{"data":{"id":"us/40-cfr-421.275","jurisdiction":"us","citation":"40 CFR 421.275","heading":"Pretreatment standards for existing sources.","body":"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:\n(a) Dryer vent water quench scrubber.\nPSES for the Primary Rare Earth Metals Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of mischmetal produced from wet rare earth chlorides\nHexachlorobenzene 0.042 0.042\nChromium (total) 1.544 0.626\nLead 1.168 0.542\nNickel 2.295 1.544\n(b) Dryer vent caustic wet air pollution control.\nPSES for the Primary Rare Earth Metals Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of mischmetal produced from wet rare earth chlorides\nHexachlorobenzene 0.007 0.007\nChromium (total) 0.272 0.110\nLead 0.206 0.095\nNickel 0.404 0.272\n(c) Electrolytic cell water quench and scrubber.\nPSES for the Primary Rare Earth Metals Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of total mischmetal produced\nHexachlorobenzene 0.094 0.094\nChromium (total) 3.474 1.409\nLead 2.629 1.221\nNickel 5.165 3.474\n(d) Electrolytic cell caustic wet air pollution control.\nPSES for the Primary Rare Earth Metals Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of total mischmetal produced\nHexachlorobenzene 0.000 0.000\nChromium (total) 0.000 0.000\nLead 0.000 0.000\nNickel 0.000 0.000\n(e) Sodium hypochlorite filter backwash.\nPSES for the Primary Rare Earth Metals Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of total mischmetal produced\nHexachlorobenzene 0.004 0.004\nChromium (total) 0.134 0.054\nLead 0.101 0.047\nNickel 0.199 0.134","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER N—EFFLUENT GUIDELINES AND STANDARDS","PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY","Subpart Y—Primary Rare Earth Metals Subcategory"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"fd1a16c74501fd2674728b67e090c1affe59d4f9fee5ea35cd57bc7baa3d3407","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-421.274","next":"us/40-cfr-421.276"},"notice":"GroundRules: Original legal text. Not legal advice."}