Manchester Part Of Eversource Project Designed To Thwart Flying Manhole Covers

MANCHESTER, CT — Eversource Energy is installing specialized manhole covers in Connecticut communities, including Manchester, as part of a long-term effort to prevent heavy covers from being propelled into the air when pressure builds up in underground electrical systems.

The utility has installed about 325 energy-release manhole covers across the state since 2024, including in Manchester, and plans to replace approximately 8,000 additional covers over the next 10 years.

The upgraded covers are designed to release built-up pressure safely while remaining attached to their frames, reducing potential hazards for pedestrians and others nearby.

"Every energy-release cover that's installed makes the system and surrounding area safer," Eversource President of Connecticut Electric Operations Don Scacco said.

The company is prioritizing installations in areas with heavy pedestrian traffic, including outdoor dining spaces and busy downtown districts, Scacco said.

The covers use a swivel-lock latch that prevents them from becoming completely dislodged. When pressure builds underground, a cover can lift about 4 inches to release the pressure before falling back into place. The covers can still be opened normally when crews need access to underground equipment.

Connecticut has more than 6,800 miles of underground electric lines operated by Eversource. Although underground systems are protected from hazards such as falling trees, they can be affected by extreme temperatures, moisture, vibration and freeze-thaw cycles.

Equipment malfunctions and cable failures also can cause pressure to build up. Corrosion, which can be accelerated by road salt used during winter weather, is another potential factor.

Eversource said it monitors underground infrastructure through maintenance inspections, atmospheric sensors that provide real-time alerts from manholes and specialized vehicles that scan the system for potential hazards.

In addition to Manchester, the company has installed energy-release covers in Hartford, West Hartford, Bloomfield, Waterbury, Stamford, Norwalk, Greenwich, Torrington and Meriden. Another cover is being installed in East Hartford.

The company said the upgrades are part of its ongoing efforts to improve electrical system safety and reliability while reducing risks to the public.