OPINION: Concerns about drought and water supply are once more building in eastern Australia. Recent reports from Victoria show the state government is considering switching on the so-far-unused desalination plant to supply Melbourne. While Melbourne doesn’t currently need extra water, this might free up other water allocated to the city to be diverted to regional communities in the north of the state where water shortages are looming.
When drought strikes, people and governments look to shore up water supplies. In Australia, politicians have focused on building more dams and long pipelines, at the expense of alternative sources such as recycled water.
It has been widely assumed that drinking recycled water, from sources such as sewage, is not acceptable to the public. But an Australia-first survey released by the Australian Water Association shows the public is ready to accept recycled water.
Water is getting further away and more expensive
Since colonisation, we have tapped increasingly distant, more energy-intensive and more expensive sources of fresh water.
We have constructed large dams to buffer variable water supplies through wet and dry seasons, as well as wet and dry years. As water consumption has exceeded the capacity of river basins to meet demand, we have constructed long pipelines, to pump water in from less populated river basins to more populated basins.
During the last decade, many of our major cities began to identify that the capacity to pump more water from distant locations was approaching sustainable limits.
New sources of water were required. So, in a very short period of time, cities including Perth, Sydney, Melbourne, Adelaide and the Gold Coast set about constructing seawater desalination plants.
Hindsight comes with 20-20 vision and it’s clear that most of these desalination decisions - with the notable exception of Perth’s - were premature since the plants have barely beeen used. Politicians and those with a financial interest in these plants often comment that the desal plants represent great “insurance policies” for when the next drought inevitably arrives.
However, these “insurance policies” came with billion-dollar price tags. Much of this has been externally financed, thus accruing significant annual interest costs.
Furthermore, the costs associated with maintaining desal plants are significant - even when they supply zero or negligible water. In some cases, such as Sydney, the real need to use the desal plant – given effective demand management - is likely to be still many years away. As such, it is arguable that these desal plants were very poor value insurance policies.
The lure of desalination
In 2006, the New South Wales Parliament undertook an Inquiry into a Sustainable Water Supply for Sydney. I appeared as a witness to that inquiry to put forward an argument that there was a more sustainable option than seawater desalination.
I argued that the technology was established to reliably purify water from sewage treatment plants to such a high degree that it would be capable of providing extremely high-quality drinking water for Sydney. This practice has been adopted in a number of US cities and is commonly referred to as “potable water recycling”.
All towns and cities are physically unique in terms of geography and historic development features. However, in the right mix of circumstances, potable water recycling can have significant advantages over seawater desalination.
These can include reduced operation and construction costs, as well as much lower energy requirements, which translate to reduced carbon emissions. Nonetheless, the suggestion that the NSW government seriously consider potable water recycling as an alternative to seawater desalination was not widely appreciated.
The general wisdom of the time was that Australians would not be prepared to accept water that was once sewage as a component of their drinking water supply. Indeed, this appeared to be supported by a telephone survey around that time.
Political thirst for dams
It is widely recognised that most opportunities for building dams on rivers to provide water for Australia’s large cities have been effectively exhausted.
Nonetheless, Australian politicians appear to yearn for opportunities to announce a new big dam project. When the federal member for Calare, John Cobb, announced a plan to dam the Belubula River at Needles Gap (NSW) in 2014, he declared: “I believe this project will lift the spirits of the central west and will inspire all of regional Australia."
Water supply projects may have many diverse objectives, and inspiring all of regional Australia may be an understandably important one for a politician. However, many politicians appear to carry some unshakeable assumptions about community water supply preferences in Australia. Most seem to think we all want to hear announcements for new big dams.
And if we can’t have new big dams, they think desalination plants are our next preferred option. Few politicians deny the sustainability advantages of potable water recycling, but most seem to think it’s just too difficult to bring the community on board to support it.
Attitudes are changing
In the recent survey, 3,316 completed responses were received from community members across Australia.
Of these, 69% agreed or strongly agreed with the statement that recycled water “can be treated and managed for safe drinking”. This compared with 56% who agreed with the same statement for stormwater and 82% who agreed for seawater desalination.
Given the prevalence of actual seawater desalination plants around Australia and a lack of any public discussion about potable water recycling, I suggest that this level of faith in the capabilities of recycling plants is remarkable.
Recent research from the United States has shown that by engaging the community and providing accurate information, the underlying level of support for recycling can be significantly increased.
When consumers were asked whether they agree with the statement that “there is scope for more dams to provide additional water supplies in the south of Australia (e.g. in the Murray-Darling Basin and the south-east coastal areas)”, only 33% agreed. This rose to 46% for northern Australia. So much for inspiring all of regional Australia.
Preparing for the dry
Worldwide, countries are preparing for the significant El Niño eventunderway. Evidence is rapidly building that the east coast of Australia will again be subjected to the drought-causing conditions that have led to major water shortages in previous decades.
When this happens, we can expect many regional areas to struggle in their management of dwindling water supplies. Many will be searching for sustainable water supply solutions and some will identify potable water recycling as the most sustainable option for their circumstances.
The challenge for the federal and state governments will be to support the needs of these towns and cities. They will do that best by ensuring that all potential water supply options are on the table and given fair consideration.
In the meantime, our politicians would serve regional Australia best by ceasing to stigmatise potable water recycling as an option that is not even entitled to consideration.
Instead, they should work to build upon the support that currently exists in our communities so that when the need arises, potable water recycling is a viable and broadly accepted water supply solution. There is already powerful evidence that this can be achieved, when state governments work constructively toward this goal.
In 2013, the Western Australian government gave strong support and approval for a potable water recycling project to provide up to 20% of Perth’s water supply. That plant has since been constructed and will soon begin replenishing one of the city’s essential, but dwindling, groundwater supplies.
Stuart Khan is an Associate Professor in Environmental Engineering at UNSW.
This opinion piece was first posted in The Conversation.