Expansion of the Greenfield Water Reclamation Plant

Project goal: To almost double the capacity of the Greenfield Water Reclamation Plant to 30 million gallons of reclaimed water per day, and 16 million gallons of bio-solids per day. The aim of the project is to expand the current capacity of the Greenfield Water Reclamation Plant from 16 to 30 million gallons of Class A+ reclaimed water per day annual average day flow, or MGD AADF. At the same time,the project investigated an increase in Class B bio-solids from 8 to 16 MGD AADF. The expansion maintains the plant’s current Arizona Department of Environmental Quality standards, and does not disrupt existing operations. Historic flow and wastewater characteristic data were analyzed, as were the processes in the plant to reduce energy and chemical usage. The designed process treats the influent wastewater using a combination of screens, grit removal, hydrocyclone separators, clarifiers, aeration basins, disk filters, and ultraviolet disinfection to remove microbes from the effluent. The sludge is treated using centrifuges and anaerobic digesters, then the Class B bio-solids are sent to the landfill. The methane produced during this process is used to heat the boilers,which generate steam to heat the sludge. The excess methane is burnt off in flares. Chemicals used in the process include sodium hydroxide and sodium hypochlorite.