Defence is working closely with industry partners and research institutions to learn more about the nature of PFAS and potential management and remediation options. Scientific research into PFAS is still developing. Defence is contributing to the growing scientific knowledge of PFAS through it’s involvement in leading edge studies and technology demonstrations. Some of these studies and technology demonstrations are listed below.

Soil Treatment Plant

In 2018 Defence entered into a collaborative arrangement with Ventia to trial a soil treatment technology it had been developing. This trial included the design, operation and maintenance of a PFAS soil treatment plant at RAAF Base Edinburgh. To date, the trial has treated 10,000 tonnes of clayey soil from RAAF Base Edinburgh and 1,500 tonnes of sandy soil from RAAF Base Williamtown from former fire-training areas.

The plant successfully removed 90% of PFAS mass from clayey soil and 98% of PFAS mass from sandy soil. 99% of the soil treated from Edinburgh was reused onsite as backfill.

Williamtown Drainage Study

In October 2017, Defence engaged Umwelt to commence a drainage study of the Williamtown, Fullerton Cove and Salt Ash local catchment areas. The aim of the study was to better understand the capabilities and limitations of the existing drainage network, within the Williamtown region, and to determine if any engineering improvements would positively impact on the efficiency of the network.

A copy of the report and a factsheet that summarises the findings are available below.

• Williamtown Drainage Study Factsheet - September 2018 Factsheet - PDF - 197KB
• Williamtown Drainage Study Report- September 2018 Report - Umwelt - PDF 65.4MB

Calibration of passive sampling devices for the monitoring of PFAS in groundwater

In March 2017, Defence partnered with the University of Queensland to investigate a passive sampling device that can measure average PFAS concentrations over a period of time in groundwater systems. Consistent uptake of PFAS was observed in the sampling devices for the majority of sites investigated with a strong correlation observed between the amount of PFAS accumulated in the device and the groundwater concentrations.

This suggests the sampling device could be a useful tool in determining PFAS concentrations in a wide range of groundwater contamination situations. Additional studies are recommended in order to further understand the sampling device’s limitations as well as to extend the use of the device to additional environmental conditions.

PFAS Uptake in Chicken Eggs Study

In January 2017, Defence partnered with AECOM to conduct a study to assess and evaluate PFAS residue in eggs, relative to a range of intake rates by chickens, and which are exposed to a range of PFAS concentrations. It also investigated the rate that PFAS residue decline in eggs if chickens are provided with a PFAS -free drinking water supply.

Further information on the Chicken Egg Uptake Study is available in the Williamtown Chicken Egg Uptake Study and Oakey Chicken Egg Uptake Study factsheets.

• Williamtown Chicken Egg Uptake Study
• Oakey Chicken Egg Uptake Study

PFAS Uptake in Plants Study

In November 2016, Defence partnered with AECOM to undertake a study to evaluate how different plants uptake PFAS at a range of different water-based concentrations within a controlled environment.

The selected test plants include: radish, beets, rocket, strawberries, alfalfa, cherry tomatoes and cucumber.

Further information on the Plant Uptake Study is available in the factsheets below:

• Williamtown Plant Uptake Study
• Oakey Plant Uptake Study

Soil Solidification and Stabilisation Study

In July 2016, Defence, in collaboration with AECOM, undertook a soil solidification and stabilisation trial. The objective of the trial was to assess the effectiveness of nine individual products in chemically immobilising PFAS in soil.

A review of the trial identified a number of products which showed the potential to reduce the ability for PFAS to migrate away from the source soil. However, a number of questions surrounding the long-term effectiveness of the respective processes were raised by both Defence and the regulators; namely, changes in soil structure and biology as well as the effects these processes may have on plant life. As such, additional testing would be required prior to any recommendations being made.