Treated waste still hard to swallow


Scientists are questioning the long-term effects of desalination plants, even though they are seen as a ‘quick fix’ for water shortages in many areas of Australia.

They argue there are financial and environmental costs and one prominent water supply expert says the future lies in Australians putting their fears aside and embracing use of treated sewage.

A desalination plant has just started operating in Sydney and another will be finished soon at Port Stanvac in Adelaide’s southern suburbs.

Professor Mike Young, of Adelaide University, questions the benefits.

“It’s expensive. It’s climate independent but it has some environmental problems and it uses (sic) a lot of greenhouse gases,” he said.

What desalination plants put back into the environment is also an issue.

At Point Lowly in South Australia’s Spencer Gulf, there is fierce opposition to the effect a proposed BHP-Billiton desalination plant may have on one of Australia’s largest giant cuttlefish breeding grounds.

The cost of desalination is also an issue, with household water bills already rising sharply to pay for construction and running of desalination plants.

Alternatives to desalination include stormwater harvesting.

At wetlands in northern Adelaide, about 12 gigalitres of stormwater per year are being stored in underground aquifers for future use.

There are studies under way to see if the stormwater could provide a regular drinking supply.

Common phobia

Professor Young says there could be an even cheaper and more effective option if people overcome over a common phobia of drinking their own treated waste.

“Sewage water is so cheap to process because it has a lot less salt in it and in terms of the energy that’s required to take the salt and manure and everything else out of the water is much less,” he said.

He says Australians are already unknowingly drinking treated waste from other animals.

“The fish are manuring in the water that’s often treated, you have cows walking around in many areas up above the dams putting, letting all their manure run down into the dams,” he said.

“We’ve been treating and removing sewage from our water supplies for at least a century and we’ll go on doing that.”

Queenslanders have already turned up their noses at the idea of a treated sewage plant at Toowoomba.

But Professor Young says ongoing drought concerns across much of Australia, coupled with population increases, mean treated waste is an idea Australians may eventually have to swallow.

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