---
kind: "section"
citation: "40 C.F.R. § 52.343"
title: "40"
number: "52.343"
heading: "Significant deterioration of air quality."
url: "https://uscodex.org/cfr/40/52.343"
---

# §52.343. Significant deterioration of air quality.

- (a) The requirements of sections 160 through 165 of the Clean Air Act are not met for the following categories of sources for preventing the significant deterioration of air quality:
  - (1) **Sources locating on Indian lands.**
  - (2) **Sources locating on Indian Reservations.**
  - (3) Sources which constructed prior to September 2, 1986 and which have not otherwise subjected themselves to Colorado's PSD permitting regulations after September 2, 1986, either through application to Colorado for a PSD permit (in the case of those sources which improperly constructed without obtaining a PSD permit) or through application to Colorado for a major modification to the source.
- (b) **Regulations for preventing significant deterioration of air quality.** The provisions of [§ 52.21](/cfr/40/52.21.md) except [paragraph (a)(1)](#a-1) are hereby incorporated and made a part of the applicable State plan for the State of Colorado for the sources identified in [paragraph (a)](#a) of this section as not meeting the requirements of [sections 160-165](/cfr/40/160-165.md) of the Clean Air Act.
- (c) The State of Colorado has clarified the generalized language contained in the Colorado Air Quality Control Regulations on the use of “applicable air quality models.” In a letter to Douglas M. Skie, EPA, dated May 19, 1989, Bradley J. Beckham, Director of the Air Pollution Control Division stated:

## Notes

### Amendments

[51 FR 31126, Sept. 2, 1986, and 52 FR 4622, Feb. 13, 1987, as amended at 52 FR 22638, June 15, 1987; 54 FR 27881, July 3, 1989; 57 FR 27000, June 17, 1992; 59 FR 42506, Aug. 18, 1994; 62 FR 2914, Jan. 21, 1997; 62 FR 13336, Mar. 20, 1997; 68 FR 11322, Mar. 10, 2003; 68 FR 74488, Dec. 24, 2003]

### Authority

Authority: 42 U.S.C. 7401 et seq.

### Amendments

[40 FR 5521, Feb. 6, 1975]

### Amendments

[51 FR 31126, Sept. 2, 1986, and 52 FR 4622, Feb. 13, 1987, as amended at 52 FR 22638, June 15, 1987; 54 FR 27881, July 3, 1989; 57 FR 27000, June 17, 1992; 59 FR 42506, Aug. 18, 1994; 62 FR 2914, Jan. 21, 1997; 62 FR 13336, Mar. 20, 1997; 68 FR 11322, Mar. 10, 2003; 68 FR 74488, Dec. 24, 2003]