40 CFR 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.