The American Water Works Association Research Foundation and the Electric Power Research Institute-Community Environmental Center have collaborated on a three-phase research effort, called the "Ozone Energy Optimization Project". The overall goals of the project are to develop, demonstrate and document an approach for achieving and maintaining optimized performance at existing ozone facilities and to identify and document optimization considerations for future ozone system designs. Phase I of the project included the development of a standardized protocol for evaluating ozone system optimization at existing facilities. Phase II involved refining the protocol and making observations regarding optimization potential. Optimization results and considerations were documented for the 12 full-scale ozone facilities that participated in the project. This paper presents selected results from Phases I and II of the project.