GHD undertakes PFAS Remediation of the Former Fire Training Area at Swartz Barracks

GHD was engaged as the Head Contractor to undertake the PFAS soil remediation and implementation of the site Remedial Action Plan of the FFTA at Swartz Barracks. The scope of work involved bench-scale and field-scale treatability trials, hydrological and geophysical modelling, mass flux modelling and assessment, excavation and treatment of PFAS-impacted soils, and a cap and containment design and implementation strategy on-site that included the development of a tailored Compaction Specification for re-use of stabilised low-permeability soils.  

The primary objectives of the project were to remediate the PFAS-impacted soils at the FFTA to an acceptable level and effectively mitigate the contribution of PFAS flux to offsite receptors from the Base.

As part of the engagement GHD completed:

• Strategic review of the remedial design
• Undertook a data gap analysis and revised options appraisal introducing sustainable remediation principles
• Developed the Technical Specifications and Contract documents as part of the Early Contractor Engagement
• Undertook bench-scale and field-scale treatability trials, hydrological and geophysical modelling.
• Excavation and onsite treatment of PFAS-impacted soils
• Cap and containment design and implementation that included the development of a site-specific Compaction Specification for re-use of stabilised low-permeability soils.

 

Deliverables:

• Delivery of an interpretive report detailing the findings of the PSI, DSI and CSM
• Biota investigation reports
• Ecological and Human Health Risk Assessments
• Development of a GMP for ongoing monitoring. 

 

GHD successfully remediated the former fire training ground to meet the remedial action plan objectives. The project is the first completed PFAS soil remediation for Defence. 

GHD in conjunction with Defence developed an innovative compaction specification for reuse of treated soils based on the integrative modelling of PFAS mobility conducted by CSIRO and Flinders University. This novel approach to reducing the contribution of PFAS mass flux allowed the project to beneficially reuse the majority of soil previously consigned for offsite disposal both achieving a significant cost saving and directly aligning with the principles of sustainable remediation. 

The project also developed a concentration model using statistical georeferencing to accurately identify PFAS impacts insitu which allowed for accurate delineation of the remedial footprint. This upfront modelling in the design phase, allowed for improved material management and provided significant value to the program through efficiency in delivery and reduction of latent condition risk with over-excavation or residual impacts remaining in situ.