D&M Staff Report: Section II, Revision I
Docket No. 217
Connecticut Light & Power Company
Development and Management Plan
Section II Revision I – Trench work and transition poles for a 115-kV
Cross-link Polyethylene (XLPE) Cable
Staff Report – July 13, 2004
On June 18, 2004, Connecticut Light Power Company (CL&P) submitted a Revised Development and Management (D&M) Plan for Section II – Trench work for a 115-kV Cross-link Polyethylene (XLPE) Cable in the Towns of Bethel, Redding, Wilton, and Norwalk, Connecticut.
Alignment maps of the route (at a scale of 1" = 40’), outline the installation of new underground 115-kV XLPE cable within 0.6 miles of the existing right-of-way adjacent to the Bethel Education Park, 5.6 miles within State Route 58 in Bethel and State Route 107 and Gallows Hill Road in Redding, and 4 miles from Norwalk Junction in Wilton along State Route 7, Main Avenue and Broad Street to Norwalk Substation, Norwalk.
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:
- At the request of the Town of Bethel, CL&P proposes to place the underground cable mostly within the existing right-of-way east of the Bethel Educational Park.
- A riser pole location for one underground cable (station number 0) at Hoyts Hill Road has been shifted 30 feet north.
- 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. This location is for 115-kV XLPE cable.
- CL&P will comply with all DOT specifications that are technically feasible and consistent with construction, operation and maintenance of the transmission facility.
- The XLPE cable will be located within a 5-foot deep by 2-foot wide trench. In some locations the cable may lay side-by-side 5 feet wide with a minimum 24 inch cover.
- The Merritt Parkway will be crossed between stations 133 and 138 where Route 7 intersects Route 15 in Norwalk. The contractor may use jack and bore or horizaontal directional drill.
- A railroad crossing via jack and bore method will be between stations 179 and 182 along Broad Street, Norwalk.
- 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. Also, CL&P and its contractor will coordinate any proposed lane closures, detours, and hourly restrictions with the applicable municipality.
The D&M Plan also contains site details for the transition poles for change from overhead to underground transmission facilities. Transition poles are steel poles with arm attachments that will be 85 feet in height. One is required where the underground cable is brought aboveground and another pole for overhead conductors to transition underground. These would be located within the existing right-of-way.
Council staff recommends approval of Section II–Revision I- for Trench work and transition poles for a 115-kV Cross-link Polyethylene (XLPE) Cable Transmission Line.