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.