Virginia Electric and Power (Dominion Virginia Power), in a Dec. 1 application filed with the Virginia State Corporation Commission (SCC), said that it proposes to rebuild four 500-kV structures, entirely within existing right of way (ROW), of the approximate 44.4 miles of existing 500-kV transmission Line #567 (Chickahominy-Surry), located in Charles City, Prince George and Surry County, Va.
The company said that there is an immediate need for the rebuild project to assure that the company can continue to provide reliable electric transmission service consistent with its obligation under Virginia law to serve retail electric customers in its exclusive service territory. With authorization from the SCC by June 2017, and the ability to obtain necessary outages from PJM Interconnection, the company said that it anticipates that the rebuild project could be in service by December 2017.
The estimated total cost of the proposed project, assuming completion by late 2017, is about $10.9m in 2016 dollars, the company said, adding that there is no station work associated with the project.
For the rebuild project, the company said that it proposes to remove the two existing “COR-TEN” anchor structures on land and the two lattice “COR-TEN” river structures in the river. The company noted that it proposes two new galvanized anchor structures – on land – and two new galvanized lattice river structures – in the river. The two new anchor structures are about 90 feet tall – measured above grade – which is about 15 feet taller than the existing anchor structures – exclusive of foundations.
The company also said that the two new river structures would be about 414 feet tall, excluding foundation heights, and are about the same height as the existing river structures. The anchor structures would have new foundations, and the existing foundations would be used for the river structures.
The company added that it also proposes to replace about 0.95 mile – from the existing anchor structure to existing anchor structure planned for replacement – of single-circuit, three-phase, 4500 ACSR (150/37) conductor with about 0.99 mile of single-circuit, three-phase triple-bundled 1351 ACSS TW HS-285 conductor. The company noted that that installation of single 4500 ACSR conductor is unique in Dominion Virginia Power’s system – the remainder of the Line #567 uses stock 2500 ACAR conductor. The company said that it has a limited ability to repair or restore 4500 ACSR conductor and equipment necessary to handle that conductor size is not readily available. Changing from the non-standard 4500 ACSR conductor to a standard conductor should reduce repair time in an emergency situation, the company said.
Among other things, the company said that the proposed facilities would afford the best means of meeting the continuing need for reliable service while reasonably minimizing adverse impact on the area’s scenic, environmental and historic assets.
Dominion Virginia Power, a subsidiary of Dominion Resources (NYSE:D), said that an undergrounding alternative was not considered for the rebuild project, as it would not be technologically feasible for a submarine crossing at that voltage and with the required capacity. The company also said that it did not investigate any other alternatives because reusing the existing foundations in the river would minimize impacts to the river, costs, and ultimately minimize the time of construction.