Niagara Mohawk Power d/b/a National Grid, in a Part 102 Report filed with New York state regulators on Feb. 2, proposed to conduct a maintenance project on the Browns Falls–Taylorville #3&4 115-kV transmission lines, which run concurrently southeast of Route 3 and Route 812 through the Towns of Fine, Pitcairn, Diana and Croghan in St. Lawrence and Lewis counties in New York.
The refurbishment project is necessary to provide system reliability to the electric utility end users, as well as provide for public safety in areas where structures are damaged or deteriorated and are in need of maintenance, and structure replacement or other methods are used to mitigate substandard clearances, the company said.
The scope of the project involves:
- Replacing shieldwire along the entire length of the line
- Replacing 12 structures
- Installing one intermediate structure
- Replacing steel bracing members on 19 steel lattice structures
- Replacing insulators, hardware, grounding, conductor attachment plates, and hanger members on 135 steel flex structures
- Replacing insulators, hardware and grounding on 44 strain structures
- Replacing guys and anchors – about 114 guys and anchors – at 61 structures
The company also said that no additional rights of way (ROWs) are required for the project, the existing or replacement structures will not carry more than two circuits, and no substantial modification will be made to existing vegetative cover within the project corridor.
The Browns Falls–Taylorville Line, as the project is referred, runs for 26.6 miles from the Browns Falls substation in Fine, N.Y., to the Taylorville substation in Croghan, N.Y.
The company added that the project is located in a fairly remote, undeveloped and sparsely populated portion of the state and is partially within the Adirondack Park. The land use in the vicinity of the line from the Taylorville substation north to the intersection of Jerden Falls Road and Foster Road is forested, both privately and publicly owned. The company also noted that land use is primarily rural, with scattered residences, active agriculture, small dairy operations and hobby farms.
North and east of Foster Road, the terrain is more mountainous with exposed bedrock in the ROW, the company said, adding that residences become more scattered, less dense and primitive cabins are more common. There is no agricultural use in that area, and the predominant land use is forestland. National Grid added that the existing transmission ROW crosses the Frank E. Jadwin Memorial State Forest between Structures 40 and 86, in Croghan and Diana Townships, Lewis County.
The replacement structures would not result in a significant degradation of the scenic quality of the Adirondack Park, and the proposed overhead work through a “priority area” would not result in adverse environmental impacts, the company said.
The Browns Falls–Taylorville Line, including the structures to be replaced, was built in the 1920s. National Grid added that the line underwent a conductor clearance refurbishment project, which included the replacement of 21 steel flexible towers with wooden two-pole davit arm suspension structures and the installation of one new intermediate wooden single pole structure with horizontal post insulator. Four additional structures are known to have been replaced since the line was originally built, the company said.
The only work being done as part of the project that is subject to Part 102 requirements is the replacement of seven structures that require structure height increases of greater than 10 feet, and an increase in the number of structures on the ROW due to the installation of one intermediate structure.
The company added that the height of the replacement structures will be increased from about 74 feet to 77 feet above ground to new heights ranging from 83.5 feet to 102.5 feet above ground.
The company added that project construction is anticipated to begin next April, and the target date for project completion is December 2017.
Among other things, the company said that the preferred overhead option is expected to have a capital construction cost of about $27.8m, while construction of the proposed line as an underground line within the Adirondack Park would result in an estimated $131.4m increase in capital construction costs for the project.
National Grid is a subsidiary of National Grid plc.