{"data":{"id":"us/40-cfr-51.1119","jurisdiction":"us","citation":"40 CFR 51.1119","heading":"Applicability.","body":"As of revocation of the 1997 ozone NAAQS on April 6, 2015, as set forth in § 50.10(c), the provisions of subpart AA shall replace the provisions of subpart X, §§ 51.900 to 51.918, which cease to apply except for § 51.907 for the anti-backsliding purposes of § 51.1105(c)(2). See subpart X § 51.919.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 51—REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS","Subpart AA—Provisions for Implementation of the 2008 Ozone National Ambient Air Quality Standards"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"6c8a647efe93402f1bc639bcea1a826fc34fb12ed0292204519cf5e20af045b3","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-51.1118","next":"us/40-cfr-51.1200"},"notice":"GroundRules: Original legal text. Not legal advice."}