40 CFR 464.43 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable.

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Title 40 - Protection of Environment last revised: Nov 01, 2025

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Table of Contents

§ 464.40 - Applicability; description of the zinc casting subcategory.

§ 464.41 - Specialized definitions.

§ 464.42 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

§ 464.43 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable.

§ 464.44 - New source performance standards.

§ 464.45 - Pretreatment standards for existing sources.

§ 464.46 - Pretreatment standards for new sources.

§ 464.47 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology. [Reserved]

§ 464.40 - Applicability; description of the zinc casting subcategory.

The provisions of this subpart are applicable to discharges to waters of the United States and to the introduction of pollutants into publicly owned treatment works resulting from zinc casting operations as defined in § 464.02(d).

§ 464.41 - Specialized definitions.

For the purpose of this subpart:

(a) Total Toxic Organics (TTO). TTO is a regulated parameter under PSES (§ 464.45) and PSNS (§ 464.46) for the zinc subcategory and is comprised of a discrete list of toxic organic pollutants for each process segment where it is regulated, as follows:

(1) Casting Quench (§ 464.45(a) and § 464.46(a)):

21. 2,4,6-trichlorophenol

22. para-chloro meta-cresol

31. 2,4-dichlorophenol

34. 2,4-dimethylphenol

39. fluoranthene

44. methylene chloride (dichloromethane)

65. phenol

66. bis(2-ethylhexyl) phthalate

68. di-n-butyl phthalate

70. diethyl phthalate

85. tetrachloroethylene

(2) Die Casting (§ 465.45(b) and § 464.46(b)):

1. acenaphthene

21. 2,4,6-trichlorophenol

22. para-chloro meta-cresol

24. 2-chlorophenol

34. 2,4-dimethylphenol

44. methylene chloride (dichloromethane)

55. naphthalene

65. phenol

66. bis (2-ethylhexyl) phthalate

68. di-n-butyl phthalate

70. diethyl phthalate

85. tetrachloroethylene

86. toluene

87. trichloroethylene

(3) Melting Furnace Scrubber (§ 464.45(c) and § 464.46(c)):

31. 2,4-dichlorophenol

34. 2,4-dimethylphenol

39. fluoranthene

44. methylene chloride (dichloromethane)

55. naphthalene

65. phenol

66. bis(2-ethylhexyl) phthalate

68. di-n-butyl phthalate

85. tetrachloroethylene

86. toluene

87. trichloroethylene

(4) Mold Cooling (§ 464.45(d) and § 464.46(d)):

21. 2,4,6-trichlorophenol

22. para-chloro meta-cresol

31. 2,4-dichlorophenol

34. 2,4-dimethylphenol

39. fluoranthene

44. methylene chloride (dichloromethane)

65. phenol

66. bis(2-ethylhexyl) phthalate

68. di-n-butyl phthalate

70. diethyl phthalate

85. tetrachloroethylene

[50 FR 45247, Oct. 30, 1985; 51 FR 21762, June 16, 1986]

§ 464.42 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

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 practicable control technology currently available, except that non-continuous dischargers shall not be subject to the maximum day and maximum for monthly average mass (kg/1,000 kkg or lb/million lb of metal poured; kg/62.3 million Sm 3 or lb/billion SCF of air scrubbed) effluent limitations for copper, lead, zinc, total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass limitations and maximum day and maximum for monthly average concentration (mg/1) limitations shall apply. Concentration limitations and annual average mass limitations shall only apply to noncontinuous dischargers.

(a) Casting Quench Operations.

BPT Effluent Limitations

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0344	0.0187
Lead (T)	0.0353	0.0174
Zinc (T)	0.0509	0.0192
Oil and grease	1.34	0.446
TSS	1.7	0.67
pH	( ¹)	( ¹)

¹ Within the range of 7.0 to 10.0 at all times.

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/1) ²	(mg/1) ²
Copper (T)	0.77	0.42	0.0076
Lead (T)	0.79	0.39	0.0098
Zinc (T)	1.14	0.43	0.0121
Oil and grease	30	10	0.223
TSS	38	15	0.446
pH	( ³)	( ³)	( ³)

¹ kg/1000 kkg (pound per million pounds) of metal poured.

