U.S. Environmental Protection Agency's (EPA's) proposed Utility Air Toxics Rule under Section 112 of the Clean Air Act would require coal and oil-fired power plants to reduce emissions of mercury, other metallic toxics, acid gases, and organic air toxics. The proposed emission limits were derived under the Act's provision for Maximum Achievable Control Technology which EPA established through analysis of extensive data provided by regulated power plants. EPA estimates that compliance will result in $10 billion in costs as facilities install emission control equipment such as activated carbon injection, scrubbers or dry sorbent injection, and upgrades to particulate controls, which are projected to provide benefits amounting to between $59 and $160 billion per year. Stakeholders are weighing in on the effects of the rule including to ratepayers, electric system reliability, and public health during the formal comment period which runs through July 5, 2011. This QT will discuss the requirements of the rule, its benefits and impacts with panelists representing EPA, the electric utility industry, and an environmental advocacy organization, each of whom has been deeply involved in the development of the rule through various regulatory actions, legal challenges, and data analyses leading up to the proposal.