---
kind: "section"
citation: "40 C.F.R. § 425.55"
title: "40"
number: "425.55"
heading: "Pretreatment standards for existing sources (PSES)."
url: "https://uscodex.org/cfr/40/425.55"
---

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


Except as provided in 40 CFR [403.7](/cfr/40/403.7.md) and [403.13](/cfr/40/403.13.md), any existing source subject to this subpart that introduces process wastewater pollutants into a publicly owned treatment works must comply with [40 CFR part 403](/cfr/40/part403.md), and achieve the following pretreatment standards:


## Notes

### Authority

Authority: 33 U.S.C. 1311, 1314 (b), (c), (e) and (g), 1316 (b) and (c), 1317 (b) and (c), 1318 and 1361.

### Source

Source: 47 FR 52870, Nov. 23, 1982, unless otherwise noted.