Leak detection has been used by water delivery companies and municipalities almost as long as the entities have existed, starting with listening sticks and acoustic devices used on water hydrants and valves. With the digital revolution, innovative companies and entrepreneurs have introduced technologies such as leak noise correlators and correlating radio loggers that have created opportunities for constant underground detection, producing data which can be stored in cloud-based communication systems to produce sophisticated analytics.
An exploration follows of a few of the latest developments in leak detection technology, starting with an example of creative engineering.
A SKIRT-WEARING ROBOT
At the Mechatronics Research Lab at Massachusetts Institute of Technology in a leak detection project, PhD student You Wu worked to develop a solution to a major problem: the average water grid loses about a fifth of its supply to leaks.
As noted in an MIT Technology Review article written by Fatima Husain, Wu sought to find a solution for detecting leaks before they grow into big ones. The lab had originally been focused on delivering robots into pipes to sense millimeter-scale gas leaks. However, Wu discovered that the same self-propelled robot with a sensing drum wouldn’t work in water due to turbulence. Wu had an epiphany while he was at a party. When he accidentally stepped on his girlfriend’s long dress, she knew it immediately. He then decided to replace the robot’s sensing drum with a sensing skirt.
The result was Daisy, a skirt-wearing leak detector made with 3D-printed and hand-molded rubbers and plastics. The robot has a hard yellow head, a semi-transparent flexible body containing electronics, and a bright blue sensor-filled skirt. It is inserted at accessible junctions into water grids. As water flows through, the robot is carried along, dragging its skirt along the inner surface of the pipe. If there’s a leak, the accompanying suction pressure tugs at the skirt, whose sensors record the force, pinpointing the leak’s location within one foot. It also detects the shape of the leak and its rate. Following its journey, Daisy’s data can be uploaded to a laptop and viewed in map form. Wu now markets Daisy as a product called Lighthouse. The company has also been conducting pilot programs in Massachusetts with the Cambridge Water Department and in Australia with Detection Services.
FIRE HYDRANT CAPS
Echologics, a Mueller technology company, has developed a platform that incorporates the latest generation of acoustic sensors, all built into a standard fire hydrant cap. These sensors are capable of identifying extremely faint acoustical noises emitted by leaks before they become detectable by conventional methods.
The EchoShore-DX leak detection node is a fixed leak detection technology that is attached to a fire hydrant. San Jose Water Company found 38 leaks within two months of installing the EchoShore-DX.
New Jersey American Water workers installed the acoustic sensors on their fire hydrants and now collect sound data produced at night. “Then we investigate and identify the location. It gives us a clue as to the location of the leak,” says Rod Oppenheimer, project manager with the water leak program, explains in a YouTube video. “In 2018, we found 198 leaks that were not surfacing. Also we produced less water—about 2 million gallons a day,” he says. “We fix leaks on a scheduled basis, and produce less water,” he adds.
New Jersey American Water’s next steps are to expand the program. It has identified additional areas around New Jersey where this technology will be installed.
MULTITUDES OF LOGGERS IN USE
SUEZ Water New Jersey, a subsidiary of SUEZ Water North America, has a long history of tracking water leaks using the traditional method of listening to fire hydrants and valves and looking for non-revenue water loss. SUEZ New Jersey serves more than 1.5 million water users at 10 utilities across New Jersey from its headquarters in Paramus, NJ.
When Jack McNaughton became manager of systems maintenance about 13 years ago, the Distribution Department was using 20 radio loggers in a “lift and shift” process where personnel would collect the loggers the morning after installation and move them to another location after uploading reports. Since that time, SUEZ has purchased 200 more radio loggers. When a city within SUEZ’s service territory announces it is repaving a street, SUEZ’s staff will use a radio logger to survey the street and repair any leaks found before repaving. Further, when a water customer calls to have the water shut off at their home, SUEZ will do a leak detection test.
