WASHINGTON ( CNN ) -- -- Federal officials have fined Exxon Mobil more than $ 6 million after it violated a three-year-old agreement to decrease air pollution at four of its refineries . Exxon Mobil 's refinery in Baytown , Texas , is one of four that the EPA said had high sulfur emissions . The Justice Department announced Wednesday that the oil giant agreed to pay $ 6.1 million after Environmental Protection Agency officials determined the company had not sufficiently reduced sulfur emissions in its refineries in Baytown and Beaumont , Texas ; Baton Rouge , Louisiana ; and Torrance , California . Exxon Mobil had paid a $ 7.7 million fine in its original 2005 agreement with the government and promised to install new emissions controls at the refineries . The petroleum company said after the latest settlement its refineries now meet the required EPA standards on sulfur emissions . The company 's role in environmental pollution has been in the spotlight ever since the 1989 Exxon Valdez accident in Alaska , the worst oil spill in U.S. history . This past summer , the U.S. Supreme Court ordered the company to pay $ 507 million in punitive damages from the incident , down from an original $ 2.5 billion judgment .
Shell says company had not sufficiently reduced sulfur emissions at four facilities . The facilities in question are in Texas , Louisiana and California . Exxon Mobil says they now meet federal standards on sulfur emissions .