15 January 2023

Spotting leaky pipes from orbit

PRIVATE utility Anglian Water, which supplies water services to around seven million people across eastern England and is under pressure to cut back on excessive wastage from leaky pipes, is turning to out-of-this-world technology for help.

The Huntingdon-based company is using space age technology, originally developed to detect water lying below the surface of Mars, the red planet, to locate hard to find underground leaks. Information gathered by the latest Earth-orbiting satellites is crunched by specialist computer algorithms and then turned into images as a way of helping engineers solve the costly environmental problem.

The system was first created to detect water on Mars and pioneering space firm Asterra is now redeploying its space know-how to help utility companies like Anglian Water solve a long-standing problem.

“It’s not just water that is wasted by leaking pipes – every drop also represents a substantial emission of carbon,” says founder and chief technology officer of the London and Tel Aviv-based company, Lauren Guy.

Anglian Water admits it loses 182 million litres of water per day across its network, an equivalent leakage of approximately 16-18 percent when compared to the amount of water running through the network each day.

“We recently used the Asterra technology to pinpoint some significant leaks that would never have been identified due to the relatively low percentage loss”, a company spokesperson said.

“These non-visible, underground leaks were in remote areas and would never have been reported by a customer, or indeed found using traditional detection sweeps.

“They often run through agricultural and rural farmland where traditional detection, or even smart distribution leakage technology, is difficult to use due to the lack of fittings and the sheer geographical size of an area.”

The water firm says the Asterra expertise allows it to use satellite data to detect leaks from otherwise difficult-to-inspect transfer pipes and trunk mains right across its system.

Before space technology stepped in, staff from water utility companies had to ‘walk the line’ in search of leaks, often manually inspecting mile upon mile of pipes each day in the hope of catching the sound of trickling water.

More modern techniques, such as installing acoustic sensors to listen automatically for leaking pipes are effective but can only cover limited areas before becoming cost prohibitive. Planetary scientists searching for the holy grail of Martian water then realised that orbiting spacecraft with special radar sensors could be used to spy out water lying below the red planet’s surface.

Asterra’s adaptation of this space-based solution for terrestrial use came after Guy realised that if satellite technology could locate water under the surface of Mars it could also be used to help track down water leakages closer to home. His discovery was made possible by sensors known in the space business as Synthetic Aperture Radar (SAR), which are used on many of the latest low Earth orbit (LEO) satellites and can peer through cloud and below Earth’s surface.

L-band SAR uses the motion of a radio antenna to build up images which typically cover areas of around 3,500 square km at a time. It works by transmitting radio frequency waves and recording what is reflected to the receiver, revealing details on the nature of the reflective material, including the moisture content of soil.

Asterra’s breakthrough relies on sophisticated data processing using proprietary geophysical modelling and analysis. “It allows us to pick up the signature of leaking water in densely populated urban areas packed with interferences to SAR imaging”, explains Guy. “The observations are much more than high-quality images and, since perfecting the art of extracting a signal from the noise, we can provide game-changing insights to the water industry.”

All this means city and county-wide systems for transporting drinking water and wastewater can be more easily analysed to identify subsurface leaks that otherwise go undetected. (See satellite image from JAXA at top of article with blue lines showing water pipes and yellow dots “points of interest” where satellite data indicates a leak).

“It goes without saying that if leaks can be plugged, then the volume of water saved can amount to an entirely new water source and the requirement to drill new wells, raise dams or invest in expensive desalination plants is significantly reduced,” says Guy.

“Cleaning, treating, pumping and distributing water is an energy-intensive process, and any water going to waste represents unnecessary greenhouse gases pumped into the atmosphere. Our mission is to help water infrastructure companies improve the distribution of clean water and cut back on waste.”

 Editor's note: an original version of this article was published on Central Bylines.

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