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 practicable control technology currently available:

Subpart C—BPT Effluent Limitations

Pollutant or pollutant propertyMaximum for any 1 dayMaximum for monthly average
Metal preparationCoating operationMetal preparationCoating operation
Metric units—mg/m2 of area processed or coated
Chromium16.346.326.632.56
Lead5.842.265.061.96
Nickel54.8521.2138.9015.04
Zinc51.7320.0121.798.43
Aluminum176.9868.4472.3527.98
Iron47.8518.5024.519.48
Oil and grease777.92300.84466.76108.50
TSS1,594.74616.68777.92300.82
pH(1)(1)(1)(1)
English units—pounds per 1 million ft2 of area processed or coated
Chromium3.351.301.370.53
Lead1.200.471.040.40
Nickel11.244.357.973.08
Zinc10.64.104.461.73
Aluminum36.2514.0214.825.73
Iron9.803.795.021.94
Oil and grease159.3361.6195.6036.97
TSS326.62126.33159.3361.61
pH(1)(1)(1)(1)

1 Within the range 7.5 to 10.0 at all times.