Perth’s Groundwater Replenishment Scheme takes shape
Construction of Australia’s first full-scale Groundwater Replenishment Scheme is progressing well, with earthworks complete and work to pour the estimated 2,500 to 3,000 cubic metres of concrete at the site under way.
Water Corporation began work on the scheme in October 2014, which plays an important role in its Water Forever plans to secure water supplies in our drying climate. This first stage of the scheme will initially be able to recharge up to 14 billion litres of water each year and can be expanded to 28 billion litres when needed.
Groundwater replenishment is the process by which secondary treated wastewater undergoes advanced treatment to produce recycled water. The recycled water is recharged to an aquifer for later use as a drinking water source.
The process of groundwater replenishment is carried out at an Advanced Water Recycling Plant. Before wastewater reaches this point, it will have already undergone rigorous treatment at the Beenyup Wastewater Treatment Plant to ensure it meets ocean discharge quality requirements.
It then takes the highly treated wastewater and uses three different tried and tested water treatment methods. First, ultrafiltration filters out suspended materials, then reverse osmosis removes any remaining dissolved materials. Finally, ultraviolet light is used to remove any trace levels of micro-organisms that may remain.
Once the water has undergone the treatment processes in the Advanced Water Recycling Plant it will pumped from a water tank to the recharge bore. Water will be recharged to groundwater supplies through a number of recharge bores.
Water Corporation carried out a successful three-year Groundwater Replenishment Trial in Craigie, Western Australia,which ended in December 2012 and clearly demonstrated the technology could be used in Perth.
During the three-year trial, more than 2.5 billion litres of recycled water was recharged and more than 70,000 water quality results were obtained, all which met stringent health and environmental guidelines.
Water Corporation also took the community along for the journey – carrying out its most extensive community engagement to date throughout the trial. More than 11,000 people toured the site of the trial and overall support for the full scale groundwater replenishment scheme remains steady at around 73 per cent.
Parts of the trial plant which are suitable to be reused are being incorporated into the full scale scheme, including the trial process building, visitors centre, recharge bore and feedwater tanks.
In our drying climate, groundwater replenishment provides a secure, rainfall independent water source that has the potential to supply up to 20 per cent of Perth’s future drinking water needs by 2060.
For more information about groundwater replenishment visit Water Corporation’s website watercorporation.com.au