Mercury Regulation

Current Status of Mercury Regulation

The Clean Air Mercury Rule (CAMR), issued by the U.S. Environmental Protection Agency (EPA) in March 2005, was the nation's first rule to regulate mercury emissions from coal-based power plants. Since then, the CAMR has been part of legal challenges that ultimately vacated the rule and led EPA and industry groups to appeal to the U.S. Supreme Court.
On February 6, 2009, the acting Solicitor General, on behalf of EPA, filed a motion with the Supreme Court to dismiss the CAMR case. The motion clearly states that EPA will regulate mercury emissions through the development of Maximum Achievable Control Technology (MACT) standards for the utility industry under section 112 of the Clean Air Act (CAA). EPA is expected to announce final standards addressing mercury and other hazardous air pollutants (HAPs) within two years.

History of Mercury Regulation

  • On December 20, 2000, EPA issued a “regulatory determination” under the Clean Air Act that regulation of mercury is “appropriate and necessary” for coal- and oil-fired power plants.”
  • In 2001-2002, EPA held meetings of a Utility MACT Working Group under the Clean Air Act Advisory Committee (CAAAC).  In October 2002, the final report of the Working Group was submitted to the CAAAC. 
  • On December 15, 2003, EPA issued Proposed Mercury Rules for coal- and oil-based power plants. The proposed mercury rules primarily focus on coal-based power plants, and include two alternative control plans: 
    • A proven, market-based cap-and-trade approach that would require emissions reductions from new and existing facilities in two phases, or 
    • A MACT standard.  
  • On March 15, 2005, EPA issued its final CAMR for coal-based power plants. The CAMR utilized a market-based cap-and-trade approach under section 111 of the CAA to require emissions reductions in two phases: a cap of 38 tons in 2010, and 15 tons after 2018, for a total reduction of 70 percent from current levels. In addition to the CAMR, EPA published a final Agency action which reversed the regulatory finding that it issued in December 2000.
  • On February 8, 2008, the U.S. Court of Appeals for the District of Columbia Circuit issued an opinion in a case, which was initiated by 15 states and other groups, challenging the CAMR and EPA's decision to "delist" mercury as a hazardous air pollutant. The Court held that EPA's reversal of the December 2000 regulatory finding was unlawful. The Court vacated both the reversal and the CAMR, and sent the CAMR back to EPA for reconsideration.
  • On February 6, 2009, the Obama Administration indicated that it would accept the Court of Appeals' decision and would develop new MACT standards for the utility industry under section 112 of the CAA.
  • In October 2009 EPA agreed to a proposed consent decree which required EPA to propose standards addressing mercury and other emissions by March 16, 2011, and finalize standards by November 16, 2011.
  • On April 15, 2010, the consent decree was approved.
  • On March 16, 2011, the EPA Administrator issued the Utility MACT proposal as per the consent decree.
  • On December 16, 2011, EPA released the final Utility MACT rule.