Nagog Pond Water Treatment Plant

  • Client

    Town of Concord

  • EP’s Role


The Town of Concord utilizes nine groundwater supply wells and the Nagog Pond surface water supply to customers in the Towns of Concord and Acton, MA. The Town has operated an ozone disinfection facility at Nagog Pond for over 20 years. Nagog Pond, which is located in the Towns of Acton and Littleton, MA, has been an active water supply source for over one hundred years, but has operated under a filtration avoidance waiver for the past twenty years.

The Town retained the services of Environmental Partners in 2012 to complete a master plan study of the Nagog Pond water supply, including a safe yield evaluation, rehabilitation of the intake facilities, a renewable energy feasibility study, and a pilot scale treatability study. The various studies were completed in 2012 and 2013.

Following the pilot program and investigation into treatment options, Environmental Partners completed essential planning and conceptual design engineering for a new 1.5 MGD water treatment plant with pre-oxidation, dissolved air floatation (DAF), ozone, and biologically activated carbon filtration, and chemical treatment, and was responsible for the extensive federal, state, and local permitting associated with the project. The design and permitting of the water treatment plant and its new 2,600 ft. HDPE intake pipe is scheduled to be completed in 2019.

In addition to the significant design and permitting responsibilities associated with the new treatment facility, Environmental Partners has provided on-going ozone system technical support services for the existing ozone disinfection facility since 2012. Technical support has included development of the procurement package for the supply of new ozone disinfection systems for the Town’s annual use from May to September until the new water treatment facility becomes operational, as well as design, permitting, and operations support for the seasonal ozone systems since 2016. The ozone system procurement also included selection of the ozone treatment system for integration into the design of the new treatment facility. The design of the 2019 seasonal ozone system was modified to include a liquid oxygen feed for the ozone generators and side-stream injection of ozone gas to the existing ozone contactor.

Key Team Members