The department found 107 underground leaks in 2014 and decided to invest in 1,100 acoustic non-correlating loggers. SUEZ began installing them at the end of 2014 and finished the job in early 2015. Furthermore, McNaughton says, “with the development of new technology, we decided to go with correlating loggers since they provide us addresses of the leaks, which the radio loggers did not.”
The correlating loggers he chose were the AQS-SYS loggers manufactured by Aquarius Spectrum and they have been working very well, McNaughton says. The department started installing 300 permanent underground correlators at the end of 2017 and finished in 2018. McNaughton indicates they will be moving these correlating loggers to another county this year after finding 13 leaks in 2018. These small leaks were repaired at a cost of between $5,000 and $10,000 each—less expensive than if they had gone unrepaired until the leaks surfaced.
The loggers correlate in multiple directions, McNaughton explains. “Based on sounds, they tell you the probability of a leak.” The loggers are programmed to stay dormant until told to wake up at a certain time, say at night when it’s quiet. The sounds are automatically sent to Aquarius’s cloud-based system. An Aquarius technician works with SUEZ and follows up on issues, he says.
McNaughton relayed an interesting story: At one point, the technician had passed on the sounds of church bells that the loggers had picked up through nighttime correlating. The recordings continued for several nights and were linked with the address of the church. “All we did was change the listening time of the correlators,” he says.
McNaughton says they have ordered another 300 AQS-SYS loggers which will be joining the others when they are moved to the second county. The 600 loggers will be permanently installed but will still not cover the multiple communities SUEZ serves. Every year they choose a town where they do “lift and shift” with the radio loggers, he says.
McNaughton also uses the iQuarius, the smartphone-based listening stick. "What is interesting is we find a leak and do a sound bite and send it to the cloud, I can listen to it immediately on my smartphone. We use everything in our toolbox,” he says.
“Every single day with no water surfacing is a success,” concludes McNaughton.
THE CLOUD & GPS
Founded in 2009 in Israel, Aquarius Spectrum has created two types of acoustic correlating sensors to monitor entire water distribution networks and detect leaks.
The first, AQS-SYS, is a continuous monitoring leak detection system that is permanently installed along a water trunk line either underground or above ground. Every sensor contains a 3G/4G SIM card to enable cellular transmission of data to the company’s cloud-based system. Automatic notifications are sent to facility engineers, indicating the location of the fault on a GIS map.
The second type of sensor is the iQuarius, a modern listening stick for smartphone-based leak detection for surveys and pinpointing leaks. The technician can walk the length of the trunk line, listening, while the leak detection equipment surveys and correlates suspected points using synchronization GPS technology. It saves data locally and can instantly upload all information to the cloud. It can also download the leak noise information captured by the sensor. Teams of technicians walking on separate areas of the trunk lines can monitor them simultaneously. A leak alert means good correlation based on constant noise heard more than one time from the same location.
The company’s founders came from an extensive background in the Navy and were no strangers to acoustics, says Oded Fruchtman, the company’s CEO. “They wanted to do something different.”
In order to improve leak detection, the technology has to be automatic, with correlating occurring 24 hours a day, so they designed an algorithm to do just that, he says. Once the AQS-SYS sensor was established three years ago, the company designed the mobile leak detection sensor—the iQuarius. This was a game-changer, says Fruchtman. “Up until then, a truck full of equipment was needed [to find leaks],” he says.
In contrast, in England, listening sticks have been used since the 1950’s, Fruchtman says. “We designed our stick to bring something more digital to the job.” Very simple to operate, the user connects the mobile sensor to his or her smartphone, presses a button on the handle, and colors—shades of orange, pink, and yellow—appear on the screen of the smart phone, indicating the quietness or loudness of flowing water. When red appears, it signals a leak.
Fruchtman explains that the company worked with Thames Water in London, England, to develop its first pilot for the newly created iQuarius mobile solution. “The United Kingdom market is the most advanced leak detection market in the world, so it is a good place to start,” he says.
