$ 467.21 Specialized definitions.

For the purpose of this subpart:

(a) The “core” of the rolling with emulsions subcategory shall include rolling using emulsions, roll grinding, stationary casting, homogenizing, artificial aging, annealing, and sawing.

(b) The term “ancillary operation” shall mean any operation not previously included in the core, performed on-site, following or preceding the rolling operation. The ancillary operations shall include direct chill casting, solution heat treatment, cleaning or etching, and degassing.

mg/off-kg (lb/million off-lbs) of

aluminum cast

Chromium

0.59

0.24 Cyanide

0.39

0.16 Zinc

1.94

0.81 Aluminum

8.55

4.26 Oil and grease

26.58

15.95 Suspended solids

54.49

25.92 PH

(')

(") * The pH shall be maintained within the range of 7.0 to 10.0 at all times except for those situations when this waste stream is discharged separately and without commingling with any other wastewater in which case the pH shall be within the range of 6.0 to 10.0 at all times.

SUBPART B

$467.22 Effluent limitations rep

resenting 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.

Chromium

0.49

0.20 Cyanide

0.27

0.11 Zinc

1.36

0.56 Aluminum

8.12

3.60 Oil and grease

13.29

13.29 Suspended solids

19.94

15.95 pH

(")

(') "The pH shall be maintained within the range of 7.0 to 10.0 at all times except for those situations when this waste stream is discharged separately and without commingling with any other wastewater in which case the pH shall be within the range of 6.0 to 10.0 at all times.

208-169 D-21