² These concentrations must be multiplied by the ratio of (5.35/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

³ Within the range of 7.0 to 10.0 at all times.

(b) Die Casting Operations.

BPT Effluent Limitations

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0066	0.0036
Lead (T)	0.0068	0.0034
Zinc (T)	0.0098	0.0037
Total phenols	0.0074	0.0026
Oil and grease	0.259	0.0864
TTS	0.328	0.13
pH	( ¹)	( ¹)

¹ Within the range of 7.0 to 10.0 at all times.

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.0015
Lead (T)	0.79	0.39	0.0019
Zinc (T)	1.14	0.43	0.0023
Total phenols	0.86	0.3	0.0017
Oil and grease	30	10	0.0432
TSS	38	15	0.0864
pH	( ³)	( ³)	( ³)

¹ kg/1000 kkg (pound per million pounds) of metal poured.

² These concentrations must be multiplied by the ratio of (1.04/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

³ Within the range of 7.0 to 10.0 at all times.

BPT Effluent Limitations

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/62.3 millions Sm ³ (pounds per billion SCF) of air scrubbed
Copper (T)	1.56	0.852
Lead (T)	1.6	0.791
Zinc (T)	2.31	0.872
Total Phenols	1.74	0.608
Oil and grease	60.8	20.3
TSS	77.1	30.4
pH	( ¹)	( ¹)

¹ Within the range of 7.0 to 10.0 at all times.

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.345
Lead (T)	0.79	0.39	0.446
Zinc (T)	1.14	0.43	0.548
Total Phenols	0.86	0.3	0.406
Oil and grease	30	10	10.1
TSS	38	15	20.3
pH	( ³)	( ³)	( ³)

¹ kg/62.3 million Sm ³ (pounds per billion SCF) of air scrubbed.

² These concentrations must be multiplied by the ratio of (0.243/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed for a specific plant.

³ Within the range of 7.0 to 10.0 at all times.

(d) Mold Cooling Operations.

BPT Effluent Limitations

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.304	0.166
Lead (T)	0.311	0.154
Zinc (T)	0.449	0.17
Oil and grease	11.8	3.94
TSS	15	5.91
pH	( ¹)	( ¹)

¹ Within the range of 7.0 to 10.0 at all times.

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.067
Lead (T)	0.79	0.39	0.0867
Zinc (T)	1.14	0.43	0.106
Oil and grease	30	10	1.97
TSS	38	15	3.94
pH	( ³)	( ³)	( ³)

¹ kg/1,000 kkg (pounds per million pounds) of metal poured.

² These concentrations must be multiplied by the ratio of (47.3/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

³ Within the range of 7.0 to 10.0 at all times.

[50 FR 45247, Oct. 30, 1985; 51 FR 21762, June 16, 1986]

§ 464.43 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable.

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 available technology economically achievable, except that non-continuous dischargers shall not be subject to the maximum day and maximum for monthly average mass (kg/1,000 kkg or lb/million lb of metal poured; kg/62.3 million Sm 3 or lb/billion SCF of air scrubbed) effluent limitations for copper, lead, zinc, and total phenols. For non-continuous dischargers, annual average mass limitations and maximum day and maximum for monthly average concentration (mg/1) limitations shall apply. Concentration limitations and annual average mass limitations shall only apply to non-continuous dischargers.

(a) Casting Quench Operations.

BAT Effluent Limitations

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0344	0.0187
Lead (T)	0.0237	0.0116
Zinc (T)	0.0339	0.0129

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.0076
Lead (T)	0.53	0.26	0.0067
Zinc (T)	0.76	0.29	0.008

¹ kg/1,000 kkg (pounds per million pounds) of metal poured.

² These concentrations must be multiplied by the ratio of (5.34/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

(b) Die Casting Operations.

BAT Effluent Limitations

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0066	0.0036
Lead (T)	0.0046	0.0022
Zinc (T)	0.0066	0.0025
Total phenols	0.0074	0.0026

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.0015
Lead (T)	0.53	0.26	0.0013
Zinc (T)	0.76	0.29	0.0016
Total phenols	0.86	0.3	0.0017

¹ kg/1,000 kkg (pounds per million pounds) of metal poured.

