AFFF formulations have been used by DoD since the 1970s to suppress fires, and there are hundreds of sites with associated PFAS contamination. The DoD used AFFF mixtures containing significant quantities of perfluorooctane sulfonate (PFOS) and related perfluoroalkyl sulfonates such as PFHxS until 2002, when production stopped, although the DoD continued to use PFOS-containing AFFF stocks for some time after. 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. Additional research on PFASs is timely given the USEPA’s recent drinking water health advisories for two common PFASs, perfluorooctanoic acid (PFOA) and PFOS, as well as the numerous states that are beginning to promulgate drinking water standards. SERDP has been funding research on AFFF contamination for several years to improve PFAS analysis, to develop tools for assessing the fate of PFASs in the subsurface, and to evaluate the potential for in situ remediation.
Although sampling guidance documents are publicly available, they contain limited information, and often include limitations on applicable sampling supplies and equipment that are not based on scientific evidence and may complicate field sampling plans and increase sampling costs. Further, existing guidance does not reflect the fact that more precautions may be needed when sampling certain media (e.g., drinking water) or when concentrations of interest are expected to be lower than in other instances (e.g., when working in a contaminated plume).
In addition, there are currently no EPA published procedures for PFAS analyses in media other than drinking water. Commercial laboratories offer analysis of these media using in-house developed methods that are based on EPA Method 537.
Development of procedures to assess the total organofluorine in environmental waters and soil and sediment are needed to help assess transformation and distribution of PFASs, as well as to assess various aspects of PFAS remediation techniques. Currently there is no standardized total organofluorine analytical procedure readily available that has been fully validated and the limitations of such procedures are yet to be determined.
Workshop participants identified a number of research needs associated with sampling and analysis of environmental matrices containing PFASs. Proposers are strongly encouraged to view the Workshop Report to obtain additional detail concerning these discussions.