Better Clarification from the Floor Baffle Up

The Centennial Water and Sanitation District in the State of Colorado upgraded the Marcy Gulch Wastewater Treatment Plant as part of their Phase II Improvements Project to meet stricter regulatory requirements. Secondary clarification enhancements were made to help mitigate the four hydrodynamic phenomena that can negatively impact clarifier performance. The District implemented a McKinney feedwell floor baffle on all four secondary clarifiers to control density currents and improve performance, and sludge removal was converted to a spiral rake mechanism from suction draft tubes. Computational fluid dynamic modeling demonstrated improved hydrodynamics with the McKinney floor baffle design. Preliminary results show improved clarification, improved thickening and sludge blanket control, and reduced floc shearing in the modified clarifiers, with effluent turbidity generally lower than the old clarifiers. Overall, the McKinney floor baffle design has demonstrated the potential to optimize clarification in secondary clarifiers.