This project was conducted by a team of researchers from Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC), Geosyntec Consultants, Inc. (Geosyntec), and the University of California at Berkeley (UC Berkeley). The overall project goal was to demonstrate and validate the effectiveness of in situ thermally-enhanced low-pH persulfate oxidation of per- and polyfluoroalkyl substances (PFAS) via treatability studies and a field demonstration at an aqueous film-forming foam (AFFF) source area. The specific technical objectives of this project were as follows:
Site-specific treatability studies were conducted to validate the performance of a promising destructive treatment technology for PFAS that could be conducted in situ: thermally-enhanced persulfate oxidation at low pH. Because this technology is not expected to be fully effective in destroying all PFAS (i.e., perfluorooctane sulfonate [PFOS] and similar perfluorosulfonic acids), the technology would need to be used in combination with pump-and-treat to fully address a mixed PFAS source zone.
After carefully reviewing the characteristics of several potential demonstration sites, the project team recommended Naval Air Station (NAS) Jacksonville former fire training area FT-02 as the demonstration site.
Due to additional funding needed to complete the field demonstration, the field demonstration portion of the project was not conducted.
The laboratory treatability studies were conducted to facilitate the design of the field demonstration. The primary objectives of the laboratory treatability studies were to assess the feasibility and efficacy of treatment including the use of hydrogen peroxide for aquifer heating, persulfate acidification and treatment of perfluorocarboxylic acids (PFCAs) and PFCA precursors at low pH, and neutralization of the aquifer following treatment. Key results and implications are as follows:
This non-proprietary technology is aligned with DoD’s preference for in situ remediation and aggressive mass reduction to accelerate site closure. As a public domain technology, it could lead to significant cost savings over proprietary methods. It could improve the sustainability of existing pump-and-treat systems, saving decades of system operation and cost.
Only the treatability assessment portion of this project was completed due to cost issues.