The Environmental Protection Agency (EPA) is approving changes to the North Carolina State Implementation Plan (SIP), submitted by the North Carolina Department of Environmental Quality (NC DEQ) through the Division of Air Quality, to EPA through a letter dated October 17, 2017. This SIP submittal modifies North Carolina's Prevention of Significant Deterioration (PSD) regulations and includes the adoption of specific federal provisions needed to meet the New Source Review (NSR) permitting program requirements for the fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standards (NAAQS). In addition, North Carolina's October 17, 2017, SIP submittal addresses portions of the PSD requirements for the infrastructure SIPs for the following NAAQS: 1997 Annual and 24-hour PM<INF>2.5</INF>; 2006 24-hour PM<INF>2.5</INF>; 2008 lead; 2008 8-hour ozone; 2010 sulfur dioxide (SO<INF>2</INF>); 2010 nitrogen dioxide (NO<INF>2</INF>); and 2012 Annual PM<INF>2.5</INF>. As a result of this approval of North Carolina's modified PSD regulations, EPA is also approving North Carolina's submittal with respect to the related PSD infrastructure SIP requirements for these NAAQS. In addition, these approvals remove EPA's obligation to promulgate a Federal Implementation Plan (FIP) to meet the relevant Clean Air Act (CAA or Act) requirements.