40 CFR § 471.41
Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT)
June 9, 2020
CFR

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

Open Table
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
Chromium 0.026 0.012
Copper 0.147 0.077
Cyanide 0.023 0.010
Silver 0.032 0.013
Oil and grease 1.54 0.925
TSS 3.16 1.51
pH (1) (1)

1Within 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

Open Table
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
Cadmium 0.016 0.007
Copper 0.091 0.048
Cyanide 0.014 0.006
Silver 0.020 0.008
Oil and grease 0.950 0.570
TSS 1.95 0.926
pH (1) (1)

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

(e) Drawing spent soap solutions.

Subpart D—BPT

Open Table
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
Cadmium 0.001 0.0005
Copper 0.006 0.003
Cyanide 0.0009 0.0004
Silver 0.001 0.0006
Oil and grease 0.063 0.038
TSS 0.128 0.061
pH (1) (1)

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

(f) Metal powder production wet atomization wastewater.

Subpart D—BPT

Open Table
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
Cadmium 2.27 1.00
Copper 12.7 6.70
Cyanide 1.94 0.802
Silver 2.70 1.14
Oil and grease 134 80.2
TSS 274 130
pH (1) (1)

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

(g) Heat treatment contact cooling water.

Subpart D—BPT

Open Table
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
Cadmium 1.42 0.626
Copper 7.93 4.17
Cyanide 1.21 0.501
Silver 1.71 0.709
Oil and grease 83.4 50.1
TSS 171 81.3
pH (1) (1)

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

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

Subpart D—BPT

Open Table
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
Cadmium 3.50 1.55
Copper 19.6 10.3
Cyanide 2.99 1.24
Silver 4.23 1.75
Oil and grease 206 124
TSS 423 209
pH (1) (1)

1Within 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

Open Table
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
Cadmium 3.67 1.62
Copper 20.5 10.8
Cyanide 3.13 1.30
Silver 4.43 1.84
Oil and grease 216 130
TSS 443 211
pH (1) (1)

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

(k) Shot casting contact cooling water.

Subpart D—BPT

Open Table
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
Cadmium 1.25 0.551
Copper 6.98 3.67
Cyanide 1.07 0.441
Silver 1.51 0.624
Oil and grease 73.4 44.1
TSS 151 71.6
pH (1) (1)

1Within 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

Open Table
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
Cadmium 0.029 0.013
Copper 0.159 0.084
Cyanide 0.024 0.010
Silver 0.034 0.014
Oil and grease 1.67 1.00
TSS 3.43 1.63
pH (1) (1)

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

(n) Surface treatment spent baths.

Subpart D—BPT

Open Table
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
Cadmium 0.033 0.015
Copper 0.183 0.097
Cyanide 0.028 0.012
Silver 0.040 0.017
Oil and grease 1.93 1.16
TSS 3.95 1.88
pH (1) (1)

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

(o) Surface treatment rinse.

Subpart D—BPT

Open Table
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
Cadmium 2.10 0.924
Copper 11.7 5.16
Cyanide 1.79 0.739
Silver 2.53 1.05
Oil and grease 123 73.9
TSS 253 120
pH (1) (1)

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

(p) Alkaline cleaning spent baths.

Subpart D—BPT

Open Table
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
Cadmium 0.021 0.009
Copper 0.114 0.060
Cyanide 0.018 0.007
Silver 0.025 0.010
Oil and grease 1.20 0.720
TSS 2.46 1.170
pH (1) (1)

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

(q) Alkaline cleaning rinse.

Subpart D—BPT

Open Table
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
Cadmium 3.81 1.68
Copper 21.3 11.2
Cyanide 3.25 1.35
Silver 4.59 1.91
Oil and grease 224 135
TSS 459 219
pH (1) (1)

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

(r) Alkaline cleaning prebonding wastewater.

Subpart D—BPT

Open Table
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
Cadmium 3.95 1.74
Copper 22.1 11.6
Cyanide 3.37 1.39
Silver 4.76 1.97
Oil and grease 232 139
TSS 476 226
pH (1) (1)

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

(s) Tumbling or burnishing wastewater.

Subpart D—BPT

Open Table
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
Cadmium 4.12 1.82
Copper 23.0 12.1
Cyanide 3.51 1.45
Silver 4.96 2.06
Oil and grease 242 145
TSS 496 236
pH (1) (1)

1Within 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

Open Table
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
Cadmium 0.032 0.014
Copper 0.178 0.094
Cyanide 0.027 0.011
Silver 0.039 0.016
Oil and grease 1.87 1.12
TSS 3.83 1.82
pH (1) (1)

1Within 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]


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