Australians will be encouraged to embrace treated sewage for drinking in the largest-ever bid to overcome the ''yuck factor'' and push the contentious option onto the national agenda.
A $10 million drive, partly funded by the federal government, aims to convince the public that introducing recycled water to drinking supplies is a palatable, cost-effective alternative to measures such as desalination.
The ''engagement strategy'' will target households, students, politicians and the water industry.
Public scepticism and fears over health risks have traditionally kept the toilet-to-tap concept off the political agenda.
In 2006, Toowoomba residents rejected a plan to drink treated effluent, even as the town faced a dire water shortage.
The chair of the project's research advisory committee, Ian Law, said recycled water for drinking should be examined before crisis loomed ''when dams are full … so we have the ducks in a row when the next drought comes''.
The project, led by the University of NSW, will develop a national engagement program to show that recycled water is safe and reliable. It will include devising education programs, a social media campaign and demonstration projects where the public could see wastewater being treated. Similar schemes overseas allow visitors to sample the water.
The Brisbane-based Australian Water Recycling Centre of Excellence is co-ordinating the project, which will also examine recycled stormwater.
In a surprise move last year, the NSW government said it would examine the viability of adding treated sewage to drinking water in a review of the metropolitan water plan.
This followed a 2011 Productivity Commission report that found that recycling wastewater for drinking was generally cheaper than desalination, although the cost of monitoring and managing health risks was higher.
The project will target politicians and their advisers, who have long considered the concept too risky to back.
In 2008, then Queensland premier Anna Bligh shelved plans to add recycled wastewater to Wivenhoe Dam after stiff public opposition.
Mr Law said political momentum was unlikely without community acceptance. ''There is nothing more powerful than an informed public,'' he said, adding those who drank recycled water wouldn't ''grow five heads''.
Sydney Water is helping to fund the three-year program, which began last year.
Critics of the concept, such as infectious diseases expert Peter Collignon, have warned of ''catastrophic'' public health implications if the treatment process fails. But the Productivity Commission found that a ban on recycled wastewater for drinking was not warranted.
Rosemary Morley, whose protest group Citizens Against Drinking Sewage led opposition to the scheme in Toowoomba, said Australians would be hard to convince.
''It would not be a natural thing for the ordinary, average citizen to think about treating sewage and then extracting water from it. It's a Third World-country option,'' she said.
The concept has been better received in Perth, where 2.7 billion litres of treated wastewater has been injected into an aquifer to replenish groundwater supplies. The two-year trial is being assessed.
About 60,000 residents in the Sydney suburbs of Richmond and Windsor already drink a mix of recycled sewage, stormwater and river water. Treated effluent is discharged from sewage treatment plants along the Hawkesbury-Nepean River before being collected and re-treated at North Richmond and delivered to homes.