a Standards of performance and compliance schedules.
40 C.F.R. § 60.24a
in effect(a) Each plan shall include standards of performance and compliance schedules.
(b) Standards of performance shall be in the form of an allowable rate, quantity, or concentration of emissions, except when it is not feasible to prescribe or enforce such a standard of performance. The EPA shall identify such cases in the emission guidelines issued under § 60.22a. Where standards of performance prescribing design, equipment, work practice, or operational standards, or combination thereof are established, the plan shall, to the degree possible, set forth the emission reductions achievable by implementation of such standards, and may permit compliance by the use of equipment determined by the State to be equivalent to that prescribed.
(1) Test methods and procedures for determining compliance with the standards of performance shall be specified in the plan. Methods other than those specified in appendix A to this part or an applicable subpart of this part may be specified in the plan if shown to be equivalent or alternative methods as defined in § 60.2.
(2) Standards of performance shall apply to all designated facilities within the State. A plan may contain standards of performance adopted by local jurisdictions provided that the standards are enforceable by the State.
(c) Except as provided in paragraph (e) of this section, standards of performance shall be no less stringent than the corresponding emission guideline(s) specified in this part, and final compliance shall be required as expeditiously as practicable, but no later than the compliance times specified in an applicable subpart of this part.
(d) Any compliance schedule extending more than twenty months from the date required for submittal of the plan must include legally enforceable increments of progress to achieve compliance for each designated facility or category of facilities. Unless otherwise specified in the applicable emission guideline, increments of progress must include, where practicable, each increment of progress specified in § 60.21a(h) and must include such additional increments of progress as may be necessary to permit close and effective supervision of progress toward final compliance.
(e)(1) The State may apply a standard of performance to a particular designated facility that is less stringent than or has a compliance schedule longer than otherwise required by an applicable emission guideline taking into consideration that facility's remaining useful life and other factors, provided that the State demonstrates with respect to each such facility (or class of such facilities) that the facility cannot reasonably achieve the degree of emission limitation determined by the EPA based on:
(i) Unreasonable cost of control resulting from plant age, location, or basic process design;
(ii) Physical impossibility or technical infeasibility of installing necessary control equipment; or
(iii) Other circumstances specific to the facility.
(2) For the purpose of this paragraph (e), the State must demonstrate that there are fundamental differences between the information specific to a facility (or class of such facilities) and the information EPA considered in determining the degree of emission limitation achievable through application of the best system of emission reduction or the compliance schedule that make achieving such degree of emission limitation or meeting such compliance schedule unreasonable for that facility.
(f) If the State makes the required demonstration in paragraph (e) of this section, the plan may apply a standard of performance that is less stringent than required by an applicable emission guideline.
(1) The standard of performance applied under this paragraph (f) must be no less stringent (or have a compliance schedule no longer) than is necessary to address the fundamental differences identified under paragraph (e) of this section. To the extent necessary to determine a standard of performance satisfying that criteria, the State must evaluate the systems of emission reduction identified in the applicable emission guideline using the factors and evaluation metrics EPA considered in assessing those systems, including technical feasibility, the amount of emission reductions, the cost of achieving such reductions, any nonair quality health and environmental impacts, and energy requirements. The States may also consider, as justified, other factors specific to the facility that were the basis of the demonstration under paragraph (e) as well as other systems of emission reduction in addition to those EPA considered in the applicable emission guideline.
(2) A standard of performance under this paragraph (f) must be in the form as required by the applicable emission guideline.
(g) Where a State applies a standard of performance pursuant to paragraph (f) of this section on the basis of an operating condition(s) within the designated facility's control, such as remaining useful life or restricted capacity, the plan must also include such operating condition(s) as an enforceable requirement. The plan must also include requirements to provide for the implementation and enforcement of the operating condition(s), such as requirements for monitoring, reporting, and recordkeeping.
(h) A less stringent standard of performance must meet all other applicable requirements, including in this subpart and in any applicable emission guideline.
(i) Nothing in this subpart shall be construed to preclude any State or political subdivision thereof from adopting or enforcing, as part of the plan:
(1) Standards of performance more stringent than emission guidelines specified in this part; or
(2) Compliance schedules requiring final compliance at earlier times than those specified in applicable emission guidelines.
(ii) [Reserved]
Source: ecfr_bulkFetched: 7/26/2026
Source: eCFR APIURL: https://www.ecfr.gov/api/versioner/v1/full/2024-07-01/title-40.xml?part=60Fetched: 5/31/2026