Air Plan Conditional Approval; Colorado; Revisions to Regulation Number 7 and Oil and Natural Gas RACT Requirements for 2008 8-Hour Ozone Standard for the Denver Metro/North Front Range Nonattainment Area

The Environmental Protection Agency (EPA) is conditionally approving portions of State Implementation Plan (SIP) revisions submitted by the State of Colorado on May 14, 2018 and May 13, 2020. The revisions are to Colorado Air Quality Control Commission (Commission or AQCC) regulations of ozone precursor and hydrocarbon emissions from oil and gas operations, and address Colorado's SIP obligation to require reasonably available control technology (RACT) for sources covered by the 2016 oil & natural gas control techniques guidelines (CTG or CTGs) for Moderate nonattainment areas under the 2008 ozone National Ambient Air Quality Standard (NAAQS). These revisions address the final pieces of the May 14, 2018 and May 13, 2020 submittals that we have not previously acted on. The EPA is taking this action pursuant to the Clean Air Act (CAA).