As a result of an international law banning the disposal of sewage sludge at sea, the proper treatment of sewage resulting from the wastewater treatment process has been becoming problematic. Generally, sewage and sludge are controlled by anaerobic digestion when they are treated and landfilled, where the methane (CH4) and nitrous oxide (N2O) from this process are discharged. Because these gases are known to be responsible for global warming, the wastewater treatment process has become known as a greenhouse gas emission source. In this paper, the energy efficiency of wastewater utilities was evaluated to explore ways to save energy via operational measures, and the findings were as follows. The database system related to energy use must be supplemented to enable more accurate analysis of energy consumption in wastewater treatment facilities. In particular, electricity consumption of relay pumps, energy usage per unit process, pump power usage to discharge treated wastewater a long distance, if necessary, and alternative energy production and utilization status must be recorded. By utilizing the results of the analysis conducted in this study, it is possible to quantify the level of energy savings needed and establish customized energy-saving measures to achieve a certain target level for benchmarking a successful case of wastewater utilities.