We assisted the City of Chattanooga in evaluating renovation options for the Citico Combined Sewer Overflow (CSO) Treatment Facility Pump Station, to allow the facility to operate effectively during high water level events, as part of the city’s Consent Decree program.
Existing weir levels in the facility settling basins don’t provide the necessary hydraulic head to allow treatment and discharge of flows into the Tennessee River during high river level events, backing flows up into the facility and threatening to damage facility components. Our team evaluated multiple options to retrofit the facility effluent chamber with pumps to transmit up to 66 million gallons per day (MGD) out of the facility during high river levels. We coordinated with vendors and operators, analyzed facility reports and record drawings, conducted field investigations, developed preliminary drawings, and conducted electrical, structural and hydraulic analysis for each option.
We produced a technical memorandum, Preliminary Engineering Report (PER), preliminary drawings and detailed cost estimates for each option for city consideration and review. If the city moves forward with detailed design and construction of the recommended renovation option, the project will include: retrofitting the facility effluent chamber with three submersible pumps to transmit up to 66 MGD, including installation of piping, equipment, electrical, instrumentation, monorail crane assembly, access road, structural modifications and reinforcement, and connections to existing facilities. The project will involve bypass pumping operations, minimal site disturbance, dewatering, testing, and facility coordination and staging.
