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Mystic - East Eagle - Chelsea Reliability Project

Electric demand is growing in eastern Massachusetts. The area needs an additional substation and transmission capacity to support the reliable delivery of electric power to meet the region's current demand.

At Eversource, we're always working to serve you better. We are installing a new substation in the East Eagle neighborhood of East Boston, Massachusetts; and two, new, underground transmission lines to connect the new substation to existing substations in Everett and Chelsea.

We are also making minor improvements within the fenced area of the existing Mystic Substation on Broadway in Everett, and the existing Chelsea Substation on Willoughby Street in Chelsea.

The East Eagle - Mystic transmission line will be constructed under the streets in Chelsea and Everett, and connect to an existing duct bank connecting Chelsea and East Boston. (A duct bank is a group of tubes buried underground that is designed to house electric lines.) The East Eagle - Chelsea transmission line will be located within an existing duct bank and manhole system in East Boston and Chelsea.

Information about the project is also available in:


* Click to Enlarge

Substation site map - East Eagle St.

Project Facts:

  • East Eagle Substation:  New substation on East Eagle Street in East Boston, Mass.
  • Route length: Approximately 5 miles
  • Cities: Boston, Chelsea and Everett, Mass.
  • Line voltage: 115,000 volts (115-kV)
  • Siting review completed by: Energy Facilities Siting Board (EFSB) and the Department of Public Utilities (DPU) in Massachusetts
  • Energy Facilities Siting Board (EFSB) approval: December 1, 2017
  • File notice of Project Change Petition with the EFSB: November 15, 2018
  • Start of construction on transmission lines: Second Quarter 2018

Estimated Timetable:

  • Projected in-service date: Fourth Quarter 2019 for transmission line

Energy Facilities Siting Board (EFSB) Links/PDFs:

Construction Updates

First, please know that Eversource takes every safety precaution while working in local communities, and that all people working on the construction project carry identification. The project work will not interrupt electric service to homes or businesses.

Eversource is committed to updating neighbors, businesses, and all community members about project activities, especially during construction. Please keep in mind that the construction schedule may change due to weather or other unexpected circumstances.

Week of September 16, 2019:

  • Eversource crews will continue site cleanup at the parcel of land on the corner of Condor Street and East Eagle Street in East Boston. Click below for additional information delivered to residents' homes in a doorhanger card, including a description of the remediation, work hours and equipment being used for site cleanup.

Week of September 16, 2019:

  • Crews will be working on Willow Street, Marginal Street and Williams Street, digging trenches for conduits. Conduits are protective tubes for electrical lines.
  • We will also be working at the Chelsea Substation at the end of Willoughby Street, completing conduit work and installing new equipment. 

Week of September 16, 2019:

  • Eversource will be working on Beacham Street, digging trenches and installing conduit. Conduits are protective tubes for electric lines.

Community Outreach

Before starting construction in a community, we host public open houses to give local residents and business owners an opportunity to learn more about the project, and ask questions of our subject matter experts.

The East Boston Substation information session was held on February 5, 2019. Following the information session, the Energy Facilities Siting Board held a public comment hearing. 

Open houses were held in Chelsea on February 8 and June 14, 2018; and in Everett on February 27, 2018. As we begin construction in the local communities, 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. 

Traffic Management Plans

Working in consultation with town and state officials, including the Mass. Department of Transportation, Eversource has developed a set of Traffic Management Plans (TMPs) for each section of the Mystic - East Eagle - Chelsea Reliability Project.

The TMPs include conditions specific to routing as made by the EFSB in its final decision. The TMPs illustrate detailed site plans, showing underground line locations, hours of construction, area-specific traffic controls, and more.

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

Contact Information

For more information about the project, send an email to or call 800-793-2202.