• In situ PFAS source treatments using SourceStop® immediately halt PFAS plume development and prevent impacts to downgradient receptors
• SourceStop approach is a sustainable remediation alternative compared to other mechanical and physical PFAS treatment methods
• Enhanced attenuation removes unacceptable PFAS exposure risk at a low cost

This case study reviews the in situ treatment of PFAS source zones at firefighting training areas on two aviation sites where PFAS-containing AFFF was historically discharged. Both pilot tests demonstrated PFAS soil leachate concentrations reduced by >99% following the source zone treatments. The PFAS source treatments applied site-specific amendment blends of SourceStop, a new concentrated form of colloidal activated carbon, in conjunction with powdered activated carbon. SourceStop is a micron scale aqueous carbon suspension emplaced as a horizontal PFAS barrier at the base of the target treatment zones to improve remediation effectiveness dramatically. In controlled laboratory studies, SourceStop has been proven to prevent PFAS leaching with >10x more effectiveness than powdered activated carbon alone.