U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 27, 2025
Except as provided in 40 CFR 403.7 and 403.13, any existing source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and achieve the following pretreatment standards for existing sources (PSES):
Subpart L—Potassium Dichromate
| Pollutant or pollutant property | PSES limitations | |
|---|---|---|
| Maximum for any 1 day | Average of daily values for 30 consecutive days | |
| Milligrams per liter (mg/l) | ||
| Hexavalent chromium | 0.25 | 0.090 |
| Total chromium | 3.0 | 1.0 |
