40 CFR 464.23: Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable.

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 representing the degree of effluent reduction attainable by the application of the best available technology economically achievable, except that non-continuous dischargers shall not be subject to the maximum day and maximum for monthly average mass (kg/1,000 kkg or lb/million lb of metal poured; kg/62.3 million Sm 3 or lb/billion SCF of air scrubbed) effluent limitations for copper, lead, zinc, and total phenols. For non-continuous discharges, annual average mass limitations and maximum day and maximum for monthly average concentration (mg/l) limitations shall apply. Concentration limitations and annual average mass limitations shall only apply to non-continuous dischargers.

(a) Casting Quench Operations.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

kg/1,000 kkg (pounds per million pounds) of metal poured

Copper (T) 0.0307 .0168

Lead (T) 0.0211 .0104

Zinc (T) 0.0303 .0116

Maximum for any 1 day Maximum for monthly average Annual average 1

(mg/l) 2 (mg/l) 2

Copper (T) 0.77 0.42 0.0068

Lead (T) 0.53 0.26 0.006

Zinc (T) 0.76 0.29 0.0072

1 kg/1,000 kkg (pounds per million pounds) of metal poured.

2 These concentrations must be multiplied by the ratio of (4.8/x) where x is the actual normalized process waste-water flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

(b) Direct Chill Casting Operations.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

kg/1,000 kkg (pounds per million pounds) of metal poured

Copper (T) 0.928 0.506

Lead (T) 0.639 0.314

Zinc (T) 0.916 0.35

Maximum for any 1 day Maximum for monthly average Annual average 1

(mg/l) 2 (mg/l) 2

Copper (T) 0.77 0.42 0.205

Lead (T) 0.53 0.26 0.181

Zinc (T) 0.76 0.29 0.217

1 kg/1,000 kkg (pounds per million pounds) of metal poured.

2 These concentrations must be multiplied by the ratio of (145/x) where x is the actual normalized process waste-water flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

(c) Dust Collection Scrubber Operations.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

kg/62.3 million Sm3 (pounds per billion SCF) of air scrubbed

Copper (T) 0.553 0.301

Lead (T) 0.38 0.187

Zinc (T) 0.545 0.208

Total phenols 0.617 0.215

Maximum for any 1 day Maximum for monthly average Annual average 1

(mg/l) 2 (mg/l) 2

Copper (T) 0.77 0.42 0.122

Lead (T) 0.53 0.26 0.108

Zinc (T) 0.76 0.29 0.129

Total phenols 0.86 0.3 0.144

1 kg/62.3 million Sm3 (pounds per billion SCF) of air scrubbed.

2 These concentrations must be multiplied by the ratio of (0.086/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for a specific plant.

(d) Grinding Scrubber Operations. No discharge of process wastewater pollutants to navigable waters.

(e) Investment Casting.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

kg/1000 kkg (pounds per million pounds) of metal poured

Copper (T) 8.48 4.63

Lead (T) 5.84 2.86

Zinc (T) 8.37 3.19

Maximum for any 1 day Maximum for monthly average Annual average 1

(mg/l) 2 (mg/l) 2

Copper (T) 0.77 0.42 1.87

Lead (T) 0.53 0.26 1.65

Zinc (T) 0.76 0.29 1.98

1 kg/1000 kkg (pounds per million pounds) of metal poured.

2 These concentrations must be multiplied by the ratio of (1,320/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.

(f) Melting Furnace Scrubber Operations.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

kg/62.3 million Sm 3 (pounds per billion SCF) of air scrubbed

Copper (T) 1.81 0.988

Lead (T) 1.25 0.612

Zinc (T) 1.79 0.673

Total phenols 2.02 0.706

Maximum for any 1 day Maximum for monthly average Annual average 1

(mg/l) 2 (mg/l) 2

Copper (T) 0.77 0.42 0.4

Lead (T) 0.53 0.26 0.353

Zinc (T) 0.76 0.29 0.424

Total phenols 0.86 0.3 0.471

1 kg/62.3 million Sm 3 (pounds per billion SCF) of air scrubbed.

2 These concentrations must be multiplied by the ratio of (0.282/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for a specific plant.

(g) Mold Cooling Operations.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

kg/1,000 kkg (pounds per million pounds) of metal poured

Copper (T) 0.392 0.214

Lead (T) 0.27 0.132

Zinc (T) 0.387 0.148

Maximum for any 1 day Maximum for monthly average Annual average 1

(mg/l) 2 (mg/l) 2

Copper (T) 0.77 0.42 0.0865

Lead (T) 0.53 0.26 0.0763

Zinc (T) 0.76 0.29 0.0916

1 kg/1,000 kkg (pounds per million pounds) of metal poured.

2 These concentrations must be multiplied by the ratio of (61/x) where x is the actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for a specific plant.