Modeling efforts performed by Cincinnati Water Works (CWW) studied the kinetics of trihalomethane (THM) formation for the CWW surface water and groundwater plants finished water. Based on experiments simulating distribution systems, multivariable kinetic models were developed to quantify the impacts of factors such as pH, temperature, total organic carbon and water age on the formation of each individual THM species as well as total THMs. Additionally, guidelines were developed on the use of kinetic models to control THMs through treatment processes and operational practices, to estimate water age and to address water quality issues associated with large-scale service area expansion.