Wastewater treatment plants in Illinois are exploring different nutrient removal technologies for future plant expansions because of the potential for future NPDES permits with limits on effluent nitrogen and phosphorus. During a master planning project for the North Side Water Reclamation Plant (NSWRP) of the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC), a 333 MGD wastewater treatment plant located in Skokie Illinois, a "technology threshold" approach was used to screen a wide range of nutrient removal technologies into a short-list of five to six proven technologies for large wastewater treatment plants. In order to select a technology from the short list, GPS-X process modelling was used. This paper will present the process of evaluating and selecting nutrient removal technologies at the NSWRP.