Both the Littleton/Englewood WWTP in Colorado, and the OWASA Mason Farm WWTP in North Carolina are being called upon to meet more stringent effluent nutrient limits in the future. The configurations and treatment processes at these two plants are quite different, but they are similar in that both require post-denitrification to meet future effluent limits. This paper will describe the process approach used to determine the sizes of the post denitrification facilities in both cases and the development of kinetic denitrification equations and their incorporation into the process models developed for the two plants.