Fruchtman says 3,000 sensors were installed above ground in Jerusalem. When asked if the company had experienced any issues with the above ground sensors, he recounted the problem with 500 sensors being stolen for the SIM cards, which were removed from the sensors so that they could be inserted into smartphones and used to search the web. Not only did Aquarius Spectrum install new above-ground sensors with SIM cards that could not be used to search the web, they then developed below-ground sensors that could be installed in manholes and pits.
Fruchtman says that the company has installed its sensors for pilot and permanent use in several US municipal utilities—at the Los Angeles Department of Water and Power; Suez New Jersey; Arlington, TX; Duluth, MN; and Miami, FL.
Aquarius Spectrum has developed two types of sensors. The first are accelerometers that sense vibrations and monitor asbestos cement or ductal iron pipes for leaks. The second type is the hydrophone which can pick up and pinpoint leaks in PVC and plastic pipe. Both types can be installed either underground or above ground.
In July 2018, Aquarius Spectrum announced it was collaborating with TaKaDu, also headquartered in Israel, to provide utilities with a centralized cloud-based event management system. TaKaDu’s system, based on big data analytics and tailored algorithms, is being integrated with Aquarius’s automatic leak detection and monitoring system.
This integration enables users to receive two independent indications about the same problem in the same area. “TaKaDu may know of a leak problem before we do,” says Fruchtman. “So we can accelerate our analysis to determine the specific location of the leak,” he says. The centralized platform allows operators to validate, track, prioritize, and resolve events more easily, even coordinating with other departments in the organization.
Aquarius Spectrum will be expanding its relationship with TaKaDu, Fruchtman says, and adds it is already strong in Australia.
“We have seen much more interest in our fixed sensors,” says Fruchtman. In the UK, there is more interest in the mobile sensors where they traditionally walk to identify leaks. But in the US, it’s the other way around, he concludes.
In mid-2018, Aquarius Spectrum began providing pipe condition assessments for utilities based on their history of installed sensors. The company offers an analysis of when pipes need to be replaced, Fruchtman says. “We have two big projects in Israel and are offering pipe condition assessments to other utilities,” he says.
Aquarius Spectrum has signed with Trimble Water to act as its exclusive US market distributer.
A LEAK FOUND UNDER A TREE
In June 2018, the City of Lawrence, KS, water department found a small non-surfacing leak on the campus of Kansas University using Gutermann Water’s Aquascan 610 Leak Noise Correlater. The campus reported that there was an unusual amount of water infiltrating a storm sewer.
The water department traced the water back to a pipeline more than five blocks away. But there was no water surfacing. Water department workers placed the AquaScan 610 on two main line valves roughly 900 feet apart. A correlation by the 610 Correlator pinpointed a leak directly under a tree in front of an Alumni building on the 16-inch cast iron transmission line leading to one of the water towers. After cutting down the tree and excavating the main, they found the leak location on a lead joint. The water department operators suspected the joint had been leaking for years. Without this leak detection equipment, they would have had no indication of where to look.
THREE LEAK DETECTION OPTIONS
Gutermann Water, founded in 1948 and family owned, has created a full correlation platform, ZONESCAN ALPHA, for water distribution pipe networks. Its ZONESCAN 820 correlating loggers provide daily and fully automatic correlation.
Headquartered in Baar, Switzerland, Gutermann Water has offices located throughout the world. Its US office is in Newmarket, NH.
Gutermann’s leaders began developing its correlating loggers over 10 years ago when they saw the limitations in the standard loggers which used noise to identify leaks. These loggers frequently led to false positives, says Cameron Keyes, director of the North American division. The standard logger measured decibel levels and the higher levels indicated leaks. However, stray electrical noises would trick the logger, he explains.
All of Gutermann’s new loggers use acoustics or hydrophonics which send data via radio links to collection units. Sensors are inserted in valve boxes or chambers and installed on the tops or sides of valve spindles. The loggers make a number of recordings and analyze frequencies to separate the leak from the electrical noise, Keyes, says.
