AWWA JAW62274

Depletion of existing groundwater sources forced Tampa Bay (Fla.) Water to use alternative sources for drinking water supply. To help determine the effect of alternate source water quality on distribution system water quality, a kinetic model for nitrification was developed using Monod kinetics. The model was tested on finished waters that had been produced from groundwater, surface water, and saline sources and then distributed to pilot distribution systems. Many US utilities have implemented chloramination for residual and disinfection by-product control. Nitrification has been reported by some of these water providers using chloramines in their distribution systems. The steady-state plug-flow model described here predicted ammonia, nitrite, and nitrate in the presence of chloramines as well as active ammonia-oxidizing bacterial biomass and nitrite-oxidizing bacterial biomass. This model is one of the first developed specifically for drinking water distribution systems and from data from a large-scale field study. It provides the water community with a tool previously unavailable, i.e., a fundamental model for predicting nitrification in chloraminated distribution systems. By using the model to estimate nitrification, water providers can take a proactive approach to controlling nitrification in their systems. Includes 43 references, 4 tables, 10 figures.