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

  1. Law
  2. CFR 40
  3. Protection of Environment
  4. Environmental Protection Agency
  5. Effluent Guidelines and Standards
  6. Nonferrous Metals Manufacturing Point Source Category
  7. Primary Precious Metals and Mercury Subcategory
  8. Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

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§ 421.252 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) Smelter wet air pollution control.

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BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold and silver smelted
Lead 0.546 0.260
Mercury 0.325 0.130
Silver 0.533 0.221
Zinc 1.898 0.793
Gold 0.130
Oil and grease 26.000 15.600
Total suspended solids 53.300 25.350
pH (1) (1)

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

(b) Silver chloride reduction spent solution.

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BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant of pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver reduced in solution
Lead 0.168 0.080
Mercury 0.100 0.040
Silver 0.164 0.068
Zinc 0.584 0.244
Gold 0.040
Oil and grease 8.000 4.800
Total suspended solids 16.400 7.800
pH (1) (1)

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

(c) Electrolytic cells wet air pollution control.

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BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold refined electrolytically
Lead 83.160 39.600
Mercury 49.500 19.800
Silver 81.180 33.660
Zinc 289.100 120.800
Gold 19.800
Oil and grease 3,960.000 2,376.000
Total suspended solids 8,118.000 3,861.000
pH (1) (1)

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

(d) Electrolyte preparation wet air pollution control.

Expand Table

BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver in electrolyte produced
Lead 0.021 0.010
Mercury 0.013 0.005
Silver 0.021 0.009
Zinc 0.073 0.031
Gold 0.005
Oil and Grease 1.000 0.600
Total suspended solids 2.050 0.975
pH (1) (1)

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

(e) Calciner wet air pollution control.

Expand Table

BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead 78.200 37.240
Mercury 46.550 18.620
Silver 76.340 31.650
Zinc 271.900 113.600
Gold 18.600
Oil and Grease 3,724.000 2,234.000
Total suspended solids 7,634.000 3,631.000
pH (1) (1)

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

(f) Calcine quench water.

Expand Table

BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead 7.392 3.520
Mercury 4.400 1.760
Silver 7.216 2.992
Zinc 25.700 10.740
Gold 1.760
Oil and Grease 352.000 211.200
Total suspended solids 721.600 343.200
pH (1) (1)

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

(g) Calciner stack gas contact cooling water.

Expand Table

BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead 1.743 0.830
Mercury 1.038 0.415
Silver 1.702 0.706
Zinc 6.059 2.532
Gold 0.415
Oil and Grease 83.000 49.800
Total suspended solids 170.200 80.930
pH (1) (1)

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

(h) Condenser blowdown.

Expand Table

BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead 5.796 2.760
Mercury 3.450 1.380
Silver 5.658 2.346
Zinc 20.150 8.418
Gold 1.380
Oil and Grease 276.000 165.600
Total suspended solids 565.800 269.100
pH (1) (1)

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

(i) Mercury cleaning bath water.

Expand Table

BPT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead 0.588 0.280
Mercury 0.350 0.140
Silver 0.574 0.238
Zinc 2.044 0.854
Gold 0.140
Oil and Grease 28.000 16.800
Total suspended solids 57.400 27.300
pH (1) (1)

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


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