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.

Progress, milestones and presentations

Below progress, milestones and information events that have been conducted in the project are presented. For some of them there is a link to an abstract, presentation or webinar.

• Fagerlund F. et al. Modelling approach to account for competitive sorption of PFAS in MODFLOW-based solute transport simulations. European Geosciences Union (EGU) Vienna 14 – 19 April 2024. (Abstract)
• Fagerlund F. et al. Modelling PFAS transport in groundwater accounting for competitive sorption. NORDROCS, Uppsala 9-12 September 2024.
• Fagerlund F. et al. Transport of PFAS in the soil groundwater system – Why is it important? Symposium on Drinking Water and PFAS, EBC Uppsala 11 October 2024.
• Fagerlund F. et al. Transport of PFAS in the soil groundwater system – Importance and challenges. Coffee Session with Baltic Sea PFAS Network, On-line seminar hosted by IVL, 25 October 2024.
• Fagerlund F. et al. Modellering av PFAS transport i grundvatten – utmaningar och möjligheter. Grundvattendagarna, Uppsala 3-4 December 2024.
• Earon R. et al. Grundläggande hydrogeologi och transport av PFAS i grundvatten – Erfarenheter från ett regeringsuppdrag. Grundvattendagarna, Uppsala 3-4 december 2024.
• Earon R. et al. Webinar hosted by Statens Geotekniska Institut (SGI) 4 February 2025. Presentation av underlagsdata till modellering för transport av PFAS i mättad och omättad zon samt beräkningsmetoder för och preliminära uppskattningar av belastning från PFAS-påverkade källområden med platsspecifik data från Örnsköldsvik. (Direkt link YouTube, Link to SGIs webinar series on PFAS)
• Fagerlund F. et al. Transportmodellering av PFAS från förorenade hotspots – utmaningar och möjligheter. Renare mark vårmöte 19-20 mars 2025. (Presentation pdf, 3 MB.)
• Fagerlund F. et al. Modelling the transport of per- and polyfluoroalkyl substances (PFAS) from source zones to recipients – challenges and model developments. European Geosciences Union (EGU) Vienna 27 April – 2 May, 2025. (Abstract)
• Earon et al. Stabilization of PFAS with activated carbon: Experience from a Governmental Assignment in Sweden. 2nd Nordic Baltic Conference on PFAS, Copenhagen, 4 June 2025.
• Earon et al. Monitoring the effects of a colloidal activated carbon barrier for stabilisation of PFAS: Insight into the development of AFFF contamination now and in the future. AquaConSoil, Liege, 18 June 2025. (Presentation pdf, 5 MB.)
• Fagerlund F. et al. PFAS fate and transport in the soil groundwater system. Keynote Groundwater Quality, Bordeaux 10 – 13 June, 2025. (Presentation pdf, 4 MB.)
• Das M. et al. Investigation of PFAS transport and retention in soil from a colloidal-activated-carbon-barrier field site using column experiments. Webinar hosted by Statens Geotekniska Institut (SGI) 3 February 2026.