Extensive upgrades to the Gloversville-Johnstown Joint Wastewater Treatment Facility (GJJWTF) provided multiple positive outcomes for the local economy and New York State energy production. To support an expansion of production at a local Greek yogurt plant by processing the increased waste, the GJJWTGF needed to expand its capacity and improve its waste-handling systems. While keeping project costs manageable, the Facility also embraced the goal of being net-zero, an electrically self-sufficient facility, with the additional benefit of pushing surplus electrical generation to the grid. The improvements supported the expansion of the FAGE yogurt plant, with its increase of 150 permanent jobs, as well as a second dairy product manufacturing facility in Fulton County, the Euphrates Cheese Co., which makes feta cheese.
CAST Process and Electricity Generation
The most recent upgrade included an innovative Contact Adsorption Settling Thickening (CAST) Process which utilizes waste activated sludge (WAS) micro-organisms from the existing aeration process to adsorb biological oxygen demand (BOD) from the dairy wash water stream, yielding approximately 60% percent chemical oxygen demand (COD) removal at relatively low energy levels required for mixing. The CAST process reduces the organic load to the existing aeration system and provides an organically-rich sludge for the plant’s anaerobic digesters, boosting biogas production. To harness the additional biogas production, a biogas scrubber and an additional 350 kW biogas generator were installed to bring the total electrical generation capacity to 1,050 kW.
The combustible gas which results from the process fuels three American-made Caterpillar engine generator sets (each rated at 350 kW). When the facility is not drawing the power for its own needs, the electricity is sold back to the power grid, providing revenue. The 1 megawatt plant creates more power than it uses. Sale of the extra 2 million kilowatt- hours per year back to the grid is expected to earn $90,000 a year in revenue, supporting the plant operations and saving money for the municipal owners. The excess electricity it creates can supply approximately 200 homes for a year.