Sewer Separation Means and Methods as Applied in Boston, MA

The Boston Water and Sewer Commission has been implementing various combined sewer separation projects throughout the City of Boston in order to significantly reduce combined sewer overflow frequency and volume to Boston Harbor. Two of these project areas include the completed South Dorchester Bay area and the Reserved Channel area which is currently under final design. Both of these project areas include ultra urban, primarily residential, watersheds within the city that are currently being served by combined sewers with installations that date back to the late 1800's and early 1900's. The Reserved Channel Project area, located in South Boston, and the Dorchester Bay Project Area are approximately 365 acres and 2,700 acres respectively. The sewer interceptor systems currently serving these areas surcharge during wet weather events and the combined sewer overflows then need to be rerouted to outfall pipes that discharge to Boston Harbor. It is evident that early identification and removal of as much stormwater inflow as possible is a key part of the success of both sewer separation projects.