The use of aqueous film-forming foams (AFFFs) containing per- and polyfluoroalkyl substances (PFAS) has led to impacted pavements that can leach into the surrounding environment. The overall objective of this project is to develop a multipronged approach to manage PFAS-impacted pavements. This includes development of advanced analytical procedures, datasets on the leaching kinetics for predicting the environmental load of PFAS from impacted pavements, an optimized thermal treatment process of impacted pavements, and datasets on the performance of recycled pavements post-treatment.

There are three major tasks to accomplish the objective: (1) develop and demonstrate standard operating procedures for the quantification of target and total PFAS in pavements; (2) evaluate the leaching potential of PFAS from pavements and develop a predictive model to estimate environmental loads; and (3) determine the optimal thermal treatment conditions to reduce the mass of PFAS in disposed pavements and conduct performance testing on recycled materials. This project will utilize both laboratory-made and field-collected impacted pavements. It also involves the use of state-of-the-art analytical approaches, including target analysis of PFAS using Environmental Protection Agency (EPA) Method 1633 and total PFAS using particle induced gamma-ray emission (PIGE) spectroscopy. The speed and low-cost of PIGE will allow more conditions to be tested within the project duration and budget.

Pavements impacted with AFFF may be a significant long-term concern. The development of analytical methods specifically for quantifying total PFAS using PIGE will allow for the rapid screening of pavements to determine which areas are highly impacted, as well as on-site analysis of disposed pavements. Datasets on the leaching kinetics of PFAS from pavements will support the development of models to predict environmental loads. Additive testing may extend the lifetime of pavements. Finally, datasets of the thermal treatment of PFAS in impacted pavements will provide an optimized scheme for reducing the amount of PFAS so the pavement can be reused in new materials. (Anticipated Project Completion - 2026)