January 2012 Capital Investment - National Grid

Exhibit ___ (EIOP-19)Page 125 of 684Area DescriptionThe Northern transmission study area includes the 115kV transmission facilities in theNorthern Region and the northeast portion of the Mohawk Valley Region.The backbone of the 115kV Northern area system runs from National Grid ALCOAsubstation to Boonville substation. The major substations along the 115kV transmissioncorridor are Browns Falls, Colton, Dennison and Taylorville.The Jefferson/Lewis county area is bounded by the #5 – #6 Lighthouse Hill-Black River linesto the west and the #5 – #6 Boonville-Taylorville lines to the east. The Ogdensburg-Gouverneur area is served by the #7 Colton-Battle Hill, #8 Colton-McIntyre and the #13ALCOA-North Ogdensburg 115kV lines. The #1 – #2 Taylorville-Black River lines and the#3 Black River-Coffeen support the load in the Watertown area. The Thousand Islandregion is served by the #4 Coffeen-Thousand Island 115kV radial line. The Colton-Malone#3, Malone-Lake Colby #5, and Willis-Malone #1 (NYPA) 115kV lines serves the Tri Lakesregion. The Akwesasne #21 115kV Tap served from the Reynolds/GM #1 (NYPA) 115kVline supplies part of the Nicholville - Malone area.Within the Northern study area, there are four distribution study areas: Nicholville-Malone,St. Lawrence, Tri-Lakes and WLOF (Watertown, Lowville and Old Forge). The Nicholville -Malone study area serves approximately 18,500 customers. There are total of twenty sevenfeeders (twenty 4.8kV and seven 13.2kV feeders) in the study area. The distributionsubstations are primarily supplied from the 34.5kV system with exception of Malone 13.2kVand Akwesasne 4.8kV substations that are served by the 115kV system. The main suppliesfor the 34.5kV sub-transmission system are Akwesasne, Malone, and Nicholvillesubstations. It is operated as a radial system due to loading issues although the system isconstructed as a loop design. There are also two hydroelectric facilities connected to thesystemThe St. Lawrence area serves approximately 44,100 customers. There are twenty-six 4.8kVfeeders and thirty 13.2kV feeders in the study area. The distribution substations aresupplied from 23kV and 34.5kV sub-transmission lines with exception of four substations,Corning, Higley, North Gouverneur and Ogdensburg substations that are served from the115kV system. The main supplies for the 23kV sub-transmission system are Balmat, LittleRiver, McIntyre, Mine Rd. and Norfolk substations. Brown Falls substation is the mainsupply for the 34.5kV sub-transmission system.The Tri Lakes area serves approximately 11,300 customers. There are twenty nine 4.8kV,two 2.4kV feeders and six 13.2kV feeders in the study area. Most of the distributionsubstations are supplied from the 46kV sub-transmission system with the exception of LakeColby and Ray Brook substations that are served from the 115kV system. The supply for46kV sub-transmission system in the area is Lake Colby substation. There are twomunicipal electric companies supplied via the 46kV sub-transmission in the Tri-Lakes area,Lake Placid and Tupper Lake.The WLOF area serves approximately 81,300 customers with a peak load of 253MW. Thestudy area has thirty six 4.8kV feeders and thirty nine 13.2kV feeders. The distributionsubstations are primarily supplied from the 23kV and 46kV sub-transmission system with theexception of a few substations that are served from the 115kV system. The main sources tothe 23kV sub-transmission system are Black River, Coffeen, Indian River, North CarthageV - 11126