Regulations last checked for updates: May 18, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
All TitlesTitle 40Chapter IPart 471Subpart D - Subpart D—Precious Metals Forming Subcategory
View all text of Subpart D [§ 471.40 - § 471.46]
§ 471.41 - Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations for the process operations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT):

(a) Rolling spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.

(b) Rolling spent emulsions.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals rolled with emulsions
Chromium0.0260.012
Copper0.1470.077
Cyanide0.0230.010
Silver0.0320.013
Oil and grease1.540.925
TSS3.161.51
pH( 1)( 1)

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

(c) Drawing spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.

(d) Drawing spent emulsions.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals drawn with emulsions
Cadmium0.0160.007
Copper0.0910.048
Cyanide0.0140.006
Silver0.0200.008
Oil and grease0.9500.570
TSS1.950.926
pH( 1)( 1)

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

(e) Drawing spent soap solutions.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals drawn with soap solutions
Cadmium0.0010.0005
Copper0.0060.003
Cyanide0.00090.0004
Silver0.0010.0006
Oil and grease0.0630.038
TSS0.1280.061
pH( 1)( 1)

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

(f) Metal powder production wet atomization wastewater.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals powder wet atomized
Cadmium2.271.00
Copper12.76.70
Cyanide1.940.802
Silver2.701.14
Oil and grease13480.2
TSS274130
pH( 1)( 1)

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

(g) Heat treatment contact cooling water.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of extruded precious metals heat treated
Cadmium1.420.626
Copper7.934.17
Cyanide1.210.501
Silver1.710.709
Oil and grease83.450.1
TSS17181.3
pH( 1)( 1)

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

(h) Semi-continuous or continuous casting contact cooling water.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals cast by the semi-continuous or continuous method
Cadmium3.501.55
Copper19.610.3
Cyanide2.991.24
Silver4.231.75
Oil and grease206124
TSS423209
pH( 1)( 1)

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

(i) Stationary casting contact cooling water—subpart D—BPT. There shall be no discharge of process wastewater pollutants.

(j) Direct chill casting contact cooling water.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals cast by the direct chill method
Cadmium3.671.62
Copper20.510.8
Cyanide3.131.30
Silver4.431.84
Oil and grease216130
TSS443211
pH( 1)( 1)

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

(k) Shot casting contact cooling water.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals shot cast
Cadmium1.250.551
Copper6.983.67
Cyanide1.070.441
Silver1.510.624
Oil and grease73.444.1
TSS15171.6
pH( 1)( 1)

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

(l) Wet air pollution control scrubber blowdown—subpart D—BPT. There shall be no discharge of process wastewater pollutants.

(m) Pressure bonding contact cooling water.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals and base metal pressure bonded
Cadmium0.0290.013
Copper0.1590.084
Cyanide0.0240.010
Silver0.0340.014
Oil and grease1.671.00
TSS3.431.63
pH( 1)( 1)

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

(n) Surface treatment spent baths.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals surface treated
Cadmium0.0330.015
Copper0.1830.097
Cyanide0.0280.012
Silver0.0400.017
Oil and grease1.931.16
TSS3.951.88
pH( 1)( 1)

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

(o) Surface treatment rinse.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals surface treated
Cadmium2.100.924
Copper11.75.16
Cyanide1.790.739
Silver2.531.05
Oil and grease12373.9
TSS253120
pH( 1)( 1)

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

(p) Alkaline cleaning spent baths.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals alkaline cleaned
Cadmium0.0210.009
Copper0.1140.060
Cyanide0.0180.007
Silver0.0250.010
Oil and grease1.200.720
TSS2.461.170
pH( 1)( 1)

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

(q) Alkaline cleaning rinse.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals alkaline cleaned
Cadmium3.811.68
Copper21.311.2
Cyanide3.251.35
Silver4.591.91
Oil and grease224135
TSS459219
pH( 1)( 1)

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

(r) Alkaline cleaning prebonding wastewater.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals and base metal cleaned prior to bonding
Cadmium3.951.74
Copper22.111.6
Cyanide3.371.39
Silver4.761.97
Oil and grease232139
TSS476226
pH( 1)( 1)

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

(s) Tumbling or burnishing wastewater.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals tumbled or burnished
Cadmium4.121.82
Copper23.012.1
Cyanide3.511.45
Silver4.962.06
Oil and grease242145
TSS496236
pH( 1)( 1)

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

(t) Sawing or grinding spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.

(u) Sawing or grinding spent emulsions.

Subpart D—BPT

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pounds per million off-pounds) of precious metals sawed or ground with emulsions
Cadmium0.0320.014
Copper0.1780.094
Cyanide0.0270.011
Silver0.0390.016
Oil and grease1.871.12
TSS3.831.82
pH( 1)( 1)

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

(v) Degreasing spent solvents—subpart D—BPT. There shall be no discharge of process wastewater pollutants.

[50 FR 34270, Aug. 23, 1985; 51 FR 2886, Jan. 22, 1986]
authority: Secs. 301, 304(b), (c), (e), and (g), 306(b) and (c), 307, 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) (the “Act”); 33 U.S.C. 1311,1314,c,e,and, 1316(b) andc,and; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217
source: 50 FR 34270, Aug. 23, 1985, unless otherwise noted.
cite as: 40 CFR 471.41
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