On March 16, 2011, the Environmental Protection Agency (EPA) issued a proposed rule that would reduce emissions of mercury, acid gases, and other toxic air pollutants from power plants. The proposed rule targets emissions from new and existing coal- and oil-fired electric utility steam generating units (EGUs) that generate electricity for sale and distribution through the national electric grid to the public. In addition, the proposed rule would revise the new source performance standards (NSPS) for fossil-fuel-fired EGUs to change the standards new coal- and oil-fired power plants must meet for particulate matter (PM), sulfur dioxide (SO2), and nitrogen oxides (NOx).

According to EPA, power plants are the largest remaining source of several toxic air pollutants in the U.S., and are responsible for half of mercury emissions and more than half of acid gas emissions nationwide. There are currently no national limits on the amount of mercury and other toxic air pollution released from power plant smokestacks. However, EPA expects the proposed rule to keep 91 percent of the mercury in coal from being released to air, and to significantly reduce harmful particle pollution. Emissions of mercury and other toxic pollutants from fossil fuel-fired EGUs can cause serious health effects, as well as impact the natural environment.

The proposed rule is directed at two subcategories of coal-fired EGUs, two subcategories of oil-fired EGUs, and a subcategory of units that combust gasified coal or solid oil based on the design of the various types of boilers at different power plants. EPA has proposed emission standards and other requirements for each subcategory. EPA estimates that approximately 1,350 units at 525 power plants nationwide will be affected by this action (1,200 existing coal-fired units and 150 oil-fired units).

In its Fact Sheet regarding the proposed rule, EPA notes that the technology to control toxic air pollution is well-developed, widely available, and already being used by some power plants; in fact, EPA states that “more than half of all coal-fired power plants already deploy the widely available pollution control technologies that allow them to meet these important standards. Once final, these standards will ensure the remaining coal-fired plants, roughly 44 percent, take similar steps to decrease dangerous pollutants.”

EPA has submitted the proposed rule for publication in the Federal Register, and will take public comment on this action for 60 days following publication of the proposal. In addition, EPA plans to hold public hearings on the proposed rule in Atlanta, GA, Chicago, IL, and Philadelphia, PA.

For additional information, or to view the text of the proposed rule, please see http://www.epa.gov/airquality/powerplanttoxics/actions.html