AWWA WQTC71605

Validation testing defines the ultraviolet (UV) dose equations that are used to size UV systems for a given application and are programmed into the UV system's programmable logic controller (PLC) for dose delivery monitoring. The U.S. Environmental Protection Agency (USEPA) UV Disinfection Guidance Manual (DGM) provides recommended approaches for validating UV reactors that include QA/QC and approaches for analyzing validation data. Since the UVDGM was published in 2006, advances in UV validation methods have improved the accuracy and precision of validation testing. Calculated dose monitoring algorithms have been developed that better account for the true relations between reduction equivalent dose (RED) and the independent variables of flowrate, UV transmittance (UVT), and lamp UV output, and account for the impact of microbe UV sensitivity on RED. CAF index calculations that quantify lamp aging and fouling as well as new criteria for test microbe UV dose-response also improve the accuracy and precision of validation testing. Includes 2 references, table, figures.