When the Newtown (Conn.) Wastewater Treatment Plant had trouble meeting its nitrogen limit, the plant manager, operator and mechanic worked as a team to improve nitrogen removal and dissolved oxygen (DO) control, while reducing energy costs.
“Our nitrogen limit in 2006 was 24 pounds a day, which the plant wasn’t achieving,” says plant manager Julio Segarra. “The oxidation ditch was hard to manage, since the drive for the mechanical mixers ran on high speed most of the time. What we really needed was a variable-speed drive.”
An aeration system upgrade in 2007, followed by exceptional teamwork from the plant staff, improved DO
