This paper reports on a series of bench-scale tests that the Passaic Valley Water Commission (PVWC) conducted to assess the effectiveness of enhanced coagulation for removing precursor materials through the sedimentation process for the purpose of controlling disinfection byproducts. Seasonal jar test evaluations were conducted for three different surface water sources. The primary objectives of these treatment evaluations were to determine: the coagulant dose required to achieve enhanced coagualtion conditions for each source water on a seasonal basis, and the resultant DBP concentrations at the coagulant dose required to achieve enhanced coagulation conditions and whether the Stage 1 DBP concentrations were achieved.