AWWA WQTC52844

The main objective of this study was to investigate the mechanismsthat contribute to the survival and persistence of pathogens in the presence of a disinfectant residual in drinking water distribution systems. Experiments were designed to assess the role of sequential exposure of the indicator organism (E. coli) to disinfectants. E. coli is used because it is a common indicator organism for fecal contamination in drinking water. Sequential exposure will simulate the event of cross contamination where microorganisms are introduced into a distribution system and are exposed to the disinfectant residual, followed by loss of the disinfectant for a period of time, and then re-exposure. Includes 6 references, figures.