The parent company of a power plant in eastern Ohio has become the first of 36 energy utilities to be tried for causing smog and health problems in the Northeast. In a lawsuit that began yesterday, the U.S. Justice Department accused FirstEnergy Corporation of significantly upgrading its W.H. Sammis plant without installing new pollution controls, as required by the New Source Review rules of the federal Clean Air Act. FirstEnergy and the other utilities that stand accused by the feds say they only conducted routine maintenance on their plants, not major improvements, and therefore were not required to update pollution-control equipment.