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Agriculture not the main culprit in algae crisis

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Media Release For further information: Parliament House, Canberra ACT 2600

Telephone; Facsimile:

06/2774193 06/2772053



A consultant's report soon to be released shows agriculture is not the major cause of the current outbreak of toxic blue-green algal blooms in Australia's river system.

The Shadow Minister for Primary Industry and National Party Deputy Leader, Bruce Lloyd, said the study for the Murray Darling Basin Commission implicated regional sewage treatment works as the main cause of the recent spate of blue-green algal blooms.

Mr Lloyd said the presence of algal blooms in Australia's river systems has emerged as a critical water management issue for the 1990s.

"The swelling tide of blue-green algae in our waterways is here as a long-term problem for water and sewage authorities,

agricultural producers and regional communities," Mr Lloyd said.

"Algal blooms are going to present as many challenges in their control and management as have land degradation and salinity for the past two decades," Mr Lloyd said.

He said the immediate problem was a question of how best to

decontaminate vital water supplies such as the Darling River to ensure water was safe for consumption by people and livestock.

Short term water quality could be improved by filtration, chemical treatment and the use of bores, Mr Lloyd said, but the long term solution was far more complex.

"The crux of the problem is the presence of high levels of the phosphorus in river systems acting as a ready supply of food for blue-green algae.

"When water flow along rivers and through storages slows as a result of drought, the concentration of these nutrients increases markedly and as water temperatures rise, they bloom.

"The result is this deadly toxic scum now polluting more than 1000km of the Darling River and threatening man and beast alike.

"These nutrients are coming from two main sources - sewage treatment works and agriculture - and the significance of the first of these sources should not be under-estimated."

Mr Lloyd said one of the main sources of phosphorus in sewage was j

laundry detergents. This problem had been remedied in Canada when authorities amended regulations to allow the detergents to I

contain only two per cent phosphorus by weight compared with the 50 per cent by weight that existed previously. /2


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Mr Lloyd said a study just completed by the Murray Darling Basin Commission showed that in times of drought, outflows into the river system from sewage treatment works were the main culprit.

The study also showed that run-off from agricultural land was a significant contributor to river phosphorus during wet periods.

He said major regional centres throughout the Murray Darling Basin, with the recent exception of Canberra and Queanbeyan, were all contributing significantly to the risk of algal blooms occurring.

Mr Lloyd said most sewage treatment systems failed to remove phosphorus from the processed effluent discharged into rivers.

He warned that if environment protection agencies continued to clamp down on river pollution, people living in rural cities and towns could face huge bills for the redesign of sewage treatment works.

Mr Lloyd said restrictions were on the way already in Victoria, where the Environment Protection Authority had given many sewage authorities notice that they would have to cease pumping treated

effluent into local rivers by the Year 2000.

Mr Lloyd said the work of the Murray Darling Freshwater Research Centre offered hope that authorities would at least be able to accurately predict future outbreaks of blue-green algae.

He said research at the centre was close to producing a test kit that measured the concentration of phosphorus in a body of water available to feed blue-green algae.

When the data was assessed in conjunction with climatic

forecasts, water management authorities would have a clear indication of the likelihood of an algal bloom occurring.

He said further research into the complex pattern of blue-green algal blooms would be needed if Australia was to overcome the problems.

ends 10/12/91