SUMMARY: EPA is proposing to approve the State Implementation Plan (SIP) revision submitted by the state of Missouri on March 17@ 2011. This revision proposes to amend the rule to provide more specificity to the interagency consultation process requirements and responsibilities. The revision to Missouri's rule does not add any additional requirements to the existing rule but merely adds language that better clarifies specific roles and responsibilities including the consultation groups' processes. Further@ these revisions do not have an adverse affect on air quality. EPA's approval of this SIP revision is being done in accordance with the requirements of the Clean Air Act (CAA).