{"data":{"id":"us/40-cfr-58.50","jurisdiction":"us","citation":"40 CFR 58.50","heading":"Index reporting.","body":"(a) The State or where applicable, local agency shall report to the general public on a daily basis through prominent notice an air quality index that complies with the requirements of appendix G to this part.\n(b) Reporting is required for all individual MSA with a population exceeding 350,000.\n(c) The population of a metropolitan statistical area for purposes of index reporting is the latest available U.S. census population.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 58—AMBIENT AIR QUALITY SURVEILLANCE","Subpart F—Air Quality Index Reporting"],"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":"76492b18ba831b987b0257cbf93d051a35c15d9e09ca5a666dbf631d8d3c4121","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-58.30","next":"us/40-cfr-58.60"},"notice":"GroundRules: Original legal text. Not legal advice."}