§ 71.23 Applicability.

(a) Sources covered. The provisions of this subpart apply to an owner or operator of an existing source who is seeking a compliance extension under section 112(i)(5) of the Act and who, pursuant to part 63, subpart D, of this chapter, is required to file a permit application for the extension prior to the date a comprehensive title V permit program is approved for the State in which the existing source is located.