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Mystic to Woburn Line Project

To improve reliability and address growing need for electricity identified by ISO-NE, New England’s power grid manager, Eversource is constructing the Mystic to Woburn Line Project.

At Eversource, we're always working to serve you better. The project includes a new 115-kilovolt (kV) underground transmission line that will connect the Mystic Substation in Everett, Mass., and the Woburn Substation. The line will extend approximately 8 miles between the two substations and will pass through Everett, Boston (Charlestown), Somerville, Medford, Winchester, and Woburn.

The project also includes improvements within the existing fence lines of the Woburn and Mystic Substations. Information about the project is also available in Spanish, Portuguese and Haitian Creole.

Map of the project route

Project Facts:

  • Route length: Approximately 8 miles
  • Towns: Everett, Boston (Charlestown), Somerville, Medford, Winchester, and Woburn, Mass.
  • Line voltage: 115,000-volt (115-kV) underground transmission line
  • Siting review by: Energy Facilities Siting Board (EFSB)
  • File Environmental Notification Form for review under the Massachusetts Environmental Policy Act (MEPA): April 30, 2015
  • File Siting Petition with the EFSB: May 20, 2015
  • Petition approval by the EFSB: March 9, 2017
  • Start of construction: July 2017

Estimated Timetable (subject to change):

  • Estimated in-service date: 2020

Energy Facilities Siting Board

For an electric transmission line project, such as the Mystic to Woburn Line Project, the Massachusetts Energy Facilities Siting Board (EFSB) Petition Filing is part of the siting regulatory view process, as defined by Massachusetts state statutes. On March 9, 2017, Eversource received approval from the EFSB to construct the Mystic to Woburn Line Project.

Traffic Management Plans

Working in consultation with town and state officials, including the Mass. Department of Transportation, Eversource has developed a Traffic Management Plan (TMP) for each section of the Mystic-Woburn Line Project.

The TMPs include conditions specific to routing by the EFSB in its decision, a detailed site plan showing underground line location, hours of construction, area-specific traffic controls and more.

Some of the TMPs below are large in size and might take some time to load or download.

Please note, TMPs are subject to change and may be updated often.

Construction Updates

Eversource is committed to updating neighbors, businesses and all community members about project activities, especially during construction.

The sections below feature construction updates for each town. Please note that the project work is not expected to interrupt electric service to homes or businesses.

Construction within public roadways around Sullivan Square will begin in 2020 after we receive all necessary permits.

Mystic Substation - Construction started at the Mystic Substation on Alford Street in late July 2017. All construction activities are within the fence at the substation. No substation expansion is planned. 

Mystic Substation - Construction started at the Mystic Substation on Alford Street in late July 2017. All construction activities are within the fence at the substation. No substation expansion is planned.


IMPORTANT: Street Closure and Detour Advisory

  • Between Monday, November 18, and Wednesday, November 20, South Street between Winthrop Street and Walnut Street will be open to residents only.
  • Beginning at 6 a.m. on Thursday, November 21, South Street will be completely closed to all traffic between Curtis Street and Walnut Street.
  • Residents whose driveways are along South Street are advised to move their cars the evening of Wednesday, November 20. Access to driveways on South Street will be restored Thursday evening, November 21.
  • On-street parking is available on the following streets:
    • Maple Avenue
    • Touro Avenue
    • Manning Street
    • Walnut Street
    • Curtis Street
    • West Street
  • Additional parking is also available at the Condon Shell parking lot on Mystic Valley Parkway.
  • A pedestrian detour around the work zone will be necessary for the duration of the work.
  • Eversource will use local police when needed to assist with traffic management.

The existing, temporary traffic/work setup is currently in place on South Street to support work associated with a horizontal directional drill (HDD) operation under the Mystic River. HDD is a method for installing underground pipe without digging trenches. This work will be expanded on Wednesday, November 20. Eversource expects to complete this work late in the evening on Thursday, November 21, and South Street will be re-opened to all traffic by the morning of Friday, November 22.

Crews will soon complete pipe installation on Mystic Avenue between Harvard Street and Crescent Street. The pipe within the trenches at these locations will contain the new transmission cable. Once installation is complete, the area will be backfilled and patched until final restoration. This work is expected to be completed the week of November 18.

Crews removed a temporary work zone on Winthrop Street between Exeter Street and Brooks Street. The pedestrian detour is no longer necessary and the sidewalk has been restored.

Eversource thanks Medford residents for their patience over the past two months as crews completed excavation, pipe and vault installation activities at these locations.

Parking restrictions will be necessary at various locations along the project route and will be posted in advance.

Construction hours in Medford will begin after 7 a.m. and will finish on or before 4 p.m., Monday through Friday, except in the following areas:

  • On Winthrop Street between Lawrence Road and the Mystic Valley Parkway, work hours will be 9 a.m. to 4 p.m., Monday through Friday.
  • On Mystic Avenue between Harvard Street and Crescent Street, work hours will be 9 a.m. to 3 p.m., Monday through Friday.

In November, crews will install an underground concrete vault on Mystic Avenue near the corner of Mystic Avenue and Grand Union Boulevard. The vault is not located within a travel lane on Mystic Avenue, but an alternate traffic pattern around the work zone will be necessary during construction. These vaults give workers access to underground electrical cables and connections.  


Crews recently installed an underground concrete vault on Woodside Road between Wildwood Street and Pond Street.

Crews recently completed cleaning and lining the Massachusetts Water Resources Authority (MWRA) sewer pipes around the MBTA Wedgemere Station on Bacon Street. Initial restoration of areas disturbed by the project is ongoing, with full restoration scheduled for the spring.

No additional construction activity within the public right of way is anticipated until the spring of 2020.

Construction is ongoing at the Woburn Substation on Pond Street. Currently, all construction activities are inside the fence at the substation.


Before starting construction in a community, we will mail start of construction letters to property owners along the route and conduct door-to-door outreach to nearby property owners, residents and local businesses. 


For more information about the Mystic to Woburn Line Project, send an email to or call 800-793-2202.