One way to increase the supply of water for cities and regions is simply to waste less of the water we already have.
“I don’t think there is a city in the world that does not have leakage in its water system,” says Kamal Youcef-Toumi, a professor of mechanical engineering. Many water systems lose vast amounts of this precious resource through leaks in the pipes that carry it to our homes and businesses. In New York and Boston, for example, some 10% of our water is lost in this way. In London the number is closer to 30%, Rome leaks away 30–40%, and some cities in the developing world lose almost half.
From aging infrastructure to damage wrought by burst pipes, it’s easy to see that “there are big challenges associated with water losses in the system,” says Andrew Whittle, the Edmund K. Turner Professor in Civil Engineering.
Youcef-Toumi and Whittle are each working to increase the world’s water supply by decreasing water loss through leaks.
Whittle’s work began as a research project through the Singapore-MIT Alliance for Research and Technology. He and colleagues approached Singapore’s Public Utility Board about installing a test bed of wireless sensors inside water pipes. The idea was that the sensors could pinpoint leaks in real time by detecting changes in the water pressure along a pipe, then transmit the data wirelessly to control centers. Sophisticated analytical tools not only allow the sensors to extract important signals from the background noise at every location, but also help pinpoint the locations of leaks.
Whittle’s team was the first to deploy instrumentation inside water pipes for the detection of leaks. The conventional approach to the problem involves utility employees who listen for leaks with acoustic devices as they traverse a neighborhood.
The researchers soon realized the potential of the technology. “We went rather quickly from concepts and prototyping to a point where we were starting to observe real events [leaks and bursts] fairly regularly,” says Whittle.
In 2011 his team formed Visenti, a company to commercialize the technology. Today, they’ve deployed sensors all the way across Singapore. Visenti has also completed pilots in Melbourne and Hong Kong, and is conducting two others in Paris and Bordeaux.
Swimming robots are key to the system being developed by Youcef-Toumi and colleagues at the Center for Clean Water and Clean Energy at MIT and King Fahd University of Petroleum and Minerals (KFUPM). The intelligent machines, which travel inside the pipes, include onboard sensors that, like Whittle’s stationary ones, detect leaks in real time due to changes in pressure. They, too, relay the data through a wireless network to control centers above ground.
The robots can not only detect leaks on the fly as they whisk past in swiftly moving water; they can also stop to fix them. “A robot can lock into place around the area of the leak, then, for example, spray a liquid compound at it that hardens very quickly,” says Youcef-Toumi, who is co-director of the MIT-KFUPM center. The robots are also designed to adjust their size automatically when moving into pipes of different diameters.
The team has tested the robots in the lab. This summer they plan to conduct their first field tests in a mile-long network of pipes in Saudi Arabia.
Both Whittle and Youcef-Toumi are excited about the potential for their technologies. “We are developing technologies for the good of mankind,” says Youcef-Toumi.