40 CFR 437.11 - Effluent limitations attainable by the application of the best practicable control technology currently available (BPT).

Regulations last checked for updates: Feb 06, 2026

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

View all text of Subpart A [§ 437.10 - § 437.16]

§ 437.11 - Effluent limitations attainable by the application of the best practicable control technology currently available (BPT).

(a) Except as provided in 40 CFR 125.30 through 125.32 or § 437.10(b), any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BPT:

BPT Limitations

Regulated parameter	Maximum daily ¹	Maximum monthly avg. ¹
Conventional Parameters
O&G	205	50.2
pH	( ²)	( ²)
TSS	60.0	31.0
Metal Parameters
Antimony	0.249	0.206
Arsenic	0.162	0.104
Cadmium	0.474	0.0962
Chromium	15.5	3.07
Cobalt	0.192	0.124
Copper	4.14	1.06
Lead	1.32	0.283
Mercury	0.00234	0.000739
Nickel	3.95	1.45
Silver	0.120	0.0351
Tin	0.409	0.120
Titanium	0.0947	0.0618
Vanadium	0.218	0.0662
Zinc	2.87	0.641

¹ mg/L (ppm).

² Within the range 6 to 9.

(b) The following in-plant limitations apply to metal-bearing wastewater containing cyanide:

In-Plant Limitations

Regulated parameter	Maximum daily ¹	Maximum monthly avg. ¹
Cyanide	500	178

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 437.11