When any water services company begins a pipeline cleansing programme there is always a danger that it will provide the catalyst for weak sections of pipe or joints to begin leaking. By way of example, when one such company commenced a five-year regional project to clean up its network of pipes, a major leak occurred on two large clean water mains within the grounds of a local power station, causing extensive waterlogging of the surrounding marsh land. This made it extremely difficult to detect the source of the leak, and thus required the specialist skills of WRc.
The waterlogging was so severe that WRc staff had to be issued with chest waders to enter the affected area. A pump was used to alleviate as much water as possible so that digging could commence. WRc was then able to insert its Sahara® acoustic leak detection umbilical system and accompanying location device, a special combination of technology that is not available elsewhere. Moving in the direction of flow, the equipment completed two surveys on the suspect mains pipe, which measured 42” in diameter.
Along a survey length of 608m, three large leaks were detected at precise locations of 21, 247 and 473m. A large leak is defined as being in excess of 0.8 mega-litres per day. Knowing exactly where to excavate avoided a huge amount of digging in the wrong locations, at significant cost. Instead, the water services company was able to dig directly in the right places, carry out the necessary repairs and recommence operations.