The Environmental Protection Agency (EPA) is conditionally approving portions of the Georgia and North Carolina infrastructure State Implementation Plan (SIP) submissions for the 2015 8-hour ozone National Ambient Air Quality Standards (NAAQS) provided to EPA on September 24, 2018, and September 27, 2018, respectively. Whenever EPA promulgates a new or revised NAAQS, the Clean Air Act (CAA or Act) requires that each state adopt and submit a SIP submission to establish that the state's SIP meets infrastructure requirements for the implementation, maintenance, and enforcement of each such NAAQS. Specifically, EPA is taking final action to conditionally approve the portions of the Georgia and North Carolina infrastructure SIP submissions related to the prevention of significant deterioration (PSD) infrastructure elements for the 2015 8-hour ozone NAAQS.