SEQ - Disease expert warns on recycled sewage ...

Excerpt from the Australian:

Disease expert warns on recycled sewage

30 October 2008

One of Australia's leading infectious disease experts has claimed technology does not exist to prevent recycled sewage from contaminating the water supply of 2.6 million residents in southeast Queensland.

In February, they will become the first Australians to drink their own waste when 60 megalitres a day of recycled water will be pumped into Brisbane's main water source, Wivenhoe Dam.

Under state government plans, recycled water will account for between 10 and 25 per cent of the region's drinking water supply.

Australian National University microbiologist Peter Collignon said yesterday he had major concerns about hundreds of viruses that could be present in the water.

"I don't believe the technology is there to ensure there are no problems," he said.

When Queensland Premier Anna Bligh was asked if she could guarantee the safety of recycled water, she said: "The scientific advice to me is that this can be guaranteed to be as safe as anything else that comes out of our taps at the moment."

Professor Collignon rejected claims by the Queensland Government that the project was comparable with recycled water schemes overseas.

Singapore, one of the examples often cited by Queensland, had a "very different" system, he said. Waste water was pumped through a pipeline separate from Singapore's reticulated system - unlike in southeast Queensland - and accounted for less than 1 per cent of the city state's dam capacity.

Professor Collignon said the Namibian capital of Windhoek, located in a desert, had the only comparable system.

"Brisbane has many times the rainfall of Windhoek," he said. "There's no need for Brisbane to be putting sewage into drinking water. There is nowhere else in the world where a large population is being forced to accept a situation where 10 or 25per cent of their drinking water is recycled sewage."

Professor Collignon said viruses that could contaminate the water supply ranged from bugs that caused gastroenteritis to potentially fatal infections leading to encephalitis and heart disease.

Test results for hazardous bacteria such as E.coli would not be available to authorities for at least a day, he said. "By the time the results come back, the water is already in the reservoir."

The Australian reported yesterday a claim by Australian National University emeritus professor Patrick Troy that it would not be possible to remove all biologically active waste molecules from the system.

Professor Troy was attacked yesterday by Ms Bligh, who dismissed his claim as "ill-informed comments by somebody who has no expertise in the field of water treatment".

Ms Bligh said the seven-stage water filtering scheme would ensure water was not contaminated. "The water processes that have been put in place to underpin our recycling project are the best in the world," the Premier said.

"They are consistent with projects of a similar nature overseas that have been operating for 40 years, and which have been scientifically tested and proven to be safe."

University of Queensland vice-chancellor Paul Greenfield, who heads an expert government advisory panel on recycled water, said that it was not possible to guarantee the safety of recycled water.

"We can only talk about improbabilities," Professor Greenfield said.

He believed the screening process was sufficient to prevent contamination. "We will have additional processes and monitoring which will ensure the risks are no higher than what people face now," he said. "The water after the fifth barrier in the seven-stage process will satisfy drinking water guidelines, and then there are another two stages after that."

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