Valero Energy Corp. agreed to pay a $4.25 million civil penalty and spend $232 million to upgrade pollution controls at its Port Arthur, Texas; Lima, Ohio and Memphis, Tennessee refineries. The new controls will reduce nitrogen oxide, sulfur dioxide and other air pollutants in compliance with the Clean Air Act. The settlement also requires Valero Energy to spend an additional $1.6 million on various environmental health projects in the three communities. The refineries were previously owned by the Premcor Refining Group, Inc., which Valero Energy acquired in September 2005.