The Environmental Protection Agency (EPA) is approving State Implementation Plan (SIP) revisions submitted by the State of North Dakota on January 28, 2013 and April 22, 2014. The revisions are to Article 33-15 Air Pollution Control rules of the North Dakota Administrative Code. The revisions include amendments to update the Prevention of Significant Deterioration (PSD) rules and the definition of "volatile organic compounds"; to add particulate matter less than 2.5 microns in diameter (PM<INF>2.5</INF>) methods of measurement; to modify the PM<INF>2.5</INF> state ambient air quality standard, permissible open burning rule, and permit fee processes; and, to remove permitting fees for sources that operate an air monitoring site. The revisions also make clarifying changes. This action is being taken under section 110 of the Clean Air Act (CAA).