision, but at a high cost, he adds.

With signal sound recordings via acoustic devices, there is a high level of precision at a medium level of cost utilizing a workforce, Costa says.

A case in point: North Miami Beach, FL, which leveraged Itron AMI to identify and repair 23 leaks to save 27 million gallons of water and $38,000 annually.

The city produces and delivers 21 million gallons of water per day to 38,000 endpoints.

Until recently, the city of North Miami Beach relied on traditional walk-up, manual meter reading, and a leak detection service that visited quarterly to survey areas of its distribution system.

Surveyors would visit two weeks per quarter to assist city staff to systematically go from one end of the 550-mile pipeline system to the other in 1-mile sections. The process took one and a half years to get through the city’s 25-square-mile service territory.

The process to maintain its system and identify leaks proved labor intensive. City officials subsequently adopted an approach of automating meter reading and leak detection simultaneously to save time, staff resources, money, and water.

The city of North Miami Beach is leveraging Itron’s AMI solution equipped with leak detection technology and cloud-based analytics utilizing the Microsoft Azure platform.

The project, completed in 2015, includes 38,000 communication modules along with 11,000 acoustic leak sensors.

The new system is providing North Miami Beach with real-time data on customer usage and on potential leaks throughout the system within three days, if a leak occurs.

“After a competitive pilot, it was evident that Itron’s solution and vision best suited North Miami Beach’s long-term strategy to expand services beyond meter reading,” says Karim Rossy, chief engineer for the city of North Miami Beach.

“Itron’s AMI solution has the ability to not only bring back hourly reads, but also survey our distribution system for leaks on a daily basis.”

Ana M. Garcia, city manager, says Itron’s AMI solution enables North Miami Beach to enhance customer service, protect revenue, forecast consumption, analyze flow, and support district metering by leveraging detailed consumption and meter alerts collected by Itron Analytics in the cloud.

The utility’s customers now have access to detailed consumption information through a secure customer web portal so they can better manage their usage, conserve water, and save money.

“Our goal is to drive down costs for the utility and our customers and reduce the amount of water we produce,” says Garcia.

Time savings is a major benefit from the new leak detection technology, in that city employees do not have to do physical surveying, says Rossy.

Improved efficiency of meter reading and billing is another benefit, as well as enhanced safety of meter readers.

With access to customer consumption data, city utility employees can identify leaks of which they were previously unaware. That’s led to more proactive customer service outreach to inform them of maintenance and other actions being taken to repair leaks as well as conveying information on abnormal usages before sending out a bill, says Rossy.

“The latest leak detection technologies are based on the fact that leaks make noise as pressurized water is forced out of a hole in a pipe,” points out Deron Austin, senior director of marketing for Mueller Water Products.

“By using high-sensitivity vibration sensors to capture the leak noise from the pipe, it can then be analyzed using sophisticated algorithms to determine the exact location,” he adds. “These acoustic sensors can identify extremely faint noises that are emitted by leaks before they become detectable by conventional methods, which enables utilities to be proactive and prioritize repair based on the location and progress of the leak.”

Modern communications and data transmission methods transmit this data to the cloud for large-scale analysis—often hundreds of thousands of recordings daily—giving accessibility to live data from any connected device, Austin adds.

Modern correlating fixed leak detection systems, such as EchoShore DX, are designed to detect leaks in distribution systems, Austin points out.

“It’s non-invasive and non-disruptive and can find leaks long before they are detectable by conventional methods,” he says.

Sensor nodes are fitted onto a standard fire hydrant pumper nozzle cap and are continually listening for the presence of small leaks in their zone. Sensors communicate with each other as well as a central collection hub.

Each node establishes an accurate acoustical baseline for its respective monitoring zone, designed to ensure accurate detection of leaks that may develop in the future, Austin says.

Through permanent monitoring and notification, it delivers critical information in a timely manner, mitigating issues before they escalate and reducing response times to lessen infrastructure damage and water loss, he adds.

In late October, New Jersey American Water (NJAW) water loss control project manager Ron Oppenheimer received a notification alert from the Echologics Leak Operations Center that their EchoShore-DX acoustic leak detection nodes had identified a potential leak 1,400 feet away from the node.

NJAW created a work order and deployed field personnel to confirm and pinpoint the leak on a residential street in Chatham Township.

While there had initially been no visual indication of the presence of a leak, a pool of water bubbled up after 3 feet of excavation.

A storm sewer pipe running adjacent to the water main had been damaged and had inadvertently been draining most of the potable water from the leaking main.

Once the excavator reached the water main, there was a spray of pressurized water shooting 20 feet high into the air from a full circumferential break in the pipe.

The likely cause for the main break appeared to be a recent road resurfacing combined with the rocky soil conditions. The pipe—when installed about 70 years ago—had been laid on bedrock and roadwork compactors may have compromised the main during paving.