Gutermann manufactures a series of cordless and portable leak noise correlators that transmit sound by radio to a processing unit, under the name AquaScan. The AquaScan TM2 has been designed for use on large diameter pipes and for extremely difficult situations. The higher processing speeds of a tablet PC allow it to detect quieter leak noise at low frequency. The AquaScan 620L is an ultra-compact easy-to-use laptop correlator and can be used with plastic pipes.
The EasyScan is a smart leak locator that is both leak noise correlator, acoustic ground microphone, and electronic listening stick. It is operated by Smart phone or tablet using an Android app.
The MultiScan is a highly sensitive, small multi-point correlator with stainless steel sensor-transmitters, Android app, and GPS-based automated geolocation and mapping on a Smartphone or tablet.
Keyes says the customer has three leak detection options for the correlating sensors. Under “lift and shift,” 10 to 20 sensors are installed one day and the data are read the next day. The sensors are then removed and installed in the next set of valve chambers. The second option is to permanently install loggers and drive by to pick up data weekly.
The third option is the ZONESCAN ALPHA, an all-in-one system which uses proprietary radio infrastructure to detect noise in the monitored pipe network. Keyes says the information collected acoustically is relayed back to Gutermann’s cloud service and then shared with the utility. The advantage is that correlation is automatically performed every night.
Gutermann maintains a regular relationship with the participating utility. It is constantly giving them results and advice on how to hone in on leaks and problems related to them, Keyes says. Ideally, it is the water utility’s job to look after sensors, he adds. Data produced by the loggers can be viewed daily in a browser interfacing with Google Maps.
Gutermann’s ZONESCAN 820 correlating radio loggers are used in all three installation options (lift and shift, drive-by, or permanent installation). “They are commonly used by utilities in a progressive way—to find leaks underground that have not surfaced and for identifying non-revenue water loss,” concludes Keyes. Sensors are spaced 600 to 700 feet apart, not necessarily in every valve chamber. Network monitoring is accomplished with ZONESCAN ALPHA collecting data in a permanent installation every morning.
HiScan is a new product that came on the market in April 2018 and can be permanently installed for unmanned trunk mains. It can also be used in plastic pipe networks. It consists of an extremely sensitive correlating hydrophone sensor that is directly installed on the pipe either by tapping or by connecting it to a hydrant. The hydrophone sensor uses radio scans to monitor the trunk lines on a nightly basis and gives utilities early warnings, Keyes explains. A solar powered 3G gateway transmits the data to the Gutermann Cloud. HiScan will find leaks that were not found in the past, he adds. It is being demonstrated at three utilities.
The ZONESCAN ALPHA gateway platform also now works on a 3G cellular technology and solar power.
Gutermann also teamed up with TaKaDu in 2018 to combine TaKaDu’s integrated event management platform with its fixed network technology. This allows network events featuring leak detection data to be integrated with TaKaDu’s analytics engine.
RUNNING TOILETS ARE THE VILLAINS
The Winstar Properties in Los Angeles has been using WaterSignal’s monitoring system for about three years, according to Mario Horowitz, maintenance manager for the 100 multifamily apartments. The buildings are scattered throughout Los Angeles, Pasadena, Anaheim, and Alhambra.
Horowitz says they adopted the system in each of four or five buildings in the beginning and soon decided to install the systems in all of their buildings. He acknowledged that the data produced by the monitors, which are installed on individual meters, don’t indicate the specific location. But when WaterSignal sends them an email saying a spike in water use occurred in the middle of the night in a specific building, Winstar notifies residents in that building, and maintenance workers inspect each unit and around and under the building.
Horowitz says 99.9% of the time they find toilets running—either a flapper stays open or a pump doesn’t work. A toilet running all day will lose 1,200 gallons of water. If it is a commercial toilet (without a tank) it will lose 1,000 gallons per day.
In one instance, Horowitz recounts, a tenant who was being evicted caused 30,000 gallons of water to be wasted when he left faucets open all night.
