Structures & Equipment
The current facility is permitted at a flow rate of 2.5 MGD and has the following treatment unit processes:
- Master pump station consisting of four 2000 gallons per minute submersible solids handling pumps. Prior to receiving the influent, all flow travels through open channel comminutor in order to reduce solids sizing.
- Rotating fine screen to remove materials greater than 0.060 inches or 1/16 inch.
- Aerated grit chamber to remove settable grit, along with grit pumps and a grit screw conveyor. All grit and solids are collected and disposed into the local landfill.
- Flow equalization basin to smooth out variations flow throughout the facility. Flows are then pumped to the next structure using 3 variable speed, vertical turbine solids-handling pumping units.
- Anoxic reactor basin where both pretreatment effluent and internal recycled flows are combined, mixed and then returned to the aeration basin for further processing. This basin is equipped with 2 slow speed mixers.
- Flow then travels by gravity to the aeration basin which is based on the "oxidation ditch" design using the horseshoe configuration. Aeration is achieved using two 100 HP variable speed slow speed surface aerators.
- Clarification is provided using 3 circular secondary clarifiers. This design includes a center feed with a perimeter effluent trough. At this
pointthe solids are settled and the clarified effluent flows to the filtration system. Solids are collected and removed using a Return Activated Sludge / Waste Activated Sludge (RAS / WAS) pumping station.
- The filter feed pump station is equipped with 3 solids handling submersible pumps and feed the clarified effluent to the filters.
- Filtration is provided using 2 cloth media discs filters rated at 2.5 MGD average daily flow (each).
Chlorination / disinfectionis accomplished using 4 channelized chlorine contact chambers.
- Flow is then directed into an effluent pump station structure prior to discharge. This structure provides multiple functions and is equipped with:
- An on-site
reuse / processpump that provides flow for wash down and other process requirements. A hydro pneumaticpressure tank provides for automatic system operation.
- 2 reject pumps for pumping sub-standard quality effluent to a 3.0mg ground storage "reject" tank.
- Further space is provided for future off-site reuse pumps.
- Post aeration and de-chlorination are provided by a "stair step" style cascade structure and the final effluent flows by gravity into the Blackwater River.
- After the flow process is split at the clarifier, settled solids or "sludge" is either returned for further mixing with raw sewage or wasted into digesters for further processing.
- Solids diverted to the aerobic digesters are aerated using floating, surface type, aerators. Biosolids are processed in order to meet the requirements of a "Class B" biosolids that are suitable for land application.
- Since the majority of the weight of sludge is water, a dewatering facility has been constructed where the sludge is dewatered using a "centrifuge" style system. The dewatered solids are then disposed of using contracted land application. As an alternate source, the City could dispose of the biosolids at the local landfill.
- In addition to the major structures and equipment outlined, the plant is equipped with offices, laboratory, electrical rooms, emergency standby power
andother related support facilities.
- The treatment facilities are operated, controlled, and monitored using a Supervisory Control And Data Acquisition (SCADA) system. This system allows for more efficient operation of the equipment while maintaining the highest reliability possible.