Practical modelling of PFAS transport and fate from source zone to recipient

Description

Per- and polyfluoroalkyl substances (PFAS) are extremely persistent, harmful chemicals that have complex transport behaviours in the environment. Highly contaminated hotspots, often connected to firefighting training sites and airports constitute important sources of PFAS spreading to the environment both in Sweden and globally. To assess the risks and long-term environmental impacts of PFAS from these sites, there is a great need for improved process understanding as well as modelling tools for PFAS fate and transport from contaminated source zones further into the environment and into recipients and drinking water resources. Accounting for the complexity of real sites based on detailed field data is essential. The overall aim of this project is to develop practically useful models for improved understanding and predictions of PFAS transport originating from contaminated hotspots. We will test existing models and further develop them to better account for transport processes and phenomena which are specifically important for PFAS, including retention processes at air-water interfaces, interaction/competition between chemical species and PFAS-specific sorption phenomena. Models for unsaturated and saturated zones will be tested and developed and will finally be integrated to create practical modelling tools to predict the transport from sources of PFAS contamination all the way to recipients. With the aim to improve practical work on risk-assessment and source identification of PFAS, these models will further be used to evaluate and revise transport aspects of PFAS risk assessment methods, such as the sub-model for contaminant transport in the guideline value model by the Swedish Environmental Protection Agency. We will use a unique, comprehensive set of field data on PFAS spreading from contaminated hotspots collected by the Swedish Geotechnical Institute (SGI) as part of their work on mitigation of PFAS contamination commissioned by the Swedish government.