Air Plan Approval; Colorado; Serious Attainment Plan Contingency Measures and RACT Requirements for the 2008 8-Hour Ozone National Ambient Air Quality Standards for the Denver Metro/North Front Range Nonattainment Area

The Environmental Protection Agency (EPA) is approving state implementation plan (SIP) submittals from the State of Colorado under the Clean Air Act (CAA) that address contingency measures and Reasonably Available Control Technology (RACT) requirements for the 2008 ozone National Ambient Air Quality Standard (NAAQS) for the Denver Metro/North Front Range (DMNFR) Serious ozone nonattainment area. The EPA finds that the State has met the applicable CAA requirements for Serious area contingency measures as well as RACT for certain stationary sources. Accordingly, the EPA is approving the respective SIP revisions to implement the submitted motor vehicle coating contingency measure, but we are not taking action on one of the identified contingency measures included in the submittals that concerns pneumatic controllers. In addition, the EPA is approving regulatory revisions that Colorado adopted to implement RACT requirements for landfill/biogas fired engines, refinery fuel process heaters, and a cold rolling mill, except that we are not taking final action on the RACT requirement for one refinery fuel process heater that was submitted by Colorado due to an identified error. The EPA is taking this action pursuant to the CAA.