Cookeville has completed an $11.7 million infrastructure project featuring a new pump station and a 1.5 million gallon storage tank to eliminate sewage overflows near Tennessee Tech.
Cookeville Water Quality Control Director Barry Turner said the Lee Avenue facility uses specialized sensors and a computer system to monitor water levels during heavy rain. Turner said the department utilized flow monitoring and system modeling to determine the necessary size of the concrete tank to capture potential overflows.
“What would have overflowed into the creek now will be pumped into a storage tank and then after the rain event it would bleed back into the sewer system,” Turner said.
Turner said the facility addresses a location that accounted for seven of the nine recorded sewage overflows in the city last year. The project includes a larger pump station and a secondary set of high capacity pumps designed to divert excess water that previously would have entered a nearby creek.
“We finally reached the point where we felt like we had to put a storage facility in to capture that and put it back into the system. We were making progress, but not fast enough to stop the overflows,” Turner said.
Turner said rainwater enters the sanitary sewer lines through various sources, including missing clean-out caps, cracked pipes, and connections like downspouts or floor drains. The department also encounters issues with aging infrastructure and accidental damage caused by directional boring through existing lines.
“So we’ll capture that overflow or what would have been an overflow and put it into the tank and then we’ll monitor the pump station, and I’m talking about the computer system that we’ve set up to control that will watch how much the water’s coming into the station,” Turner said. “And when it feels like it’s safe to start letting some flow in it’ll start gradually bringing some of that flow back into the pump station and drain the tank all the way down.”
Turner said the site features a backup generator to ensure the pumps remain operational if a major storm causes a localized power outage. While the system is designed to handle most significant rain events, Turner said extreme downpours could still potentially lead to overflows in the future.
“We hope we’ve got something that will greatly reduce those overflows,” Turner said. “Most of our overflows in the past year were from that station so we want to get it transported and get it treated.”
The department is currently working to purchase property for a second projected wet weather storage facility near Maple Avenue and Interstate 40. Turner said that future project is expected to cost more than $20 million and will likely be larger than the Tennessee Tech facility.