In 1992, Camp Dresser & McKee (CDM) conducted an intensive, year long bench and pilot study at the Sweeney Water Treatment Plant in Wilmington to determine which treatment processes would ensure the city high quality water well into the 21st century. CDM evaluated and optimized the current conventional process and compared its treatment efficiency to various alternative treatment approaches. From these findings CDM was able to recommend to the City of Wilmington a plan for water treatment improvements and expansion that will provide high quality water to the city's customers that meets all current and anticipated future regulations at a savings of over two million dollars compared to previous conventional treatment options. The selected treatment process that has been designed for the plant expansion is conventional coagulation with upflow clarification, ozone for oxidation/disinfection and BAC filtration. This treatment process has been designed for a 10-mgd expansion in parallel with the existing 15-mgd treatment facilities which are being modified to also include ozone oxidation/disinfection and BAC filtration. This paper presents both pilot testing results and the concepts of the final design.