Under a very tight schedule, Eversource Energy sought to obtain permits for reconstruction of lines accommodating delivery of increased power to the new Towantic Generating Station. The power line corridor traverses a salt marsh, freshwater wetlands, an ash landfill, numerous residential properties, and Federal Aviation Administration airspace. The transmission line upgrades (structure replacements and new conductors) encompass over 10 miles of existing Eversource right-of-way and 106 structure replacements. Under these complex conditions, GZA was tasked to plan structure locations that avoided or minimized impacts to the regulated areas.


GZA prepared federal and state permit documents including: US Army Corps of Engineers (USACE) Section 404/10 permits; CT Department of Energy and Environmental Protection (DEEP) Natural Diversity Data Base (NDDB) and Structures & Dredging permits; DEEP Stormwater Construction Permit and Stormwater Pollution Control Plan (SWPCP); Soil Management Plan; and a Petition for Declaratory Ruling for the Connecticut Siting Council (CSC). GZA also coordinated Phase 1 Archaeological Survey work.

GZA conducted presence/absence surveys for State Species of Special Concern plants located within a sensitive tidal marsh area owned and managed by DEEP. During construction, GZA performed weekly environmental monitoring and monthly turbidity monitoring for this and all other areas for Stormwater Permit compliance.

One of the new transmissions structures is in a former fly ash landfill area owned and managed by a third party; GZA prepared a comprehensive Soil Management Plan (SMP) that satisfied the property owner and DEEP. GZA’s efforts included soil testing and construction inspection, as well as site/civil design services for a road and staging area to access a structure on a steep cliff.


GZA’s extensive knowledge of the local, state and federal permitting process, its relationships with the regulators, and proactive development of solutions prior to application submission served Eversource well in being able to complete this challenging project on schedule.