The science and technology of site characterization for per-and polyfluoroalkyl substances (PFAS) has advanced in the five years since FRTR last addressed the topic in 2018. Federal agency budgets for PFAS remediation have grown substantially during this time. As a result, site characterization efforts such as Remedial Investigations, as well as early response actions, are underway at many Federal facilities. Funding for field-scale projects to further advance PFAS characterization technology and methodologies also has increased substantially. The FRTR 2023 Fall General Meeting provides an opportunity for member agencies to share results of recent and on-going PFAS projects that are improving our understanding of PFAS characterization technologies. Specifically, invited presentations and roundtable discussions will explore current best practices for PFAS site characterization, emerging technologies and methods, case studies and current agency needs for technology transfer and future research. To view this archive online or download the slides associated with this seminar, please visit http://www.clu-in.org/conf/tio/FRTRFall23_110723/