Regulations last checked for updates: May 19, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
§ 421.266 - Pretreatment standards for new sources.

Except as provided in 40 CFR 403.7, any new source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and achieve the following pretreatment standards for new sources. The mass of wastewater pollutants in secondary precious metals process wastewater introduced into a POTW shall not exceed the following values:

(a) Furnace wet air pollution control.

PSNS 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

(b) Raw material granulation.

PSNS 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
Ammonia85.31037.500

(c) Spent plating solutions.

PSNS 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 materail
Copper1.2800.610
Cyanide (total)0.2000.080
Zinc1.0200.420
Combined metals0.300
Ammonia (as N)133.30058.600

(d) Spent cyanide stripping solutions.

PSNS 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 metals1.110
Ammonia (as N)493.200216.800

(e) Refinery Wet Air Pollution Control. 1

1 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.

PSNS 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

(f) Gold solvent extraction raffinate and wash water.

PSNS 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

(g) Gold spent electrolyte.

PSNS 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
Zinc0.0090.004
Combined metals0.300
Ammonia (as N)1.1600.510

(h) Gold precipitation and filtration.

PSNS 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

(i) Platinum precipitation and filtration.

PSNS 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

(j) Palladium precipitation and filtration.

PSNS 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
Copper7.6803.660
Cyanide (Total)1.2000.480
Zinc6.1202.520
Combined Metals1.800
Ammonia (as N)799.800351.600

(k) Other platinum group metals precipitation and filtration.

PSNS 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

(l) Spent solution from PGC salt production.

PSNS 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

(m) Equipment and floor wash.

PSNS 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

(n) Preliminary treatment.

PSNS for the Secondary Precious Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly averge
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
[50 FR 38365, Sept. 20, 1985, as amended at 55 FR 31711, 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 421.266