With both pipes damaged, the leak could have gone unnoticed for a significantly long period of time.

A water main repair clamp was used to fix the leak with no shutdown or loss of supply to customers. The damaged sewer pipe was also repaired, all with a minimal impact to the road.

New Jersey American Water has more than 4,500 permanent leak detection monitors spread across multiple water systems, with additional deployments planned in the next three years.

“Echologic’s leak detection technology has allowed us to schedule repairs and improve our customer experience,” notes Russell G. Titus, senior superintendent at New Jersey American Water.

He adds that the pilot deployment of nodes in 2016 saved the company approximately 1.7 million gallons of water per day of water, reducing operating expenses by $1.9 million in less than two years of operation.

“In targeted areas, permanent acoustic monitoring is a very effective way to minimize leakage in our water systems,” says Titus.

Amber Thurman, business strategist for Informational Data Technologies, notes that “compared to where the industry has been, today’s technology far surpasses the ‘wait-and-see’ or ‘walk-the-area’ methods that many associations still use.

“The latest developments are satellite imagery, fiber optics, acoustic monitoring with fixed networks, personal in-home leak detection, PIGs, and mass balancing.”

The IDT solution combines mass-balancing with satellite-based AMR/AMI technologies.

“This technology focuses on finding an area to review and focuses the management company into a specific branch of the system,” says Thurman. “The impact to operation efficiency and effectiveness comes from identifying and fixing leaks on the utility side of the meter, not at the customer level where many solutions focus.”

End-users are able to benefit from the ease of billing and general water management in combination with leak detection by implementing the IDT solution, she says, adding it makes it a financially-responsible option for low-density, rural areas.

No option is 100% precise, says Thurman.

“The application depends on what the supplier is looking for and how much they are able to spend,” she adds. “Density, terrain, and distribution are some of the items that have to be considered when identifying what is the most precise and cost-effective way to address leaks based on a utility’s infrastructure.”

In South Dakota, the West River/Lyman-Jones Rural Water Systems covers an 8,100-square-mile service area with eight operations specialists supported by three office staff members, including manager Jake Fitzgerald.

Flow alarms were set on the individual meters, with a full implementation done by the end of 2012.

“When the meter alarms, we will notify the water user and let them know their flow was higher than normal,” says Fitzgerald. “In notifying our users, they have found leaks on their own private systems.”

Within the first 60 days of launching IDT’s zone analysis tool, customers in the system were alerted to 30 leaks ranging from 4,000–49,000 GPD.

West River/Lyman-Jones provides service to 200,000 head of livestock.

“A lot of the leaks are pasture taps where a tank float has been broken,” notes Fitzgerald, adding that accounts for more than half of the leaks detected.

“In general, we’ve got a very large service area, so it’s nice to use our users’ collective usage and compare it to a zone meter to calculate our water loss in areas of our system,” says Fitzgerald of when the IDT system alarmed for abnormal flow.

West River/Lyman-Jones has an IDT AMR system with satellite units at each of its individual service points.

“We are experimenting with some cellular units as well because the cellular units send back more data and generally, it’s less expensive than the satellite units,” says Fitzgerald.

Fitzgerald says the IDT technology has enabled West River/Lyman-Jones to streamline its meter reading and data collection, “which has helped us streamline the billing more accurately. We’ve improved the accuracy of water sales all the way around.”

Among the leak detection options, acoustic detection through permanent installation and continuous acoustic monitoring is the most cost-effective, says Oded Fruchtman, CEO of Aquarius Spectrum.

“Acoustic methods are divided to noise logging and correlation,” adds Fruchtman. “The correlation is more advanced—it provides the exact location of the leak and is less sensitive to external noises.”

Aquarius Spectrum’s AQS-SYS correlated detection system is designed to inform end-users when and where a leak is starting to develop. AQS is based on correlating sensors integrating 3G cellular communication, GPS synchronization, and cloud-based automatic signal processing.

End-users can analyze the leak map/GIS through the AQS-SYS web interface at any time to help make informed system decisions. Aquarius Spectrum water engineers are available for consultancy as part of the service.

AQS-SYS is designed to maintain urban water distribution assets through acoustic sensors installed on the water supply infrastructure to monitor the entire water system of a municipality 365 days a year.

AQS-SYS is designed to enable detection of very small leaks, which cannot be detected by surveys and noise loggers, due to its continuous correlation-based detection method.

By detection of all evolving leaks, AQS-SYS allows water utilities to prioritize leak repair and water pipe segment replacement based on the leak’s flow rate due to pipe deterioration. The system also detects sections with high corrosion so you can treat these areas accordingly.

Leaks are detected by acoustic correlating sensors and located the moment they start from 1.5 mm, with the data transmitted via 3G cellular communication.

Automatic notifications are issued to the facility engineers, indicating the location of the fault on the map while the system continues to monitor the pipe for further deterioration.

