The Metropolitan Wastewater Treatment plant in St. Paul was the first Minnesota plant to be converted to biological phosphorus removal (BPR) and is currently the largest BPR plant in the world. The phased conversion took 7 years and saved its customers about $100 million, compared to the original project proposal.
No Chemicals Required
Authors: Denny Parker, John Bratby, Timothy Block, Donavan Esping, Jennifer Gruman (Brown and Caldwell); Larry Rogacki, Christine Voigt
2008 WE&T magazine, pgs. 42-47