Statutes, codes, and regulations
Code of Federal Regulations
Title 40 - PROTECTION OF ENVIRONMENTChapter I - ENVIRONMENTAL PROTECTION AGENCYSubchapter N - EFFLUENT GUIDELINES AND STANDARDSPart 421 - NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY
Subpart X - SECONDARY PRECIOUS METALS SUBCATEGORY
Section 421.262 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available

40 C.F.R. § 421.262

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Current through October 31, 2024
Section 421.262 - 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 shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable technology currently available:

(a) Furnace wet air pollution control.

BPT Limitations 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
Copper136.40071.800
Cyanide (total)20.8208.616
Zinc104.80043.800
Ammonia (as N)9,571.0004,207.000
Combined metals21.54
Total suspended solids2,944.0001,400.000
pH(1)(1)

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

(b) Raw material granulation.

BPT Limitations for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metal in the granulated raw material
Copper12.0506.340
Cyanide (total)1.8390.761
Zinc9.2563.867
Ammonia (as N)845.100371.500
Combined metals1.902
Total suspended solids259.900123.600
pH(1)(1)

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

(c) Spent plating solutions.

BPT Limitations 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
Copper1.9001.000
Cyanide (total)0.2900.120
Zinc1.4600.610
Ammonia (as N)133.30058.600
Combined metals0.300
Total suspended solids41.00019.500
pH(1)(1)

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

(d) Spent cyanide stripping solutions.

BPT Limitations 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
Copper7.0303.700
Cyanide (total)1.0730.444
Zinc5.4022.257
Ammonia (as N)493.200216.800
Combined metals1.110
Total suspended solids151.70072.150
pH(1)(1)

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

(e) Refinery wet air pollution control.

BPT Limitations 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
Copper39.90021.000
Cyanide (total)6.0902.520
Zinc30.66012.810
Ammonia (as N)2,799.0001,231.000
Combined metals6.300
Total suspended solids861.000409.500
pH(1)(1)

1 Within the range of 7.5 to 10.0 at alltimes.

(f) Gold solvent extraction raffinate and wash water.

BPT Limitations 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
Copper1.1970.630
Cyanide (total)0.1830.076
Zinc0.9200.384
Ammonia (as N)83.98036.920
Combined metals0.189
Total suspended solids25.83012.290
pH(1)(1)

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

(g) Gold spent electrolyte.

BPT Limitations 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
Copper0.0170.009
Cyanide (total)0.0030.001
Zinc0.1030.005
Ammonia (as N)1.1600.510
Combined metals0.003
Total suspended solids0.3570.170
pH(1)(1)

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

(h) Gold precipitation and filtration.

BPT Limitations 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
Copper8.3604.400
Cyanide (total)1.2760.528
Zinc6.4242.684
Ammonia (as N)586.500257.800
Combined metals1.320
Total suspended solids180.40085.800
pH(1)(1)

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

(i) Platinum precipitation and filtration.

BPT Limitations 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
Copper9.8805.200
Cyanide (total)1.5080.624
Zinc7.5923.172
Ammonia (as N)693.200304.700
Combined metals1.560
Total suspended solids213.200101.400
pH(1)(1)

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

(j) Palladium precipitation and filtration.

BPT Limitations 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
Copper11.4006.000
Cyanide (total)1.7400.720
Zinc8.7603.660
Ammonia (as N)799.800351.600
Combined metals1.800
Total suspended solids246.000117.000
pH(1)(1)

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

(k) Other platinum group metals precipitation and filtration.

BPT Limitations 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
Copper9.8805.200
Cyanide (total)1.5080.624
Zinc7.5923.172
Ammonia (as N)693.200304.700
Combined metals1.560
Total suspended solids213.200101.400
pH(1)(1)

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

(l) Spent solution from PGC salt production.

BPT Limitations 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
Copper1.7100.900
Cyanide (total)0.2610.108
Zinc1.3140.549
Ammonia (as N)120.00052.740
Combined metals0.270
Total suspended solids36.90017.550
pH(1)(1)

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

(m) Equipment and floor wash.

BPT Limitations 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
Ammonia (as N)0.0000.000
Combined metals0.0000.000
Total suspended solids0.0000.000
pH(1)(1)

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

(n) Preliminary treatment.

BPT Limitations 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
Copper95.00050.000
Cyanide (Total)14.5006.000
Zinc73.00030.500
Ammonia (as N)6665.0002930.000
Combined Metals15.000
Total Suspended Solids2050.000975.000
pH(1)(1)

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

40 C.F.R. §421.262

50 FR 38365, Sept. 20, 1985, as amended at 55 FR 31705, 31706, Aug. 3, 1990