The City of Napoleon’s wastewater treatment plant had operational deficiencies that required correction. Areas needing improvement included headworks, pumping to the biotowers, primary settling, digestion, and solids dewatering.
Improvements to the treatment plant liquid and solids processes were completed. The new headworks facility consisted of screens and a high efficiency grit removal. Space was made available for future septage receiving equipment. A new primary tank to supplement the two existing clarifiers was included. New variable speed vertical turbine biotower lift pumps with a larger wet well will allow the plant to treat peak wet weather flows without flooding the primaries. Due to the large inert content of the solids, testing was completed to determine the most efficient process for solids digestion. As a result, the former anaerobic digesters were converted to aerobic with a jet mixing system. Also included was a new dewatering facility within the existing dewatering building. The system included volute presses, conveyors and a pathway to place material into containers or the sludge storage building. The existing influent pump station was converted to a recycle and site drainage pump station. Other improvements included SCADA, electrical improvements, and a new plant generator.
An innovative approach to this project included a proposal process to select the screen and grit equipment. The selected equipment manufacturer was then included with the Design-Bid-Build bidding documents. This allowed the City to be involved in the equipment selection process and realize a cost savings. The dewatering equipment was acquired through a procurement process where two manufacturers provided bids for the equipment. This allowed the City to review volute press manufacturers while competitively bidding the equipment.
