Regulations last checked for updates: May 19, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
Table of Contents
GENERAL PROVISIONS

§ 421.1 - Applicability.

§ 421.2 - [Reserved]

§ 421.3 - Monitoring and reporting requirements.

§ 421.4 - Compliance date for pretreatment standards for existing sources (PSES).

§ 421.5 - Removal allowances for pretreatment standards.

Subpart A [§ 421.10 - § 421.16] - Subpart A—Bauxite Refining Subcategory

Subpart B [§ 421.20 - § 421.27] - Subpart B—Primary Aluminum Smelting Subcategory

Subpart C [§ 421.30 - § 421.37] - Subpart C—Secondary Aluminum Smelting Subcategory

Subpart D [§ 421.40 - § 421.47] - Subpart D—Primary Copper Smelting Subcategory

Subpart E [§ 421.50 - § 421.57] - Subpart E—Primary Electrolytic Copper Refining Subcategory

Subpart F [§ 421.60 - § 421.67] - Subpart F—Secondary Copper Subcategory

Subpart G [§ 421.70 - § 421.77] - Subpart G—Primary Lead Subcategory

Subpart H [§ 421.80 - § 421.87] - Subpart H—Primary Zinc Subcategory

Subpart I [§ 421.90 - § 421.97] - Subpart I—Metallurgical Acid Plants Subcategory

Subpart J [§ 421.100 - § 421.107] - Subpart J—Primary Tungsten Subcategory

Subpart K [§ 421.110 - § 421.117] - Subpart K—Primary Columbium-Tantalum Subcategory

Subpart L [§ 421.120 - § 421.127] - Subpart L—Secondary Silver Subcategory

Subpart M [§ 421.130 - § 421.137] - Subpart M—Secondary Lead Subcategory

Subpart N [§ 421.140 - § 421.147] - Subpart N—Primary Antimony Subcategory

Subpart O [§ 421.150 - § 421.157] - Subpart O—Primary Beryllium Subcategory

Subpart P [§ 421.180 - § 421.187] - Subpart P—Primary and Secondary Germanium and Gallium Subcategory

Subpart Q [§ 421.190 - § 421.197] - Subpart Q—Secondary Indium Subcategory

Subpart R [§ 421.200 - § 421.207] - Subpart R—Secondary Mercury Subcategory

Subpart S [§ 421.210 - § 421.217] - Subpart S—Primary Molybdenum and Rhenium Subcategory

Subpart T [§ 421.220 - § 421.227] - Subpart T—Secondary Molybdenum and Vanadium Subcategory

Subpart U [§ 421.230 - § 421.237] - Subpart U—Primary Nickel and Cobalt Subcategory

Subpart V [§ 421.240 - § 421.247] - Subpart V—Secondary Nickel Subcategory

Subpart W [§ 421.250 - § 421.257] - Subpart W—Primary Precious Metals and Mercury Subcategory

Subpart X [§ 421.260 - § 421.267] - Subpart X—Secondary Precious Metals Subcategory

Subpart Y [§ 421.270 - § 421.277] - Subpart Y—Primary Rare Earth Metals Subcategory

Subpart Z [§ 421.280 - § 421.287] - Subpart Z—Secondary Tantalum Subcategory

Subpart AA [§ 421.290 - § 421.297] - Subpart AA—Secondary Tin Subcategory

Subpart AB [§ 421.300 - § 421.307] - Subpart AB—Primary and Secondary Titanium Subcategory

Subpart AC [§ 421.310 - § 421.317] - Subpart AC—Secondary Tungsten and Cobalt Subcategory

Subpart AD [§ 421.320 - § 421.327] - Subpart AD—Secondary Uranium Subcategory

Subpart AE [§ 421.330 - § 421.337] - Subpart AE—Primary Zirconium and Hafnium Subcategory

GENERAL PROVISIONS
§ 421.1 - Applicability.

This part applies to facilities producing primary metals from ore concentrates and recovering secondary metals from recycle wastes which discharge or may discharge pollutants to waters of the United States or which introduce or may introduce pollutants into a publicly owned treatment works. The applicability of this part to alloying or casting of nonferrous metals is limited to alloying or casting of hot metal directly from the nonferrous metals manufacturing process without cooling. Remelting followed by alloying or cooling is included in the aluminum forming, nonferrous metals forming, or metal molding and casting point source categories.

§ 421.2 - [Reserved]
§ 421.3 - Monitoring and reporting requirements.

The following special monitoring requirements apply to all facilities controlled by this regulation:

(a) The monthly average regulatory values shall be the basis for the monthly average discharge in direct discharge permits and for pretreatment standards. Compliance with the monthly discharge limit is required regardless of the number of samples analyzed and averaged.

(b) Periodic analysis for cyanide are not required for a facility in the primary beryllium subcategory (subpart O of this part) when both of the following conditions are met:

(1) The first wastewater sample taken in each calandar year has been analyzed and found to contain less than 0.07 mg/1 cyanide.

