---
kind: "section"
citation: "40 C.F.R. § 63.7731"
title: "40"
number: "63.7731"
heading: "When must I conduct subsequent performance tests?"
url: "https://uscodex.org/cfr/40/63.7731"
---

# §63.7731. When must I conduct subsequent performance tests?

- (a) You must conduct subsequent performance tests to demonstrate compliance with all applicable PM or total metal HAP, VOHAP, and TEA emissions limitations in [§ 63.7690](/cfr/40/63.7690.md) for your iron and steel foundry no less frequently than every 5 years and each time you elect to change an operating limit or to comply with a different alternative emissions limit, if applicable. The requirement to conduct performance tests every 5 years does not apply to an emissions source for which a continuous emissions monitoring system (CEMS) is used to demonstrate continuous compliance.
- (b) You must conduct subsequent performance tests to demonstrate compliance with the opacity limit in [§ 63.7690(a)(7)](/cfr/40/63.7690.md?p=a-7) for your iron and steel foundry no less frequently than once every 6 months.

## Notes

### Amendments

[69 FR 21923, Apr. 22, 2004, as amended at 73 FR 7219, Feb. 7, 2008]

### Source

Source: 69 FR 21923, Apr. 22, 2004, unless otherwise noted.

### Authority

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

### Source

Source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.

### Amendments

[69 FR 21923, Apr. 22, 2004, as amended at 73 FR 7219, Feb. 7, 2008]