The U.S. Environmental Protection Agency (EPA) has finalized updates to the Mercury and Air Toxics Standards (MATS) for new power plants. The final standards update certain emissions limits for coal- and oil-fired power plants to be built in the future. The updates do not impact the requirements for existing power plants.

The MATS were published in the Federal Register on February 16, 2012. After many petitions, EPA granted reconsideration of certain parts of the rule, updates were proposed in November 2012, and the final rule was signed by EPA Acting Administrator Bob Perciasepe on March 28, 2013. The final reconsideration rule revises the following emissions limits, but EPA expects the same types of control technologies to be used as would have been used to meet the previous standards:

• For all new coal-fired units: hydrogen chloride (HCl), filterable PM, sulfur dioxide (SO2), lead, and selenium;
• For the “units designated for coal ≥ 8,300 Btu/lb” subcategory: mercury;
• For new solid oil-derived fuel-fired units: filterable PM and SO2;
• For new continental liquid oil-fired: filterable PM; and
• For new integrated gasification combined cycle units: most of the emissions limits.

EPA’s reconsideration also included requirements applicable during periods of startup and shutdown, as well as definitions and monitoring provisions in the Standards of Performance for Fossil-Fuel-Fired Electric Utility, Industrial-Commercial-Institutional, and Small Industrial-Commercial-Institutional Steam Generating Units (Utility NSPS). The final reconsideration rule addresses the Utility NSPS definitions and monitoring requirements. However, it does not address any issues related to startup and shutdown, as EPA stated that more time is required to address public comments on those issues.