The Massachusetts Siting Board will hold a public comment hearing on Oct. 22 on National Grid USA’s proposal to install two new 115-kV underground electric transmission cables in a new duct bank system extending from the Salem Harbor substation to the Canal Street substation in Salem, Mass.
For the first phase of the proposed cable replacement, New England Power (NEP) d/b/a National Grid would install the new “S Cable” and “T Cable” in the new duct bank system in a new transmission corridor underneath existing roadways, according to a notice of adjudication and public comment hearings. Then, the existing direct buried S Cable would be removed from its current location and the existing T Cable would be pulled from its duct bank. The replacement of the two separate 115-kV cables and the improvements at the two substations comprise the proposed project.
National Grid filed petitions on Sept. 20 with the state Energy Facilities Siting Board and the Department of Public Utilities (DPU) for approval to build, operate and maintain the two underground transmission lines replacing the company’s existing S-145 and T-146 115-kV underground electric transmission cables, together with related upgrades within the existing Salem Harbor and Canal Street substations, the notice added.
The existing cables have a history of leaking dielectric and are of an outmoded design, which is increasingly difficult to repair.
National Grid also filed a petition with the DPU for a determination that the upgrades within the existing Canal Street substation are “reasonably necessary for the convenience or welfare of the public” and that certain exemptions from the Salem Zoning Ordinance are warranted.
The notice further stated that the siting board will review the filing to determine whether the proposed project will provide a reliable energy supply with a minimum impact on the environment at the lowest possible cost.
The DPU will review the petition to determine whether the proposed project is necessary, serves the public convenience and is consistent with the public interest. The DPU will also consider whether the upgrades to the Canal Street substation are “reasonably necessary for the convenience or welfare of the public” such that the requested zoning exemption concerning a special permit for a new control house at the Canal Street substation is warranted.
National Grid has identified a preferred route for the proposed new transmission lines and a noticed alternative route.
A company spokesperson told TransmissionHub on Sept. 23 that the estimated cost of the preferred route is about $64m.
The preferred route is about 1.63 miles long and extends from the Salem Harbor substation along Fort Avenue and Webb Street, southwesterly on Essex Street, turns northwest to connect to Forrester Street, then continues west onto Forrester and Washington Square South, according to the notice. The route then turns south along Hawthorne Boulevard and Congress Street, west onto Leavitt Street, continues on Fairfield Street, north on Cabot Street, west on Cypress Street and then north on Canal Street to connect to the Canal Street substation, the notice added.
New switches, circuit breakers and other equipment will be installed at Salem Harbor substation. The substation fence line will be extended about 43 feet to the east to accommodate new overhead support structures for new transmission conductors, which will connect to the new underground cables.
The notice further stated that the modifications to the Canal Street substation include the installation of a new control house, new cable riser steel structures, cable termination structures, new surge arrestors, switches and other electrical equipment. In order to accommodate the new structures, existing slopes adjacent to the new structures will be regraded and an existing retaining wall will be replaced. The addition of the new control house to the Canal Street substation requires a special permit under the Salem Zoning Ordinance, according to the notice.
National Grid is a subsidiary of National Grid plc.