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Mystic - East Eagle - Chelsea Reliability Project

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

To address this issue, we are proposing a new 115/14-kilovolt (kV) substation in the East Eagle neighborhood of East Boston and two new 115-kV underground transmission lines to connect the new substation to existing substations in Everett and Chelsea.

We will also make minor improvements within the footprint of the existing Mystic Substation in Everett and the existing Chelsea Substation in Chelsea to support this project.

This project will improve the transmission system in the east Boston area so customers will have reliable electric power to meet their growing energy needs. It will also ensure that the area’s electric grid conforms to national and regional reliability standards.

Mystic - East Eagle - Chelsea Project Map 

Project Facts:

  • East Eagle Substation:  New substation on a property owned by Eversource on East Eagle Street in East Boston, Mass.
  • Transmission Lines:  The East Eagle - Mystic line in East Boston, Chelsea and Everett is 3.2 miles long. The East Eagle - Chelsea line in East Boston and Chelsea is 1.5 miles long.  The transmission lines are solid dielectric cables that will be installed underground in public ways in a duct bank and manhole system.  The East Eagle - Chelsea line will be built within an existing duct bank system in Chelsea; the East Eagle - Mystic Line requires installation of a new duct bank and manhole system.
  • Towns: East Boston, Chelsea and Everett, Mass.
  • Line Voltage: 115,000 volts (115-kV)
  • Siting Review By: Energy Facilities Siting Board and the Department of Public Utilities in Massachusetts

Estimated Timetable:

  • Public Comment Hearing conducted by the Energy Facilities Siting Board: July 29, 2015
  • Project Design and Engineering: Ongoing
  • Public Outreach and Consultation with Municipal Authorities: Ongoing
  • Permitting: Fourth Quarter 2014 through First Quarter 2018
  • Start of Construction:  To be determined (pending approval)
  • Projected In-Service Date:  To be determined

Contact Information

Keeping the lines of communication open is an important part of our work in your community.  For more information about the project send an email to or call 800-793-2202.