AWWA WQTC62500

This slide presentation addresses the problem of the simultaneous presence of microorganisms and disinfectant residuals in distribution systems. Specific goals include: assess the impact of dynamic water quality conditions in distribution systems on microorganism inactivation (microorganisms in suspension); benefits of specific disinfectant levels; disinfectant residual as an indicator of microbial integrity; minimum disinfectant residual to maintain microbial water quality; concentration of microorganisms that induce a measurable decrease in disinfectant residual The research approach consists of four phases: revisit existing information including literature review, modeling effort, utility survey, and, historical water quality data analysis; determine inactivation potential of microorganisms at the bench scale (2 challenges); evaluate impact of acute and chronic water quality changes on disinfection efficacy (bench scale, annular reactors); and, evaluate impact of water quality changes on disinfection efficacy at the pilot scale (pipe loops), and analytical limitations of secondary disinfectant.