Development of a Forensics Based Approach to Evaluating Impacts of PFAS Contamination in the Environment

Polyfluoroalkyl Substances (PFAS) in the Environment - Session 2
Oral (pre-recorded) Presentation

Prepared by
1 - US EPA Region 9, 619 Mound, South Pasadena, CA, 91030, United States
2 - Ocean P3 Systems, 67 Prospect Rd, Piedmont, California, 94610, United States
3 - Ocean P3 Systems, 1230 Clay Street, APT 203, San Francisco, CA, 94108, United States

Contact Information:; 717-556-7231


Background/Objectives. Per- and polyfluoroalkyl substances (PFAS) are considered persistent organic pollutants (POPs). As such our expectation is that they remain in the environment for years and in many cases are not biodegradable. As the analysis and investigation of sites contaminated with PFAS continues to mature there is a growing interest in determining the contributions of different sources, to the overall contamination. Treatment technologies are also maturing in application and complexity of remedy options. The complexity and magnitude of the treatment can significantly impact costs for said treatment. Therefore, the development of analytical methodologies that can at least, start to delineate sources/contributions and assign responsibility can be a useful tool in environmental investigations.
Approach/Activities. There are several tools already available in the analytical chemist’s toolbox, from the recognition of the presence of branched chain isomers and relative ratios, to the unique targeted compound profile presented by certain PFAS contamination sources. Add to that, the judicious use of results from the Total Oxidizable Precursor (TOP) Assay and a reasonably good foundation has been established upon which to build a forensics discipline. If we now add the results of accurate mass qTOF, applied to targets, known/unknowns and unknown/unknowns, we are progressing towards a robust forensic profiling application. In addition to the limited libraries that have been obtained, we will show how we have assembled libraries from known sources (AFFF and other products) that can be used like a fingerprint, to borrow terminology from our petroleum hydrocarbon colleagues.
Results/Lessons Learned. The presentation will describe the process that we went through in deriving a forensics based approached to identifying PFAS source/contributions. We will demonstrate how the various techniques complement each other towards source identification and how the use of some relatively standard statistical programs improve the strength of the analytical results and solidify the conclusions drawn from the data.