415.24—Pretreatment standards for existing sources (PSES).
         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):
    
    | Pollutant or pollutant property | PSES limitations | |
|---|---|---|
| Maximum for any 1 day | Average of daily values for 30 consecutive days | |
| Milligrams per liter (mg/l) | ||
| Zinc | 5.0 | 2.5 |