40 CFR § 421.263
Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable
June 9, 2020
CFR

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 available technology economically achievable:

(a) Furnace wet air pollution control.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metals, including silver, incinerated or smelted
Copper 5.760 2.745
Cyanide (total) 0.900 0.360
Zinc 4.590 1.890
Combined metals 1.350
Ammonia (as N) 599.900 263.700

(b) Raw material granulation.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metals in the granulated raw material
Copper 0.819 0.390
Cyanide (total) 0.128 0.051
Zinc 0.653 0.269
Combined metals 0.192
Palladium 0.064
Platinum 0.064
Ammonia (as N) 85.310 37.500

(c) Spent plating solutions.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/liter of spent plating solution used as a raw material
Copper 1.280 0.610
Cyanide (total) 0.200 0.080
Zinc 1.020 0.420
Gold
Combined metals 0.300
Ammonia (as N) 133.300 58.600

(d) Spent cyanide stripping solutions.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold produced by cyanide stripping
Copper 4.736 2.257
Cyanide (total) 0.740 0.296
Zinc 3.774 1.554
Combined metals 1.110
Ammonia (as N) 493.200 216.800

(e) Refinery wet air pollution control2.

2This 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.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metals, including silver, produced in refinery
Copper 1.280 0.610
Cyanide (total) 0.200 0.080
Zinc 1.020 0.420
Combined metals 0.300
Ammonia (as N) 133.300 58.600

(f) Gold solvent extraction raffinate and wash water.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold produced by solvent extraction
Copper 0.806 0.384
Cyanide (total) 0.126 0.050
Zinc 0.643 0.265
Combined metals 0.189
Ammonia (as N) 83.980 36.920

(g) Gold spent electrolyte.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold produced by electrolysis
Copper 0.0111 0.0053
Cyanide (total) 0.0017 0.0007
Zinc 0.0089 0.0037
Combined metals 0.0030
Ammonia (as N) 1.1600 0.5100

(h) Gold precipitation and filtration.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold precipitated
Copper 5.632 2.684
Cyanide (total) 0.880 0.352
Zinc 4.488 1.848
Combined metals 1.320
Ammonia (as N) 586.500 257.800

(i) Platinum precipitation and filtration.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of platinum precipitated
Copper 6.656 3.172
Cyanide (total) 1.040 0.416
Zinc 5.304 2.184
Combined metals 0.560
Ammonia (as N) 693.200 304.700

(j) Palladium precipitation and filtration.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of palladium precipitated
Copper 7.680 3.660
Cyanide (total) 1.200 .480
Zinc 6.120 2.520
Combined metals 1.800
Ammonia (as N) 799.800 351.600

(k) Other platinum group metals precipitation and filtration.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of other platinum group metals precipitated
Copper 6.656 3.172
Cyanide (total) 1.040 0.416
Zinc 5.304 2.184
Combined metals 1.560
Ammonia (as N) 693.200 304.700

(l) Spent solutions from PGC salt production.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold contained in PGC product
Copper 1.152 0.549
Cyanide (total) 0.180 0.072
Zinc 0.918 0.378
Combined metals 0.270
Ammonia (as N) 120.000 52.740

(m) Equipment and floor wash.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of precious metals, including silver, produced in refinery
Copper 0.000 0.000
Cyanide (total) 0.000 0.000
Zinc 0.000 0.000
Combined metals 0.000
Ammonia (as N) 0.000 0.000

(n) Preliminary treatment.

BAT Limitations for the Secondary Precious Metals Subcategory

Open Table
Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
Mg/troy ounce of total precious metals produced through this operation
Copper 64.000 30.500
Cyanide (Total) 10.000 4.000
Zinc 51.000 21.000
Combined metals 15.000
Ammonia (as N) 6665.000 2930.000

[50 FR 38365, Sept. 20, 1985, as amended at 55 FR 31706, Aug. 3, 1990; 55 FR 36932, Sept. 7, 1990]


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