Treated sewage will be part of Perth's drinking supplies within three years after the State Government today confirmed it was going ahead with Australia's first recycled drinking water scheme.
About six years after the idea was first flagged, Water Minister Terry Redman said purified wastewater injected into Perth's underground aquifers would be drawn later and put into the scheme system.
The announcement follows a three-year, $50 million landmark trial of the technology at Beenyup in the city's northern suburbs, which ended last year.
Mr Redman said the Government would expand the trial into a fully-fledged project by initially building a $119 million plant at the site which would produce seven billion litres of drinking water a year.
Construction of the first phase would start soon and be completed by June 2016 and the plant would eventually be expanded to have a capacity of 28 billion litres a year, he said.
According to Mr Redman, the decision to forge ahead with water recycling would "drought proof" Perth at a time when a drying climate was leaving it increasingly dependent on alternative water sources.
The second stage of the Binningup desalination plant is being commissioned.
When it comes online it will take the amount of Perth's drinking water sourced from that technology to about half.
"Groundwater replenishment will underpin Perth's water security at a time of reduced rainfall," Mr Redman said.
"It adds another water supply option for the city, building diversity for the future and complementing other initiatives, such as desalination."
After water recycling plans elsewhere were sunk by public anxiety about drinking treated wastewater - most notably in Toowoomba in Queensland - Mr Redman insisted the Water Corporation's proposal would be accepted.
"This advanced treatment process means that the water is actually pure before we put it back in the aquifers for naturalisation - it will be there for potentially 30 years before it will flow out of taps again," he said.
"By the time the water is extracted, it will be the same as any other groundwater in this aquifer."