The Peak Wastewater Flow Improvements Project for the Paducah McCracken Joint Sewer Agency (JSA) in Paducah, Kentucky includes several projects being implemented to increase JSA’s ability to pump, store, and treat peak combined sewer flows. JSA operates the Paducah Wastewater Treatment Plant (WWTP) with a design biological treatment capacity of 9.0 million gallons per day (MGD) and a design peak hydraulic capacity of 17 MGD. A 102-inch reinforced concrete semi-elliptical sewer line constructed in 1922 conveys combined sewer to the Terrell Street Sewage Pumping Station (SPS) which transports flow to the WWTP. During rainfall events, the flow in the 102-inch sewer line can reach over 300 MGD, exceeding the capacity of the SPS and WWTP. To capture peak flow events, improvements including a 15 million gallon storage tank, combined sewer diversion structure and pumping station, and screening and disinfection facilities are being implemented as part of a Long-Term Control Plan by JSA.
A 15 million gallon prestressed concrete storage tank intended to store peak flows from the 102-inch sewer line was located on a property adjacent to the Terrell Street SPS. The subsurface and seismic conditions of the site required the installation of 399 Continuous Flight Auger Cast (CFA) Piles that were drilled approximately 95 feet into the ground. Site piping around the tank included two influent force main pipes, two effluent drain lines, and one overflow line. The project was constructed by Crom, LLC of Gainesville, Florida at a final construction cost of $6,705,000.00.
A combined sewer diversion structure and pumping station intended to screen and pump peak flows from the 102-inch sewer line is currently being constructed on the site of the 15 million gallon tank. A combination of gates are proposed to be lowered and raised as required during peak flow events to either divert flow from the cast-in-place diversion structure or to the cast in-place pumping station. Flow entering the pumping station is proposed to be screened by a multi-rake bar screen with 1 ½-inch openings with the screenings raked above the structure and discharged to an onsite container. Four submersible pumps specified to pump 20 MGD each at the peak design condition are proposed to transport sewer to either the 15 million gallon tank or future screening and disinfection facilities. The project is currently under construction by TyBe Company of Newbern, Tennessee at a current construction cost of $6,146,760.00 and a contract completion date of September 2022.
The future screening and disinfection facilities intend to provide treatment of up to 90 MGD of sewer during peak flow events from the diversion SPS, 15 million gallon tank overflow line, and the Harrison Street SPS. The concept of these facilities includes a headworks structure with a 96-inch Parshall Flume for flow monitoring and two 45 MGD fine screens with 1/4-inch openings. A disinfection contact tank and sedimentation tanks can be added to provide additional treatment processes as required. Effluent from these facilities is proposed to travel through a 72-inch pipe and discharge into the Ohio River.
Project Name: Peak Combined Sewer Flow Improvements Project for the Paducah McCracken Joint Sewer Agency
Utility Name and Location: Paducah McCracken Joint Sewer Agency, Paducah, Kentucky
Date of Completion: 2022