This training class builds on the earlier information for fate and transport and site characterization presented in the PFAS 101 CLU-IN training. It provides more in-depth information for fate and transport, site characterization, source identification and some introductory information on environmental forensics. These topics will be presented along with options and a framework for data visualization. This training will focus largely on PFAS fate and transport in groundwater. The goal is to provide detailed information about the inputs practitioners can use to develop a robust conceptual site model to help understand fate and transport at PFAS sites, and how to gather evidence of multiple sources.