Mass DEP Gap III Grant Project: Fine Bubble Diffusers
Project Video Summary
Project Description
The Town of Montague operates the Clean Water Facility (CWF) as an extended aeration facility with two aeration basins for biological (secondary) treatment of wastewater. The CWF was originally constructed in 1962, with a secondary treatment addition in 1980.
The facility operates both aeration basins throughout the year, typically cycling each one on and off to maximize nitrification/denitrification. The original aeration blowers and coarse bubble diffusers were installed when a substantial portion of the facility’s wasteload consisted of paper mill pulp wastes and the higher blower horsepower and mixing capabilities of coarse bubble diffusers were needed. As the paper mills closed, the facility found that the higher horsepower blowers and coarse bubble diffusers were no longer necessary.
In 2020, the facility contracted with JK Muir and Wright-Pierce to evaluate potential energy saving projects, where they found that one of the highest returns on capital improvements for energy consumption was to update the aeration systems for both basins. In working with DEP, Montague was able to maximize the utilization of Gap grants to assist with funding the replacement of the aeration system, utilizing Gap II and Gap III funding for the aeration blowers and diffusers, respectively.
The Town of Montague engaged with Wright-Peirce to design the improvements which included replacing the three original blowers (one 100 HP and two 50 HP) with two 75 HP blowers and replacing the coarse bubble diffusers with fine bubble diffusers. It is important to mention that the CWF staff performed the majority of the site work and labor for installation in-house in order to save money on both projects.
The purpose for the Gap III grant application (this Final Report) was to act as Phase II of the Aeration System upgrade by updating the old coarse bubble diffusers to new fine bubble diffusers. Design phase on the project was completed in Fall 2023, construction phase work began in April 2025 and the project was completed in June 2025.
Project Summary
Project Images
Old coarse bubble diffusers
Newly installed fine bubble diffusers
Testing the fine bubble diffusers