Anzac Park in Ayr.
Anzac Park in Ayr.

Toxic town water contamination a mystery

THE SOURCE of toxic contamination in a bore that supplied Ayr with drinking water remains a mystery after almost two months of investigating.

Burdekin Shire Council shut down two bores in the Nelson's Lagoon Borefield connected to the town water supply on May 25 after the toxic chemical PFAS - per and poly-flouroalkyl substances - was detected at above the national standard for human consumption.

Bores 2 and 5 have remained switched off since, but only number 2 has consistently returned PFAS contamination results above the health standard.

The council has now implemented a three-monthly testing region across the borefield with extra tests to be undertaken on Bore 5 to determine if it can be integrated back into the water system in the future.

Bore 2 will remain switched off indefinitely.

Infrastructure, Planning and Environmental Services director Nick Wellwood said the results in the contaminated bores had been "up and down".

"There is no discernible trend to date," he said.

"No definitive cause has been determined and council continues to ascertain if any of the older infrastructure has affected the total PFAS readings."

Sources said it was believed a substance within the physical bore could be the cause of the contamination but no tests had been conclusive.

Mr Wellwood said the council would look to improve the "resilience" of Ayr's water supply as the multi-agency investigation into the cause continued.

"A water resilience strategy is currently being developed and will be submitted to council for consideration in the first or second quarter of this financial year," he said.

Mr Wellwood said the council's "principal concern" was the health of the community.

"The town potable water supply continues to test below the draft health-based guidelines, confirming it is safe to drink," he said.

"We will continue to concentrate on making sure the drinking water is safe."

Mr Wellwood said the council had conducted a physical site investigation in the area surrounding the borefield looking for sources of contamination above ground.

"A search and investigation of properties surrounding the Nelson's Lagoon Borefield has been undertaken by council and no contaminants have been located," he said.

"Council is always vigilant about environmental contaminants within the district."