GHD leads Sydney water recycling consortium

A consortium led by engineering consultants GHD has been selected by the City of Sydney, Australia, to develop a decentralised water masterplan for the Local Government Area (LGA), which would include Australia’s first city-wide recycled water network and significantly reduce demands on drinking water supplies.

The consortium, selected after a competitive tender process, also includes the Institute of Sustainable Futures at the University of Technology, Sydney, and public private partnership consultants P3iC. It will develop different business models to implement the decentralized water plan including a private-sector water-services company or a public/private joint venture.

The LGA currently imports 32 million m³ of drinking-quality water each year. An estimated 80% of the uses could be supplemented by recycled water, including toilet flushing, laundry, air-conditioning cooling towers and irrigation.

The recycled water network would, for the first time in Australia, allow buildings to take recycled water from the network and to supply any excess recycled water to the network.

Allan Jones, chief development officer, energy and climate change, said, “The type of city- wide recycled water network has not been implemented anywhere else in Australia. Therefore, the plan will also look at the business models to implement the network and any regulatory barriers that may prevent or limit the implementation of this very much needed climate change adaptation measure.”

The recycled water networks will be integrated with the city’s planned low-carbon zones powered by trigeneration plants, with common trenches used to house pipes for recycled water, district heating, cooling and automated waste collection. The zero-carbon waste heat from trigeneration plants could also be used for water treatment by the local recycled water treatment stations.