---
kind: "section"
citation: "40 C.F.R. § 60.6670"
title: "40"
number: "60.6670"
heading: "How must I monitor opacity for air curtain incinerators that burn 100 percent wood waste, clean lumber, and/or yard waste?"
url: "https://uscodex.org/cfr/40/60.6670"
---

# §60.6670. How must I monitor opacity for air curtain incinerators that burn 100 percent wood waste, clean lumber, and/or yard waste?

- (a) Use the procedures specified in Table 5 to [Subpart WWWW](/cfr/40/subpartWWWW.md) to determine compliance with the opacity limit for air curtain incinerators under [§ 60.6665](/cfr/40/60.6665.md).
- (b) Conduct an initial test for opacity as specified in [§ 60.8](/cfr/40/60.8.md) of [subpart A](/cfr/40/subpartA.md) of this part.
- (c) After the initial test for opacity, conduct annual tests (no less than 9 calendar months and no more than 15 calendar months following the previous test). You must complete five performance tests in each 5-year calendar period.

## Notes

### Source

Source: 91 FR 11860, Mar. 10, 2026, unless otherwise noted.

### Authority

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

### Source

Source: 36 FR 24877, Dec. 23, 1971, unless otherwise noted.