The Environmental Protection Agency (EPA) is taking final action to approve revisions to Idaho's State Implementation Plan (SIP) related to agricultural crop residue burning. The Director of the Idaho Department of Environmental Quality (IDEQ) submitted the revisions to EPA on September 22, 2017. IDEQ supplemented the original submission with photochemical modeling analyses on October 23, 2017. The revisions change the ambient ozone concentration level at which IDEQ may approve a permittee's request to burn. This final action is being taken for the reasons set out in EPA's proposed action in this matter. This action is being taken under section 110 of the Clean Air Act (the Act or CAA).