Kleinfelder was retained by the Town of Pepperell to evaluate the existing Pepperell Wastewater Treatment Plant (WWTP), constructed and placed into operation in the mid-1970s.
Many of the existing facilities, processes, and components of the WWTF were beyond their design life. Although the facility consistently met its National Pollutant Discharge Elimination System (NPDES) permit for major pollutant parameters, the equipment did not have the lifespan, capacity, or flexibility to meet future effluent limits for an expanded facility. The project also required a low capital and long-term lifecycle cost, while reusing much of the existing facility.
After an extensive study, Kleinfelder delivered a preliminary engineering report that identified several upgrades required for the facility to meet future wastewater needs, while providing consistent wastewater treatment to meet stringent NPDES limitations on its discharge. The study evaluated several treatment processes, including sequencing batch reactors, submerged membrane filtration, and extended aeration. Kleinfelder recommended the extended aeration process for its ability to meet existing permit limits and produce a high-quality effluent in the most cost-effective, reliable, and easy-to-operate manner.
The upgraded and expanded facility was successfully designed, permitted, and constructed within the Town’s limited budget. The facility is consistently meeting the permitted effluent limits, with the ability to increase flows from 0.7 to 1.1 million gallons per day to meet future wastewater capacity need. Furthermore, the WWTF won an Environmental Protection Agency Operation & Maintenance Award.