40 CFR § 420.97 - Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional technology (BCT).

---
identifier: "/us/cfr/t40/s420.97"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 420.97 - Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional technology (BCT)."
title_number: 40
title_name: "Protection of Environment"
section_number: "420.97"
section_name: "Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional technology (BCT)."
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: "2026-03-24"
last_updated: "2026-03-24"
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"
---


# 420.97 Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional technology (BCT).

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional technology.

(a) *Sulfuric acid pickling (spent acid solutions and rinse waters)*—(1) *Rod, wire and coil.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.0819 | 0.0350 |
| O&G | 0.0350 | 0.0117 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(2) *Bar, billet and bloom.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.0263 | 0.0113 |
| O&G | 0.0113 | 0.00376 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(3) *Strip, sheet and plate.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.0526 | 0.0225 |
| O&G | 0.0225 | 0.00751 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(4) *Pipe, tube and other products.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.146 | 0.0626 |
| O&G | 0.0626 | 0.0209 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(5) *Fume scrubbers.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kilograms per day |  |
| TSS | 5.72 | 2.45 |
| O&G | 2.45 | 0.819 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

The above limitations shall be applicable to each fume scrubber associated with a sulfuric acid pickling operation.

(b) *Hydrochloric acid pickling (spent acid solutions and rinse waters)*—(1) *Rod, wire and coil.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.143 | 0.0613 |
| O&G | 0.0613 | 0.0204 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(2) *Strip, sheet and plate.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.0819 | 0.0350 |
| O&G | 0.0350 | 0.0117 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(3) *Pipe, tube and other products.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.298 | 0.128 |
| O&G | 0.128 | 0.0426 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0 |  |  |

(4) *Fume scrubbers.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kilograms per day |  |
| TSS | 5.72 | 2.45 |
| O&G | 2.45 | 0.819 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

The above limitations shall be applicable to each fume scrubber associated with a hydrochloric acid pickling operation.

(5) *Acid regeneration (absorber vent scrubber).*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kilograms per day |  |
| TSS | 38.2 | 16.3 |
| O&G | 16.3 | 5.45 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

The above limitations shall be applicable to the absorber vent scrubber wastewater associated with hydrochloric acid regeneration plants.

(c) *Combination acid pickling (spent acid solution and rinse waters)*—(1) *Rod, wire, and coil.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.149 | 0.0638 |
| O&G | 0.0638 | 0.0213 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(2) *Bar, billet, and bloom.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.0672 | 0.0288 |
| O&G | 0.0288 | 0.00960 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(3) *Strip, sheet, and plate—continuous.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.438 | 0.188 |
| O&G | 0.188 | 0.0626 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(4) *Strip, sheet and plate—batch.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.134 | 0.0576 |
| O&G | 0.0576 | 0.0192 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(5) *Pipe, tube, and other products.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kg/kkg (pounds per 1,000 lb) of product |  |
| TSS | 0.225 | 0.0964 |
| O&G | 0.0964 | 0.0321 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

(6) *Fume scrubbers.*

Subpart I

|  |  |  |
| --- | --- | --- |
|  | Kilograms per day |  |
| TSS | 5.72 | 2.45 |
| O&G | 2.45 | 0.819 |
| pH | () | () |
| The limitations for oil and grease shall be applicable when acid pickling wastewaters are treated with cold rolling wastewaters. |  |  |
| Within the range of 6.0 to 9.0. |  |  |

The above limitations shall be applicable to each fume scrubber associated with a combination acid pickling operation.

[47 FR 23284, May 27, 1982; 47 FR 41739, Sept. 22, 1982]