Pretreatment standards for existing sources (PSES).

(a) Except as provided in § 425.04 and 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 achieve the following pretreatment standards: Pollutant or pollutant property PSES Maximum for any 1 day Maximum for monthly average Milligrams per liter (mg/l) Sulfide 24 Total chromium 12 8 pH ( 1 ) ( 1 ) 1 Not less than 7.0. (b) Any existing source subject to this subpart which processes less than 275 hides/day shall comply with § 425.15(a), except that the total chromium limitations contained in § 425.15(a) do not apply. [47 FR 52870, Nov. 23, 1982; 48 FR 30116, June 30, 1983, as amended at 53 FR 9182, Mar. 21, 1988; 61 FR 35685, July 8, 1996]