Approval, Disapproval and Promulgation of Air Quality Implementation Plans; Colorado: Smoke, Opacity and Sulfur Dioxide Rule Revisions; Regulation 1

EPA is partially approving and partially disapproving State Implementation Plan (SIP) revisions to Colorado's Regulation 1. The partial approval of the State's revisions allows for the use of obscurants during military exercises at the Fort Carson Military Base and Pin[oacute]n Canyon Maneuver Site in Colorado when precautionary steps are taken during the exercise to maintain air quality. EPA approves the State's revised determination of averaged over time emission rates and the expansion of recordkeeping requirements. EPA, however, is disapproving the revised provision governing fuel burning equipment. These revisions were adopted by the State of Colorado on July 21, 2005 and submitted to EPA on August 8, 2006. The proposed partial approval and partial disapproval appeared in the Federal Register on August 10, 2011 (76 FR 49391). EPA has determined that the approved revisions in Colorado's submittal are consistent with the Clean Air Act (CAA). This action is being taken under section 110 of the Clean Air Act.