Demonstration of decentralised wastewater recycling in urban villages in Western Australia

Decentralised wastewater recycling and irrigation demonstration projects were established in three urban villages located within the Perth Metropolitan Region, to determine whether decentralised systems can achieve equal public health and environmental standards, and improved sustainability outcomes at comparable costs to centralised systems. The trial sites were located at Bridgewater Lifestyle Village, a development of 389 home sites, with lot scale greywater recycling; Timbers Edge Residential Village, a development of 260 homes, with a central greywater recycling system; and Banksia Tourist Park, a caravan park comprising 76 permanent park homes and 95 caravan bays, with the potential for a central wastewater recycling system. A review of current regulations, legislation, existing water modelling concepts, and existing wastewater decision tools highlighted the need for both a new water modelling concept and a new wastewater model appropriate for urban villages. This paper focuses on monitoring conducted at the Bridgewater Lifestyle Village trial site, which showed that environmental and sustainability considerations favour decentralised systems, with the economic and public health outcomes being similar. The real test for cost effectiveness will be the community's choice of whether to retain the decentralised system in preference to connecting to a centralised system when the option becomes available. Social acceptance of small scale systems requires the test of time, and urban villages considered in this study, which incorporate sustainability features into their design, will assist to overcome the stigma associated with wastewater reuse. However, a change to regulations and policies is required to recognise village and cluster scale systems that have centralised management, to encourage developers to implement these sustainable features into their plans.