After a leak has been discovered by AQS-SYS, water utilities employ water leak detection equipment to pinpoint and mark the position ready for the repair team within 10 yards of the known leak.

Customer service benefits are also offered in that AQS-SYS enables water utilities to reduce the number of water stoppages, issue notifications of urgent repairs in advance by catching impending bursts before they happen, and notify residents of leakage identified below private yards and buildings. Energy is saved through reduced water wastage.

The iQuarius solution can be used to pinpoint leaks to an accuracy of 1 foot.

Aquarius Spectrum’s iQuarius technology is designed to provide smartphone-based leak detection sensors. End-users can utilize a smartphone-based sensor for leak mapping with automatic noise analysis and GPS positioning, leak pinpointing through correlation between two sensors and a sensitive ground microphone, measuring and analyzing vibrations, performing high-resolution correlation, reviewing results, and getting online expert support.

In an implementation in cooperation with HaGihon Water & Wastewater Utility of the City of Jerusalem, more than 2,000 acoustic correlating sensors cover the city’s water distribution network.

The deployment was done in a challenging urban environment in one of the oldest cities in the world, dating back to 4500–3500 BCE, which is also situated in hilly terrain.

Two years after its deployment, there was a 20% reduction in non-revenue water and more than 200 leaks were found and repaired in the public distribution network in addition to 60 private property leaks. Some 265 network interferences were detected by the AQS monitoring system.

There also is a trend of a yearly decline in the number of visible reported bursts, reversing a trend from two years prior to the implementation of the AQS system.

The AQS system also has enabled the utility to pinpoint hundreds of non-leak faults, including partially closed valves, faulty water meters, malfunctioning non-return valves, and other items of equipment under the utility’s responsibility.

Neptune Technology Group offers leak detection at the point of the meter.

Neptune Technology Group’s mobile automatic meter reading (AMR) and fixed network advanced metering infrastructure (AMI) systems are designed to enhance leak detection programs, starting with the E-Coder PLUS protocol in their solid state absolute encoder registers that pair with Neptune mechanical and ultrasonic meters.

The E-Coder-based system is designed to provide an advanced level of leak detection and detailed consumption data to accurately identify water leaks on the downstream side of the meter.

With eight-digit, high-resolution data, the meter provides resolution down to 1/10 of a gallon, enabling utilities to identify leaks that might otherwise be overlooked by providing lower resolution readings.

Neptune’s R900 radio frequency (RF) MIU offers data logging capabilities, transmitting a rolling 96 days of hourly meter readings, as well as leak and reverse flow flags.

An algorithm classifies consumption as either normal flow, a minor leak, or a major leak. Normal flow is defined as measurable usage from 0 to 49 of the 15-minute intervals, an intermittent leak is usage during 50 to 95 of the intervals, and a continuous leak is consistent usage on all 96 of the 15-minute intervals over a rolling 24 hour period.

It also tracks the number of days the leak condition has existed, with flags set in the register to mark leak conditions, updating the flags every 15 minutes.

The hourly readings and leak flag data generated by the E-Coder are transmitted by the MIU; collected via handheld, mobile, or fixed network means; and then automatically imported to Neptune 360 software, where utilities can view reports that identify not only when leaks start but also the duration of the leak event.

Consumption data is displayed in graphical and tabular formats.

Utilities can have their billing or customer information system provider transfer the leak information directly to customers’ bills to alert them to fix water leaks before they receive a high water bill.

For utilities using the R900 System, Neptune has combined its R900 technology with acoustic leak monitoring devices.

When mounted on a distribution main, the acoustic sensor transmits data through the MIU and to the host software for early leak detection. Neptune’s fixed network data systems are designed to allow utilities to compare production water versus revenue water and conduct District Metered Area (DMA) analyses.

A utility can use the system’s meter readings to get the total consumption for any given collection of meters within a district or area, comparing it to the master or bulk meters servicing the area.

A large discrepancy between the total consumption in the area and the respective master meter indicates potential distribution system leaks within a particular area.

Caleb Jones, product manager, Neptune Technology Group, notes that the meter does the “grunt work” in leak detection.

“If the meter can’t register that flow rate and most leaks are a low flow, then the register doesn’t know there’s a leak; therefore, the leak is not found,” he says. “All Neptune encoded registers have the leak detection capability in them that can be sent over our AMR/AMI network.

“The utility can use that data to notify the customer they have a leak on their property. Not only is the utility reducing its non-revenue water, but also helping the end customer by helping them reduce their own water usage.”

Neptune partners with acoustic leak detection company SebaKMT.

Neptune’s new MACH 10 ultrasonic meters are designed to detect leaks down to 1/20 of a gallon per minute.

About the Author

Carol Brzozowski

Carol Brzozowski specializes in topics related to resource management and technology.