Bitumen in water sparked illness - The Australian

The NSW government has rubbished claims that Sydney Water covered up the cause of contaminated drinking water in Sydney's south.

Some residents were issued with a health warning in December last year after reports of people falling ill with nausea and vomiting.

Sydney Water says the problems were caused by bitumen getting into water pipes during routine maintenance.

But the incident sparked claims the contamination could be linked to Orica's former ChlorAlkali Plant at Botany.

The NSW opposition's spokesman for water Walt Secord says Sydney Water has a culture of cover-ups and the NSW government should order the company to provide details about the cause of the incident.

Premier Barry O'Farrell was quick to deny claims of a cover-up.

"The opposition is talking through an orifice that I won't mention,'' he told reporters in Sydney today.

Mr O'Farrell said he would happily drink from taps in Sydney's south because the health department had ruled there was no evidence the incident was linked to the Orica plant.

"The fact is the department of health is the independent water regulator and they are very clear, there is no connection,'' he said.

The department found levels of chemicals in the water supply were within the national standards.

"They are very clear that it didn't pose a threat to health,'' the premier said.

Mr O'Farrell said Sydney Water had failed to flush the pipes before they put them back into operation during maintenance.

It was "nonsense'' that chemicals could have leaked into the water supply from the ground unnoticed.

"Sydney Water comes through pipes that are under enormous pressure,'' he told reporters.

"The suggestion that chemicals leached into the ground and could make their way into that highly pressurised water system, without it being known to the Department of Health is a nonsense.''

Mr O'Farrell said the incident was the result of incompetence by Sydney Water workers and warned the company to ensure it did not happen again.

"This should be the last instance by Sydney Water or else those at the top of Sydney Water will have a lot more to worry about,'' he said.