Approval and Disapproval and Promulgation of Air Quality Implementation Plans; Colorado; Revision to Definitions; Common Provisions Regulation

EPA is partially approving and partially disapproving State Implementation Plan (SIP) revisions submitted by the State of Colorado on June 20, 2003. The intended effect of this final rule is to approve and make federally enforceable those portions of the revisions to Colorado's Common Provisions that are consistent with the Clean Air Act (CAA). Primarily, the revisions involved changes designed to fix ambiguous language, to make the definitions more readable or to delete obsolete definitions. In addition, a number of definitions were revised to reflect developments in federal law or were deleted to eliminate duplicative provisions that appear in other Colorado regulations. EPA is approving portions of the revision that delete duplicative or obsolete definitions, or that clarify existing definitions in a manner consistent with the CAA. In addition, EPA is disapproving those portions of the rule revisions that EPA determined are inconsistent with the CAA. This action is being taken under section 110 of the CAA.