Infiltration and Inflow Program

2013: An Infiltration and Inflow Study was conducted to identify areas of the District’s interceptors that would need further investigation and repair. The study modeled flow through the interceptors, groundwater elevations and rainfall data during the spring and summer months (wet and dry periods).

2015: A manhole inspection program was performed on 35 manholes along the Charles River Interceptor and six manholes along the Shepards Brook interceptor. Based on the results of the manhole inspection program, it was recommended that 32 manholes be rehabilitated.

2016: Closed-circuit television (CCTV) and multi-sensor (MSI) inspections were performed for the Charles River Interceptor subsystem, which included about 11,000 feet of the Charles River Interceptor and about 2,000 feet of the Shepards Brook Interceptor. Three sewer reaches had visible infiltration and it was recommended that five joints be sealed.

2019: 32 manholes were rehabilitated and five joints were sealed in the Charles River Interceptor subarea.

2020: 98 manholes were inspected and CCTV and MSI inspections were performed on 28,400 linear feet in the Mine Brook Interceptor (MBI) Subsystem.

2022: A portion of the interceptor near Elm Street in Franklin, MA was rehabilitated by installing cured-in-place-pipe (CIPP). The 350 feet length of pipe was deteriorated and the CIPP lining restored the structural integrity of the pipe. Additionally, the two adjacent manholes were cementitious lined.

2023: Inspection work will begin in the Shepards Brook and Black Swamp Interceptors (SBI and BSI) by locating the manholes. Please refer the these maps for the location of the pipeline: SBI Map and BSI Map. Also, 14 joints are planned to be grouted in the MBI Subsystem to stop infiltration from entering the sewer system.