Project Schematics and Pipeline Interiors (PDF)

The sewer and chamber convey wastewater not only from West Roxbury but also from Ashland, Framingham, Natick, Wellesley, Needham, Dedham, Newton, and Brookline to the High Level Sewer in Hyde Park. Once in the

High Level Sewer, wastewater flows via Nut Island to Deer Island for treatment prior to discharge into Massachusetts Bay.

PROJECT BACKGROUND

Inspection conducted in 1999 revealed significant pipeline corrosion (concrete and rebar) in the Wellesley Extension Relief Sewer and the New Haven Street Drop Chamber.

Corrosion was also found in portions of the West Roxbury Tunnel which connects to the New Haven Street Drop Chamber.

PROJECT OVERVIEW

Plan for Repair
In August 2000, JE/Sverdrup Civil, Inc. published its Preliminary Design Report outlining the initial approach for immediate pipeline and chamber repairs. The Wellesley Extension Relief Sewer Pipe will be rehabilitated through insertion of a structural pipe liner and the New Haven Street Drop Chamber repaired through open-cut excavation and reconstruction.

Design Consultants
In April 2000, JE/Sverdrup Civil Engineering, Inc. became an engineering consultant to MWRA for rehabilitation of about 1,000 feet of the Wellesley Extension Relief Sewer (Section 138) and the drop chamber at the west portal of the West Roxbury Tunnel at New Haven Street.

Easements
Temporary construction easements are required to facilitate the work. No permanent easements beyond those currently held are proposed. Temporary easements have been acquired from:

• Homeowners immediately adjacent to the New Haven Street Drop Chamber
• Owners of the McDonalds and Arby’s properties on VFW Parkway
• MBTA (license to enter)
• City of Boston

Odor Control
To minimize release of odors the following measures are included in the construction contract:

• Treatment of wastewater stream — Injection of oxidizing chemicals upstream of the work to prevent in-stream transformation of sulfates to sulfides, and then to hydrogen sulfide gas.
• Treatment of sewer air — Withdrawal of entrained air, which otherwise would exit the sewer system at the excavation, through installation of fans upstream of the work. Treatment of the air prior to discharge will be provided in the form of chemical and/or carbon-type scrubbers.
• Electronic monitoring devices — Devices will be located on New Haven Street. The equipment will monitor odors within a defined are of the New Haven Street Drop Chamber. Equipment will be strategically placed on New Haven Street to monitor odors within a defined radius of the construction site.
  

CONTACTS

Jeff McLaughlin, Public Affairs: 617-788-1170