Lower Beacon Street Sewer Separation, Brookline, Mass.
Located on the Brookline/Boston town line, this project's primary objective was to separate sanitary flows from Brookline's 120-year-old combined brick sewer system by installing large diameter sewers to redirect the flows into the Massachusetts Water Resources Authority's (MWRA) regional interceptors and treatment facilities.
The existing combined sewer was then converted into a dedicated stormwater conduit discharging to the Charles River.
Contractors accomplished this separation by constructing three MWRA interceptors—one at the South Charles Relief Sewer (SCRS) and two at the Charles River Valley Low Level Sewer (CRVLLS); constructing a 57-in. sewer in Monmouth Street to divert flow from Brookline directly to the CRVLLS; constructing 18-in. and 48-in. sanitary sewers in Beacon Street to divert flow from Brookline to SCRS; converting Brookline's existing combined sewer to a dedicated drainage conduit; and converting the existing CSO regulator to a drainage outfall and decommissioning the existing regulator.
One judge called the sewer separation an "extremely complex project."
The difficult location of the project proved troublesome in many aspects, however. For example, pipeline designs and installations were difficult due to varying soil and groundwater conditions prevalent to the Back Bay areas of Boston, and constructing six large cast-in-place junction chambers while maintaining traffic and protecting public safety was no easy task.
But through a phased construction approach and interagency communi- cation and coordination, the project proved to be a success, with a recorded incident rate of only 0.07 per 1,000 man-hours worked.
Owner/Developer Town of Brookline, Mass.
General Contractor P. Gioioso & Sons Inc.
Lead Design Firm BETA Group Inc.
Funding Sources Massachusetts Water Resources Authority, Massachusetts Dept. of Environmental Protection
Design Survey Green International Affiliates Inc.
Geotechnical GZA GeoEnvironmental Inc.
GC Subcontractor Michels Corp.