The Environmental Protection Agency (EPA) of the USA is conducting an investigation into suspicions that coal-fired power plants are emitting more pollution than is permitted by law.
Administration officials have said that preliminary findings suggest a consistent pattern of violations of the 1990 Clean Air Act. In 1990, Congress exempted over 100 coal-fired plants from the new pollution controls on the understanding that these plants would be phased out. The law also required that these plants not be expanded to produce more power without first upgrading their emission control systems.
According to EPA officials, a 6 month investigation has found evidence that many electricity utilities have upgraded these units to produce more electricity without installing the legally necessary upgrade in emission control.