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EPA Proposes New Standards for Air Toxics from Power Plants

March 18, 2011

On March 16, 2011, USEPA proposed the first-ever national standards for mercury, arsenic, and other toxic air pollution from power plants. The standards, proposed under a court-ordered deadline, are aimed at reducing emissions from older coal- and oil-fired plants that have yet to install emissions controls such as scrubbers and baghouses. It is estimated that 44 percent of all coal-fired plants lack these controls. A previously proposed rule known as the Clean Air Mercury Rule was struck down by the DC Circuit court in February 2008, and in October 2009, EPA entered into a consent decree that required a new proposed rule to be signed by March 16, 2011, and a final rule by November 2011. EPA estimates that there are approximately 1,350 units affected by the rule—approximately 1,200 existing coal-fired units and 150 oil fired units at about 525 power plants.

The requirements of the rule include the following:

  • For all existing and new coal-fired units, the proposed standards would establish numerical emission limits for mercury, particulate matter (PM) (a surrogate for toxic non-mercury metals), and hydrogen chloride (HCl) (a surrogate for toxic acid gases).
  • For all existing and new oil-fired units, the proposed toxics rule would establish numerical emission limits for total metals, HCl, and hydrogen fluoride. Compliance with the metals standards is to be assured through fuel testing.
  • The proposal would establish alternative standards, including SO2 (as an alternate to HCl), individual non-mercury metal air toxics (as an alternate to PM), and total non-mercury metal air toxics (as an alternate to PM) for certain subcategories of power plants.
  • The proposed standards would establish work practices, instead of numerical emission limits, to limit emissions of organic air toxics, including dioxins and furans, from existing and new coal and oil-fired power plants. Because dioxins and furans are products of inefficient combustion, the proposed work practice standards would require an annual performance test program for each unit that would include inspection, adjustment, and/or maintenance and repairs to ensure optimal combustion.

The rule provides up to four years for facilities to meet the new standards. EPA will take public comment on the rule for a period of 60 days. More information about the rule is available on the EPA website at http://www.epa.gov/airquality/powerplanttoxics/actions.html.