Three years ago, an energy audit of the Freeport (Maine) Wastewater Treatment Plant found many ways to save energy by upgrading old equipment, changing processes and insulating the building. Now the Freeport Sewer District is saving more than $90,000 in electricity and $25,000 in heating oil annually.
To serve a population of 8,300, the district operates a secondary treatment facility and maintains 18 miles of gravity pipes, 11 miles of force main and 11 lift stations. The treatment plant has three independent trains, and operators can divert water to as many trains as necessary. The 0.75 mgd plant treats 0.350 mgd
