This proposed rule, the most significant update since MATS was first issued in February 2012, meets EPA’s responsibility under the Clean Air Act to periodically review emission standards. Earlier this year EPA reaffirmed the scientific, economic, and legal underpinnings of the standards, reversing a rule issued by the previous Trump mis-administration that undermined the legal basis for crucial health protections.

MATS requires significant reductions of mercury, acid gases, and other harmful pollutants from coal and oil-fired electric generating units. After reexamining the previous administration’s required review of MATS, EPA is proposing more stringent emissions limits and additional, cost-reasonable monitoring and control methods to further reduce harmful pollution from these sources, resulting in cleaner air for surrounding communities.

EPA forecasts that the proposed rule would reduce emissions of mercury and non-mercury metal pollution, such as nickel, arsenic, and lead. These pollutants are known to cause significant health impacts including fatal heart attacks, cancer and developmental delays in children. The proposal would also result in emissions reductions of fine particulate matter, sulfur dioxide, nitrogen oxides, and carbon dioxide nationwide.