Waste Water Treatment Plant
The City of Elizabethton’s award winning Waste Water Treatment Plant first began operation in 1958. Since that time it has undergone several expansions to keep up with the City’s growth. Upgrades were completed in 1968, 1998, and 2001. The most recent upgrade was just completed in May of 2015 and consisted of adding new headwork’s screening equipment, dewatering equipment, new aeration equipment, and a major pump station upgrade.
Our system consists of 3 major pump stations in the City’s collection system. One pump station collects all the flow from the East end of the City and the other two collect all the flow from the West end of the City.
At the WWTP, the waste stream first enters through 2 fine screens where most of the big solids are removed. The waste then proceeds to an aerated grit channel where the heavy solids and floatable solids are removed from the waste stream. From there we have the option of sending the waste stream to an equalization basin or to the oxidation ditch for biological processing. The equalization basin can hold up to 3.85 Million Gallons of excess (storm) flow, which is held there until it can be treated during normal flow time.
Currently, the plant holds a permit for 3.5 million gallons per day and is composed of 2 extended air oxidation ditches that hold 1.8 million gallons of activated sludge each.
The extended air oxidation ditch process is very efficient at removing Solids, biological oxidation demand, and ammonia from the waste stream. It is also very efficient at helping to reduce total nitrogen and phosphorus from the waste stream.
Solids are removed from the activated sludge process to a holding tank for dewatering and thickening before it is processed through 2 Centrifuges to approximately 22% solids. The solids are then hauled to the landfill for disposal.
All of the system’s process, equipment and pump stations are monitored through a supervisory control and data acquisition (SCADA) system, which alarms us of any problems that might arise.
For the past eight consecutive years, The City of Elizabethton wastewater plant has earned the Operator Excellence Award in the State of Tennessee. The award was given to our operations staff as a result of operational efficiency which resulted in no violations of our Discharge monitoring permit during each of those 12 month periods.
Plant tours of our wastewater treatment plant are available to school groups and others. We welcome the opportunity to serve our community by providing complete details for the process of wastewater treatment.