AI tool uses sound to pinpoint leaky pipes, saving precious drinking water
In the battle to conserve water, leaking pipes form an insidious enemy, accounting for average losses of 30 percent – but in some localities as much as 70 percent – of piped drinking water across the world. The leaks can be very difficult to pinpoint, but a new AI tool is making the process faster and more accurate.
A white X marks a leaking fire hydrant in the San Tan water district, just southeast of metropolitan Phoenix. The leak is a medium one of three to seven gallons per minute. That adds up quickly, with each day of leaking equivalent to the average water consumption of 43 households.
In this case, the typical giveaways of a leak aren’t present – no puddles, no unexpected greenery in the desert landscape, no caved-in street. The water has been seeping away through the bottom of the hydrant.
“That’s something that probably most likely would have leaked until the next fire hydrant maintenance cycle, which could be up to five years,” says Jacob Rogers, division director at EPCOR, the biggest private water utility in Arizona.
But this leak was detected sooner, thanks to an AI acoustic tool developed by FIDO Tech, whose technology not only detects leaks more precisely to their location, but also ranks them by size so that utilities can prioritize which to repair first. Oxford, U.K.-based FIDO is working with several utilities, such as EPCOR in Arizona and the State Water Commission in Querétaro, Mexico, as part of a Microsoft program to act responsibly by replenishing water in the same watersheds around the world where it has operations, including datacenters.
Replenishment can take different forms. Tactics include harvesting rainwater and conserving swaths of land to return water to the source; improving water access or quality for communities in watersheds where Microsoft operates.
Microsoft has invested in a global portfolio of more than 75 diverse replenishment projects as of the end of June 2024. It is working with Audubon Dakota to restore prairie habitats in Fargo, North Dakota, with a collective in Cape Town, South Africa, to clear invasive species and restore water catchment, and to acquire conservation easements to help recharge the Edwards Aquifer in Comal County, Texas. A contract with the Jicarilla Apache Nation in New Mexico aims to protect threatened fish species and improve water security in that state, while the restoration of ponds in Karnataka, India, helps recharge that community’s groundwater.
“There are also projects we fund that increase efficiency and decrease overall water use, thus increasing availability for the basin and local communities,” explains Eliza Roberts, director of water at Microsoft.
That’s the case with Microsoft’s collaboration with FIDO, which began in 2023 with a contract to detect leaks in part of London for the Thames Water utility. Microsoft also helped FIDO develop its leak detection technology during Microsoft hackathons in London. FIDO’s tool uses OpenAI’s GPT-4 on Microsoft Azure OpenAI Service to take acoustic leak detection to a new level.
FIDO’s AI tool takes acoustic files from small, mobile sensors placed on water pipeline networks, then “we let the AI do all the work from that acoustic file anywhere in the world. We don’t need to know the pipe material, the pipe depth, the pipe size. Water pipes are really noisy. We can tell if that noise it listens to is a leak or not. The AI cuts through all that noise and says that is definitely a leak,” explains Victoria Edwards, CEO and co-founder of FIDO.
FIDO is also deploying its AI leak detection through Water United, a new initiative co-created by Microsoft and other partners to unite the public and private sectors across the Colorado River Basin, which provides water for more than 40 million people in seven states, including 30 indigenous tribes. Starting by scaling the deployment of AI to detect and repair leaks, Water United’s aim is to connect datasets using FIDO’s technology, validate the effectiveness of other solutions like agricultural water efficiency and ultimately build out the AI tool for long-term watershed-level water resilience. One of the first Water United participants is Las Vegas Valley Water District, a not-for-profit water utility that provides water to more than 1.7 million people. Water is especially precious in the parched Colorado River Basin as well as in Arizona and Mexico.
Microsoft pays FIDO for leak detection, and the utilities pay for the repairs – which they would have had to cover anyway. The volume of water saved with Microsoft’s support will count toward its replenishment target in proportion to the amount it invested compared with the total cost of detecting and repairing the leaks, Roberts says.
Leaks waste more than water
Stopping municipal water leaks prevents waste and increases water availability for the customers and communities that a utility serves. For the communities involved, leaks represent not only lost water, but also the cost of pumping it, of transporting it – which requires huge pipes and tremendous energy to push it, because it’s very heavy – of filtering it and of the chemicals needed to treat it. This lost water is called non-revenue water because it never arrives at a paying customer. Instead, everybody foots the bill.
“We’ve acquired troubled utilities in Arizona that had 30 to 40 percent water loss,” says Shawn Bradford, senior vice president of regulated water in Arizona and New Mexico for EPCOR, which has been working with FIDO under Microsoft’s program for about a year. “We’re having to pump 40 percent more water than they need just to cover the leaks that it takes to get it from the well or the water treatment plant to homes, and that’s a tremendous cost that all customers face.”
EPCOR has cut non-revenue water to around 10 percent from 27 percent, in part thanks to FIDO. FIDO provides sensors that are placed so they touch a pipe, whether that’s on top of an easily accessible pipe, on a hydrant, in a valve chamber or on a tap, FIDO’s Edwards says. EPCOR has 4,554 such sensors on its pipe network in the 160-square-mile San Tan service area. The sensors record everything, even the lowest, quietest noises.
