---
kind: "section"
citation: "40 C.F.R. § 437.25"
title: "40"
number: "437.25"
heading: "Pretreatment standards for existing sources (PSES)."
url: "https://uscodex.org/cfr/40/437.25"
---

# §437.25. Pretreatment standards for existing sources (PSES).


Except as provided in 40 CFR [403.7](/cfr/40/403.7.md), [403.13](/cfr/40/403.13.md) or [§ 437.20(b)](/cfr/40/437.20.md?p=b), and no later than December 22, 2003, any existing source subject to this subpart must achieve the following pretreatment standards:


## Notes

### Amendments

[65 FR 81300, Dec. 22, 2000, as amended at 68 FR 71023, Dec. 22, 2003]

### Authority

Authority: 33 U.S.C. 1311, 1314, 1316, 1317, 1318, 1342, and 1361.

### Source

Source: 65 FR 81300, Dec. 22, 2000, unless otherwise noted.

### Amendments

[65 FR 81300, Dec. 22, 2000, as amended at 68 FR 71023, Dec. 22, 2003]