East Boston Branch Sewer Interceptor Microtunnel
Location: East Boston, Massachusetts
Contract Value: $62,095,217
Project Dates: August 2008 – March 2011
The East Boston Branch Sewer Relief contract involved the installation of 2.5 miles of new sewer interceptor primarily using micro-tunneling methods to reduce conflicts with heavily congested utilities and high traffic volumes along the East Boston streets.
The project included construction of 12 receiving shafts, 12 jacking shafts, and the rehabilitation by cured-in-place pipe lining of 230 lf of 12”, 675lf of 15” and 25lf of 24” clay pipe. Installation of new pipe by open cut excavation consisted of 780lf of 24”, 820lf of 36”, 415lf of 48” and 45lf of 66”. Installation of new pipe by micro-tunneling consisted of 2,660lf of 36”, 7,070lf of 48” and 1,035 of 66”. Also included was the installation of regulators with underflow baffles, a tide gate and structure, large junction chamber, the rehabilitation, modification and installation of manholes and catch basins, and relocation of local sewers and water mains.
Knowing that utility conflicts would be a critical and difficult issue, biweekly utility coordination meetings were held with NSTAR, NationalGrid, Comcast, Verizon, Massachusetts Bay Transit Authority (MBTA), and Boston Water and Sewer Commission (BWSC) to identify utility conflicts and plan mitigation on a case by case basis for each shaft location, and several shaft layout changes and additional utility relocations were made to address conflicts.
The work was also coordinated with the reconstruction of the Chelsea Street bridge by the Massachusetts Highway Department (MHD) and with construction by NationalGrid and ConocoPhillips in the area. At the start of the project, a series of public informational meetings, as well as meetings with the City of Boston Public Works Department, were held.
This project was selected by the North American Society of Trenchless Technology as the 2011 Project of the Year.