First surface water facility in the Northeast to adopt Mn contactor technology

Groton Water Treatment Plant

With a 1939-vintage water treatment plant serving 44,000 customers, Groton Utilities (GU) needed to upgrade its facility in Southeastern, Connecticut. Seeing an opportunity to innovate—GU called upon our experience in leading edge water treatment technologies, to exceed regulated standards for water quality. We first helped GU secure a $54,000,000 Drinking Water State Revolving Fund (DWSRF) grant – the largest in the program’s history. Then, we provided planning and design for upgrading the facility to the latest treatment technologies, including a novel approach to manganese removal.

We performed pilot studies using dissolved air flotation (DAF), followed by deep bed granular activated carbon (GAC) filtration, and second stage manganese (Mn) contactors. Our study demonstrated that these technologies would meet GU's forward-thinking treatment goals and go beyond the regulations. Following the pilot study, our team collaborated with GU to finalize the design of facility upgrades with improved safety, sustainability, and ease of operation.

Operating since April 2022, GU’s is the first surface water utility in the Northeast, and one of only a few in North America, to adopt the use of a second-stage manganese adsorptive contactor. Customers may not notice any change, but now they have a new water treatment facility providing safe and secure water for decades to come.