{"data":{"id":"us/40-cfr-52.771","jurisdiction":"us","citation":"40 CFR 52.771","heading":"Classification of regions.","body":"(a) The Indiana plan was evaluated on the basis of the following classifications:\nAir quality control region Pollutant\nParticulate matter Sulfur oxides Nitrogen dioxide Carbon monoxide Photochemical oxidants (hydrocarbons)\nEast Central Indiana Intrastate II II III III III\nEvansville (Indiana)-Owensboro-Henderson (Kentucky) Interstate I II III III III\nLouisville Interstate I I III III I\nMetropolitan Chicago Interstate (Indiana-Illinois) I I I I I\nMetropolitan Cincinnati Interstate I II III III I\nMetropolitan Indianapolis Intrastate I I I I I\nNortheast Indiana Intrastate II III III III III\nSouth Bend-Elkhart (Indiana)-Benton Harbor (Michigan) Interstate I IA III III III\nSouthern Indiana Intrastate IA IA III III III\nWabash Valley Intrastate I I III III III\n(b) The requirements of § 51.150 of this chapter are not met by the classification of counties in APC-22 for the purposes of attainment and maintenance of the total suspended particulate ambient air quality standards.\n(c) The requirements of § 51.150 of this chapter are not met by the classification of counties in APC-22 for the purposes of attainment and maintenance of the photochemical oxidant (hydrocarbon) ambient air quality standards.\n(d) The requirements of § 51.150 of this chapter are not met by the classification of Jefferson, LaPorte, Porter, Vigo and Warrick Counties in Indiana in Regulation APC-22 for the purposes of attainment and maintenance of the sulfur dioxide ambient air quality standards.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS","Subpart P—Indiana"],"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":"dcad4ab3f686cb53703d5c7d8017f346ccc0ad176a31e5779298a5ce68bb70e5","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-52.770","next":"us/40-cfr-52.772"},"notice":"GroundRules: Original legal text. Not legal advice."}