20-year Valve Replacement at the Deer Island Treatment Plant

The Massachusetts Water Resources Authority (MWRA) has begun the process at its Deer Island Treatment Plant (referred to as Deer Island) of replacing over 250 valves that are near the end of their useful life. MWRA awarded a $17 million contract to Carlin Construction Company of Connecticut to replace valves and piping throughout the Deer Island Treatment Plant. Many of these valves are critical isolation valves for the North Main Pump Station (NMPS), the largest pump station at Deer Island, requiring the isolation and draining of major wastewater conduits. MWRA and the MWRA’s design consultant, AECOM, determined that up to sixty-two (62) shutdowns of the NMPS would be necessary to complete this work. Hydraulic modeling and past experience indicated that during dry periods it would be possible to “store” the wastewater in the MWRA owned interceptors and community sewers during nighttime low-flow periods. Because twenty-six (26) communities discharge into the northern collection system (see figure 1), this work requires substantial planning and extensive communication with MWRA service communities. To date the project is 44% complete, and there have been no permit violations, environmental mishaps or wastewater service interruptions as a result of the work.