Approval of Missouri Air Quality Implementation Plans; Infrastructure SIP Requirements for the 2010 Sulfur Dioxide National Ambient Air Quality Standard; Withdrawal of Direct Final Rule

Due to adverse comments, the Environmental Protection Agency (EPA) is withdrawing the direct final rule for "Approval of Missouri Air Quality Implementation Plans; Infrastructure SIP Requirements for the 2010 Sulfur Dioxide National Ambient Air Quality Standard" published in the Federal Register on October 6, 2017. The direct final rule was an approval of a State Implementation Plan (SIP) revision from the State of Missouri for the 2010 Sulfur Dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS). Section 110 of the CAA requires that each state adopt and submit a SIP for the implementation, maintenance, and enforcement of each new or revised NAAQS promulgated by 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.