To serve a growing population, the Eau Claire Wastewater Treatment Plant needed improvements.A 2007 facility plan for the plant in northwestern Wisconsin pointed toward adding an activated sludge process with biological phosphorus removal (bio-P) capability to meet increasing demand and satisfy new regulations.A higher level of treatment normally means using more energy. But Jeff Pippenger, utilities administrator, says Eau Claire has offset that increase by using more biogas and heat recovery; adding high-efficiency motors, blowers, mixers and variable frequency drives; upgrading heating and lighting; and reducing chemical usage in treatment.Multiple changesThe facility plan included a number of changes to improve
