A national survey carried out by Flinders University researchers has found a high level of acceptance towards the use of treated wastewater in non potable (not-for-drinking) applications, with very high approval of its use for toilet flushing and for uses such as watering public parks and domestic gardens.
Dr June Marks, a Research Fellow in the Department of Sociology, said that while the signs are encouraging for proponents of recycled water schemes, it remains very important for the public to be fully informed when various options are under consideration.
Since the late 1980s, more than eight communities overseas and in Australia had rejected water schemes in which suppliers introduced recycled water for drinking without timely and proper public consultation.
Among Australians, willingness to recycle reclaimed water for household use ran at very high levels for tasks such as toilet flushing (96.5 per cent), garden irrigation (95.9 per cent), hand watering (95.1 per cent) and car washing (91.3 per cent), and at somewhat lower levels for use in washing machines (73.3 per cent) and for hand-washing (67.4 per cent).
Dr Marks said approval tended to decline with uses that involved more direct bodily contact: "The crunch comes when you ask about doing more personal things with the water."
Even so, Dr Marks said it is quite possible that so-called indirect potable reuse - the mixing of recycled water and water from conventional sources for drinking - is not far away in Australia. The national survey found that currently around 42 per cent of people expressed moderate or great confidence about the idea of using water from an indirect potable reuse system.
"This is consistent with the result in Toowoomba, and is a much stronger indication of approval than we have seen before," Dr Marks said.
Dr Marks said it appears that unease about body contact with recycled water stems from entrenched cultural attitudes towards flows in and out of the body.
"Cultural conventions, and most existing engineering systems, reflect the notion that what flows into the body and what flows out should be strictly separated: never the twain shall meet," she said.
"Everyone is more familiar with the logical order provided by separation than they are with the concept of joining the two systems together."
"The problem is that it is a new concept for people to get their minds around - only a third of the respondents had previously heard of the idea - and not all experts agree."
Dr Marks said that some scientists have expressed concerns over the possible long-term effects of residues such as pharmaceuticals and antibiotics in the water.
Deciding on and implementing an appropriate regime of testing is a major part of the problem, Dr Marks said.
"Just what is drinking-water quality?"
"For example, if your water source is Bolivar (Adelaide's main sewage treatment works), should your standards be modified to pick up things that might not be found if your source is the Happy Valley reservoir?
"These are legitimate and rational concerns."
At the same time, Dr Marks said, the standards of tertiary treatment available for effluent are now so advanced it can be argued that the quality of the resulting water is already equal to that of some drinking waters.
Significantly, Dr Marks said that the source of the water used to supplement conventional supples for drinking was influential, with attitudes among potential consumers being more positive towards rainwater and water derived from the ocean (desalination) than to stormwater and treated wastewater.
Current users of recycled water are satisfied with it for toilet flushing and garden watering, as Dr Marks found from three surveys conducted with householders already involved in recycling water through schemes in Sydney and Adelaide.
"We were asking these people how confident they were of the uses they were already engaged in, and between 85 and 99 per cent were moderately or greatly confident," she said.
"Additionally, their levels of confidence in drinking recycled water through an indirect system were similar to the national finding."
For recycled water projects to succeed, it is vital for consumers to be fully informed at every step, Dr Marks said, as proponents of potable reuse schemes in the United States and here in Australia have learned to their cost.
"If proponents don't share the project ideas and various options from the start, they cannot expect the community to trust them.
"Recycled water has to be out there and under open discussion for it to be thoroughly considered for its wider use."
She said that the survey findings show that people are very aware of the problems of water supply. And not only are they very accepting of the need for water restrictions to ameliorate the problem, they are also very much in favour of recycled water.
"Often in the literature, the public are referred to as an impediment to recycled water projects going ahead," Dr Marks said.
"Only water recycling for ingestion meets with considerable opposition, and much of this is due to the approach made to a particular community. We would argue that the public are waiting for water recycling for non-drinking uses to happen."
"There are always people who will ask questions, and there is nothing wrong with that. It is important that with any water recycling project the industry respects local and diverse opinion, takes on board data and evidence gathered by the community and fosters a constructive debate."
The Department of Sociology research, undertaken by Dr June Marks with Professor Bill Martin and Associate Professor Maria Zadoroznyj, is supported under the Australian Research Council's Linkage Project funding scheme in conjunction with United Water International Pty Ltd.
