AWWA ACE93147

To address a seasonal bacterial regrowth problem, commencing in 1988 a multiple year study was carried out comparing chlorine and chloramine as secondary disinfectants. The study evaluated residual attainability and biocidal effectiveness of the two secondary disinfectants. Public response was also evaluated. Chloramine consistently outperformed chlorine in the areas of residual attainability and biocidal effectiveness. Initial public response was more negative in the chloraminated area, however, this trend appeared to reverse in the second year of the study. The environmental impact of increased chlorine residuals, especially a chloramine residual, should be considered if a utility is situated in an environmentally sensitive area.