Riverhead to Canal Second Cable Project

The Long Island Power Authority (LIPA) proposes to install a new 138 kilovolt (kV) transmission cable in an existing, underground conduit approximately 16 miles long previously installed in 2000, between LIPA’s existing Riverhead Substation, located south of the Peconic River and Canal Substation, located on New York State (NYS) Route 27 (0.4 miles east of Canal Road) in the Town of Southampton.

The proposed project is part of LIPA’s plan to reinforce the existing transmission capacity of the South and North Forks of Long Island. The electric transmission cable is subject to the licensing requirements of Article VII of the Public Service Law and must receive a Certificate of Environmental Compatibility and Public Need from the New York State Public Service Commission (PSC).

Description of Facility
LIPA’s proposed 16 mile long underground transmission cable consists of an underground three-phase transmission line. The project will consist of three cables, each approximately 16 miles of solid dielectric cable. Each cable will be constructed of 2500 kcm (1200 mm sq) copper conductor approximately 1.7 inches in diameter. A corrugated metallic sheath will surround the insulation to provide mechanical protection and prevent water migration into the cable. Overall diameter of each cable is approximately 5 inches. Each of the three cables will be installed within its own 8-inch high-density polyethylene (“HDPE”) conduit. The cable conduits are already in place and were installed in a trefoil (triangular) configuration. The Second Cable is a new circuit which is being added to a parallel, existing cable circuit previously approved by the PSC and installed in 2000 to support the energy needs of the region.

Proposed Route
From the Riverhead Substation located south of the Peconic River, southeast of the intersection of NYS Route 25 and Mill Road, the 16 mile installation route migrates east and south along LIPA’s Right-of-Way (“ROW”) for approximately 1.6 miles, between LIPA’s existing 69 kilovolt (“kV”) tower and wood pole lines on County Road 51 (Riverhead-Moriches Road), crossing County Road 94, Nugent Drive. The route crosses under the westbound lanes of County Road 51 and heads southwest along the northern segment of the median for approximately 0.8 miles to Speonk-Riverhead Road. The transmission line then turns south along the western shoulder of Speonk-Riverhead Road and NYS Route 27 for 2.4 miles. At the intersection of Speonk-Riverhead Road and NYS Route 27, the conduits were directionally drilled under Route 27 to its south side where they travel east along the southern side of the roadway. The conduits were installed approximately 30 feet south of the edge of the eastbound lanes for 11.2 miles to the Shinnecock Canal. Stainless steel conduits are attached to the underside of the Shinnecock Canal Route 27 Bridge, crossing the Canal. The route continues approximately 0.4 miles along Canal Road and onto the shoulder of the NYS Route 27 entrance ramp and enters the Canal Substation on the west side. The cable route terminates near the western fence line of the substation.

Alternate Routes
Various alternate routes as well as overhead and underground construction were considered and studied extensively when the First Cable was proposed, subsequently approved by the PSC and installed in 2000. In addition to the alternate routes evaluated for the First Cable, State Route 24 has been evaluated as an alternate route for the Second Cable. The use of an alternate route for this Second Cable would be undesirable from engineering, environmental, and economic perspectives.

Date of Article VII Filing
LIPA filed its Article VII application with the PSC on November 21, 2008. Copies of the application may be reviewed at the Riverhead Public Library, Westhampton Public Library, Quogue Library, Rogers Memorial Library, and the Hampton Bays Public Library.

Application to the NYS Public Service Commission For a Certificate of Environmental Compatibility and Public Need

Last Updated: 05/21/2009