40 CFR 464.24 - New source performance standards.

Regulations last checked for updates: Oct 15, 2026

Title 40 - Protection of Environment last revised: Oct 13, 2026

View all text of Subpart B [§ 464.20 - § 464.27]

§ 464.24 - 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)	0.0307	0.0168
Lead (T)	0.0211	0.0104
Zinc (T)	0.0303	0.0116
Oil and grease	1.2	0.399
TSS	0.598	0.479
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	0.0068
Lead (T)	0.53	0.26	0.006
Zinc (T)	0.76	0.29	0.0072
Oil and grease	30	10	0.199
TSS	15	12	0.104
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 (4.8/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) Direct Chill 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)	0.928	0.506
Lead (T)	0.639	0.314
Zinc (T)	0.916	0.35
Oil and grease	36.2	12.1
TSS	18.1	14.5
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	0.205
Lead (T)	0.53	0.26	0.181
Zinc (T)	0.76	0.29	0.217
Oil and grease	30	10	6.03
TSS	15	12	3.13
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 (145/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.

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)	0.553	0.301
Lead (T)	0.38	0.187
Zinc (T)	0.545	0.208
Total phenols	0.617	0.215
Oil and grease	21.5	7.18
TSS	10.8	8.61
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	0.122
Lead (T)	0.53	0.26	0.108
Zinc (T)	0.76	0.29	0.129
Total phenols	0.86	0.3	0.144
Oil and grease	30	10	3.59
TSS	15	12	1.87
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 (0.086/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) Grinding Scrubber Operations. No discharge of process wastewater pollutants to navigable waters.

(e) Investment Casting.

NSPS

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	kg/1,000 kkg (pounds per millions pounds) of metal poured
Copper (T)	8.48	4.63
Lead (T)	5.84	2.86
Zinc (T)	8.37	3.19
Oil and grease	330	110
TSS	165	132
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	1.87
Lead (T)	0.53	0.26	1.65
Zinc (T)	0.76	0.29	1.98
Oil and grease	30	10	55.1
TSS	15	12	28.6
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 (1,320/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.

(f) Melting Furnace Scrubber Operations.

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)	1.81	0.988
Lead (T)	1.25	0.612
Zinc (T)	1.79	0.673
Total phenols	2.02	0.706
Oil and grease	70.6	23.5
TSS	35.3	28.2
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	0.4
Lead (T)	0.53	0.26	0.353
Zinc (T)	0.76	0.29	0.424
Total phenols	0.86	0.3	0.471
Oil and grease	30	10	11.8
TSS	15	12	6.12
pH	( ³)	( ³)	( ³)

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

² These concentrations must be multiplied by the ratio of (0.282/x) where x is the actual normalized process waste-water 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.

(g) 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)	0.392	0.214
Lead (T)	0.27	0.132
Zinc (T)	0.387	0.148
Oil and grease	15.3	5.09
TSS	7.63	6.11
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	0.0865
Lead (T)	0.53	0.26	0.0763
Zinc (T)	0.76	0.29	0.0916
Oil and grease	30	10	2.54
TSS	15	12	1.32
pH	( ³)	( ³)	( ³)

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

² These concentrations must be multiplied by the ratio of (61/x) where x is the actual normalized process waste-water 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 21761, June 16, 1986]

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

cite as: 40 CFR 464.24