Approval of Implementation Plans; State of Iowa; Elements of the Infrastructure SIP Requirements for the 2010 Nitrogen Dioxide National Ambient Air Quality Standard (NAAQS)

The Environmental Protection Agency (EPA) is taking final action to approve certain elements of Iowa's 2013 State Implementation Plan (SIP) submission, and a 2017 amendment to that submission, for the 2010 Nitrogen Dioxide (NO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS). States are required to have a SIP that provides for the implementation, maintenance, and enforcement of the NAAQS. Whenever EPA promulgates a new or revised NAAQS, states are required to make a SIP submission establishing that the existing approved SIP has provisions necessary to address various requirements to address the new or revised NAAQS or to add such provisions. 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.