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Seacoast Reliability Project

To help ensure that the New Hampshire Seacoast Region can continue to grow and thrive, Eversource completed the Seacoast Reliability Project, a new transmission line connecting two existing substations, on May 29, 2020. The Seacoast Reliability Project was one of several projects supporting the delivery of electric power required to strengthen the New Hampshire Seacoast Region's critical transmission system.

The project includes a new 115-kilovolt (kV) transmission line extending approximately 13 miles between substations in Madbury and Portsmouth, N.H., along with associated substation upgrades. 


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The new transmission line further improves the transmission system in the Seacoast area so that our customers will have reliable electric power to meet their current and growing energy needs. It also ensures that the area's electric grid conforms to national and regional reliability standards.

Eversource invested more than $123 million in this New Hampshire project designed to bolster the regional infrastructure. The project resulted in direct benefits for New Hampshire communities, residents and businesses ― including the enhanced system reliability for customers, the creation of local jobs and property tax payments to host communities.

New Hampshire Site Evaluation Committee

For an electric transmission line project, such as the Seacoast Reliability Project, the New Hampshire Site Evaluation Committee (SEC) Application Filing is part of the siting regulatory review process, as defined by the New Hampshire state statutes. On December 10, 2018, the SEC voted unanimously to approve the construction of the project. On January 31, 2019, the SEC issued its written order, reaffirming its oral approval. The committee’s approval followed a series of public information sessions and public hearings in Concord and in the communities that host the new 115-kV transmission line.

Click here for Post-Certificate Filings for the project, including reports for and from the Department of Environmental Services (NHDES).

Construction Status: 

Construction and the majority of restoration was completed in 2020. Additional restoration was performed this spring and at this time all restoration for the Project is now complete. Environmental monitoring will continue weekly through the summer of 2021.

Project Outreach

We are committed to being a good neighbor and keeping you informed about our work. Similar to the siting, construction and restoration phases of the project, we will continue working directly with the community to provide information about the ongoing monitoring and any remaining close-out work activities and to quickly answer any questions or concerns. 

COVID-19 Safety

Eversource is committed to delivering safe, reliable service to our customers. This commitment has taken on even more importance during these unsettled times. We continue to call on our employees and contractors to perform essential work in the field that maintains and improves the reliability of our networks and serves customers' best interests while also adapting our work practices to incorporate social distancing, proper protective equipment, heightened hygiene, and other best practices to protect their, and the public's, health to avoid the spread of coronavirus.

Eversource representatives will continue to abide by all COVID-19 safety guidelines, which include wearing personal protective equipment, following social distancing, enhanced sanitizing requirements and other federal and state health and safety guidelines.

Contact Us

For any questions or concerns about the Seacoast Reliability Project, please call us at 888-926-5334, email us at, or discuss directly with the Eversource Field Outreach Representative. We will make every effort to promptly respond to your questions or address your concerns.

In the unlikely event that we are unable to address your concerns to your satisfaction, a process has been developed by the New Hampshire Counsel for the Public and Eversource to provide more help with resolving issues. That process can be found here (see pages 212-218).