Horowitz says that the company invested about $1,000 per building for the WaterSignal monitors. The service is $50 per month per building. If the building has more than one meter, the company gets a discount on monitoring the additional meter. If a building has a sprinkler system, its meter does not need a monitor. “It’s pretty straightforward,” he says.
Horowitz adds that WaterSignal has very good service. Local technicians representing WaterSignal are sent to troubleshoot problems, he says.
A SIMPLE NON-INTRUSIVE MONITOR
WaterSignal is based in Alpharetta, GA. Its water monitoring system is designed for multi-family housing, commercial buildings, and schools. It signals water leaks with a very simple, nonintrusive technology. A monitor is attached to the building’s water meter and by sensing the pulse of the meter, it measures water flow.
“We are giving people a better way to monitor their water use, to save money, and to conserve water,” says Aaron Beasley, vice president of sales at WaterSignal. He describes the monitoring system as a stand-alone intelligent system that listens for pulses generated by flowing water to which the monitor is calibrated. The data is collected around the clock and transmitted to WaterSignal’s cloud and then to the dashboard at the engineering desk of the client. Users also have access through smart phones.
When the monitoring system is installed, Beasley explains that a company technician studies usage and sets a threshold of water usage. “We look at average trends based on similar buildings or schools,” he says.
Caleb LaPointe, director of marketing, describes the specific process: “We look at the water bills, analyze them, and benchmark against similar companies. We walk through the property, determine the type of meters and check out the cooling towers.” He also checks out the parking lots for what he calls “alligator pavement” that has been broken up by, most likely, an underground leak.
Once the technician handling the process has the information calibrated on the dashboard, a customer can see the water usage for the building and may recommend the amount of water the building should be using. He or she can then set the “leak mark,” when an alert should be sent identifying a potential leak, says LaPointe. Leak alerts can be sent hourly and/or daily, he says.
Beasley explains that in an apartment complex the average tenant usage trends are identified at the lowest and highest trends. There will be fast flows over a short amount of time. “Because we monitor at the meter, we don’t identify the point of the leak. But we can give the apartment owner hints,” he says, especially if water flow increases suddenly at 3:35 a.m. for example.
A Better Buildings Challenge is driving commercial buildings to work on water conservation, Beasley says. And there is a lot of equipment that uses water in commercial buildings. “We set thresholds between 6:00 a.m. and 6:00 p.m. at high levels, but when nobody is in the building, the threshold is set very low between 6:00 p.m. and 6:00 a.m.,” explains Beasley. The chief engineer takes action based on the monitored water usage.
In both commercial buildings and schools, cooling towers are a target for WaterSignal. Beasley says about 50% of commercial buildings use natural gas for heating and cooling. “We can monitor both makeup and blowdown water flow on the building’s dashboard.” LaPointe explains that chemical usage ratios will affect how much water is being used in the cooling tower. With proper ratios, water usage will be reduced. Some cities provide credits if monitoring can demonstrate water reduction, he says. It is a big draw for commercial buildings, but the ordinance will be different in every city, he says.
Also, he explains, when irrigation systems are being monitored, “we can tell the users how much rainfall is falling in their areas.” The company recommends turning off irrigation systems automatically when it rains using rain sensors which detect extra moisture.
Finally, Beasley says some schools are using WaterSignal data for teaching water conservation. At least one university is using analytics to show students how much water they are using, he says. Over the last four years, “we’re seeing schools hiring energy managers who are focusing on the water side of their facilities,” concludes Beasley.
WaterSignal can also help a utility, school, or multi-residential building obtain LEED certification by providing the data needed to qualify for points under the water conservation category. If the existing building has an unmetered system, WaterSignal’s water monitoring system may be a good substitute to satisfy a LEED certification requirement.
Other customers use WaterSignal’s water monitoring service for social and environmental reasons—they are conscious of the brand value for shareholders and the public, LaPointe says. Their customers like seeing leak alerts and not necessarily the data.
