40 CFR § 420.25 - Pretreatment standards for existing sources (PSES).
---
identifier: "/us/cfr/t40/s420.25"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 420.25 - Pretreatment standards for existing sources (PSES)."
title_number: 40
title_name: "Protection of Environment"
section_number: "420.25"
section_name: "Pretreatment standards for existing sources (PSES)."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "N"
subchapter_name: "EFFLUENT GUIDELINES AND STANDARDS"
part_number: "420"
part_name: "IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "33 U.S.C. 1311, 1314, 1316, 1317, 1318, 1342, and 1361."
regulatory_source: "47 FR 23284, May 27, 1982, unless otherwise noted."
cfr_part: "420"
---
# 420.25 Pretreatment standards for existing sources (PSES).
Except as provided in 40 CFR 403.7 and 403.13, any existing source subject to this subpart that introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 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:
Subpart B—Pretreatment Standards for Existing Sources (PSES)
| Regulated parameter | Maximum daily | Maximum monthly avg. |
| --- | --- | --- |
| Ammonia-N | 0.0150 | 0.00501 |
| Cyanide | 0.00300 | 0.00150 |
| Phenols (4AAP) | 0.000100 | 0.0000501 |
| Lead | 0.000451 | 0.000150 |
| Zinc | 0.000676 | 0.000225 |
| 2,3,7,8-TCDF | <ML | |
| Pounds per thousand lb of product. | | |
| The pretreatment standards for these parameters apply only when sintering wastewater is co-treated with ironmaking wastewater. | | |
| The pretreatment standards for ammonia are not applicable to sources that discharge to a POTW with nitrification capability (defined at § 420.02(s)). | | |
(b) *Sintering operations with dry air pollution control system.* There shall be no discharge of process wastewater pollutants to POTWs.
[67 FR 64265, Oct. 17, 2002]