Sudbury to Hudson Transmission Reliability Project

Eversource will be constructing a new,115-kilovolt (kV) transmission line between Sudbury and Hudson, Mass. This upgrade is one of a group of projects designed to improve the reliability of the electric system serving the Greater Boston area, both today and in the future.

The new line will be constructed between the Eversource substation in Sudbury, and the Hudson Light and Power substation in Hudson.

The approved route includes 7.6 miles of underground line within an existing, inactive Massachusetts Bay Transportation Authority (MBTA) railroad corridor, passing through Sudbury, Marlborough, Stow and Hudson. The remaining 1.4 miles of line will be located under streets in Hudson.

Eversource is working closely with the Massachusetts Department of Conservation and Recreation (DCR) to co-locate compatible uses within the existing, inactive MBTA corridor. Eversource will conduct the civil work and bridge replacement to prepare the site, install the new transmission line and leave a compacted gravel sub-base to support the Massachusetts Central Rail Trail (MCRT). After the Eversource project is complete, DCR will pave their trail, install safe road crossings and complete final restoration of this publicly accessible shared-use path. This partnership and close coordination of projects has been designed to avoid and minimize impacts to environmental resource areas while leaving behind a key recreational asset.



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Project Facts (approved underground route):

  • Route length: 9 miles
  • Line location: Hudson, Marlborough, Stow and Sudbury, Mass.
  • Line voltage: 115,000-volt (115-kV) transmission line
  • Siting review: Massachusetts Energy Facilities Siting Board (EFSB)
  • Filed Environmental Notification Form for review under the Massachusetts Environmental Policy Act (MEPA): May 15, 2017
  • Received Certificate of the Secretary of Energy and Environmental Affairs on the Final Environmental Impact Report (FEIR): September 14, 2018
  • Filed Siting Petition with the EFSB: April 20, 2017
  • EFSB Public Hearings: May 25 and June 1, 2017
  • Received EFSB Approval: December 17, 2019

Estimated Timetable (subject to change):

  • Start of construction (pending all necessary approvals): Q3 2022
  • Projected in-service date: Q4 2023


The EFSB Petition Filing is part of the siting regulatory review process for an electric transmission line project. On December 17, 2019, Eversource received approval from the EFSB to construct the Sudbury to Hudson Reliability Project. The Massachusetts Supreme Judicial Court upheld the decision on June 25, 2021. 

The EFSB's docket is available for viewing in the organization’s file room. Eversource’s filing is docket number EFSB17-02.


On May 15, 2017, Eversource submitted an Environmental Notification Form (ENF) to the MEPA Office for review. On June 12, 2017, the MEPA Office held a public site tour and scoping session for the project.

On September 14, 2018, Eversource received the Certificate of the Secretary of Energy and Environmental Affairs on the Final Environmental Impact Report (FEIR) for the Sudbury - Hudson Transmission Reliability Project.

For more information on the MEPA process, please visit their website


We have engaged town officials, residents, businesses, community groups and other stakeholders through municipal briefings, public open houses and a variety of meetings – answering questions and listening to concerns about the project.

We will continue these outreach efforts as the project proceeds through the permitting process and then into the construction and restoration processes.

Community members are encouraged to join the email list where updates will be distributed during the construction phase of the project.  


For more information about the Sudbury to Hudson Transmission Reliability Project, send an email to or call 800-793-2202.