Hendersonville Wastewater Treatment Plant (WWTP)
The City’s current wastewater treatment plant was constructed and put into service in 2002. It replaced the original treatment facility, located on the opposite side of Balfour Road, which was constructed in the early 1960s. The old plant site was renovated for solids (process sludge or biosolids) handling, treatment and storage. The new treatment plant was the result of a comprehensive planning study used to develop the most logical and economical wastewater treatment facility required to meet stringent water quality requirements. The study area encompassed not only the corporate limits of the City, but also the central region of Henderson County including portions of the Town of Laurel Park, the Village of Flat Rock and Henderson County’s former Mud Creek Water and Sewer District.
It was projected in the City’s comprehensive plan that the City’s resident population may increase to approximately 21,000, a 38% increase from the 2009 population, by the year 2030 resulting in an increased demand for sewer service. The average daily design flow was projected, in the comprehensive planning study completed in the late 1990’s, to be 4.8 million gallons per day (MGD). The new facility was constructed with a capacity to treat 4.8-MGD, but can be expanded up to 12 MGD, which should serve our community well into the future. The daily average flow in 2016 was 3.08-MGD (3,140,000-gallon per day) or ~64% of existing treatment capacity.
The plant utilizes an activated sludge process to achieve an outstanding level of treatment. There are two aeration basins, each holding 2,400,000 gallons of wastewater, where the primary treatment occurs; the mixing of the wastewater and return activated sludge (RAS) with oxygen helps to support the biological treatment process. Sedimentation and flotation occurs in two 90-ft. diameter clarifiers. Effluent sand filters reduce the amount of solids in the treated wastewater (effluent); while disinfection is achieved by the use of ultraviolet (UV) light. All effluent from the plant flows through the disinfection channel before being discharged to Mud Creek.
Sludge removed from the bottoms of the two 90-foot diameter clarifiers is either recycled to the aeration basins or is removed (waste activated sludge – WAS) from the treatment process and is pumped into two thickeners where the wasted sludge is allowed to settle (dewatered). Once the sludge has settled in the thickeners, it is processed through one of two automated belt presses where the material is further dewatered to approximately 18% solids (82% water) and is stored for transporting and disposal off site.
The City’s current sewer service area includes the City of Hendersonville, portions of Laurel Park, the Village of Flat Rock and a portion of the central region (urban services area) of Henderson County. The total population served in the existing service area is approximately 21,000 with nearly 14,000 being residents of the City, through a total of approximately 9,800 sewer connections. Residents not connected to the City’s sewer system are located in the unsewered areas outside the City or have chosen to maintain their own private systems.
We welcome visitors and can arrange tours of the plant for groups, school classes and others interested in the wastewater treatment process.