Village of Pawling Wastewater Treatment Plant

LaBella designed upgrades to the Village of Pawling’s wastewater treatment plant. The goal was to increase the permitted flow of the facility from 0.32 million gallons per day (MGD) to 0.75 MGD and add phosphorous removal, aerobic/anoxic digestion, and sludge dewatering.

Major challenges included phasing and coordination with existing treatment systems that must remain online during construction and odor control due to the plant’s location near a school. The site is also quite small and most of the new structures were constructed into the side of a hill, so the team was tasked with managing existing groundwater flows in a manner that worked during both the construction and operation phases of the project.

The process improvements included mechanical screening and grit removal, three Sequencing Batch Reactors (SBRs), tertiary filtration, ultraviolet disinfection, post-aeration, and rehabilitation of existing aerobic digesters. As an initial phase of construction, sludge dewatering via a belt filter press was implemented to eliminate costs associated with liquid sludge hauling.

In support of this work, LaBella performed State Pollutant Discharge Elimination System (SPDES) permitting tasks and assisted the Village in securing grants and zero-interest funding from the New York State Environmental Facilities Corporation (NYS EFC) through the Clean Water State Revolving Fund.

The project was successfully completed in 2020 and continues to meet the client’s overall goals of protecting the environment and local waterways, being electrically efficient, and sustaining anticipated population growth.