Marathon Petroleum Co has agreed to cap the flaring of excess natural gas and implement efficiency controls on combustion devices to settle an emissions dispute with the Obama administration. The Ohio-based company reached an agreement with the Environmental Protection Agency and the U.S. Department of Justice in response to allegations that Marathon had violated the Clean Air Act, according to an EPA statement on Thursday. Some oil companies burn off excess gas that cannot be reused or transported. Environmentalists decry the practice as a waste of energy and a contributor to harmful emissions. The EPA is pushing companies to improve infrastructure so that they flare less gas and burn off the gas they must flare more efficiently. Marathon has already spent about $45 million on equipment to improve combustion efficiency and plans to spend an additional $6.5 million, according to the statement. Along with the cap on flared waste volumes, these changes are expected to reduce air pollution from the company\'s six petroleum refineries by about 5,400 tons per year and will allow the company to save money, the EPA said. Marathon also will pay a $460,000 penalty, the agency said.