# 40 CFR § 51.112: Demonstration of adequacy

> Federal · Regulations · In force

URL: https://www.frixlaw.com/law-library/statutes/ecfr-40-51.112

## Section

- **Citation:** 40 CFR § 51.112
- **Heading:** Demonstration of adequacy
- **Jurisdiction:** Federal
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** September 22, 2026
- **Source:** Publisher's official text
- **Location:** Title 40—Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS > PART 51—REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS > Subpart G—Control Strategy

## Text

(a) Each plan must demonstrate that the measures, rules, and regulations contained in it are adequate to provide for the timely attainment and maintenance of the national standard that it implements.
(1) The adequacy of a control strategy shall be demonstrated by means of applicable air quality models, data bases, and other requirements specified in appendix W of this part (Guideline on Air Quality Models).
(2) Where an air quality model specified in appendix W of this part (Guideline on Air Quality Models) is inappropriate, the model may be modified or another model substituted. Such a modification or substitution of a model may be made on a case-by-case basis or, where appropriate, on a generic basis for a specific State program. Written approval of the Administrator must be obtained for any modification or substitution. In addition, use of a modified or substituted model must be subject to notice and opportunity for public comment under procedures set forth in § 51.102.
(b) The demonstration must include the following:
(1) A summary of the computations, assumptions, and judgments used to determine the degree of reduction of emissions (or reductions in the growth of emissions) that will result from the implementation of the control strategy.
(2) A presentation of emission levels expected to result from implementation of each measure of the control strategy.
(3) A presentation of the air quality levels expected to result from implementation of the overall control strategy presented either in tabular form or as an isopleth map showing expected maximum pollutant concentrations.
(4) A description of the dispersion models used to project air quality and to evaluate control strategies.
(5) For interstate regions, the analysis from each constituent State must, where practicable, be based upon the same regional emission inventory and air quality baseline.
[51 FR 40665, Nov. 7, 1986, as amended at 58 FR 38821, July 20, 1993; 60 FR 40468, Aug. 9, 1995; 61 FR 41840, Aug. 12, 1996]

## Nearby sections

- [40 CFR § 51.100 § 51.100 Definitions.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.100.md)
- [40 CFR § 51.101 § 51.101 Stipulations.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.101.md)
- [40 CFR § 51.102 § 51.102 Public hearings.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.102.md)
- [40 CFR § 51.103 § 51.103 Submission of plans, preliminary review of plans.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.103.md)
- [40 CFR § 51.104 § 51.104 Revisions.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.104.md)
- [40 CFR § 51.105 § 51.105 Approval of plans.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.105.md)
- [40 CFR § 51.110 § 51.110 Attainment and maintenance of national standards.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.110.md)
- [40 CFR § 51.111 § 51.111 Description of control measures.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.111.md)
- [40 CFR § 51.112 § 51.112 Demonstration of adequacy.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.112.md)
- [40 CFR § 51.114 § 51.114 Emissions data and projections.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.114.md)
- [40 CFR § 51.115 § 51.115 Air quality data and projections.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.115.md)
- [40 CFR § 51.116 § 51.116 Data availability.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.116.md)
- [40 CFR § 51.117 § 51.117 Additional provisions for lead.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.117.md)
- [40 CFR § 51.118 § 51.118 Stack height provisions.](https://www.frixlaw.com/law-library/statutes/ecfr-40-51.118.md)

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/ecfr-40-51.112. Check the current official text before relying on it. Not legal advice.