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

§ 420.122 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 representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

(a) Galvanizing, terne coating, and other coatings -

(1) Strip, sheet, and miscellaneous products.

Subpart L

Pollutant or pollutant property	BPT effluent limitations
	Maximum for any 1 day	Average of daily values for 30 consecutive days
	Kg/kkg (pounds per 1,000 lb) of product
TSS	0.175	0.0751
O&G	0.0751	0.0250
Lead	0.00113	0.000376
Zinc	0.00150	0.000500
Chromium (hexavalent)1	0.000150	0.0000501
pH	(2)	(2)

¹ The limitations for hexavalent chromium shall apply only to galvanizing operations which discharge wastewaters from the chromate rinse step.

² Within the range of 6.0 to 9.0.

(2) [Reserved]

(b) Galvanizing and other coatings -

(1) Wire products and fasteners.

Subpart L

Pollutant or pollutant property	BPT effluent limitations
	Maximum for any 1 day	Average of daily values for 30 consecutive days
	Kg/kkg (pounds per 1,000 lb) of product
TSS	0.701	0.300
O&G	0.300	0.100
Lead	0.00451	0.00150
Zinc	0.00601	0.00200
Chromium (hexavalent)1	0.000600	0.000200
pH	(2)	(2)

¹ The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge wastewaters from the chromate rinse step.

² Within the range of 6.0 to 9.0.

(2) [Reserved]

(c) Fume scrubbers.

Subpart L

Pollutant or pollutant property	BPT effluent limitations
	Maximum for any 1 day	Average of daily values for 30 consecutive days
	Kg per day
TSS	38.1	16.3
O&G	16.3	5.45
Lead	0.245	0.0819
Zinc	0.327	0.109
Chromium (hexavalent)1	0.0327	0.0109
pH	(2)	(2)

¹ The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge wastewaters from the chromate rinse step.

² Within the range of 6.0 to 9.0.

The above limitations shall be applicable to each fume scrubber associated with any of the coating operations specified above.

[47 FR 23284, May 27, 1982; 47 FR 41739, Sept. 22, 1982, as amended at 49 FR 21036, May 17, 1984]