Southern Water and Ben Lomond Water have reported no requests for additional testing while a Cradle Mountain Water spokeswoman said there had been minimal interest.

Plantations cover less than 5 per cent of the George River catchment that flows into St Helens, where extra water treatment precautions have been implemented to allay community concerns about drinking water quality.

The Opposition yesterday confirmed it had agreed to a Government request under caretaker conventions for $250,000 for carbon powder filters and further scientific testing of the water supply.

It follows claims made on a the ABC that toxins from the trees could be causing health problems in humans, Tasmanian devils and oysters.

The percentage of eucalyptus niten plantations is highest in the North-West but there has been no significant outcry from local residents or environmental groups in that area.

Local Government Association of Tasmania president Barry Easther said he had not been contacted by any concerned councils.

"Right now I think it is a shame the way the situation at Break O'Day is playing out," he said.

"I am looking to (director of public health) Dr Roscoe Taylor to do whatever is necessary to allay the fears if they need to be allayed or to do something about it if it needs to be done."

Dr Taylor said a "useful exchange of preliminary information and questions" had taken place over the weekend after concerns that not all scientific information and evidence was being received from Dr Alison Bleaney, the general practitioner at the centre of the claims.