The Boston Water and Sewer Commission’s (BWSC) Bulfinch Triangle Sewer Separation Project involves separating the combined sewer system in the Bulfinch Triangle Historic District. The purpose of this federal court ordered project is to reduce pollution levels in Boston Harbor by substantially decreasing the number and volume of Combined Sewer Overflows (CSOs) into the Charles River and Boston Harbor.

Combined sewers, found in many older cities, carry both sanitary sewage and stormwater in the same pipe. During heavy rainstorms, stormwater takes up the greater portion of space in the pipe and at times exceeds the capacity of the sewer system, which results in a discharge into a local body of water, known as a CSO or combined sewer overflow. The project CSO (BOS 049) currently discharges into the Charles River off the new Nashua Street Park. The Bulfinch Triangle Sewer Separation Project will help eliminate the existing combined sewer system in this area by establishing two separate systems – one for sanitary flow and one for stormwater flow.

When the project is complete, sanitary sewers will carry sewage flows to the Massachusetts Water Resources Authority’s (MWRA) Deer Island Wastewater Treatment Plant, and storm drains will discharge stormwater into the Charles River. The project will reduce the number of CSOs, limiting the harmful effects of pollution from CSOs to Boston Harbor during heavy rainstorms. In addition, less stormwater will be sent to the MWRA’s plant for treatment.

Community Relations

BWSC is committed to a proactive community relations program. The program is designed to keep residents, businesses and officials informed about the project by holding public meetings, listing details of the project on BWSC’s website, locating a field office within the project area, and meeting with community groups and officials, as requested. In addition, before construction begins on a street, a notice will be mailed or posted announcing the work to be performed. Any questions may be directed to Thomas Bagley, Deputy Director of Communications, at 617-989-7000.

Sewer separation is accomplished by installing new storm drains in the street and converting existing combined sewers into sanitary sewers. If existing water mains or sewers are found to be in need of repair or replacement, this work will be performed concurrently to reduce the need for future construction in the area once sewer separation is complete.

Project design began in September 2006. Preliminary design was completed in summer 2007, and final design will be completed in December 2007. Construction of the court ordered project will begin in March 2008 and be completed in September 2009.

Project Area

The Bulfinch Triangle Sewer Separation Project area is generally bounded by Causeway Street, Merrimac Street, Market Street and Canal Street. Construction will take place on Canal Street, Causeway Street, Friend Street, Lancaster Street, Merrimac Street, Portland Street, Market Street, and Valenti Way. Land use in the project area is characterized by multi-story mixed residential and commercial buildings. The area is a vibrant business district and includes the TD BankNorth Garden, an important regional sports and entertainment venue. The area is home to many architecturally and historically significant buildings and it is listed on the National Register of Historic Places.

With the removal of the elevated Central Artery and MBTA Green Line, the Bulfinch Triangle Historic District is experiencing a renaissance. The City, residents and businesses in the area are working to make the Triangle a vibrant retail, office, residential and entertainment district. BWSC is committed to working closely with the Mayor’s Office, Boston Redevelopment Authority, Boston Public Works Department, Boston Transportation Department and others to ensure the successful completion of this project, while facilitating redevelopment by ensuring the presence of an adequate infrastructure and mitigating construction impacts.

The Bulfinch Triangle Sewer Separation Project is mandated by a federal court order as part of the Boston Harbor Project. Because BWSC has extensive experience in managing sewer separation projects and is well equipped to complete these projects, MWRA asked BWSC to implement the separation project.

Under the provisions of the agreement between MWRA and BWSC, MWRA will be responsible for eligible construction costs. The remainder will be funded by BWSC through its Capital Improvement Program (CIP) for additional water and sewer system improvements being completed concurrently with this project.