Brief Project Description
The existing Mt. Jackson WWTF is a parallel oxidation ditch process with a design flow of 0.2 MGD that is not designed for nutrient removal. The process consists of grit removal, parallel oxidation ditches followed by clarification, chlorination, dechlorination, and discharge to the North Fork of the Shenandoah River. The waste solids are aerobically digested and dried on sand beds before disposal.
Under the proposal submitted for nutrient removal cost share, the existing process will be replaced with enhanced nutrient removal (ENR) capability, and the plant will be expanded to a permitted design flow of 0.7 MGD. The proposed WWTF will consist of entirely new equipment. The influent pump station will be a submersible pump station with a 2.4 MGD capacity, a grinder, wet well, and building structure with a new entrance onto the State highway. The wastewater plant will consist of a bar screen, an aerated grit chamber, dual 367,000 gallon Sequencing Batch Reactors (SBRs), alum addition for phosphorus removal, tertiary filtration by cloth disk filters, postaeration by diffused air, and ultraviolet (UV) disinfection. A new 150,000 gallon aerobic digester and new 1,600 lb/day rotary filter press will comprise the solids dewatering system. Associated solids handling equipment such as pumps, conveyor, and building will also be constructed. The project will consist of the following:
- Installation of an influent pumping station, grit removal equipment, and mechanical screening
- Installation of two Sequencing Batch Reactors and combined equalization structure
- Installation of aerobic solids digestion and fan press dewatering
- Construction of a coagulant (alum) feed system for phosphorus removal
- Installation of cloth disk filters for tertiary filtration
- Installation of effluent postaeration
- Installation of non-potable water (NPW) system, UV disinfection process, and effluent flow monitoring and sampling
- Construction of a combined control building to house the control room, the solids dewatering equipment, the laboratory, the maintenance shop, and chemical feed facility