The presence of per- and polyfluoroalkyl substances (PFAS) in water resource recovery facilities (WRRFs) has been widely reported. However, comprehensive quantitative data on specific PFAS compounds, their fate and phase partitioning through WRRF treatment processes, and the factors that control PFAS distribution in finished biosolids remain poorly understood. The absence of this fundamental information is a critical barrier for utilities to effectively manage and respond to a rapidly evolving public perception and regulatory climate related to PFAS. There is a significant body of research on PFAS fate and transport in the environment, and many of these recently developed tools and insights can be leveraged to investigate much-needed information specific to WRRFs. The overall goal of this project is to provide utilities with a comprehensive, methodologically consistent dataset regarding PFAS occurrence, fate, and mass distribution in WRRFs. This dataset will provide the scientific justification to develop appropriate guidance for site managers that benchmarks typical PFAS mass flows from WRRFs, sampling procedures and analytical methods, as well as potential mitigation strategies specific to WRRF unit processes. Research partners: Anchorage Water & Wastewater Utility, Atlanta Department of Watershed Management, City of Portland Bureau of Environmental Services, East Bay Municipal Utility District, Great Lakes Water Authority, Gwinnett County, King County Wastewater Treatment Division, Metropolitan Water Reclamation District of Greater Chicago, Metro Wastewater Reclamation District, Milwaukee Metropolitan Sewerage District, Mount Pleasant Waterworks, Northeast Ohio Regional Sewer District, Passaic Valley Sewerage Commission, Pinellas County Utilities, Sacramento Regional County Sanitation District, Upper Occoquan Service Authority, and Ventura Water.