Senversa and Valenza Engineering were commissioned by EnviroPacific Services Pty Ltd to assess an in-situ groundwater treatment method at the former fire training area within RAAF Base Williams, Point Cook.
The objective of this work was to design and assess a trial groundwater injection program. The injection program assessed the potential impact on Port Phillip Bay and RAAF Lake from groundwater injection in selected areas on-site.
Impacts to Port Phillip Bay and the RAAF Lake were assessed through the development of a numerical groundwater model and comparison against site discharge limits.
We reviewed historical data from previous reports to develop a site conceptual model, prepared and conducted an injection trial test which included step-rate testing to assess a reasonable injection rate for the purposes of stressing the aquifer.
We modelled reinjection with a seepage modelling package and prepared a contaminant transport model based on optimised design obtained from the seepage modelling. We refined the site conceptual model with field testing results, defined a monitoring program with trigger levels and reinjection criteria, and designed dewatering and reinjection phasing and infrastructure.