New Transmission Project Will Serve Golden Pass Liquefied Natural Gas Terminal
Entergy Texas, Inc. Transmission Line Project Fact Sheet
Who - Entergy Corp.’s transmission workgroup began designing Transmission Lines 829/830 late in 2007.
What - Transmission Line 829/830 is a double circuit, 3 phase 230kV line designed to provide additional, high-voltage power in South Jefferson County. The lines extend through marsh, wetlands and cross a small portion of the J.D. Murphy Wildlife Refuge, areas that are difficult to access and must be treated with great care. This means that construction methods and processes have been anything but business as usual. The line involves 116 transmission structures reaching 75 to 160 feet tall. The structures are constructed with multiple parts, including base-plated caissons and base-plated structures, which means each part, base and structure, has a thick mounting plate for field attachment. These are bolted together on site and once completed, each weighs between 6 and 44 tons.
Where - The line extends 11.7 miles from Entergy’s Port Acres Bulk Substation northwest of the intersection of Highways 73 and 87 southward to a new substation, Keith Lake Substation, off Highway 87 near Sabine Pass. For construction purposes, Entergy has created “lay-down” material storage yards in several locations where construction materials and equipment are kept.
When - Actual construction began in March and is expected to be finished this summer.
How - In addition to the basic design process, construction of the line has required partnerships with numerous plant, pipeline, governmental and regulatory agencies and construction specialists. Because the project is in Gulf Coast wetlands, it required a U.S. Army Corps of Engineers Nationwide 12 permit. The Texas Parks and Wildlife Department, the U.S. Fish and Wildlife Service and the Public Utility Commission of Texas were also involved in route selection. In accord with Nationwide 12 permit requirements for power line construction, the required Storm Water Pollution Prevention Plan utilizes best management practices as outlined in the construction plan. The PUCT was also responsible for granting a Certificate of Convenience and Necessity that enabled the project to move forward.
Entergy Texas’ Transmission business unit is providing construction oversight and has contracted with specialized businesses that use heavy lift helicopters to transport structure materials and the actual electrical conductor wire. This minimizes the impact on wetlands where the line is being built. Erickson Air-Crane (www.ericksonaircrane.com), based in Central Point, Oregon, is working with the power line construction contractor, North Houston Pole Line (www.nhplc.com) while AIR2 (www.air2.com), based in Timonium, Maryland, is providing helicopters and support personnel to run the conductor between the structures. Woodson Inc, Little Rock, Arkansas (www.woodsonincorporated.com) was selected to clear the sensitive right of way in conjunction with Columbia Helicopter (www.colheli.com), based in Portland, Oregon which transported trees out of the wetland areas for disposal.
With construction well under way, about 100 contractors will be on hand for 120 days, adding up to some 120,000 man-hours of work. Because the project is in an area impacted by hurricanes, the transmission structures and lines will meet new construction and design requirements for potential wind loading.