PECI evaluated biological nutrient removal (BNR) process configurations for a 33 MGD regional wastewater treatment plant. Historical operating and additional sampling data were collected, organized and analyzed to define design conditions, including diurnal fluctuations. Unit processes, equipment sizes and configurations were determined for three BNR processes using BioWin models and preliminary layouts were developed for each configuration. Life cycle cost comparisons were prepared for each of the three BNR alternatives.
The first 13.9 MGD phase was constructed at a cost $4.5 million. Improvements include replacing three existing multistage centrifugal blowers with high speed turbo blowers (6,000 scfm each), addition of a new CMU electrical building and adding baffle walls, anaerobic and anoxic zone submersible mixers, mixed liquor recycle pumps and piping, and new effluent gates to six existing Aeration Basins.