Modeling of full-scale water treatment plants has been demonstrated by the authors to provide valuable, practical, and reliable information on a real-time basis. At the present time, the Lake Michigan Filtration Plant (Grand Rapids, MI) is employing its coagulation model that informs plant operators of the recommended coagulant dose, as well as anticipated settled and filtered turbidities. This greatly enhances operator abilities to quickly respond to changing water quality. Models that predict plant chlorine residuals and disinfection byproduct (DBP) formation have also been developed. Coupled with distribution system hydraulic models, these models will provide vital information on control strategies directed towards minimizing DBP formation. The methodology utilized in this project has the potential to simulate virtually any plant process. Includes 9 references, table, figures.