AWWA WQTC62534

This paper examines a large dataset of dose response curves generated during ultraviolet (UV) reactor validations undertaken according to the U.S. Environmental Protection Agency's (USEPA) Ultraviolet Disinfection Guidance Manual 1 (UVDGM), and discusses the range and implications of their variability and accuracy. The surrogate most commonly used in the U.S. and Canada for UV validation is the coliphage MS2. Guidance on acceptable ranges of that organism's UV dose response has been issued, in the UVDGM, and in the NWRI/AwwaRF 2 guidelines. However, each of these guidelines was prepared from limited historical databases; their validity in light of the recent impetus to precisely measure UV irradiance during dose response characterization has not been fully evaluated. This presentation examines a large database of MS2 dose response curves generated during UV reactor validations involving this research team and assesses these against the above guidelines, and vise versa. Also, these datasets are compared using the UVDGM's criteria for assessing differences between dose response curves, and variability of inactivation kinetics within and across a range of doses are evaluated. Includes 5 references, figures.