40 CFR 466.21: Effluent limitations 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 must achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

(a) There shall be no discharge of process wastewater pollutants from metal preparation operations.

(b) The discharge of process wasterwater pollutants from all porcelain enameling coating operations shall not exceed the values set forth below:

Subpart B—BPT Effluent Limitations

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

Mg/m2 (pounds per/1million ft 2) of Area Coated

Chromium 0.29 (0.06) 0.12 (0.024)

Lead 0.11 (0.02) 0.09 (0.02)

Nickle 0.98 (0.02) 0.7 (0.15)

Zinc 0.93 (0.19) 0.39 (0.08)

Aluminum 3.16 (0.65) 1.29 (0.27)

Iron 0.86 (0.18) 0.44 (0.09)

Oil and grease 13.86 (2.84) 8.32 (1.71)

TSS 28.42 (5.82) 13.86 (2.84)

pH (1) (1) (1) (1)

1 Within the range 7.5 to 10.0 at all times.