This $25 million sewer separation project was completed for the Town of Brookline, MA in conjunction with the Massachusetts Water Resource Authority’s (MWRA’s) Long-term CSO Control Plan as mandated by the Federal District Court. The project objective was to separate a 110-year-old large-diameter combined sewer system located in the highly congested, urbanized area of Beacon Street in Brookline, bordering the City of Boston.
New sanitary sewer work included:
- Microtunnel installation of 4,410 feet of 18-inch, 48-inch, and 57-inch sanitary sewer, including crossings beneath an above-ground branch of the Massachusetts Bay Transportation Authority’s (MBTA) mass transit system (Green Line)
- Open trench installation of 2,330 feet of 8-inch to 57-inch sanitary sewer
- Modifications to the existing regulator structure beneath Commonwealth Avenue in Boston
- Six (6) cast-in-place diversion structures
- Sanitary connection to existing 108-inch MWRA Charles River Relief Sewer Tunnel
- Two (2) sanitary connections to the existing 66-inch Charles River Valley Low-Level Sewer
- Rehabilitation of 1,340 linear feet of combined sewer via CIP lining for conversion to a sanitary sewer
New storm drainage work included:
- 11,660 feet of 12-inch to 42-inch storm drains
- Conversion of 4,450 feet of large-diameter combined sewer to a dedicated storm drain
- Conversion of existing CSO outfall to the Charles River to an active stormwater discharge
Special Challenges during design included major utility conflicts, excavation support/groundwater control, and traffic management. U.S. District Court Judge Richard G. Stearns was quoted as saying “The court cannot help but express its pleasure with the progress on all projects in the past quarter and especially the completion (ahead of schedule) by the Town of Brookline of its multi-year sewer separation project.”
In 2014, this project was designated by APWA National as a Project of the Year, receiving a Silver Award for Engineering Excellence from ACEC/MA. The project also received an Award of Merit as “Best 2014 Projects” by ENR-New England.