---
kind: "section"
citation: "40 C.F.R. § 420.25"
title: "40"
number: "420.25"
heading: "Pretreatment standards for existing sources (PSES)."
url: "https://uscodex.org/cfr/40/420.25"
---

# §420.25. 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 pollutants into a publicly owned treatment works must comply with [40 CFR part 403](/cfr/40/part403.md) and must achieve the following pretreatment standards for existing sources (PSES):

- (a) **Sintering operations with wet air pollution control system.** The following table presents PSES for sintering operations with wet air pollution control systems:
- (b) **Sintering operations with dry air pollution control system.** There shall be no discharge of process wastewater pollutants to POTWs.

## Notes

### Amendments

[67 FR 64265, Oct. 17, 2002]

### Authority

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

### Source

Source: 47 FR 23284, May 27, 1982, unless otherwise noted.

### Amendments

[67 FR 64265, Oct. 17, 2002]