Wastewater Treatment Plants have formed a key part of WJ’s project portfolio across the world since the company was first formed in the 1980s. These projects can range from small pipeline diversions to the construction of large scale tanks and shafts. It therefore felt almost inevitable when WJ were brought on board by DMCI and Maynilad Water to provide groundwater control services for the construction of Camana Wastewater Treatment plant.
The Camana Wastewater Treatment plant is scheduled to be the largest sewage treatment plant in the Philippines, with a capacity to process 205 million litres of used water daily – something that is vital to help provide a clean supply to the 26.7 million people living in the Manilla Metropolitan area.
WJ were brought on board specifically to aid the construction of a new water inlet pumping station shaft, approximately 45m in diameter and 25m deep. The standing groundwater level at the site was only 3m below ground level in permeable sandstone, therefore a significant amount of drawdown would be required to enable dry sinking of the shaft – a not inconsiderable task.
WJ designed and installed a deepwell dewatering system consisting of 6no wells, providing a total pumping capacity of between 15l/s and 9l/s. The dewatering ran for approximately 10 months, providing an effective and efficient dewatering solution for the project.
WJ’s performance on the project was particularly appreciated by DMCI, who noted:
‘WJ optimised the dewatering design to minimise interference with the main works and they worked with us to ensure reliable operation throughout the construction phase. With their help, we were able to hand over the shaft to Maynilad 3 weeks early’.