Two new electric distribution cables will be installed between Torrey and Romulus.
Plans are underway to replace four aging underwater electric transmission lines running under the waters of Seneca Lake from Torrey to Romulus. The N.Y. State Department of Environmental Conservation (DEC) sent a request to the supervisors and town boards of Torrey and Romulus notifying them of the application they have received from NYSEG, and requesting coordination as the lead agency in the State Environmental Quality Review because they must oversee the construction.
The requests states, “As proposed, two new electric distribution cables will be installed south of the existing cables to allow for continued operation of the existing cables during construction. The two new cables will be trenched separately from shore extending outward to a minimum depth of 10 feet. In depths greater than 10 feet, the cables will be directly laid on the lake bottom. Once the new cables have been installed, the four existing cables will be removed. Two existing riser structures on either side of the lake will also be replaced, with new structures being constructed south of the existing structures.”
According to the project description, the cables were originally installed in 1942 to connect the electrical systems on the east and west sides of the lake, and must be replaced “for reasons of life expectancy, existing condition, and to safeguard system reliability.” The old lines also contain mineral oil-impregnated paper insulation, a lead sheath, and asphalt slush coating, all of which are potential environmental hazards. There is also a concern the mineral oil may contain PCPs, though samples of silt taken in Sept. 2018 along the cables show no evidence of contamination. The cables will therefore be removed by methods that will not release any oil into the lake, and then be inspected and recycled.
The two riser structures are located 2.8 miles apart: on the western shore, at the Greenidge Electric property south of Dresden, and on the eastern shore at Sampson State Park in Romulus, which was formerly a naval training station during World War II and after. The new risers will be four poles arranged in a box structure about 35 feet tall. Once the two new structures are built, the old risers will be removed.
Prior to excavation on the shore, silt curtains will be installed beyond the 10 foot depth to contain the disturbance of the water. A barge mounted excavator will dig the trenches, and the weighted silt curtain will remain in place at least 24 hours or until the silt settles after backfilling. This portion of the project is expected to take just one or two days.
The cable installation barge will be assembled at Sampson State Park Marina. The sectional barge will hold a cable engine, a crane, and the spool of cable. The cable engine will pull the cable from the spool and feed it through the installation downshoot into the water down to the bottom of the lake as much as 500 feet below, and will monitor tension on the cable to ensure it isn’t damaged. Once the new cables are energized, the same barge will be used to take up the old cables, and the same precautions taken at the shore to remove them without contamination of the water.
One complication is the U.S. Navy’s sonar testing barge, which has four anchors. A chain for one of those anchors rests on top of one of the lines, and it cannot be moved. The project calls for that cable to be cut and capped, and then pulling the section under the chain either by the cable engine or bya remote operated submarine.
The project is anticipated to begin in mid August and continue to the end of the year.