² These concentrations must be multiplied by the ratio of (1.04/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

BAT Effluent Limitations

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/62.3 million Sm ³ (pounds per billion SCF) of air scrubbed
Copper (T)	1.56	0.852
Lead (T)	1.07	0.527
Zinc (T)	1.54	0.588
Total phenolse	1.74	0.608

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.345
Lead (T)	0.53	0.26	0.304
Zinc (T)	0.76	0.29	0.365
Total phenols	0.86	0.3	0.406

¹ kg/62.3 million Sm ³ (pounds per billion SCF) of air scrubbed.

² These concentrations must be multiplied by the ratio of (0.243/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

(d) Mold Cooling Operations.

BAT Effluent Limitations

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.304	0.166
Lead (T)	0.209	0.103
Zinc (T)	0.3	0.114

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.067
Lead (T)	0.53	0.26	0.0591
Zinc (T)	0.76	0.29	0.071

¹ kg/1,000 kkg (pounds per million pounds) of metal poured.

² These concentrations must be multiplied by the ratio of (47.3/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

[50 FR 45247, Oct. 30, 1985; 51 FR 21762, June 16, 1986]

§ 464.44 - New source performance standards.

Any new source subject to this subpart must achieve the following new source performance standards (NSPS), except that non-continuous dischargers shall not be subject to the maximum day and maximum for monthly average mass (kg/1,000 kkg or lb/million lb of metal poured; kg/62.3 million Sm 3 or lb/billion SCF of air scrubbed) effluent standards for copper, lead, zinc, total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards and maximum day and maximum for monthly average concentration (mg/l) standards shall apply. Concentration standards and annual average mass standards shall only apply to non-continuous dischargers.

(a) Casting Quench Operations.

NSPS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0344	0.0187
Lead (T)	0.0237	0.0116
Zinc (T)	0.0339	0.0129
Oil and grease	1.34	0.446
TSS	0.67	0.536
pH	( ¹)	( ¹)

¹ Within the range of 7.0 to 10.0 at all times.

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.0076
Lead (T)	0.53	0.26	0.0067
Zinc (T)	0.76	0.29	0.008
Oil and grease	30	10	0.223
TSS	15	12	0.116
pH	( ³)	( ³)	( ³)

¹ kg/1,000 kkg (pounds per million pounds) of metal poured.

² These concentrations must be multiplied by the ratio of (5.34/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

³ Within the range of 7.0 to 10.0 at all times.

(b) Die Casting Operations.

NSPS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0066	0.0036
Lead (T)	0.0046	0.0022
Zinc (T)	0.0066	0.0025
Total phenols	0.0074	0.0026
Oil and grease	0.259	0.0864
TSS	0.13	0.104
pH	( ¹)	( ¹)

¹ Within the range of 7.0 to 10.0 at all times.

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.0015
Lead (T)	0.53	0.26	0.0013
Zinc (T)	0.76	0.29	0.0016
Total phenols	0.86	0.3	0.0017
Oil and grease	30	10	0.0432
TSS	15	12	0.0225
pH	( ³)	( ³)	( ³)

¹kg/1,000 kkg (pounds per million pounds) of metal poured.

²These concentrations must be multiplied by the ratio of (1.04/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

³Within the range of 7.0 to 10.0 at all times.

NSPS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/62.3 million Sm ³ (pounds per billion SCF) of air scrubbed
Copper (T)	1.56	0.852
Lead (T)	1.07	0.527
Zinc (T)	1.54	0.588
Total phenols	1.74	0.608
Oil and grease	60.8	20.3
TSS	30.4	24.3
pH	( ¹)	( ¹)

¹ Within the range of 7.0 to 10.0 at all times.

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.345
Lead (T)	0.53	0.26	0.304
Zinc (T)	0.76	0.29	0.365
Total phenols	0.86	0.3	0.406
Oil and grease	30	10	10.1
TSS	15	12	5.27
pH	( ³)	( ³)	( ³)

¹ kg/62.3 million Sm ³ (pounds per billion SCF) of air scrubbed.

² These concentrations must be multiplied by the ratio of (0.243/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for a specific plant.

³ Within the range of 7.0 to 10.0 at all times.

(d) Mold Cooling Operations.

