On March 28, 2013, the U.S. Environmental Protection Agency (EPA) finalized reconsideration of its National Emission Standards for Hazardous Air Pollutants (NESHAP) for Coal- and Oil-fired Electric Utility Steam Generating Units (a.k.a., EPA’s Mercury and Air Toxics Standards, or MATS). After publishing its original MATS final rule in early 2012, EPA announced it was taking some aspects of the rule under reconsideration and, in November 2012, proposed revisions primarily consisting of lowered emission limits for new sources and some revisions to startup and shutdown work practice standards. In its March 28th final rule, EPA has finalized lowered emission limits for new sources, but is not taking any action with respect to startup and shutdown provisions, which EPA indicates it will address at a later date. EPA’s March 28th final rule also adjusts certain monitoring and testing requirements for new sources, including removal of quarterly stack testing as an option for new source particulate matter limits, revision of particulate matter continuous parameter monitoring requirements, and inclusion of a presumption of violation if more than four emission tests are required in a 12-month period. EPA’s final rule will be effective upon publication in the Federal Register. More information regarding MATS is available here.