Connecticut Siting Council

D&M Staff Report: Section I, Revision I

Docket No. 217
Connecticut Light & Power Company
Development and Management Plan
Section I Revision 1– Trench work for a 345-kV High Pressure Fluid-Filled (HPFF) Transmission Line
Staff Report – June 23, 2004

On June 15, 2004, Connecticut Light Power Company (CL&P) submitted a Revised Development and Management (D&M) Plan for Section I – Trench work for a 345-kV High Pressure Fluid-Filled (HPFF) Transmission Line between transition sites located at Archers Lane in the Town of Redding and Norwalk Junction in Wilton, Connecticut.

The Revised D&M Plan reflects changes to text (grey highlight) pertaining to Department of Transportation (DOT) comments and Council conditions set forth on May 19, 2004. Most of the changes are not substantive except for the following:

    • CL&P will comply with the requirement of locating manholes outside the paved roadways wherever practical. In places where the DOT right-of-way is limited, such as Grist Mill Road in Norwalk, CL&P would need to place a vault within the paved roadway.
    • CL&P will comply with all DOT specifications that are technically feasible and consistent with construction, operation and maintenance of the transmission facility.
    • The HPFF pipes will be located within a 5-foot deep by 5-foot wide trench.
    • CL&P and its contractor will coordinate any proposed lane closures, detours, and hourly restrictions with applicable municipality.
    • The Norwalk River will be crossed twice, one via jack and bore method above a box culvert located in the vicinity of the intersection Routes 53 and 107 near the town boundary between Redding and Wilton (station 175 to 176) and the other via horizontal directional boring in the vicinity of Route 7 and School Street in Wilton (between stations 380 to 396).
    • Both the Norwalk River crossings would also cross beneath the existing railroad corridor.
    • Goetzen Brook located near Cannondale Road, in Wilton (station 355) will be crossed via jack and bore method.
    • CL&P’s contractor will work with the DOT to establish plating and patching requirements. Construction may proceed through the winter.
    • CL&P will utilize DOT approved fabricators for vaults.
    • CL&P will comply with applicable Department of Environmental Protection conditions and the Connecticut Guidelines for Erosion and Sediment Control prior, during and after construction activities near inland wetlands or water bodies.
    • CL&P has updated its Traffic Management Plan consistent with DOT comments.

An alignment map outlines the installation of 9.7 miles of a new underground 345-kV HPFF transmission line. The Norwalk River and Goetzen Brook crossings require adjustment to trench location.

The D&M Plan contains site details for the transition stations for change from overhead to underground transmission facilities. CL&P contends such site details for transition stations would be submitted in a D&M Plan, for Council action, at a later date.

Council staff recommends approval of Section I–Revision- for Trench work for a 345-kV High Pressure Fluid-Filled (HPFF) Transmission Line.