NSPS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.304	0.166
Lead (T)	0.209	0.103
Zinc (T)	0.3	0.114
Oil and grease	11.8	3.94
TSS	5.91	4.73
pH	( ¹)	( ¹)

¹ Within the range of 7.0 to 10.0 at all times.

	Maximum for any 1 day	Maximum for monthly average	Annual average ¹
	(mg/l) ²	(mg/l) ²
Copper (T)	0.77	0.42	0.067
Lead (T)	0.53	0.26	0.0591
Zinc (T)	0.76	0.29	0.071
Oil and grease	30	10	1.97
TSS	15	12	1.03
pH	( ³)	( ³)	( ³)

¹ kg/1,000 kkg (pounds per million pounds) of metal poured.

² These concentrations must be multiplied by the ratio of (47.3/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

³ Within the range of 7.0 to 10.0 at all times.

[50 FR 45247, Oct. 30, 1985; 51 FR 21762, June 16, 1986]

§ 464.45 - Pretreatment standards for existing sources.

Except as provided in 40 CFR 403.7 and 403.13, any existing source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and achieve the following pretreatment standards for existing sources.

(a) Casting Quench Operations.

PSES

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0344	0.0187
Lead (T)	0.0237	0.0116
Zinc (T)	0.0339	0.0129
TTO	0.093	0.0304
Oil and grease (for alternate monitoring)	1.34	0.446

(b) Die Casting Operations.

PSES

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds of metal poured)
Copper (T)	0.0066	0.0036
Lead (T)	0.0046	0.0022
Zinc (T)	0.0066	0.0025
Total phenols	0.0074	0.0026
TTO	0.0196	0.0064
Oil and grease for alternate monitoring)	0.259	0.0864

PSES

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/62.3 million Sm ³ (pounds per billion SCF) of air scrubbed
Copper (T)	1.56	0.852
Lead (T)	1.07	0.527
Zinc (T)	1.54	0.588
Total phenols	1.74	0.608
TTO	3.95	1.29
Oil and grease for alternate monitoring)	60.8	20.3

(d) Mold Cooling Operations.

PSES

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.304	0.166
Lead (T)	0.209	0.103
Zinc (T)	0.3	0.114
TTO	0.821	0.268
Oil and grease for alternate monitoring)	11.8	3.94

§ 464.46 - Pretreatment standards for new sources.

Except as provided in 40 CFR 403.7, any new source subject to this subpart which introduces pollutants into publicly owned treatment works must comply with 40 CFR part 403 and achieve the following pretreatment standards for new sources.

(a) Casting Quench Operations.

PSNS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0344	0.0187
Lead (T)	0.0237	0.0116
Zinc (T)	0.0339	0.0129
TTO	0.093	0.0304
Oil and grease (for alternate monitoring)	1.34	0.446

(b) Die Casting Operations.

PSNS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.0066	0.0036
Lead (T)	0.0046	0.0022
Zinc (T)	0.0066	0.0025
Total phenols	0.0074	0.0026
TTO	0.0196	0.0064
Oil and grease (for alternate monitoring)	0.259	0.0864

PSNS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/62.3 million Sm ³ (pounds per billion SCF) of air scrubbed
Copper (T)	1.56	0.852
Lead (T)	1.07	0.527
Zinc (T)	1.54	0.588
Total phenols	1.74	0.608
TTO	3.95	1.29
Oil and grease (for alternate monitoring)	60.8	20.3

(d) Mold Cooling Operations.

PSNS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per million pounds) of metal poured
Copper (T)	0.304	0.166
Lead (T)	0.209	0.103
Zinc (T)	0.3	0.114
TTO	0.821	0.268
Oil and grease (for alternate monitoring)	11.8	3.94

[50 FR 45247, Oct. 30, 1985; 51 FR 21762, June 16, 1986]

§ 464.47 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology. [Reserved]

authority: Secs. 301, 304 (b), (c), (e), and (g), 306 (b) and (c), 307, 308, and 501 of the Clean Water Act (Federal Water Pollution Control Act Amendments of 1972, as amended by the Clean Water Act of 1977) (the “Act”); 33 U.S.C. 1311,1314,c,e, 1316 (b) andc, 1317 (b) andc,1318,and; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217

source: 50 FR 45247, Oct. 30, 1985, unless otherwise noted.

cite as: 40 CFR 464.43