Read this case study from a Wastewater Treatment Plant in Carthage, TN that implemented energy efficiency measures to save energy and money.
Staff participated in the Energy Management Initiative of the Tennessee Water and Wastewater Energy Efficiency Partnership, a joint technical assistance program through the U.S. EPA Southeast Regional Office, U.S. Department of Energy, and the Tennessee Department of Environment and Conservation.
A site assessment conducted in March 2017 identified many ways to improvement treatment efficiency. The team observed that the solids retention time in the aeration basin and first digester were sufficient to treat the solids, and the aeration to the second digester was redundant. Accordingly, the team recommended reducing the operating time of the aerator in the second digester from constant operation to only six hours per day. Beginning in April 2017, the plant staff has manually adjusted the aerator operation schedule as part of routine duties. This single change reduced electricity use by 14% and saved over 7,000 kWh per month despite a 15% increase in wastewater loading.