This project addresses the presence and cause of chemical peaks that can escape full advanced treatment (FAT) of recycled water. By conducting a literature review, three case studies at full-scale FAT facilities, and experimentation on commercial total organic carbon (TOC) analyzers, the project identified families of compounds that can escape FAT at full-scale facilities, along with additional treatment processes (including blending) that are appropriate to dampen potential chemical peaks. This research will help regulators and utilities address the challenges of potable reuse without significant environmental buffers. Research partner: California State Water Resources Control Board. Published in 2021.