The Environmental Protection Agency (EPA), Region 4 is approving a portion of a State Implementation Plan (SIP) revision submitted by the State of North Carolina, through the North Carolina Division of Air Quality (NC DAQ), in a letter dated June 5, 2017, which changes North Carolina's SIP-approved rule regarding nitrogen oxides (NO<INF>X</INF>) emissions from large internal combustion engine sources. In so doing, Region 4 is first adopting an alternative policy regarding startup, shutdown, and malfunction (SSM) exemption provisions in the North Carolina SIP that departs from the national policy on this subject, as described in EPA's June 12, 2015 action (2015 SSM SIP Call Action). Accordingly, Region 4 is also withdrawing the SIP Call issued to North Carolina for exemptions contained in the State's existing SIP- approved provisions for SSM events. This action is limited to the SIP Call issued to North Carolina and the associated evaluation of the North Carolina SIP and does not otherwise change or alter EPA's 2015 SSM SIP Call Action.