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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.
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) |