Defence is working on ways to stop toxic PFAS chemicals from migrating off the Nowra Hill naval base, HMAS Albatross.
That was the message from assistant secretary PFAS Investigation and Management Program, Luke McLeod at the latest community walk in session about the contamination at the naval base.
“We [Defence] accept responsibility for placing these chemicals in the environment and we remain open and transparent about the investigation and what we need to do is respond in a responsible and proportionate way,” Mr McLeod said.
Defence also released the addendum findings to the Human Health and Ecological Risk Assessment into PFAS at Albatross at the walk-in session.
“From a waterway perspective, we have a number of water treatment plants at a range of properties where we have had success removing PFAS out of water,” Mr McLeod said.
“As for soil there are less viable technologies available and we are still looking at what we could use.”
We [Defence] accept responsibility for placing these chemicals in the environment and we remain open and transparent about the investigation and what we need to do is respond in a responsible and proportionate way.Assistant secretary PFAS Investigation and Management Program, Luke McLeod.
Mr McLeod said Defence’s focus was principally to look at the source area.
“We have had high levels of detections of PFAS in certain hot spots on the base,” he said.
Those locations include former fire fighting training grounds and the sewage treatment works on base.
“We are maybe looking at removing the soil or doing things that would retard these chemicals from migrating into either the groundwater or surface water,” Mr McLeod said.
“Soil from those hot spots may be removed and the site remediated.
“If it [PFAS in the the soil] was in high concentrations we would stockpile it on site. We’d do that in a focused way, lining the soil with a leachate product so any leaching of these chemicals through the soil is captured. That would be our approach until there is an efficient way to dispose of the soils.
“Due to the nature of these chemicals, because it is somewhat of an emerging issue, there are limited options to prevent the migrate of these chemicals and getting into exposure pathways. These options are consistent with those looked at on other sites.”
But there was no indication of how long that work might take or how much it might cost.
He also said he was not surprised PFAS chemicals from Albatross had been linked with contamination in the Shoalhaven River.
Defence contractors’ Aurecon conducted further testing well upstream of the Shoalhaven River bridge crossing, first indicated as a possible contaminated area. That new testing showed PFAS present in fish species.
That testing was conducted almost as far up as Meadow Creek, also at the junction of Calymea Creek and further east near Longreach.
Testing of aquatic species in Currambene Creek also revealed elevated levels in some fish and cretaceous.
Despite again stating there was no consistent evidence of any human health effects related to PFAS exposure, Mr McLeod reiterated the EPA’s warning over minimising exposure to certain fish species in both the Shoalhaven River and Currambene Creek.
Defence is currently developing a PFAS Management Area Plan (PMAP) for Albatross to provide options to manage potential exposure risks identified within the environmental investigation.