40 CFR § 421.95 - Pretreatment standards for existing sources.

Except as provided in 40 CFR 403.7 and 403.13, any existing source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and achieve the following pretreatment standards for existing sources. The mass of wastewater pollutants in metallurgical acid plant blowdown introduced into a POTW shall not exceed the following values:

Subpart I—Metallurgical Acid Plant—PSES

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pound per/million pounds) of 100 pct sulfuric acid capacity
Cadmium	0.511	0.204
Zinc	2.605	1.073

[50 FR 38343, Sept. 20, 1985]