Air Plan Approval; Colorado; Interim Final Determination To Stay and Defer Sanctions in the Denver Metro/North Front Range 2008 Ozone Nonattainment Area

In the Proposed Rules section of this Federal Register, EPA is proposing approval and conditional approval of portions of a State Implementation Plan (SIP) submission from the State of Colorado dated May 3, 2024. The submission relates to Colorado Air Quality Control Commission Regulation Number 7 (Reg. 7) and Regulation Number 21 (Reg. 21), and addresses Colorado's SIP obligation to require sources to meet reasonably available control technology (RACT) requirements for nonattainment areas for the 2008 ozone National Ambient Air Quality Standard (NAAQS), which includes requiring adequate reporting by sources. In this action, EPA is making an interim final determination based on that proposed approval and conditional approval. The effect of this interim final determination is that the imposition of sanctions that were triggered by EPA's May 9, 2023 limited disapproval are now deferred. Although this action is effective upon publication, EPA will take comment on this interim final determination.