About this Project:
MWRA’s Dorchester Interceptor Sewer is approximately 6,500-linear feet and was constructed in 1895-1896 of brick. Recent internal inspections have revealed many structural and non-structural deficiencies in the 120-year-old sewer.
The Dorchester Interceptor conveys flows from MWRA’s Neponset Valley Sewer, as well as directly connected service areas in Boston and Milton, and discharges its flows to the BWSC owned and operated “BWSC Dorchester Interceptor” that carries flows to MWRA’s Columbus Park Headworks.
Internal inspections revealed that several segments of the MWRA Dorchester Interceptor had progressed from cracked to broken pipe since previous inspections. In addition, numerous areas of heavy root intrusion and light to heavy infiltration also exist (Manholes along the MWRA Dorchester Interceptor are mostly of brick construction with infiltration/inflow and deteriorating mortar issues. The Dorchester Interceptor is subject to high groundwater, and its rehabilitation will decrease the amount of infiltration from it into the BWSC Dorchester Interceptor.
Design and construction bidding services, performed by CDM Smith, are nearly complete and the construction contract is expected to be put out to bid in May 2019. Construction is estimated to take 18 months.