University of Technology, Sydney. Faculty of Engineering and Information Technology.Pressure on the availability of Australian freshwater resources is significantly increasing due to emerging climate change and population growth factors. Sustainable urban water consumption has become a critical issue in Australia due to the increasing urbanization, country’s dry climate and increasingly variable rainfall. Water recycling is considered vital in alleviating the demand on existing and limited water supplies. It is the process by which wastewater, typically from sewage and/or stormwater collection, is treated to a variety of quality levels depending on the intended use and required safety standards. The benefits of using recycled water include protection of water resources, prevention of coastal pollution, recovery of nutrients for agriculture, augmentation of river flow, savings in wastewater treatment, enhancing groundwater recharge, and sustainability of water resource management. This will help in alleviating the pressure on existing water supplies and on the other hand protects remaining water sources from being polluted. Therefore, demands on water utilities to develop water recycling capacity and supplies are expected to intensify in Australia to cope with the persisting and increasing water stress. Numerous initiatives have been embraced Australia-wide to increase the availability of less-climate dependent water sources. Dual reticulation systems are one of the integral parts of such initiatives. Many cities in Australia are already equipped with dual reticulation system and this is likely to expand in many other cities in the future due to the persisting and increasing water stress. Considerable amount of fresh water conservation has been achieved due to the use of recycled water in urban communities. However, the end uses of the recycled water in such systems are limited and confined to toilet flushing, garden irrigation and car washing. Washing machine involves significant amount of household water (almost 20%) in most of the countries of the world including Australia. In this regards, use of recycled water for washing machine as a new end use of recycled water could be one innovative thought. Hence, this study aims to introduce a new end use to recycled water for urban water.
The recycled water parameters in terms of maximum allowable values of heavy metals in recycled water for laundry were formulated as the result of the study. Vision of community and their major concerns in regards to use of recycled water for washing machine were identified. The investigations with recycled water for washing clothes in washing machines were carried out to address all the major concerns of the general community regarding this new end use. The results indicated that Class A recycled water being supplied to the dual reticulation systems in urban community is safe for this new end use and highly recommended. The conceptual design criteria of educational leaflets for the dissemination of information on use of recycled water for various end uses were presented. Hence, this study proposes clear pathway to assist the adoption of water reform by actively engaging members of the community in this particular new recycled water application. Public acceptance of this new end use would be a significant step forward into sustainable thinking of urban communities. Conclusively, a new end use for recycled water for washing machines is acceptable and considered as a sustainable approach for Australian urban water