40 CFR 439.4 - General limitation or standard for pH.

Regulations last checked for updates: Feb 11, 2026

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

§ 439.4 - General limitation or standard for pH.

The pH must remain within the range 6.0 to 9.0 in any discharge subject to BPT, BCT or NSPS limitations or standards in this part.

[68 FR 12271, Mar. 13, 2003]

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

source: 48 FR 49821, Oct. 27, 1983, unless otherwise noted.

cite as: 40 CFR 439.4