Wastewater Treatment Plant Improvements City of Greenfield

Portfolio / Wastewater



  • Originally constructed in the 1960s, updated and expanded through the 2000s
  • Includes one (1) main activated sludge wastewater treatment facility and two (2) trains of Actiflow high rate settling processes
  • Peak flow was designed to be 10.0 MGD and is exceeded during wet weather events
  • This overall situation is unsustainable as the aeration system will need a major service in the future
  • The laboratory, office, and locker facilities are old or generally not available as well


The purpose of the project was to document operational issues and analyze the function of the existing wastewater treatment plant with respect to common design standards and provide alternative improvements and recommendations for the wastewater treatment plant improvements for a 20-year planning period.

The selected solution included the replacement of the existing WWTP with a new plant consisting of raw sewage lift station, valve vault, and controls building; headworks building with screening, grit, and odor control equipment; SBR treatment system with blowers, mixers, and decanters; UV disinfection system; low-profile cascade aeration system; non-potable water system; sludge processing system including sludge holding tank, blowers, mixers, decanters, sludge pumps, centrifuge dewatering, polymer feed, and conveyor system; chemical feed system for phosphorus removal, septage receiving station, vac truck screenings drying beds, lab and office building, emergency generators, and demolition of existing plant equipment, process tanks, and buildings.