LANCASTER, Tenn. — Lt. Col. James A. DeLapp, U.S. Army Corps of Engineers Nashville District commander (right), and Professor Thomas Bauer, chief executive officer for the Bauer Group, pose in front of a drill rig July 11, 2012 that made the first excavation in the earthen portion of Center Hill Dam to install a concrete barrier wall. The $106 million project is scheduled for completion in late 2015.