40 CFR 421.262 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

Regulations last checked for updates: May 19, 2024

Title 40 - Protection of Environment last revised: May 16, 2024

View all text of Subpart X [§ 421.260 - § 421.267]

§ 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
Copper	136.400	71.800
Cyanide (total)	20.820	8.616
Zinc	104.800	43.800
Ammonia (as N)	9,571.000	4,207.000
Combined metals	21.54
Total suspended solids	2,944.000	1,400.000
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
Copper	12.050	6.340
Cyanide (total)	1.839	0.761
Zinc	9.256	3.867
Ammonia (as N)	845.100	371.500
Combined metals	1.902
Total suspended solids	259.900	123.600
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
Copper	1.900	1.000
Cyanide (total)	0.290	0.120
Zinc	1.460	0.610
Ammonia (as N)	133.300	58.600
Combined metals	0.300
Total suspended solids	41.000	19.500
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
Copper	7.030	3.700
Cyanide (total)	1.073	0.444
Zinc	5.402	2.257
Ammonia (as N)	493.200	216.800
Combined metals	1.110
Total suspended solids	151.700	72.150
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.

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
Copper	39.900	21.000
Cyanide (total)	6.090	2.520
Zinc	30.660	12.810
Ammonia (as N)	2,799.000	1,231.000
Combined metals	6.300
Total suspended solids	861.000	409.500
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
Copper	1.197	0.630
Cyanide (total)	0.183	0.076
Zinc	0.920	0.384
Ammonia (as N)	83.980	36.920
Combined metals	0.189
Total suspended solids	25.830	12.290
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
Copper	0.017	0.009
Cyanide (total)	0.003	0.001
Zinc	0.103	0.005
Ammonia (as N)	1.160	0.510
Combined metals	0.003
Total suspended solids	0.357	0.170
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
Copper	8.360	4.400
Cyanide (total)	1.276	0.528
Zinc	6.424	2.684
Ammonia (as N)	586.500	257.800
Combined metals	1.320
Total suspended solids	180.400	85.800
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
Copper	9.880	5.200
Cyanide (total)	1.508	0.624
Zinc	7.592	3.172
Ammonia (as N)	693.200	304.700
Combined metals	1.560
Total suspended solids	213.200	101.400
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
Copper	11.400	6.000
Cyanide (total)	1.740	0.720
Zinc	8.760	3.660
Ammonia (as N)	799.800	351.600
Combined metals	1.800
Total suspended solids	246.000	117.000
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
Copper	9.880	5.200
Cyanide (total)	1.508	0.624
Zinc	7.592	3.172
Ammonia (as N)	693.200	304.700
Combined metals	1.560
Total suspended solids	213.200	101.400
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
Copper	1.710	0.900
Cyanide (total)	0.261	0.108
Zinc	1.314	0.549
Ammonia (as N)	120.000	52.740
Combined metals	0.270
Total suspended solids	36.900	17.550
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
Copper	0.000	0.000
Cyanide (total)	0.000	0.000
Zinc	0.000	0.000
Ammonia (as N)	0.000	0.000
Combined metals	0.000	0.000
Total suspended solids	0.000	0.000
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
Copper	95.000	50.000
Cyanide (Total)	14.500	6.000
Zinc	73.000	30.500
Ammonia (as N)	6665.000	2930.000
Combined Metals	15.000
Total Suspended Solids	2050.000	975.000
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 31705, 31706, 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 421.262

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