The PJM Interconnection (PJM; Norristown, Pennsylvania, U.S.) approved American Electric Power's (AEP) 765-kV joint transmission-line proposal with Allegheny Energy Inc. to build 250 miles (402 km) of 765-kV extra-high-voltage transmission from AEP's Amos substation near St. Albans, West Virginia, U.S., to Bedington substation, northeast of Martinsburg, West Virginia. Another 40 miles (64 km) of transmission, consisting of twin-circuit 500-kV transmission, will be constructed from Bedington to a new substation to be built at Kemptown, located southeast of Frederick, Maryland, U.S.

AEP will have lead responsibility for engineering, designing and managing the construction of the 765-kV elements of the project. Allegheny will have similar responsibilities for the twin-circuited 500-kV line. Each company will provide services to the joint venture for siting, acquiring rights-of-way, securing regulatory approvals from the states the line crosses and maintenance of the project.

The total project is estimated to cost approximately $1.8 billion. AEP's estimated share of the costs will be approximately $600 million. PJM's Regional Transmission Expansion Plan calls for the line to be in service by June 2012 to meet the reliability needs of the region.