(2) The owner or operator of the primary beryllium manufacturing facility certifies in writing to the POTW authority or permit issuing authority that cyanide is neither generated nor used in the beryllium manufacturing process employed at that facility.

[49 FR 8790, Mar. 8, 1984, as amended at 55 FR 31697, Aug. 3, 1990]
§ 421.4 - Compliance date for pretreatment standards for existing sources (PSES).

The PSES compliance deadline in subparts A through M is March 8, 1987. The PSES compliance deadline for plants in subparts N through AE is September 20, 1988.

[50 FR 52776, Dec. 26, 1985]
§ 421.5 - Removal allowances for pretreatment standards.

Removal allowances pursuant to 40 CFR 403.7(a) may be granted for the toxic metals limited in 40 CFR part 421 when used as indicator pollutants.

Subpart A [§ 421.10 - § 421.16] - Subpart A—Bauxite Refining Subcategory
Subpart B [§ 421.20 - § 421.27] - Subpart B—Primary Aluminum Smelting Subcategory
Subpart C [§ 421.30 - § 421.37] - Subpart C—Secondary Aluminum Smelting Subcategory
Subpart D [§ 421.40 - § 421.47] - Subpart D—Primary Copper Smelting Subcategory
Subpart E [§ 421.50 - § 421.57] - Subpart E—Primary Electrolytic Copper Refining Subcategory
Subpart F [§ 421.60 - § 421.67] - Subpart F—Secondary Copper Subcategory
Subpart G [§ 421.70 - § 421.77] - Subpart G—Primary Lead Subcategory
Subpart H [§ 421.80 - § 421.87] - Subpart H—Primary Zinc Subcategory
Subpart I [§ 421.90 - § 421.97] - Subpart I—Metallurgical Acid Plants Subcategory
Subpart J [§ 421.100 - § 421.107] - Subpart J—Primary Tungsten Subcategory
Subpart K [§ 421.110 - § 421.117] - Subpart K—Primary Columbium-Tantalum Subcategory
Subpart L [§ 421.120 - § 421.127] - Subpart L—Secondary Silver Subcategory
Subpart M [§ 421.130 - § 421.137] - Subpart M—Secondary Lead Subcategory
Subpart N [§ 421.140 - § 421.147] - Subpart N—Primary Antimony Subcategory
Subpart O [§ 421.150 - § 421.157] - Subpart O—Primary Beryllium Subcategory
Subpart P [§ 421.180 - § 421.187] - Subpart P—Primary and Secondary Germanium and Gallium Subcategory
Subpart Q [§ 421.190 - § 421.197] - Subpart Q—Secondary Indium Subcategory
Subpart R [§ 421.200 - § 421.207] - Subpart R—Secondary Mercury Subcategory
Subpart S [§ 421.210 - § 421.217] - Subpart S—Primary Molybdenum and Rhenium Subcategory
Subpart T [§ 421.220 - § 421.227] - Subpart T—Secondary Molybdenum and Vanadium Subcategory
Subpart U [§ 421.230 - § 421.237] - Subpart U—Primary Nickel and Cobalt Subcategory
Subpart V [§ 421.240 - § 421.247] - Subpart V—Secondary Nickel Subcategory
Subpart W [§ 421.250 - § 421.257] - Subpart W—Primary Precious Metals and Mercury Subcategory
Subpart X [§ 421.260 - § 421.267] - Subpart X—Secondary Precious Metals Subcategory
Subpart Y [§ 421.270 - § 421.277] - Subpart Y—Primary Rare Earth Metals Subcategory
Subpart Z [§ 421.280 - § 421.287] - Subpart Z—Secondary Tantalum Subcategory
Subpart AA [§ 421.290 - § 421.297] - Subpart AA—Secondary Tin Subcategory
Subpart AB [§ 421.300 - § 421.307] - Subpart AB—Primary and Secondary Titanium Subcategory
Subpart AC [§ 421.310 - § 421.317] - Subpart AC—Secondary Tungsten and Cobalt Subcategory
Subpart AD [§ 421.320 - § 421.327] - Subpart AD—Secondary Uranium Subcategory
Subpart AE [§ 421.330 - § 421.337] - Subpart AE—Primary Zirconium and Hafnium Subcategory
authority: Secs. 301, 304 (b), (c), (e), and (g), 306 (b) and (c), 307 (b) and (c), 308 and 501 of the Clean Water Act (the Federal Water Pollution Control Act Amendments of 1972, as amended by the Clean Water Act of 1977) and the Water Quality Act of 1987 (the “Act”); 33 U.S.C. 1311,1314,c,e,and, 1316 (b) andc, 1317 (b) andc,1318; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217; 101 Stat. 7, Pub. L. 100-4
source: 49 FR 8790, Mar. 8, 1984, unless otherwise noted.
cite as: 40 CFR 421.3