SUGAR LAND--December 28, 2012--Written by John Egan for Industrial Info Resources (Sugar Land, Texas)--Public Service Company of Oklahoma (PSO) (Tulsa, Oklahoma), a unit of American Electric Power Company (NYSE:AEP) (AEP) (Columbus, Ohio), plans hefty outlays in 2013 and beyond to keep plants in compliance with various regulations from the U.S. Environmental Protection Agency (EPA) (Washington, D.C.). The utility, which serves about 535,000 customers in eastern and southwestern Oklahoma, will spend about $350 million to install pollution-control equipment at Unit 3 of its Northeastern Power Station , a 450 megawatt (MW), coal-fired unit located in Oologah, Oklahoma. To comply with the EPA's Regional Haze Rule and the Mercury and Air Toxics Standards (MATS), PSO will lower emissions of oxides of nitrogen by installing a dry sorbent injection system, an activated carbon-injection system and a baghouse on Unit 3. That work will be completed by 2016, and that unit will be retired by 2026, company spokesman Stan Whiteford told Industrial Info.