Regulations last checked for updates: May 19, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
All TitlesTitle 40Chapter IPart 421Subpart X - Subpart X—Secondary Precious Metals Subcategory
View all text of Subpart X [§ 421.260 - § 421.267]
§ 421.264 - Standards of performance for new sources.

Any new source subject to this subpart shall achieve the following new source performance standards:

(a) Furnace wet air pollution control.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metals, including silver, incinerated or smelted
Copper5.7602.745
Cyanide (total)0.9000.360
Zinc4.5901.890
Combined metals1.350
Ammonia (as N)599.900263.700
Total suspended solids67.50054.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(b) Raw material granulation.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metals in the granulated raw material
Copper0.8190.390
Cyanide (total)0.1280.051
Zinc0.6530.269
Combined metals0.192
Ammonia (as N)85.31037.500
Total suspended solids9.6007.680
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(c) Spent plating solutions.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/liter of spent plating solution used as a raw material
Copper1.2800.610
Cyanide (total)0.2000.080
Zinc1.0200.420
Combined metals0.300
Ammonia (as N)133.30058.600
Total suspended solids15.00012.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(d) Spent cyanide stripping solutions.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold produced by cyanide stripping
Copper4.7362.257
Cyanide (total)0.7400.296
Zinc3.7741.554
Combined metals1.11
Ammonia (as N)493.200216.800
Total suspended solids55.50044.400
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(e) Refinery wet air pollution control 2.

2 This allowance applies to either acid or alkaline wet air pollution control scrubbers. If both acid and alkaline wet air pollution control scrubbers are present in a particular facility the same allowance applies to each.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metals, including silver, produced in refinery
Copper1.2800.610
Cyanide (total)0.2000.080
Zinc1.0200.420
Combined metals0.300
Ammonia (as N)133.30058.600
Total suspended solids15.00012.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(f) Gold solvent extraction raffinate and wash water.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold produced by solvent extraction
Copper0.8060.384
Cyanide (total)0.1260.050
Zinc0.6430.265
Combined metals0.189
Ammonia (as N)83.98036.920
Total suspended solids9.4507.560
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(g) Gold spent electrolyte.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold produced by electrolysis
Copper0.0110.005
Cyanide (total)0.0020.001
Combined metals0.003
Zinc0.0090.004
Ammonia (as N)1.1600.510
Total suspended solids0.1310.104
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(h) Gold precipitation and filtration.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold precipitated
Copper5.6322.684
Cyanide (total)0.8800.352
Zinc4.4881.848
Combined metals1.320
Ammonia (as N)586.500257.800
Total suspended solids66.0052.800
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(i) Platinum precipitation and filtration.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of platinum precipitated
Copper6.6563.172
Cyanide (total)1.0400.416
Zinc5.3042.184
Combined metals1.560
Ammonia (as N)693.200304.700
Total suspended solids78.00062.400
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(j) Palladium precipitation and filtration.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of palladium precipitated
Copper7.6803.660
Cyanide (total)1.2000.480
Zinc6.12002.520
Combined metals1.800
Ammonia (as N)799.800351.600
Total suspended solids90.00072.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.00 at all times.

(k) Other platinum group metals precipitation and filtration.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of other platinum group metals precipitated
Copper6.6563.172
Cyanide (total)1.0400.416
Zinc5.3042.184
Combined metals1.560
Ammonia (as N)693.200304.700
Total suspended solids78.00062.400
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(l) Spent solution from PGC salt production.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold contained in PGC product
Copper1.1520.549
Cyanide (total)0.1800.072
Zinc0.9180.378
Combined metals0.270
Ammonia (as N)120.00052.740
Total suspended solids13.50010.800
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(m) Equipment and floor wash.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metals, including silver, produced in refinery
Copper0.0000.000
Cyanide (total)0.0000.000
Zinc0.0000.000
Combined metals0.000
Ammonia (as N)0.0000.000
Total suspended solids0.0000.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(n) Preliminary treatment.

NSPS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of total precious metals produced through this operation
Copper64.00030.500
Cyanide (Total)10.0004.000
Zinc51.00021.000
Combined metals15.000
Ammonia (as N)6665.0002930.000
Total Suspended Solids750.000600.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

[50 FR 38365, Sept. 20, 1985, as amended at 55 FR 31708, Aug. 3, 1990]
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 421.264
© 2014 CustomsMobile | Disclaimer | Privacy | About