There is a battle underway beneath Boston Harbor. On one side is Harbor Electric Energy Co., a subsidiary of New England utility NStar (now known as Eversource Energy), and on the other side is the Massachusetts Water Resources Authority. They are battling over who should pay as much as $20 million to repair a construction job done 25 years ago.
At issue is whether an electric cable was laid to the proper depth below the harbor, an issue that has gained urgency with the approach of a $310-million project to dredge Boston’s ship channel to accommodate deep-draught ships.