40 CFR 437.25 - Pretreatment standards for existing sources (PSES).

Regulations last checked for updates: Feb 11, 2026

Title 40 - Protection of Environment last revised: Dec 22, 2026

View all text of Subpart B [§ 437.20 - § 437.26]

§ 437.25 - Pretreatment standards for existing sources (PSES).

Except as provided in 40 CFR 403.7, 403.13 or § 437.20(b), and no later than December 22, 2003, any existing source subject to this subpart must achieve the following pretreatment standards:

Pretreatment Standards (PSES)

Regulated parameter	Maximum daily ¹	Maximum monthly avg. ¹
Metal Parameters
Chromium	0.947	0.487
Cobalt	56.4	18.8
Copper	0.405	0.301
Lead	0.222	0.172
Tin	0.249	0.146
Zinc	6.95	4.46
Organic Parameters
Bis(2-ethylhexyl) phthalate	0.267	0.158
Carbazole	0.392	0.233
n-Decane	5.79	3.31
Fluoranthene	0.787	0.393
n-Octadecane	1.22	0.925

¹ mg/L (ppm).

[65 FR 81300, Dec. 22, 2000, as amended at 68 FR 71023, Dec. 22, 2003]

authority: 33 U.S.C. 1311,1314,1316,1317,1318,1342,and

source: 65 FR 81300, Dec. 22, 2000, unless otherwise noted.

cite as: 40 CFR 437.25