The Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision submitted by the State of North Carolina through the North Carolina Division of Air Quality (NCDAQ) via a letter dated April 13, 2021. The SIP revision seeks to modify the State's emission control standards by amending several air quality rules and removing a redundant rule for electric utility boilers. EPA is approving these changes pursuant to the Clean Air Act (CAA or Act).