By Crystal Burns
Despite a wet winter that included the rainiest February on record, construction of a $10 million Sequencing Batch Reactor (SBR) wastewater treatment plant is well underway on North College Street in Trenton.
Scott Daniel, engineer and vice president of J.R. Wauford & Company, welcomed the city mayor and board members, Trenton Light & Water leaders, and a handful of subcontractors to the sixth progress meeting for the project last week. J.R. Wauford is the city’s engineering firm.
Construction is just over a third of the way into the 545-day contract that should be completed March 17, 2019.
The mechanical SBR plant works in batches, allowing a single basin to provide the functions of flow equalization, anoxic zone, aeration, and clarification (settling). The Trenton plant will have two basins. A typical cycle for the SBR plant consists of four phases: fill, react, settle, and decant.
Construction includes installation of new pumps in the existing influent pumping station, a new headworks with mechanically cleaned bar screen and grit removal system, a new two-basin SBR system, and a new chlorine contact chamber with effluent pumps. Engineers are repurposing the city’s existing lagoon cells as sludge digesters.
In recommending the SBR plant, J.R. Wauford & Company’s evaluation report noted that SBR technology would allow the city to meet its National Pollutant Discharge Elimination System (NPDES) permit. The permit program is authorized to state governments by the Environmental Protection Agency (EPA) to perform many permitting, administrative, and enforcement aspects of the program.
Trenton’s current wastewater treatment plant, a lagoon system, has failed to meet its permits, and the Tennessee Department of Environment and Conservation (TDEC) mandated that Trenton city officials solve the problems or face stiff penalties.
Daniel said the bulk of the project thus far has been the massive excavation to make room for the 2-basin SBR, which will hold roughly 1.7 million gallons of water. The new plant will be smaller and more efficient than the lagoons.
“You should see good progress with the weather fairing up,” Joe Smith, of Smith Contractors, said.
Daniel said the plant’s dewatering system has helped get crews back on the job quickly after rain delays because they don’t have to wait for conditions to dry out. Daniel also said the biggest risk for change orders, which can lead to the project going over budget, has passed since the gaping hole has been dug.
Daniel said there have been no safety issues and complimented the contractor and subcontractors.
“They run a good, tight ship,” he said.