AWWA JAW49901

The authors investigated microbiological behavior of a distribution system supplied initially with biologically treated water and then with nanofiltered water. Their purpose was to identify and evaluate the changes in microbiological water quality attributable to modifications in water treatment at the plant. During the course of the study, all data from various indicators of microbiological quality (i.e., heterotrophic plate counts, coliform enumeration, total direct counts, and fixed bacterial biomass) showed similar trends. Results indicated that the use of nanofiltration allows utilities to reduce chlorination of teated water and at least maintain or increase the microbiological quality of distributed water for areas with high residence times. Includes 27 references, tables, figures.