In the United States, the newly promulgated regulations for drinking water force water treatment utilities to be more concerned with finished and distributed water qualities. Water treatment utilities face new challenges with regard to maintaining disinfectants as well as reducing disinfection by-products (DBPs). The need to fulfill the more stringent DBP rules has stimulated scientific-based model development to represent in-plant and distribution-system DBPs. Numerous models for DBP formation, including trihalomethanes (THMs) and haloaceticacids (HAAs), have been proposed in recent decades, but these models simulation of full-scale DBP formation has not been significantly examined. In this study, which combines chemical DBP models (empirical power functional models) and hydraulic simulations, DBPs including THMs and HAAs were successfully simulated from full-scale monitoring data, indicating that the empirical DBP model offers a potential tool for accessing DBP formation in real plants. Modification of DBP prediction models using correction factors improved the accuracy of the DBP simulations.