SUGAR LAND--December 23, 2013--Written by John Egan for Industrial Info Resources (Sugar Land, Texas)--Oklahoma Gas & Electric Company (OG&E) (Oklahoma City, Oklahoma), plans to make significant environmental compliance investments, but it's not clear yet if the utility will spend $1 billion, $1.5 billion or some other sum to bring its coal-fired power plants into compliance with federal laws. The utility is a unit of OGE Energy Corporation (NYSE:OGE) (Oklahoma City).