40 CFR § 420.84 - New source performance standards (NSPS).

---
identifier: "/us/cfr/t40/s420.84"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 420.84 - New source performance standards (NSPS)."
title_number: 40
title_name: "Protection of Environment"
section_number: "420.84"
section_name: "New source performance standards (NSPS)."
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"
---


# 420.84 New source performance standards (NSPS).

The discharge of wastewater pollutants from any new source subject to this subpart shall not exceed the standards set forth below.

(a) *Salt bath descaling, oxidizing*—(1) *Batch, sheet and plate.*

Subpart H

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.204 | 0.0876 |
| Chromium | 0.00292 | 0.00117 |
| Nickel | 0.00263 | 0.000876 |
| pH | () | () |
| Within the range of 6.0 to 9.0. |  |  |

(2) *Batch, rod and wire.*

Subpart H

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.123 | 0.0526 |
| Chromium | 0.00175 | 0.000701 |
| Nickel | 0.00158 | 0.000526 |
| pH | () | () |
| Within the range of 6.0 to 9.0. |  |  |

(3) *Batch, pipe and tube.*

Subpart H

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.496 | 0.213 |
| Chromium | 0.00709 | 0.00284 |
| Nickel | 0.00638 | 0.00213 |
| pH | () | () |
| Within the range of 6.0 to 9.0. |  |  |

(4) *Continuous.*

Subpart H

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.0964 | 0.0413 |
| Chromium | 0.00138 | 0.000551 |
| Nickel | 0.00124 | 0.000413 |
| pH | () | () |
| Within the range of 6.0 to 9.0. |  |  |

(b) *Salt bath descaling, reducing*—(1) *Batch.*

Subpart H

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.0949 | 0.0407 |
| Cyanide | 0.00102 | 0.000339 |
| Chromium | 0.00136 | 0.000542 |
| Nickel | 0.00122 | 0.000407 |
| pH | () | () |
| Within the range of 6.0 to 9.0. |  |  |

(2) *Continuous.*

Subpart H

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.532 | 0.228 |
| Cyanide | 0.00569 | 0.00190 |
| Chromium | 0.00759 | 0.00304 |
| Nickel | 0.00683 | 0.00228 |
| pH | () | () |
| Within the range of 6.0 to 9.0. |  |  |