South Berwick Substation

South Berwick Substation

Reliability Upgrades

South Berwick Substation

Project Overview

Central Maine Power Company (CMP), in conjunction with its parent company AVANGRID, is undertaking a multi-year effort to upgrade or replace 10 distribution substations throughout its service territory, including one in South Berwick, that have aged and/or have condition or capacity issues in need of attention.

As part of our commitment to provide safe, reliable service to all our customers, Central Maine Power Company (CMP) is constructing a new substation located off the gravel portion of Wadleigh Lane in South Berwick by replacing an existing, antiquated substation located at 6 Liberty Street in South Berwick.

CMP is working with communities and reaching out to neighbors to ensure that all improvements are performed safely and with minimal disruptions to their daily lives, the community, and the environment.

Project Purpose and Need

The existing electric distribution substation on Liberty Street is nearing capacity to support the 34.5V transmission load. Construction, includes a new, modern substation that will interconnect with an existing 34.5kV transmission line. The facility will be located on a portion of a 2.11- acre open field located at Wadleigh Lane equipment and will provide modern-day operation plus meet Avangrid and National Electrical Safety Code (NESC) standards.

The new substation will be outfitted with infrastructure that includes a 34.5/12kV transformer, line and trans-former breakers on foundations, switches, insulators, oil containment system, lightning masts, yard lights, and an overhead electrical bus. Improved substation operations technology will be installed in a new, locked control house, as well as enhanced remote substation monitoring capabilities and connections to CMP’s control center. A substation manager periodically will be on-site for routine maintenance and inspections.

Once the new substation is completed and on-line,  the existing substation will be demolished, and grass will be planted on the site. All components will be situated behind security fencing that will be monitored by CMP. For security reasons, the substation will be visible through the fence. Vegetation that does not block visibility will be planted to support a small wetland near the site and to beautify the property. CMP will access the property by a driveway from a 135-foot-wide by 269-foot-long access easement from the gravel portion of Wadleigh Lane. A gate will cross the portion of the drive leading to the substation.  The end of the asphalt pavement portion of Wadleigh Lane will be resurfaced with new asphalt pavement to accommodate a turning radius, and the gravel road portion will be resurfaced with gravel to a consistent width of 15-feet. The substation’s gravel driveway will be approximately 20 feet wide by 275 feet long.

Fact Sheet

  • Please call the Electrical Infrastructure Projects Information Line number below

Estimated Timetable

  • Construction Start: April 2021
  • Completion/In-Service Date: December 2021

For more information or questions

Please contact the Electrical Infrastructure Projects Information Line at 1-888-267-0831 and include the name of the project - South Berwick Substation - with your detailed message.  A representative from the project team will return your call within three (3) business days. Or please email us at

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