Power and Water has released the results of testing in Katherine which found low levels of PFAS which have leached into the water supply from firefighting foam used at the Tindal RAAF Base between 1988 and 2004.

The town’s tap water was found to contain 0.052 micrograms per litre of PFAS.

The interim Australian recommended maximum is 0.5.

Bores at the Katherine water treatment plant which are used to blend with Katherine River water and supply the town were tested at 0.33 micrograms per litre.

Bore water when blended with river water at the plant was found to be 0.07 micrograms per litre.

The bores supply up to 10-20 per cent of town water supplies.

Despite being below the maximum allowed level, Katherine’s results were found to be the highest in the territory.

The results of that testing – which has been conducted by laboratories interstate – has found that samples of drinking water provided are well below the 0.5 microgram per litre interim guidelines, Power and Water said.

Power and Water water services general manager John Pudney said PFAS detected in water quality testing were at extremely low levels.

“To put it into context, a microgram is one part per billion,” Mr Pudney said.

“In simple terms, a microgram is the equivalent to a quarter of a teaspoon in an Olympic-sized swimming pool – so we’re talking very low levels.

“Power and Water never take chances with our water quality and this issue is no different,” Mr Pudney said.

Based on results that have been submitted to the Health Department, chief health officer Dr Hugh Heggie said public drinking water was safe for consumption in Alice Springs, Katherine, Batchelor, Adelaide River and Darwin regions.

The Health Department has advised Katherine residents using private bores in the vicinity of Tindal to contact Defence on 1800 365 414 (business hours) to discuss their water supply.

Community information sessions were told last week 11 people in the Tindal area were already receiving alternative water supplies with another 11 expected to join the list.

For more information, go to the NT Environment Protection Authority (EPA) website or call the NT EPA Pollution Hotline on 1800 064 567.

A PFAS factsheet is also available from the NT EPA.

Results of PFAS testing October 2016:

Adelaide River (surface water and bore at Power and Water Treatment Plant) 0.023 µg/L

Alice Springs bore (Roe Creek) not detected

Batchelor bores (two) 0.0664 µg/L

Darwin River dam and bore (Howard East) 0.00017 µg/L

Katherine bores (two at Power and Water Treatment Plant - East of Katherine) 0.33 µg/L

Katherine bore blended with surface water 0.079 µg/L

Katherine (November 2016) Reticulation (tap) water from the water supply network 0.052 µg/L

The NT Health Department also released guidelines on exposure to PFAS,.

“National health authorities advise there is currently no consistent evidence that exposure to PFAS causes adverse health effects,” the department said.

“The national Environmental Health Standing Committee (enHealth) recommends that human exposure to these chemicals be minimised as a precaution because these chemicals persist in humans and the environment.”

The departmental advice also said in answer to questions on the health effects of exposure to PFAS.

“Whether significant health problems in humans occur because of exposure to PFAS is currently unknown, but on current evidence from studies in animals, the potential for adverse health effects cannot be excluded.

“Because the elimination of PFAS from the human body is slow there is a risk that continued exposure to PFAS could cause adverse health effects, hence the current precautionary approach.”

And whether residents with contaminated supplied supplies should use bottled water.

“If your water contains PFAS, you may reduce exposure by using an alternative water source for drinking, food preparation, cooking, brushing teeth, and any activity that might result in ingestion of water.”

Showering in the water and using the water for washing clothes is believed to be safe.