CSC: DO 302 Opinion

DOCKET NO. 302 – Northeast Utilities Service Company, on behalf of The Connecticut Light and Power Company (CL&P) application for a Certificate of Environmental Compatibility and Public Need for the construction, maintenance and operation of the proposed Killingly 2G Substation at 193 Tracy Road and 227-257 Park Road in the Towns of Killingly and Putnam, and the proposed connections to the existing #347 345-kV line and the existing #1607 and #1505 115-kV lines.








May 11, 2005


On November 29, 2004, the Connecticut Light and Power Company (CL&P) applied to the Connecticut Siting Council for a Certificate of Environmental Compatibility and Public Need (Certificate) for the construction, operation and maintenance of a new 345-kV/115-kV substation as well as the connections to the existing overhead #347 345-kV transmission line and the existing overhead #1607 and #1505 115-kV transmission lines at 193 Tracy Road, Killingly and 227-257 Park Road, Putnam. The proposed project would also require protection system and equipment upgrades to the following existing substations: Tracy, Lake Road, Sherman Road, Tunnel, and possibly Fry Brook, Brooklyn and Exeter; the installation of an additional 345-kV circuit breaker at the Card Street Substation; and the replacement of the existing lightning shield wires with fiber optic shield wires between the Lake Road, Killingly, and Tracy substations. The Council held a field review and public hearing on the proposed Killingly 2G Substation project on March 1, 2005.

The proposed substation would be located on a 33.2 acre CL&P property, a portion of which is in Killingly and the other portion in Putnam. The substation would be located in Killingly and the 1,200’ long access drive would extend to Park Road in Putnam. The substation would have dimensions of 400’ by 600’ and would be surrounded by a 7’ chain link fence with barbed wire.

The 345-kV portion of the proposed substation would include: two circuit breakers, three motor operated line and transformer disconnect switches, fifiten coupling capacitor voltage transformers, one line trap, six surge arresters, and three single phase 345-kV/115-kV autotransformers. The 115-kV portion of the substation would include: eight circuit breakers, four motor operated line and transformer disconnect switches, sixteen circuit breaker disconnect switches, one bypass switch, 27 coupling capacitor voltage transformers, two line traps, and 12 surge arresters. Both the 345-kV and the 115-kV portions of the substation would share a common control house that would be 70’ long by 30’ wide. The protection system and equipment upgrades to existing substations would take place within the existing fence lines of the respective substations.

The proposed substation would alleviate transmission capacity constraints and improve the electric system reliability in the eastern Connecticut service area. Without the proposed substation, CL&P’s analysis shows that many normal planning criteria contingencies would result in overloaded transmission lines and unacceptable low voltages, including the potential for voltage collapse. The major concern with the eastern Connecticut 115-kV transmission system is that it is not capable of transferring sufficient power from supply sources at the Montville and Card substations to the load pockets in the vicinity of and north of the Tunnel Substation. The proposed substation would alleviate these deficiencies by increasing transmission capacity at a point in the system that requires reinforcement in order to reliably serve future load requirements.

The Council is concerned about the significant amount of tree clearing required for the proposed project, as approximately 1,350 trees with a diameter at breast height of six inches or greater would have to be removed. However, despite the significant tree clearing, the visibility of the proposed substation from nearby residences is not expected to be significant due to the land topography and the existing trees that would remain.

The substation would have low level lighting for security purposes and to accommodate security cameras. Additional lighting capability would exist for emergency conditions. Given that the substation would be adjacent to the Staples distribution warehouse that is lit 24 hours a day, the substation is not expected to have significantly increased visbility at night due to its lighting.

The proposed transformers’ insulating oil would contain less than one part per million of polychlorinated biphenyls (PCBs). However, the proposed substation site is within a state-designated Preliminary Aquifer Protection Zone and is also classified by the Connecticut Department of Environmental Protection (DEP) as a GA groundwater area. The Council is concerned about possible contamination of groundwater due to accidental oil leakage from the transformers. However, each single phase transformer would have an oil sump capable of holding 110% of the transformer’s oil capacity.

The whip-poor-will (Caprimulgus vociferous), a species of special concen, occurs in the vicinity of the proposed substation site. However, its customary habitats, young mixed forest and palustrine forested wetland, would not be disturbed by the proposed project. The brown thrasher (Toxostoma rufum), another species of special concern, was found the proposed project area. Although development of the proposed substation would result in the displacement of some habitat favored by the brown thrasher, the amount of this habitat affected on the substation property would be approximately 16%. To further minimize the effects of the proposed project on both the whip-poor-will and the brown thrasher, the Council will order that all tree clearing occur outside of the breeding seasons of the brown thrasher and the whip-poor-will. (The breeding season of the whip-poor-will begins runs from approximately late May through July. The breeding season of the brown thrasher runs from approximately mid-April through August.)

No state or local scenic roads are in the vicinity of the proposed substation. No historic or cultural resources would be affected by the construction of the facility.

Sound levels generated by the proposed substation equipment at the site boundaries are expected to be below both the Class A residential zone standards (51 dBA nighttime and 61 dBA daytime) and the Class B commercial zone standards (66 dBA nighttime or daytime) allowed by the DEP.

Electric and magnetic fields (EMF) and their possible effects are a concern to both the Council and to citizens living in the vicinity of substations and electric transmission lines. The dominant source of EMFs before and after the activation of the Killingly 2G substation would be the existing 345-kV and 115-kV transmission lines. The nearest home to the proposed substation (approx. 1,100’ away) is at a distance such that the magnetic fields from the proposed substation (as well as the existing transmission lines) would be indistinguishable from typical home background levels. This is also true of the home closest to the existing 345-kV line. (That home is approximately 434’ from the center conductor.) The State of Connecticut has not established standards for exposure to electric and/or magnetic fields and there is no evidence for the Council to conclude that the proposed substation and transmission line connections would be hazardous to persons or property near the proposed facility. However, the Council will order that the proposed facility be brought into compliance with any future State or federal standard, should such a standard be adopted. Futhermore, CL&P shall use the same locations to perform electric and magnetic field measurements before and after construction and provide the results to the Council.

There are no wetland or watercourse areas located in the portion of the proposed substation property located in Killingly. However, limited site work would result in indirect wetland effects within 50’ of wetlands in Putnam during the construction of the access drive. Minor effects on an existing watercourse in Putnam would occur due to the extension of an existing culvert associated with the intermediate watercourse located beneath the proposed access drive.

Based on the record in this proceeding, the Council finds that the effects associated with the construction, operation and maintenance of the proposed Killingly 3G substation, connection to the existing transmission lines and associated equipment upgrades, including effects on the natural environment; ecological integrity and balance; forests and parks; scenic, historic, and recreational values, air and water purity; fish and wildlife; and public health and safety are not disproportionate either above or cumulatively with other effects when compared to need, are not in conflict with the policies of the State concerning such effects, and are not sufficient reason to deny the application.

Therefore, the Council will issue a Certificate for the construction, operation, and maintenance of the proposed Killingly 2G Substation and associated transmission line connections and equipment upgrades. To ensure that the facility is constructed as indicated in the plans, we will require a D&M plan. The Development and Management Plan would also include a final site plan depicting the location of all substation and interconnection equipment; provisions for storm water management and oil containment; and the placement of proper erosion and sediment controls installed in accordance with the Connecticut Guidelines for Soil Erosion and Sediment Control, as amended. The Council will also require provisions for EMF measurements and compliance with any future EMF standards promulgated by State or federal regulatory agencies.

Content Last Modified on 5/18/2005 11:27:42 AM