Pretreatment standards for existing sources.

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. The mass of wastewater pollutants in primary rare earth metals process wastewater introduced into a POTW must not exceed the following values: (a) Dryer vent water quench scrubber. PSES for the Primary Rare Earth Metals Subcategory Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/kg (pounds per million pounds) of mischmetal produced from wet rare earth chlorides Hexachlorobenzene 0.042 0.042 Chromium (total) 1.544 0.626 Lead 1.168 0.542 Nickel 2.295 1.544 (b) Dryer vent caustic wet air pollution control. PSES for the Primary Rare Earth Metals Subcategory Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/kg (pounds per million pounds) of mischmetal produced from wet rare earth chlorides Hexachlorobenzene 0.007 0.007 Chromium (total) 0.272 0.110 Lead 0.206 0.095 Nickel 0.404 0.272 (c) Electrolytic cell water quench and scrubber. PSES for the Primary Rare Earth Metals Subcategory Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/kg (pounds per million pounds) of total mischmetal produced Hexachlorobenzene 0.094 0.094 Chromium (total) 3.474 1.409 Lead 2.629 1.221 Nickel 5.165 3.474 (d) Electrolytic cell caustic wet air pollution control. PSES for the Primary Rare Earth Metals Subcategory Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/kg (pounds per million pounds) of total mischmetal produced Hexachlorobenzene 0.000 0.000 Chromium (total) 0.000 0.000 Lead 0.000 0.000 Nickel 0.000 0.000 (e) Sodium hypochlorite filter backwash. PSES for the Primary Rare Earth Metals Subcategory Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/kg (pounds per million pounds) of total mischmetal produced Hexachlorobenzene 0.004 0.004 Chromium (total) 0.134 0.054 Lead 0.101 0.047 Nickel 0.199 0.134