---
kind: "section"
citation: "40 C.F.R. § 51.151"
title: "40"
number: "51.151"
heading: "Significant harm levels."
url: "https://uscodex.org/cfr/40/51.151"
---

# §51.151. Significant harm levels.


Each plan for a Priority I region must include a contingency plan which must, as a minimum, provide for taking action necessary to prevent ambient pollutant concentrations at any location in such region from reaching the following levels:


## Notes

### Amendments

[51 FR 40668, Nov. 7, 1986, as amended at 52 FR 24713, July 1, 1987]

### Source

Source: 51 FR 40668, Nov. 7, 1986, unless otherwise noted.

### Authority

Authority: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.

### Source

Source: 36 FR 22398, Nov. 25, 1971, unless otherwise noted.

### Amendments

[51 FR 40668, Nov. 7, 1986, as amended at 52 FR 24713, July 1, 1987]