A report has revealed traces of the toxic chemicals PFAS exceed drinking water guidelines at one Wagga wetland site.
Attendees at a community forum held at Forest Hill this week heard the ingredients found in firefighting foam, used from the 1970s until 2004, had spread to contaminate the Gumly Gumly wetland.
The detailed site investigation was launched in 2017, after traces of PFAS – per-fluoroalkyl and poly-fluoroalkyl – were found in ground and surface water surrounding RAAF Base Wagga.
But local residents, like Frank O’Donnell, said they were not too concerned at this stage, after they were reassured no one had consuming the contaminated water.
Even if they had been exposed to the substances, an expert panel had in May dismissed links between PFAS and adverse health.
However, the chemicals are persistent, remaining in soil for years and migrating through water systems.
As such, investigators said their focus in Wagga was on stemming the spread of PFAS to the Murrumbidgee River.
“It would be a like a drop in the ocean by the time it reached the river,” Mr O’Donnell said. “I don’t think it’s a big problem.”
Thursday’s results revealed three possible PFAS migration pathways from the air force base through surface water .
But only one of these pathways – the site’s north-west storm water drainage system, leading to the wetlands – was found to carry levels above recreational water use guidelines.
While a fortunate layer of clay managed to keep the chemical from groundwater at the base, the Gumly wetlands’ soil was found to be more permeable, with samples revealing levels of PFAS above safe drinking-water values.
With a survey last year revealing no one was consuming water from these sources, the investigation’s chief Luke McLeod said concerns were largely ecological.
He said a focus was now on preventing further spread into the Murrumbidgee River via runoff into Marshalls Creek.
Traces of PFAS were found in the groundwater used to supply the aquaculture ponds at the Murray Cod Hatchery.
Thursday’s forum heard the amount detected had led to the assumption the chemicals could be impacting the hatchery’s operations.
Mr McLeod said a risk assessment was now being prepared to identify potential bio-accumulation of PFAS in the site’s fish and further tests are underway into contamination at Wagga City Council’s landfill site and sewerage plant.
City councillor Paul Funnell on Wednesday said the initial discovery of the chemicals in areas outside RAAF Base Wagga had been troubling, but he praised Defence for its transparency throughout the investigation process.
Cr Funnell said the agency had shown more integrity than others known to have used the triple-A foam across the same time period.