Facing a sudden shift from coal to natural gas, the Environmental Protection Agency is likely to revise its Clean Power Plan to give states more clean energy options, EPA Administrator Gina McCarthy signaled in Chicago Friday. Forbes. 13 April 2015.
http://www.forbes.com/sites/jeffmcmahon/2015/04/12/epa-were-not-picking-fuels/#6e219e63b4be