---
kind: "section"
citation: "40 C.F.R. § 439.42"
title: "40"
number: "439.42"
heading: "Effluent limitations attainable by the application of the best practicable control technology currently available (BPT)."
url: "https://uscodex.org/cfr/40/439.42"
---

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


Except as provided in [40 CFR 125.30 through 125.32](/cfr/40/125.30..125.32.md), any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BPT:

- (a) The limitation for BOD5 is the same as specified in [§ 439.12(a)](/cfr/40/439.12.md?p=a). No facility shall be required to attain a monthly average limitation for BOD5 that is less than the equivalent of 45 mg/L.
- (b) The limitation for TSS is the same as specified in [§ 439.12(b)](/cfr/40/439.12.md?p=b).
- (c) The limitations for COD are the same as specified in § [439.22(c)](/cfr/40/439.22.md?p=c) and [(d)](/cfr/40/439.22.md?p=d).

## Notes

### Amendments

[63 FR 50435, Sept. 21, 1998, as amended at 68 FR 12274, Mar. 13, 2003]

### Authority

Authority: 33 U.S.C. 1311, 1314, 1316, 1317, 1318, 1342 and 1361.

### Source

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

### Amendments

[63 FR 50435, Sept. 21, 1998, as amended at 68 FR 12274, Mar. 13, 2003]