Project 3052-FR3 | Assessment of PFAS Distribution and Retention in Surface Soil and Vadose Zone Environments

Per- and polyfluoroalkyl substances (PFAS) are persistent and highly mobile contaminants increasingly detected in wastewater, recycled water, soils and groundwater systems worldwide. As the use of recycled water for irrigation grows, understanding how PFAS behaves in soils and the vadose zone is critical for managing long-term environmental and groundwater risks. 

Through Project 3052-FR3, a crcCARE research team investigated PFAS occurrence, retention and transport in recycled water-irrigated soils across Victoria and Western Australia. Combining field investigations, soil geochemistry, sorption science and machine learning, the project has generated new insights into the factors controlling PFAS mobility and supports more risk-informed management of recycled water irrigation systems. 

This webinar will showcase the project outcomes, including findings from soil investigations across multiple irrigation sites and new evidence demonstrating that PFAS mobility cannot be reliably predicted using concentrations alone. Attendees will hear how soil properties such as mineralogy, organic carbon, clay content and cation exchange capacity influence PFAS retention and transport, and why these factors are critical to understanding environmental risk. 

The session will also introduce the project's innovative machine-learning predictive framework using Gaussian Process Regression (GPR) and the PFAS Predictor, a practical web-based decision-support tool that enables rapid assessment of PFAS retention and mobility in irrigated soil systems. 

Join the project team to explore the research findings, predictive modelling approach and practical applications that can help utilities, regulators and contaminated land practitioners move towards more predictive, process-based and risk-informed PFAS management. 

This event, FREE and exclusively for WaterRA members, will provide an opportunity to learn more about the project outcomes.