“Sound propagates differently in different materials, just like it does in a school orchestra. You know, the longer the trombone, the longer the pipe, the deeper the sound compared to the trumpet, with shorter length and higher frequency. The largest leaks are the quietest – the human ear cannot hear them – especially in a plastic pipe,” Edwards says.
Utilities have long relied on acoustic devices to detect leaks. FIDO’s technology goes a step further, running the data its sensors have collected through a deep-learning AI tool that has learned to accurately determine whether a noise is caused by a leak or something else, like machinery or a train rumbling by. It can also assess how big the leak is and pinpoint its location. The other benefit of FIDO’s technology is that utilities’ technicians can easily interact with the AI in natural language.
EPCOR, too, had used acoustic leak detectors elsewhere, but “you have to spend a lot of time trying to figure out exactly where between those two devices the leak is actually located,” Bradford says. “The benefit of FIDO is it takes all that raw data and runs it through AI to help pinpoint where the leak is. FIDO in particular can do this on plastic pipe, which has always been a challenge for the industry – the leak doesn’t resonate like it does in metal pipe.”
The lack of resonance in plastic pipes means many acoustic leak detectors struggle. Yet most new pipe infrastructure is plastic, or PVC, because it’s lighter and easier to maneuver, making it easier to install and repair. On top of that, plastic pipe is better suited to the soil chemistry in the southwestern U.S., Bradford says, and dominates in the San Tan Valley, which has developed in the past three decades and continues to be among the fastest-growing U.S. communities. The utility does also have metal pipes – some are 60 to 70 years old and still in top condition. Pipes can break for many reasons besides age – for example, shifts in the ground from freeze-thaw cycles. In fast-growing San Tan, the leaks tend to occur in areas under construction.
Before FIDO, the utility relied on satellite imagery to spot such giveaways as green vegetation growing in unlikely places, Roger says. But such greenery doesn’t sprout overnight – it takes days or weeks to grow. FIDO can find leaks much more quickly.
A fast and flexible solution
The AI also analyzes the utility’s network map to advise where to place sensors to avoid deaf spots, Edwards says. Results pour in immediately. “You can leave it overnight or for years at a time,” she says. The sensors are easy to move to monitor different swathes of the pipe infrastructure.
The sensors can also be placed on either side of a leak after it’s repaired, to make sure the fix is successful, or to spot whether the digging during the repair has caused another leak. And then the sensors can be moved to start detecting in a different part of the network. Meanwhile, FIDO’s AI can assess the likely volume of the leaking water so the repair work can be prioritized for maximum impact.
The leaky hydrant marked with an X turned out to have a faulty seal, and the repair was quick. Not all leaks are fixed as easily. Repairing buried pipes may require digging holes. Precision in locating leaks is essential to avoid tearing up streets, sidewalks or yards any more than necessary. It isn’t just a matter of minimizing traffic disruption – the utility is required to repave the street after the repair, which represents a significant cost that grows with the size of the excavation.
Bradford recalls some exceptional leaks over his career in different locations, such as a large leak that surfaced on Christmas on the East Coast of the U.S. Amid the cold and snow, the team excavated for the leak, but “we couldn’t find it. We could see water running into the trench but we didn’t know where it was from,” he says.
They used traditional acoustic leak detection technology and determined that the leak was 20 feet farther up the road. So they dug another 20 feet, but still didn’t find the source of the leak.
“We ended up going about 150 feet up the road to find it,” Bradford says. The street was a mess, but worse, because it was a very large leak, it was causing neighboring homes to lose water or experience very low pressure.
Another time, in Edmonton, Canada, Bradford’s team chased a leak that was gushing 13 million gallons a day, which took four days to find. The difficulty was that Edmonton is a very big city, with dramatic changes in the population size and weather extremes – both factors that can cause leaks. The leak ultimately was found in a development under construction, so nobody noticed that water was leaking out of the ground and running into stormwater collection.
In contrast, in a year, EPCOR has identified more than 250 leaks in Arizona’s San Tan Valley, the company said.
Repairing leaks is a Sisyphean task. “You will always get new leaks,” FIDO’s Edwards says. Culprits include environmental factors like the ground settling near the pipe, nearby construction and corrosion. Pipes with even small leaks are “like teeth with cavities – they never get better. They don’t fix themselves,” she says.
The unending nature of pipe maintenance is why Microsoft committed to a decade-long program with FIDO and the utilities it is serving with its AI leak detection.
“Water challenges can be complicated and daunting. And yet, there are many simple ways we can save water and ensure we are getting the most value from every drop,” Roberts says. “Using AI to identify and validate the repair of the leaks is just one example and we are excited to leverage partnerships like this one to scale our impact in protecting freshwater resources.”
Related links:
Read more: Water replenishment: Our learnings on the journey to water positive
Read more: Our 2024 Environmental Sustainability Report
Read more: Microsoft will replenish more water than it consumes by 2030
Top image: A FIDO sensor attaches easily to any fitting or a pipe carrying drinking water without the need to interrupt water supply. Photo courtesy of Microsoft.