The Environmental Protection Agency (EPA) is taking final action to approve certain elements of a State Implementation Plan (SIP) submission from the State of Iowa addressing the applicable requirements of section 110 of the Clean Air Act (CAA) for the 2015 Ozone (O<INF>3</INF>) National Ambient Air Quality Standard (NAAQS). Section 110 requires that each state adopt and submit a SIP revision to support the implementation, maintenance, and enforcement of each new or revised NAAQS promulgated by the EPA. These SIPs are commonly referred to as ``infrastructure'' SIPs. The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA.