Water & Wastewater Treatment

22 | MAY 2020 | WWT | www.wwtonline.co.uk The Knowledge Gary Wyeth, SE Asia regional account manager for Mueller Water Products, discusses the importance of early leak detection and draws on examples from the US. adding important details such as pipelines, including material, age and burst frequency. By using a GIS system, the utility can then develop a plan for managing its pipelines, which would include pipe rehabilitation, pipe replacement, pressure management and leak detection activities. There are two basic leak- detection strategies — periodic surveys (ad hoc or scheduled) and permanently installed monitoring solutions — but a combination of the two is what works best. A periodic survey will reveal active leaks, but it cannot tell exactly how long a leak has been active. As a re- sult, there is no accurate way to quantify the volume and subsequent cost of the water lost. By contrast, a permanent- ly installed monitoring system can track the progression of a leak, from the moment it first Real-time leak detection reduces repair costs appears, allowing a utility to allocate resources based on priority of leak size and progression speed. The extent of a survey programme o€en depends on the size and scope of the water utility. Smaller utilities can assess their entire systems in a matter of days. A larger utility will typically conduct condition assessments and periodic surveys on a rolling basis (see table). This can of- ten mean that some pipelines are only surveyed once every year or two. Real-time data pinpoints leaks as they form Surveys are o€en prioritised around existing desktop hydraulic simulation models, based on the oldest sections of infrastructure, or on zones with the highest break rates. But this can still lead to teams surveying hundreds of kilometres to find just a hand- ful of leaks. If a utility has a permanent monitoring system installed across broad swathes of the system, they can use real time data to direct survey crews to pinpoint leaks as they form. To demonstrate both how sensitive and elusive leak detection can be, Brandon S ooner or later, every water distribution system leaks, both in remote rural areas as well as dense urban cities. The consequences of a pipeline leaking in a forest, forming a small stream that appears to be part of the natural surroundings, may not necessarily justify the need for leak detection systems in remote areas. However, permanent leak monitoring in high density areas can reduce the disastrous impacts of pipe bursts which trigger a tsunami of costs far beyond the expense of the pipeline repair alone. The key is being prepared, to minimise the costs and complications related to those leaks. This starts with mapping the utilities water distribution system using a solid Geographic Information System (GIS), and then

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