CONCORD — The Conservation Law Foundation has filed a lawsuit in attempt to prevent Eversource from installing a 13-mile-long power line that would run beneath part of Great Bay Estuary.

State regulators approve $84M transmission line project
Opponents of Seacoast transmission line project don't rule out court fight

The lawsuit filed last week in U.S. District Court in Concord contends that the project would violate federal environmental regulations, including the Clean Water Act.

The Seacoast Reliability Project would run transmission lines passing through Madbury, Durham, Newington and Portsmouth. Part of the plan calls for installing an underwater line along a 1-mile stretch of Little Bay, which the CLF contends would cause damage to the estuary and surrounding wetlands.

The lawsuit is the latest effort to block the project, which received approval in December from the Site Evaluation Committee. Work on the project is already underway. An appeal the CLF filed with the New Hampshire Supreme Court is pending.

In the federal lawsuit, the CLF said the U.S. Army Corps of Engineers improperly granted a permit to allow work on the project to begin. The CLF said the Corps relied heavily on Eversource’s own analysis and failed to evaluate viable alternatives brought up in public comments.

The lawsuit names Eversource, the Corps and several of the Corps’ administrators as defendants.

Eversource spokesman William Hinkle said the utility worked closely with the Army Corps of Engineers to ensure the project and its potential impacts were properly vetted.

“We share the Corps’ position that the appropriate steps were taken in issuing this permit and that it was legally done so within existing regulations,” Hinkle said.

“This project is imperative to providing Seacoast residents and businesses with the power they depend on, and we will continue to work closely with our host communities to make this critical reliability project a reality for the benefit of all residents and businesses in the Seacoast region.”