Water and Effluent Treatment Magazine
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16 WET NEWS FEbrUArY 2016 When MidCoast Water took over Gloucester's ageing water distribution network, outages, pressure fluct- uations and asbestos cement pipe had to be overcome. The challenge: Eliminating pump and pipe failures INSIGHT IT & TElEMETrY The Gloucester water network stretches north to south over a very hilly 15km improve the network performance while minimising energy use. The Gloucester water network stretches north to south over a very hilly 15km, with elevations spanning more than 60m. The highest points in the system are the northern and southern extents, with some additional intermediate high points. None of the three existing reservoirs is at a sufficient elevation to provide adequate pressure to all Gloucester residents. Currently, seven booster pumps are required to provide adequate water pressure. Without the pumps, most residents would have reduced water pressure, and some residents would have no water at all. Water pressure provided by booster pumps is not as reliable as pressure provided by a reservoir at sufficient elevation. Pressure According to the Water Services Association of Australia (WSAA) Water Supply Code, booster pumps should only be used to boost pressure and should not be the only means of supplying water to the required service levels. The existing water system also contains nearly 30km of asbestos cement pipe that was installed between the 1930s and 1980s. The pipe is currently being replaced, but this project will take many years. Because of the poor condition of much of the pipe, pressures within the system must be maintained at relatively low levels (compared to the usual maximum desirable pressure), adding another constraint to the solution design. M idCoast Water delivers water and sewerage services to 40,000 households in the Manning, Great Lakes, and Gloucester communities of New South Wales in Australia. It also supplies eight billion litres of water a year to Karuah in the south, Crowdy Head in the north, and Gloucester in the west. In 2011, MidCoast Water accepted responsibility for the operation of the ageing water and sewer networks in the Gloucester Shire Council area. The Gloucester water distribution network, parts of which date back to 1914, involves three reservoirs and seven booster pumps. Residents experienced water pressure fluctuations, as the entire water system relied on booster pumps, which switched on and off based on downstream pressures. A combination of pump and pipe failures also caused outages. At one point, many residents remained without sufficient water for a couple of days, with 11 main breaks and one leak reported in Gloucester over a 24-hour period. Energy use MidCoast Water sought to find a solution that would increase the residents' level of water services while reducing the system's reliance on booster pumps. This would subsequently reduce the ongoing energy use required to operate the system. Using WaterGEMS, MidCoast Water was able to assess more than 100 what-if scenarios and to select the optimal solution that would The existing water system contained asbestos cement pipe