AECOM, in collaboration with Defence, undertook a soil solidification and stabilisation trial as part of the PFAS investigations at Williamtown. 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 several products which showed the potential to reduce the ability for PFAS to migrate away from the source soil. However, 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.

These works have included the most comprehensive trials to date of the effectiveness of PFAS stabilisation agents.