IWRA Proceedings

AbstractGlobal urbanisation, the growth of mega cities, shanty towns and poor rural communities continues to challenge the water industry. Extremes in weather patterns and environmental disasters demonstrate the need for more robust and flexible water management strategies which encompass recycling. In Australia, water reuse projects have been successfully implemented in agriculture, domestic dual-reticulation, industrial and municipal use. In each case, the recycling process is adapted to suit the end use and regulatory water quality requirements. This paper will present two innovative reuse schemes including associated research which depend upon recycled water from the Bolivar Wastewater Treatment Plant (WWTP) in South Australia. And highlight the issues of quality, risk management and the supply and storage of recycled water. The Bolivar Wastewater Treatment Plant (WWTP) has a design flow of 150,000 m3/d and supplies water for two recycling schemes; the agricultural Virginia Pipeline Scheme (VPS) and the Mawson Lakes dual reticulation housing scheme. Virginia is home to Australia’s largest concentration of greenhouse fruit and vegetable production. The Virginia Pipeline Scheme (VPS) is one of the largest schemes in the world and was designed to protect ground water resources in the northern Adelaide Plains. Irrigation is essential for crop productivity and prior to the VPS, irrigators relied totally on groundwater extraction to meet crop production. The recycled water is delivered via an 18 km pipeline and is providing 240 growers with 15 million m3 of recycled water each year. The recycled water from the Bolivar WWTP is also reused to supply the Mawson Lakes residential and business precinct, with a design capacity of 10,000 people. The development features a state-of-the art recycled water system to complement the potable water supply, and is the first scheme of its type to combine both recycled water and stormwater. The water is used for toilet flushing, domestic garden watering, and irrigation of municipal parks and gardens and reduces potable water use in the area by up to 50 percent. Public health is protected by a range of strategies including ongoing risk assessments, detailed audit processes, public education programs and online system monitoring. This paper will give an overview of the risk management techniques. Public Perception studies were also undertaken. In winter or when demand for recycled water at Virginia and Mawson Lakes is low, the recycled water is discharged to the sea. Research has been undertaken to evaluate options for storing and retrieving the injected recycled water through Aquifer Storage and Recovery (ASR). The project involved the injection of recycled water diverted from the VPS into a brackish limestone aquifer for subsequent reuse during the summer irrigation season. This paper will also present some of the key findings of this research. The Aquifer Storage Transfer and Recovery, research project is located near Mawson Lakes and involves injecting urban stormwater harvested via an engineered wetland into a brackish aquifer and recovering it as water fit for continuous supply at a potable water quality. The scope and results from this scheme will be presented at this conference as it forms part of the case study of the EU funded project RECLAIM WATER.