Dubbo Regional Council is interested in replenishing the Upper Macquarie alluvial aquifer with robustly-treated effluent and trading it for groundwater belonging to irrigators. Replacing potable water with treated effluent is also being considered because it is seen as "an extremely reliable source of water" unlike rain. The council's investigation into the reuse of effluent is accompanied by reassurance that it would be first subject to an "extensive" treatment process and ongoing water-quality testing regime regulated by the state government. READ ALSO: Re-use of effluent is a key component in a new council strategy aimed at creating a "more diverse and resilient" water supply system for Dubbo. A Managed Aquifer Recharge (MAR) scheme would be a first for the council and "possibly NSW", reports chief executive officer Michael McMahon. It operates by injecting effluent into the aquifer in a controlled manner, where it can be stored without any evaporation, then extracted at a later time for use, he says. "There are extensive controls on the actual section of the aquifer where the effluent is stored, such that its location can be carefully monitored to ensure it can be recovered in the future. "As well the quality of the effluent injected is of a very high standard to ensure it doesn't create any contamination risk for the aquifer. "This process is used extensively overseas and a similar scheme is currently in use by the WA Water Corporation in Perth." Mr McMahon said the council was looking at the possibility of trading treated effluent water for groundwater used by irrigators. "That would see irrigators use council's treated effluent water instead of allocated irrigation water, and council would take the irrigators' allocation of groundwater," he said. "This would allow council and irrigators to continue operating, with minimal impact to their water-use activities while making better use of available recycled (treated effluent) water." Council and Taronga Western Plains Zoo staff are in talks on a proposal for it to use treated effluent instead of 350 Megalitres (ML) of high security surface water. Dubbo produces about 3000 ML of effluent annually. It is used to irrigate the council's Greengrove property and supplied to commercial entities.