AWWA JAW51284

Semimechanistic models that describe the formation of disinfection byproducts (DBPs)(including trihalomethanes and haloacetic acids) were developed for the Massachusetts Water Resource Authority, an unfiltered surface water system using chlorine. The model's parameters were hydroxide concentration, chlorine decay kinetics or chlorine reacted, ultraviolet light absorbance at 254 nm, and algae concentration. One of the challenges in estimating or predicting DBP concentrations is that treatment processes at various points in the transmission system have substantial effects on the factors that affect DBP formation and rates of DBP formation. This article describes the formation of total trihalomethanes and haloacetic acids in the Massachusetts Water Resources Authority system and takes into account three treatment processes within the system. Coefficients used in the model were based on monitoring data collected from October 1997 to July 1999 and were validated with monitoring data from August 1999 to January 2000. Includes 12 references, tables, figures.