The Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision submitted by the State of Iowa as meeting the Clean Air Act (CAA) requirement that each State's SIP contain adequate provisions to prohibit emissions that will significantly contribute to nonattainment or interfere with maintenance of the 2015 8-hour ozone national ambient air quality standards (NAAQS) in any other state. This action is being taken in accordance with the CAA.