---
kind: "section"
citation: "40 C.F.R. § 141.627"
title: "40"
number: "141.627"
heading: "Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results."
url: "https://uscodex.org/cfr/40/141.627"
---

# §141.627. Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results.


You may remain on reduced monitoring after the dates identified in [§ 141.620(c)](/cfr/40/141.620.md?p=c) for compliance with this subpart only if you qualify for a 40/30 certification under [§ 141.603](/cfr/40/141.603.md) or have received a very small system waiver under [§ 141.604](/cfr/40/141.604.md), plus you meet the reduced monitoring criteria in [§ 141.623(a)](/cfr/40/141.623.md?p=a), and you do not change or add monitoring locations from those used for compliance monitoring under [subpart L](/cfr/40/subpartL.md) of this part. If your monitoring locations under this subpart differ from your monitoring locations under [subpart L](/cfr/40/subpartL.md) of this part, you may not remain on reduced monitoring after the dates identified in [§ 141.620(c)](/cfr/40/141.620.md?p=c) for compliance with this subpart.


## Notes

### Source

Source: 71 FR 488, Jan. 4, 2006, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 300j-9, and 300j-11.

### Source

Source: 40 FR 59570, Dec. 24, 1975, unless otherwise noted.