A DEFENCE investigation has found “no evidence of any unacceptable exposure or risk” to residents living near HMAS Cerberus or workers at the base from the historic use of firefighting foams.
The all-clear extends to those eating fish caught at nearby Hanns Inlet, on-base workers doing non-surface soil works and trainees or visitors through direct exposure to soil at the base.
However, traces of the chemicals were found where the PFAS foam was used and stored, such as the fire ground and station, ornamental lake, sullage pit, irrigated sports fields and former sewage treatment plant.
Also within the base but outside these areas of impact “low levels of PFAS were found in soils, groundwater and surface water”. This means there is “evidence of potential unacceptable exposure risk” to construction or maintenance workers inside the base through “potential incidental ingestion of soil, sediment, bio-solids, surface water or groundwater”.
PFAS investigation and management branch assistant secretary Luke McLeod presented the findings to the fourth – and final – community information session at Crib Point Primary School last week before 15 people.
He said 495 samples of soil, groundwater, surface water, grass and fish were tested over 18 months for contamination as part of the investigation. “We know enough about the issue to say that PFAS migrates through ground and surface water into Hanns Inlet, and that samples of fish caught there have shown some detections,” he said.
“We are trying now to identify the source of the contamination.”
The investigation found that ground and surface water from the base flows away from the adjacent residential and community land to discharge into Hanns Inlet. Despite this, the findings state that “while there is evidence of PFAS accumulation within Hanns Inlet, there is no exposure risk to potential human consumers”. The report noted that public access to the inlet was prohibited.
Mr McLeod said the Navy was now developing a management strategy to identify practical solutions “to prevent or minimise the migration of PFAS beyond the Defence property boundary and manage identified on-base exposure risks”.
