The Department of Defence has released the Interim Human Health Risk Assessment Report on the chemicals leaching from the Tindal RAAF Base.
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The key findings of the interim report were presented in Katherine last month.
The assessment was conducted as part of the detailed environmental investigation into per- and poly-fluoroalkyl substances (PFAS) on, and in the vicinity of, RAAF Base Tindal. This investigation is following a nationally agreed framework for the investigation of contaminated sites.
The Defence consultants, Coffey, said this interim report “is limited in scope” and limited to information obtained in the dry season to address the exposure routes most likely to drive risk using the information currently available in the Investigation Area.
“A more detailed Human Health Risk Assessment will be conducted in early 2018 and will include a broader evaluation of potential health risks based on the detailed conceptual site model (CSM) developed using wet and dry season information.”
The IHHRA seeks to identify major pathways and risk-factors with the aim of informing future advice provided by government agencies and authorities on how to minimise risk from PFAS.
“Environmental investigations conducted during the 2017 dry season reported detectable PFAS in water in each residential setting. Fruit and vegetables obtained from residential gardens, eggs from locally raised poultry and fish from Katherine River were found to contain PFAS compounds to varying degrees where PFAS impacted water was present,” the interim report said.
The interim report concluded:
The key foods and activities that are indicated to result in intake above the tolerable daily intake are:
- Sourcing drinking water from private groundwater bores in the Investigation Area in Zone 1 and Zone 2, or from the Katherine River downstream of Stuart Highway Bridge in Zone 3.
- Young children in swimming pools filled with groundwater extracted from private bores within Zone 1, where swimming exposures are representative of upper estimate assumptions.
- Consumption of eggs (representative of upper estimate assumptions) where poultry is watered from private groundwater bores located in Zone 1.
- Consumption of fish and crustaceans from Tindal Creek or Katherine River (based on both typical and upper estimate assumptions).
- The variability associated with PFAS uptake by different fruits and vegetables has also resulted in a conservative conclusion that consumption of large amounts home grown fruits irrigated with PFAS impacted water from Zone 1 or Zone 2, or river water from Zone 3, (and large amounts of vegetables from Zone 1) may exceed the tolerable daily intake for sensitive groups in the population (i.e. young children).
As well, the interim report said:
Based on the nature and extent of PFASs impact detected at the Base and off-Base, the identified stakeholders are considered to include:
Residents, workers and businesses (particularly agricultural or tourism) in Katherine, RAAF Base Tindal and surrounding rural communities within the Investigation Area.
Katherine Town Council
Northern Territory government
Department of Defence
Other Commonwealth government agencies
Traditional custodians
This assessment informs the advice provided to the public by the relevant health, water and environmental authorities.
The findings of the IHHRA report were used to inform the Government’s decision on the $5.7 million Katherine Community Support Package, which was announced on December 3.
The IHHRA is available at: http://www.defence.gov.au/environment/pfas/Tindal/publications.asp
For more information on the PFAS investigation at RAAF Base Tindal see: http://defence.gov.au/environment/pfas/tindal/
Chris McLennan
ACM national rural property writer based in Bacchus Marsh, Victoria. Career journalist. Multi award winner.
ACM national rural property writer based in Bacchus Marsh, Victoria. Career journalist. Multi award winner.
