Under the presidential directive regarding the streamlining of regulatory permitting requirements, the U.S. EPA is currently reviewing the New Source Review (NSR) program to identify opportunities for improvement. On December 8, 2017, EPA Administrator Scott Pruitt published a memorandum regarding the applicability of NSR permitting requirements in situations where a proposed modification will not cause an increase in actual emissions that trigger NSR requirements. The memo describes EPA's intended approach for procedures under New Source Review Reform for sources using “projected actual emissions” to determine NSR applicability and the associated pre- and post-project source obligations. EPA has issued this clarification in light of recent litigation with DTE Energy regarding pre-project NSR emission projects and subsequent post-project emissions monitoring requirements, some aspects of which have been requested for Supreme Court review. Essentially, EPA has clarified that it will not “second guess” an applicant's emissions projections, assuming the applicant has performed a pre-project NSR applicability analysis as prescribed, and that, when an applicant projects emissions increases are less than the significant emissions rate, EPA will focus on the actual emission during the post-project recordkeeping or reporting period to determine whether to exercise its enforcement discretion.