---
kind: "section"
citation: "40 C.F.R. § 420.45"
title: "40"
number: "420.45"
heading: "Pretreatment standards for existing sources (PSES)."
url: "https://uscodex.org/cfr/40/420.45"
---

# §420.45. Pretreatment standards for existing sources (PSES).


Except as provided in 40 CFR [403.7](/cfr/40/403.7.md) and [403.13](/cfr/40/403.13.md), any existing source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with [40 CFR part 403](/cfr/40/part403.md) and achieve the following pretreatment standards for existing sources.

- (a) **Electric arc furnace steelmaking—semi-wet.** No discharge of process wastewater pollutants to navigable waters.
- (b) **Basic oxygen furnace steelmaking—wet-suppressed combustion.**
- (c) **Basic oxygen furnace steelmaking—wet open combustion; and electric arc furnace steelmaking—wet.**
- (d) **Basic oxygen furnace steelmaking—semi-wet.**
  - (1) **No discharge of process wastewater pollutants to navigable waters.**
  - (2) If the permittee demonstrates to the satisfaction of the pretreatment control authority that safety considerations prevent attainment of these limitations, the pretreatment control authority may establish alternative limitations on a best professional judgment basis.

## Notes

### Amendments

[47 FR 23284, May 27, 1982, as amended at 67 FR 64267, Oct. 17, 2002]

### Authority

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

### Source

Source: 47 FR 23284, May 27, 1982, unless otherwise noted.

### Amendments

[47 FR 23284, May 27, 1982, as amended at 67 FR 64267, Oct. 17, 2002]