Historical use of per- and polyfluoroalkyl substances (PFAS) at firefighting training grounds (FTGs) has led to PFAS retention within concrete and subsequent releases of PFAS into the environment. This project seeks to better understand the release of PFAS from concrete cores collected from an old FTG. The vertical profile of these cores was assessed, and then surface ponding and rainfall simulations were conducted on the cores. The results of the simulation will be used in the development of a model to predict PFAS releases in similar environments. This project extends to incorporate concrete and asphalts in other PFAS impacted sites and explore new methods of investigating the distribution of PFAS in the impacted materials.
Outcomes
After extensive testing, it was determined that perfluorooctane sulfonate (PFOS) had the highest concentrations in the cores and in ponded water on their surface. This was followed by 6:2 fluorotelomer sulfonate (6:2 FTS) and perfluorohexane sulfonate (PFFHxS). The maximum concentrations of PFAS in runoff water of five rainfall simulations were similar, suggesting the recurring release of PFAS from Aqueous Film Forming Foam (AFFF) impacted concrete, which could be sustained by upward transport of PFAS in the concrete subsurface layers through a potential "wicking" effect. Essentially, this is the movement of the liquid (PFAS, in this case) through tiny spaces in the concrete cores due to the molecular forces between the liquid and the core.
Research outputs
Conference Abstracts
Key, T.A., Mueller, J.F., Thai, P.K., Barns, G., Porman, S., McDonough, J.T. Management and mitigation of PFAS from old concrete, Battelle Conference, San Francisco, USA, 22-26 May 2022.
