Section 51.390 - Implementation plan revision(a)Purpose and applicability. The federal conformity rules under part 93, subpart A, of this chapter, in addition to any existing applicable state requirements, establish the conformity criteria and procedures necessary to meet the requirements of Clean Air Act section 176(c) until such time as EPA approves the conformity implementation plan revision required by this subpart. A state with an area subject to this subpart and part 93, subpart A, of this chapter must submit to EPA a revision to its implementation plan which contains criteria and procedures for DOT, MPOs and other state or local agencies to assess the conformity of transportation plans, programs, and projects, consistent with this subpart and part 93, subpart A, of this chapter. The federal conformity regulations contained in part 93, subpart A, of this chapter would continue to apply for the portion of the requirements that the state did not include in its conformity implementation plan and the portion, if any, of the state's conformity provisions that is not approved by EPA. In addition, any previously applicable implementation plan conformity requirements remain enforceable until the state submits a revision to its applicable implementation plan to specifically remove them and that revision is approved by EPA.(b)Conformity implementation plan content. To satisfy the requirements of Clean Air Act section 176(c)(4)(E), the implementation plan revision required by this section must include the following three requirements of part 93, subpart A, of this chapter: §§ 93.105 , 93.122(a)(4)(ii) , and 93.125(c) . A state may elect to include any other provisions of part 93, subpart A. If the provisions of the following sections of part 93, subpart A, of this chapter are included, such provisions must be included in verbatim form, except insofar as needed to clarify or to give effect to a stated intent in the revision to establish criteria and procedures more stringent than the requirements stated in this chapter: §§ 93.101 , 93.102 , 93.103 , 93.104 , 93.106 , 93.109 , 93.110 , 93.111 , 93.112 , 93.113 , 93.114 , 93.115 , 93.116 , 93.117 , 93.118 , 93.119 , 93.120 , 93.121 , 93.126 , and 93.127 . A state's conformity provisions may contain criteria and procedures more stringent than the requirements described in this subpart and part 93, subpart A, of this chapter only if the state's conformity provisions apply equally to non-federal as well as federal entities.(c)Timing and approval. A state must submit this revision to EPA by November 25, 1994 or within 12 months of an area's redesignation from attainment to nonattainment, if the state has not previously submitted such a revision. The state must also revise its conformity implementation plan within 12 months of the date of publication of any final amendments to §§ 93.105 , 93.122(a)(4)(ii) , and 93.125(c) , as appropriate. Any other portions of part 93, subpart A, of this chapter that the state has included in its conformity implementation plan and EPA has approved must be revised in the state's implementation plan and submitted to EPA within 12 months of the date of publication of any final amendments to such sections. EPA will provide DOT with a 30-day comment period before taking action to approve or disapprove the submission. In order for EPA to approve the implementation plan revision submitted to EPA under this subpart, the plan revision must address and give full legal effect to the following three requirements of part 93, subpart A: §§ 93.105 , 93.122(a)(4)(ii) , and 93.125(c) . Any other provisions that are incorporated into the conformity implementation plan must also be done in a manner that gives them full legal effect. Following EPA approval of the state conformity provisions (or a portion thereof) in a revision to the state's conformity implementation plan, conformity determinations will be governed by the approved (or approved portion of the) state criteria and procedures as well as any applicable portions of the federal conformity rules that are not addressed by the approved conformity SIP. 73 FR 4438 , Jan. 24, 2008