New EGU – MATS and NSPS Revisions Finalized by U.S. EPA

On March 28, 2013, U.S. EPA finalized updates to the mercury and air toxics standards (MATS) for new power plants as well as the Utility New Source Performance Standards (NSPS).  Changes were made to both 40 CFR Part 63 Subpart UUUUU and 40 CFR Part 60 Subpart Da as a result of U.S. EPA’s reconsideration of these rules announced in July 2012.  Main highlights of the changes include:

MATS New EGU Emission Limit Revisions

• Updated filterable particulate matter (FPM), Selenium (Se), Hydrogen Chloride (HCl), Sulfur Dioxide (SO2) and Mercury (Hg) emission limits for coal-fired units not designed for low rank virgin coal.
• Updated FPM, Se, HCl, and SO2 emission limits for coal-fired units designed for low rank virgin coal.
• Updated FPM emission limit for liquid oil-fired unit – continental (excluding limited-use liquid oil-fired subcategory units).
• Updated FPM and SO2 emission limits for solid oil-derived fuel-fired unit. 

MATS Testing and Monitoring

• Removed the quarterly stack testing option to demonstrate compliance with the new source FPM emission limits.
• Revised approach to establish an operating limit for those new EGUs that choose PM continuous parametric monitoring systems (CPMS).
• Required inspections and retests within 45 days of an exceedance of the operating limit for new EGUs using PM CPMS.
• Finalized the presumption that a violation of the emissions limit occurs if more than four (4) emissions tests are required in a 12 month period (rolling monthly).

NSPS Monitoring

• Finalized the same monitoring procedures for PM as for new EGUs subject to MATS (and is not finalizing the quarterly stack testing option).

Additionally several definitions were updated in the NSPS and MATS, including an integrated gasification combined cycle (IGCC) definition in the NSPS that is broader based than in MATS.  U.S. EPA did not take action on several topics they solicited comments on including startup and shutdown provisions as they need additional time to consider data and comments.   U.S. EPA feels there is sufficient time to address the topic since no sources will have to comply with the existing source MATS standards until April 16, 2015.  (Not sure industry feels the same way.)