Researchers from Concordia University have developed a method of locating underground in distribution networks with a 99.5% accuracy.
Water scarcity is a worldwide problem that will challenge 33% of the global population by 2025. This water crisis can be averted if one of the main culprits — leaks — can be addressed. It is estimated that between 20-30% of water leaving water treatment plants is lost as a result of water leakage, which can be resolved if the problem is addressed and fixed.
But first we have to find the leaks, which can be difficult to detect when pipes are buried underground. When repair work is undertaken, this needs to be done as precisely as possible, to not only limit the cost involved with excavation work and resurfacing, but also to limit disruptions to traffic, commuter frustration, and loss of income due to disruptions to local trade and industry.
Furthermore, leaking pipes not only waste valuable water; damaged water pipes allow pollutants to enter the water flowing through them via the holes in the pipelines, posing a drinking water hazard and health risk to consumers.
Thankfully, scientists from Concordia University, Montreal, have developed an innovative tool — known as a noise logger — to address this problem. They recently conducted a study to test the effectiveness of the tool, traveling to Doha in the water scarce nation of Qatar to apply the noise logger in detecting water leaks within Qatar University's water network.
Qatar not only has one of the lowest rainfall rates globally, but also among the highest evaporation rates globally. Consequently, when rain does fall it quickly evaporates back into the atmosphere in the form of water vapor.
According to co-author, Tarek Zayed, a professor in the Department of Building, Civil and Environmental Engineering at Concordia University: "Qatar is currently facing significant challenges regarding its water supply. Its water distribution network currently suffers from 30-35% water loss due to leakage."
The results of the study, which where recently published in the Journal of Infrustructure, show that the noise logger is not only effective at detecting leaks, but can do so with fine accuracy before any major earthworks are required.
"This approach can reduce the duration of a leak, as well as the cost and time involved in locating the site in need of repair." " explains Zayed
To test their theory, the researchers installed noise loggers on Qatar University's water mains network to record sounds generated by water leaks over a 2-hour period. They then scrutinized the sound readings, comparing noise level and spread. The researchers deemed a leak investigation necessary when a consistent sound anomaly was detected.
After monitoring Qatar University's water mains for several weeks they collected sound readings from 140 points across the water network. They then used mathematical model simulations to pin-point the exact location of where water leaks were occurring. After investigating the locations of the leaks, Qatar University's facilities management reported that the researchers had detected the leaks with 99.5% accuracy.
The researchers now plan to conduct surveys of leak data from real-life municipal water networks where noise loggers are used in an effort to develop tailor-made leak location prediction models.
El-Abbasy, M., Mosleh, F., Senouci, A., Zayed, T., and Al-Derham, H. (2016). "Locating Leaks in Water Mains Using Noise Loggers." J. Infrastruct. Syst. , 10.1061/(ASCE)IS.1943-555X.0000305 , 04016012.