The Environmental Protection Agency (EPA or Agency) is finalizing the approval of changes to the North Carolina State Implementation Plan (SIP), submitted by the State of North Carolina through the North Carolina Division of Air Quality (NCDAQ), through a letter dated October 9, 2020. The SIP revisions include changes to NCDAQ's regulations regarding monitoring and performance testing for stationary sources of air pollution. EPA is approving these changes pursuant to the Clean Air Act (CAA or Act).