Approval and Promulgation of Air Quality Implementation Plans; North Dakota; Revisions to Air Pollution Control Rules

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 add EPA Reference Method 22 to determine compliance with a visible emissions limit, add significance levels for PM2.5, modify existing significance levels for NO2 and SO2 and remove the significance level for PM10. This action is being taken under section 110 of the Clean Air Act (CAA).