The Environmental Protection Agency (EPA) is taking final action to approve State Implementation Plan (SIP) revisions submitted by the State of South Dakota on October 23, 2015 and July 29, 2013 related to South Dakota's Air Pollution Control Program. The October 23, 2015 submittal revises certain definitions and dates of incorporation by reference and contains new, amended and renumbered rules. In this rulemaking, we are taking final action on all portions of the October 23, 2015 submittal, except for those portions of the submittal which do not belong in the SIP. This action is being taken under section 110 of the Clean Air Act (CAA).