On February 16, 2012, the U. S. Environmental Protection Agency (EPA) published its Mercury and Air Toxics Standards (MATS) rule. MATS imposes new emissions standards for Hazardous Air Pollutants (HAPs), including mercury, on all 1,350 coal and oil powerplants nationwide. The Rule also revises new source performance standards on fossil-fuel powerplants for particulate matter, sulfur dioxide and nitrogen oxides. The proposed rule elicited over 900,000 comments, identifying a broad array of serious defects, technical errors, and other mistakes in the proposed rule. The cost impact of this ruling is significant to Kentucky’s businesses. MATS requirements will demand enormous expenditures to install pollution control technologies by 2015 (or 2016, if case-by-case statutory extensions are granted), just three to four years from now. MATS costs will result in more expensive electricity for consumers and will likely close numerous powerplants, creating potential ramifications for electric reliability throughout the nation. The Kentucky Chamber has joined other state chambers and business groups across the nation is challenging EPA’s MATS rule by filing a petition for judicial review with the U.S. Court of Appeals for the District of Columbia. The Chamber will update its members as this case moves forward.