Onondaga County Department of Water Environment Protection
The Oak Orchard Wastewater Treatment Plant (WWTP) had been experiencing increased influent loading for both BOD and TSS and the plant had exceeded the rated design capacity of the plant for BOD. The New York State Department of Environmental Conservation (NYSDEC) had required the development of a plan for future growth in accordance with 6 NYCRR Part 750-2.9(c)(2). An evaluation was performed that looked at re-rating the plant based on the current performance and for upgrading the plant to gain additional capacity. The goal of the evaluation was to increase the rated capacity of the WWTP without adding additional process tanks.
The existing capacity of the unit treatment process at the WWTP was evaluated based current design standards and the historical effluent performance of the WWTP was reviewed. It was determined that the WWTP could be re-rated to approximately a 15% higher capacity without performing any upgrades to the plant.
Alternative enhanced treatment processes were evaluated for increasing the capacity of the WWTP. These processes were evaluated based on performance data provided by the system manufacturers and by utilizing computer modeling of the Oak Orchard WWTP using the BioWin simulation model. The enhanced treatment processes evaluated included Magnetite Ballasted Settling, Moving Bed Biofilm Reactor (MBBR), Integrated Fixed-Film Activated Sludge (IFAS) and Membrane Bioreactor (MBR).