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

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 for the process operations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT): (a) Rolling spent neat oils—subpart H—BPT. There shall be no discharge of process wastewater pollutants. (b) Rolling spent emulsions. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc rolled with emulsions Chromium 0.0006 0.0003 Copper 0.003 0.002 Cyanide 0.0004 0.0002 Zinc 0.002 0.0009 Oil and grease 0.028 0.017 TSS 0.057 0.027 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (c) Rolling contact cooling water. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc rolled with contact cooling water Chromium 0.236 0.0097 Copper 1.02 0.536 Cyanide 0.156 0.065 Zinc 0.783 0.327 Oil and grease 10.7 6.43 TSS 22.0 10.5 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (d) Drawing spent emulsions. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc drawn with emulsions Chromium 0.003 0.001 Copper 0.011 0.006 Cyanide 0.002 0.0007 Zinc 0.009 0.004 Oil and grease 0.116 0.070 TSS 0.238 0.113 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (e) Direct chill casting contact cooling water. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc cast by the direct chill method Chromium 0.222 0.091 Copper 0.960 0.505 Cyanide 0.147 0.061 Zinc 0.738 0.308 Oil and grease 10.1 6.06 TSS 20.7 9.85 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (f) Stationary casting contact cooling water—subpart H—BPT. There shall be no discharge of process wastewater pollutants. (g) Heat treatment contact cooling water. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc heat treated Chromium 0.336 0.138 Copper 1.45 0.763 Cyanide 0.221 0.092 Zinc 1.12 0.466 Oil and grease 15.3 9.16 TSS 31.3 14.9 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (h) Surface treatment spent baths. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc surface treated Chromium 0.039 0.016 Copper 0.169 0.089 Cyanide 0.026 0.011 Zinc 0.130 0.054 Oil and grease 1.78 1.07 TSS 3.64 1.73 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (i) Surface treatment rinse. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc surface treated Chromium 1.58 0.645 Copper 6.80 3.58 Cyanide 1.04 0.430 Zinc 5.23 2.19 Oil and grease 71.6 43.0 TSS 147 69.8 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (j) Alkaline cleaning spent baths. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc alkaline cleaned Chromium 0.002 0.0007 Copper 0.007 0.004 Cyanide 0.001 0.0004 Zinc 0.005 0.002 Oil and grease 0.071 0.043 TSS 0.146 0.069 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (k) Alkaline cleaning rinse. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc alkaline cleaned Chromium 0.744 0.304 Copper 3.21 1.69 Cyanide 0.490 0.203 Zinc 2.47 1.03 Oil and grease 33.8 20.3 TSS 69.3 33.0 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (l) Sawing or grinding spent emulsions. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc sawed or ground with emulsions Chromium 0.011 0.005 Copper 0.045 0.024 Cyanide 0.007 0.003 Zinc 0.035 0.015 Oil and grease 0.476 0.286 TSS 0.976 0.464 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (m) Electrocoating rinse. Subpart H—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of zinc electrocoated Chromium 1.01 0.412 Copper 4.35 2.29 Cyanide 0.664 0.275 Zinc 3.35 1.40 Oil and grease 45.8 27.5 TSS 93.9 44.7 pH ( 1 ) ( 1 ) 1 Within the range of 7.5 to 10.0 at all times. (n) Degreasing spent solvents—subpart H—BPT. There shall be no discharge of process wastewater pollutants. [50 FR 34270, Aug. 23, 1985; 51 FR 2888, Jan. 22, 1986]