PFAS testing results prompt detailed investigation

In November 2019, Dubbo Regional Council (DRC), as part of its overall response to the worst drought of record, undertook studies into the feasibility of using some of Dubbo City’s groundwater bores — currently used for parkland irrigation — to supplement town water supply. During these studies, levels of perfluoroalkyl and polyfluoroalkyl substances (PFAS) were detected in six (6) bores.

DRC reported the findings of PFAS to the NSW Environment Protection Authority (EPA) and NSW Health.

“We notified the EPA when PFAS was detected and the EPA requested further investigations to identify areas of contamination, levels, and possible sources,” said Julian Geddes, Director of Infrastructure.

“Of the six bores to return PFAS contamination readings, three are used for parks and open space irrigation (Elston, Capari and Showground), three are used for town water supply (Driftwells, Thorby and Ronald),” said Mr Geddes. “Of critical note, additional tests of the city’s water supply from the water treatment facility indicate no traces of PFAS leaving the facility and entering the town water supply – something we continue to closely monitor.”

As a precaution, Council also took immediate steps to ‘offline’ one bore providing water to the town water supply; with a frequent water testing regime put in place at the water treatment plant to look for any traces of PFAS.

“While there were PFAS readings detected at the remaining operational bores out of the six identified, those figures were within the range of the Australian standards for drinking water and recreational water guidelines,” said Mr Geddes.

Dubbo’s town water remains safe to drink.

The origin of the PFAS contamination found in Dubbo’s bores is unknown. Most commonly throughout the western world, historical PFAS contamination has been attributed to types of firefighting foam, including aviation firefighting foams (Aqueous Film-Forming Foams [AFFF]). There are also over 3000 PFAS compounds found in chemicals manufactured for over half a century and used in everyday items, including stain and water-repellent fabrics, non-stick products (e.g., Teflon), polishes, waxes, paints, cleaning product etc.

As part of a detailed further investigation into PFAS contamination around the identified bores, Council will commence more intensive testing in the coming week. A preliminary investigation involving undertaking a Sampling and Analysis Quality Plan (SAQP) will determine if other parts of the environment have been affected by PFAS. Those results will be compared against initial findings, and also determine the size of area affected and inform what further actions are required.

“Based on advice from third party specialists and the EPA, I expect sampling and analysis to take several weeks,” said Mr Geddes.

Source: Dubbo Regional Council