PORTLAND — The City of Portland's Back Cove South Storage Facility project is entering its next phase of work, which is to connect the existing utilities (new or replaced) within the intersection of Marginal Way and Franklin Street to the new storage tanks under the Preble Street playing fields. As a result, there will be an approximate eight week period of alternating closures to the on and off ramps of the I-295 Exit 7 (Franklin St) interchange beginning March 15.

The City will be placing variable message boards with the latest ramp closure information in the vicinity of the work. The ramp closures will vary during the eight week timeframe so motorists should pay attention to the message boards or make plans to seek alternate routes during this time.

This project is one of the City's latest sewer separation projects to prevent combined sewer overflows into Back Cove. The work to reduce overflows is part of the City's agreement with the U.S. EPA to reduce and eliminate the flow of combined waste being discharged. A combined sewer system transports wastewater from home, industries, and businesses, as well as storm water collected from streets, parking lots, roofs, and yards to the East End Wastewater Treatment Plant. A combined sewer overflow occurs when the combined sewer capacity is overwhelmed during heavy rain events and a mix of sewer and storm water is discharged into Back Cove.

The Department of Public Works has been coordinating with the prime contractor, Sargent Corporation, and the Maine Department of Transportation to put forth a sequencing and staging plan as part of a traffic control plan to minimize the impacts to the traveling public. MaineDOT has requested that all work be completed by Memorial Day, May 31, 2021.

Work Detail

Installation of approximately 750 feet of 72" Combined Sewer Overflow (CSO) pipe (to replace failing pipe), including the installation of new CSO structure, backflow prevention and outfall.
Installation of approximately 850 feet of 8x6 box culvert storm drain including new outfall with backflow prevention.
Installation of approximately 1,500 feet of 12-inch force main (to the intersection of Marginal Way and Diamond Street).
Associated work including staging, excavation, shoring, other underground utility installation (storm drainage and electrical), road reconstruction, sidewalk construction, fencing, guardrail, paving, striping and signage.

The project schedule and related graphics can be found on the City of Portland Public Works website.