The U.S. Army Corps of Engineers gave final approval July 27 to Central Maine Power, a subsidiary of the Spanish-owned company Iberdrola USA, to begin work on a $1.4-billion electricity transmission network, one of the largest construction projects in Maine’s history. The project includes five, 345-kV substations linked by 450 miles of new or rebuilt transmission line. The line’s southern end will tie into the New England grid near the New Hampshire border and its northern end will link with Canadian transmission lines in Orrington, Maine. The utility has contracted with Maine contractors Cianbro Corp., Pittsfield, and RJ Grondin & Sons, Gorham, to begin site development, and expects to announce additional contractors over the next several weeks. The project received approval from state regulators in May after two years of review. Work is set to start this month and could generate up to 2,000 construction jobs over the next five years, according to published reports.