The upgrade of the Medford Township Wastewater Treatment Plant was initiated in response to a decrease in discharge limits for Phosphorus in the Plant’s 2004 NJPDES Permit. The resulting evaluation of the 1.75 MGD capacity facility revealed numerous design shortcomings from an operational and maintenance perspective, and noted that older portions of the facility were nearing their design life and beginning to fail. This situation was causing significant compliance issues, as the facility lacked the required redundancy to allow units to be taken offline to facilitate repairs.
The ensuing upgrades consisted of five (5) separate improvement projects addressing all parts of the facility, focusing on features such as: redundancy, minimal operator oversight and maintainability. Each phase utilized funding from the NJDEP EIT loan program (including ARRA funding) and sought to maximize the re-use of existing equipment and facilities in order to maximize the Township’s return on their investment.
Today, the Upgraded Plant boasts:
- A full headworks providing: grinding, screening and grit removal
- An effective Flow Equalization System
- Three (3) RBC Treatment Trains:
- Each with Primary Clarification
- Five (5) shaft RBC Units
- Secondary Clarification – with integral flocculater to facilitate chemical treatment for phosphorus removal
- Tertiary Filters with Backwash Reclamation System
- Disinfection System – utilizing Sodium Hypochlorite and Sodium Bisulfite for dechlorination
- Sludge Treatment System – consisting of:
- A sludge Equalization Tank
- Two (2) Sludge Treatment Units – providing for Aerobic Sludge Digestion, Gravity Sludge Thickening and Aerated Sludge Holding
- A Supernatant Treatment System consisting of a Polishing Tank
Ancillary facilities also include a new Electrical Distribution System, SCADA Control System utilizing a fiber optic network, and centralized Plant Blower Systems. Separately, the Township also arranged for a power purchase agreement which provides for up to 85% of electrical requirements of the plant.
The upgrades were staged to permit the facility to maintain operation while the improvements were being implemented, requiring the design to constantly adapt based on the ongoing construction.
While the selected treatment system is not as “state of the art” as a Biological Nutrient Removal System utilizing variants of the Activated Sludge System, the system design provides the required level of treatment with a more traditional approach. This approach utilizes a combination of conventional, fixed-film RBC system and chemical addition to provide a very resilient operation without constant Operator technical and analytical oversight and adjustment. The Operators essentially only have to keep the equipment running, and the system does the rest.