KATHERINE’s drinking water contains traces of the chemicals which have leached from the Tindal RAAF Base.
The Northern Territory’s Department of Health is expected to announce confirmation of its test results tomorrow.
The Katherine Times understands government tests have found levels of the PFAS group of chemicals in the town water supply at a concentration of 0.05 micrograms per litre.
The interim Australian standard, which is under review, is 0.5 micrograms per litre.
Health Department officials told yesterday’s packed chemical contamination meetings in Katherine the water was well under the recommended levels and was safe to drink.
Much higher concentrations of the chemicals, blamed on the use of firefighting foams for training at the Tindal RAAF base between 1988 and 2004, have been found in preliminary testing of surface and ground water adjacent to the base.
Defence Department spokesman Steven Grzeskowiak said the best science indicated “there is no consistent evidence even high concentrations of the chemicals cause any negative health impacts”.
“But as a precaution, human exposure should be minimised,” he said.
More than 200 people attended two sessions of the Defence Department’s chemical contamination forums at Knotts Crossing yesterday, said to be the biggest turnout at a public meeting in Katherine for at least a decade.
During a lengthy question and answer sessions, Mr Grzeskowiak said thousands of more tests are likely to be made in and around Tindal over the next year on surface and ground water, soil, sediment and biota.
Depending on what the experts find, there may even be a “human health assessment” involving blood testing of citizens, once the year-long study was complete.
The department is now supplying 11 homes with drinking water with a further 11 homes expected to receive supplies in the next few days because of fears over the contamination.
Mr Grzeskowiak said the department was not likely to supply drinking water to Katherine because the NT Health Department had declared the town’s water supply safe.
He said Tindal was in the “first batch” of the 12 RAAF bases to receive more detailed testing even though the study is not likely to begin until February.
”We want to do this right and do it carefully,” he said.
The meetings were told several people had commissioned their own testing of their bore water with one man saying his results found levels at 1.345 micrograms per litre.
Mr Grzeskowiak said even rainwater tanks which had been used to store bore water would need to be tested.
He said “there was no value in getting blood tests” which other officials said could cost $500 per person even if they revealed elevated levels of PFAS chemicals.
“There is no conclusive evidence they cause any harm,” he said.
Mr Grzeskowiak said preliminary testing around Tindal had confirmed the department’s fears.
“We wanted to find out if it was off the base and our tests found that yes, it was.”
Other officials said the focus of the testing was to ensure human safety.
“Most concern is about drinking the water and eating the fish,” one official said.
Mr Grzeskowiak said most people already “have amounts of this chemical” in their bodies.
He said if PFAS were trapped underground, away from sunlight which speeded up their degradation, they could last 100 years.
Even if people stopped drinking the contaminated water it could take four to eight years to pass out of their bodies, he said.
Mr Grzeskowiak said the department would drill test bore around Tindal to continue monitoring contamination levels years into the future.
“This is a long term process, we will keep trying to understand this.
“Who knows what we will know about this in 20 years time,” he said.