A wastewater plant staff member said Smyrna recently completed an expansion that raised the towns wastewater treatment capacity from about 5,850,000 gallons per day to 9,000,000 gallons per day and cost about $35 million, financed with State Revolving Fund loans.

The upgrade added advanced biological treatment and a five-stage Bridal Flow system for nutrient removal to help the plant meet increasingly stringent state requirements and to protect the receiving creek, the staff member said. The expansion also added new mechanical and control systems intended to improve effluent quality and operator safety.

"We recently completed the expansion of the plant. We were at 5,850,000 gallons a day and went to 9,000,000 gallons a day," the wastewater plant staff member said. "This is the largest single financial project that the town has ever completed. Came in somewhere in the neighborhood of $35,000,000. We were able to secure, state revolving fund loans, which are low interest rates loans for the project."

Officials described work across the plants process train. In the preliminary phase, crews added two bar screens and bar screen racks and installed three new raw pumps to move flow into the biological treatment process. The biological phase was upgraded with dissolved oxygen (DO) probes, oxidation-reduction potential (ORP) probes and new motors; staff said that configuration provided a 6,000,000-gallon operational capacity for that phase. An additional aeration upgrade using a Barton 4 system increased capacity by about 3,000,000 gallons, producing the 9,000,000-gallon daily capacity the plant can now handle.

Clarifiers, disc filters and a larger ultraviolet disinfection channel were also added. Staff said the UV channel capacity was increased from 1,500,000 to 3,000,000 gallons to provide better disinfection at higher flows, and the disc filters improved effluent quality and helped reduce total suspended solids and phosphorus.

The project also introduced a new SuperControl data acquisition system for process control, monitoring and analysis. "We're very pleased. Judy Construction did the project for us. They did an outstanding job," the staff member said, and thanked the town manager, mayor and council for approving and supporting the project.

The staff member said the upgrades will allow future commercial and residential connections without exceeding plant capacity and will help the town meet current and anticipated state effluent requirements.

No formal vote or other council action was recorded in the provided transcript excerpt; the staff member repeatedly thanked municipal leadership for approval and support during the project.