A mathematical model for the removal of micropollutants in PAC/UF systems was successfully verified with experimental data. The model was based on a single set of equilibrium and kinetic parameters that were independently evaluated in bench-scale experiments. Laboratory-scale UF pilot plant experiments were conducted to determine the accuracy of model predictions for atrazine removal in the presence of natural organic matter. Good agreement was obtained between model predictions and experimental data. Greater mass of atrazine was adsorbed when all PAC was dosed at one time at the beginning of the membrane cycle as compared to PAC dosage at a constant rate throughout the membrane cycle. The model can be used to rapidly test different types of PAC and to optimize the process operating procedures for the removal of trace organic compounds in the presence of natural organic matter.