40 C.F.R. § 52.23
Failure to comply with any provisions of this part, or with any approved regulatory provision of a State implementation plan, or with any permit condition or permit denial issued pursuant to approved or promulgated regulations for the review of new or modified stationary or indirect sources, or with any permit limitation or condition contained within an operating permit issued under an EPA-approved program that is incorporated into the State implementation plan, shall render the person or governmental entity so failing to comply in violation of a requirement of an applicable implementation plan and subject to enforcement action under section 113 of the Clean Air Act. With regard to compliance schedules, a person or Governmental entity will be considered to have failed to comply with the requirements of this part if it fails to timely submit any required compliance schedule, if the compliance schedule when submitted does not contain each of the elements it is required to contain, or if the person or Governmental entity fails to comply with such schedule.
40 C.F.R. §52.23