When a water treatment plant noticed that water was pooling near the banks of its contact tank, it had to find the leak source fast to prevent long-term infrastructure damage and prevent significant water loss.
The tank feeds two 1400mm diameter mains (70m and 40m in length) that turn through 90° and travel downwards into banking that in places reaches 10m in height. Another problem was the low pressure (0.5 bar) of the system, which can make it difficult for many acoustic detection systems to hear the leak.
WRc dropped its Sahara® acoustic leak location umbilical system into the open water of the contact tank, where natural flow sucked the device into the mains outlets. As the Sahara® system is designed to work at pressures as low as 0.5 bar, the application proved straightforward.
The real added-value came from deploying the Sahara location system alongside the acoustic leak location device, a technology combination not available elsewhere. This allows highly precise leak location to within 0.5m in either direction. WRc’s work was completed in just one shift.
Two leaks were found on the 70m-long pipe, at 8m and 10m from the contact tank. A further leak was discovered on the 40m pipe, 18m from the tank. Knowing exactly where to excavate the bank avoided a huge amount of digging in the wrong locations, at massive cost. Instead, the plant was able to dig directly in the right places, perform its repairs and resume operations.
That was in 2009. Since then, WRc has been called back on one other occasion, in 2016, after a new leak materialised. Following the success of the first encounter, the plant re-engaged the services of WRC: a leak was duly found on the 40m pipe, 17m from the contact tank which was losing 5Ml/d.