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 process wastewater pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and meet the following pretreatment standards for existing sources (PSES): Subpart H [PSES Effluent Limitations] Pollutant or pollutant property Maximum for any 1 day (mg/l) Oil and grease 100 Copper 5 Chromium 4 Arsenic 4 In cases where POTWs find it necessary to impose mass limitations, the following equivalent mass limitations are provided as guidance. Subpart H [PSES Effluent Limitations; grams per cu m of production] Pollutant or pollutant property Maximum for any 1 day Oil and grease 20.5 Copper .62 Chromium .41 Arsenic .41