The new Sequencing Batch Reactor (SBR) Wastewater Treatment Plant for Trenton Light and Water in Trenton, Tennessee was constructed to replace the existing Lagoon Treatment Plant which was unable to meet the requirements of the National Pollutant Discharge Elimination System (NPDES) permit. These violations led to an Agreed Order from Tennessee Department of Environment and Conservation (TDEC) for NPDES permit violations. The existing Wastewater Treatment Lagoons were constructed in the flood way of the North Fork Forked Deer River leaving a small site with constraints on all sides. The existing site constraints along with having to keep the lagoons in service during construction led the design to focus on the SBR technology for a smaller footprint. The new SBR Wastewater Treatment Plant is rated for a biological capacity of 1.6 million gallons per day (MGD) and a hydraulic capacity of 6.8 MGD. The influent is pumped up to a new headworks that was constructed and includes a ¼” multi-rack mechanically cleaned bar screen, vortex grit removal system, and parshall flume for influent flow measurement. The wastewater then flows by gravity to one of the two new SBR basins where it goes through the fill, aerated fill, react, and settle phases prior to being decanted to the chlorine contact chamber. During the fill phase, raw influent is mixed with the existing biomass in the basin with submersible mixers. Then, in the aerated fill, the mixers are turned off and air is injected into the basin through the full floor fine bubble diffuser system. This provides mixing as well as the needed oxygen for the biological process. During the react phase, the influent valve is closed and the aeration continues. At the end of the reaction phase, the aeration is stopped and the biomass settles leaving clear liquid at the top. Then, the top few feet or “batch” is decanted off to the chlorine contact chamber by gravity. At the chlorine contact chamber, hypochlorite is added for disinfection and the calcium thiosulfate is added for dechlorination. The final effluent is then pumped to the North Fork Forked Deer River by the new vertical turbine effluent pumps. The new SBR Wastewater Treatment Plant also included a new chemical feed building, blower/electrical building, a sludge dewatering facility and an addition on the existing administration building. The project was constructed by Smith Contractors, Inc. of Lawrenceburg, Kentucky at a cost of $8,888,000.
Project Name: Peak Wastewater Flow Improvements Project
Utility Name and Location: Jackson Energy Authority in Jackson, Tennessee
Key Personnel: W. Scott Daniel, P.E., J. Gregory Davenport, P.E, Stephen C. Lee, P.E., Robert S. Qualman, Jr., P.E., Dwight Phillips, Electrical Engineer
Construction Cost: $8,888,000
Date of Completion: 2019
Engineering Services: Planning, Detailed Design, Bidding and Award, Construction Administration, and Resident Observation