May 2-3, 2017
Washington Navy Yard
Aqueous Film Forming Foam (AFFF) formulations have been used by the Department of Defense (DoD) since the 1970s to suppress fires, and there are hundreds of sites with resulting contamination by per- and poly-flouroalkyl substances (PFASs). The DoD used AFFF mixtures containing significant quantities of perfluorooctane sulfonate (PFOS) and related perfluoroalkyl sulfonates such as perfluorohexane sulfonate (PFHxS) until 2002, when production stopped. However, the DoD continued (until only recently) to use PFOS-containing AFFF stocks. Although the DoD’s legacy use of AFFF included various fluorotelomer-based formulations, the vast majority of DoD’s environmental liability likely results from the use of PFOS-based AFFF formulations.
Research on AFFF sites is timely given USEPA’s recent drinking water health advisories for PFOS and perfluorooctanoic acid (PFOA), both of which have been found at AFFF sites. In addition, numerous states are beginning to promulgate drinking water standards. These advisory levels are sufficiently low that large volumes of groundwater can exceed these criteria by orders of magnitude at many sites, and complete in situ treatment will be very challenging.
Due to their chemical structure, PFASs are very stable in the environment and are relatively resistant to biodegradation, photooxidation, direct photolysis, and hydrolysis. However, some PFASs, notably the polyfluoroalkyls, can be degraded in the environment, in some cases producing perfluoroalkyls, including PFOA. Both PFOS and PFOA are relatively soluble and recalcitrant, and therefore migrate rapidly and form large plumes. The options for treatment are limited because of the recalcitrance of these compounds, particularly PFOS, so ex situ treatment with granular activated carbon (GAC) is common. As a result, management of AFFF sites is often very costly.
The potential magnitude of the DoD’s PFAS liabilities will require a sustained effort to identify the best technologies to characterize, treat, and manage these sites. SERDP and ESTCP have been funding research on AFFF contamination for several years, including improvements in PFAS analysis and the fate of PFASs in the subsurface, and the potential for in situ remediation. Ongoing research includes work on a range of potential remediation technologies, ecotoxicological effects, and improved AFFF site characterization and technology transfer regarding PFAS contamination. Recent Statements of Need focused on improved source zone characterization and improved ex situ and in situ groundwater treatment. It is an appropriate time to review the current state of the science and identify the most pressing needs for future research, development, and demonstrations.
To provide strategic guidance for future research on site management of PFAS-impacted sites, the objectives of this workshop are to (1) review the current state of the science regarding PFAS contamination in general, and AFFF in particular, (2) evaluate current and potential characterization and remediation technologies, and (3) identify research and demonstration needs that can improve remediation performance and efficiency and ultimately reduce the costs to manage these sites.
Scheduled for May 2-3, 2017 in Washington, DC, the two-day workshop will consist of a limited number of formal presentations describing the current PFAS management challenges by each branch of DoD, the barriers and limitations in technology to achieving cleanup goals, and a group discussion period to strategize the optimal role that SERDP and ESTCP can take to aid in managing AFFF sites.
Preliminary focus questions for discussion during the group discussion are provided below:
This meeting will provide guidance for the future direction of investments and technology transfer efforts under the SERDP and ESTCP Environmental Restoration Program Area to assist in achieving restoration goals and reducing the CTC. Specifically, this workshop will provide (1) a review of cleanup goals and management processes of the Services which identifies the current and potential future obstacles to remediating existing sites, and (2) a summary of RDT&E needs to better address restoration goals and reduce the CTC.