CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 58—AMBIENT AIR QUALITY SURVEILLANCE > SUBPART F—Air Quality Index Reporting (§58.50 to §58.50) > 58.50—Index reporting.

58.50—Index reporting.

(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.
(b) Reporting is required for all individual MSA with a population exceeding 350,000.
(c) The population of a MSA for purposes of index reporting is the most recent decennial U.S. census population.

Code of Federal Regulations

[71 FR 61302, Oct. 17, 2006]