AWWA ACE91035

An interactive, user-friendly computer program was developed to simulate inorganic water quality changes, THM formation, disinfectant decay and removal of natural organic matter (NOM) in water treatment processes. The selection, development and verification of empirical models include in the program is discussed. Specifically, these are: total and individual THMs, removal of THM precursors as quantified by total organic carbon and absorbance of UV light (involving removal of natural organic matter by alum coagulation and other unit processes), alkalinity and pH adjustment, and chlorine and chloramine decay. Further research needs are outlined. The model was developed to help the US Environmental Protection Agency determine disinfectant byproduct (DBP) concentrations that can be achieved by existing treatment technologies, given the requirements for microbiological safety; identify best available technologies for DBP control; and provide a tool to assess the impacts of new regulations on DBP formation in existing treatment plants. Many equations, charts, and graphs supplement the text.