{"data":{"id":"us/40-cfr-471.24","jurisdiction":"us","citation":"40 CFR 471.24","heading":"Pretreatment standards for existing sources (PSES).","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 by August 23, 1988 achieve the following pretreatment standards for existing sources (PSES). The mass of wastewater pollutants in magnesium forming process wastewater introduced into a POTW shall not exceed the following values:\n(a) Rolling spent emulsions.\nSubpart B—PSES\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of magnesium rolled with emulsions\nChromium 0.033 0.014\nZinc 0.109 0.046\nAmmonia 9.95 4.37\nFluoride 4.44 1.97\n(b) Forging spent lubricants—subpart B—PSE. There shall be no discharge of process wastewater pollutants.\n(c) Forging contact cooling water.\nSubpart B—PSES\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of magnesium cooled with water\nChromium 0.127 0.052\nZinc 0.422 0.177\nAmmonia 38.5 17.0\nFluoride 17.2 7.63\n(d) Forging equipment cleaning wastewater.\nSubpart B—PSES\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of magnesium forged\nChromium 0.002 0.0007\nZinc 0.006 0.003\nAmmonia 0.532 0.234\nFluoride 0.238 0.106\n(e) Direct chill casting contact cooling water.\nSubpart B—PSES\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of magnesium cast with direct chill methods\nChromiun 1.74 0.711\nZinc 5.77 2.41\nAmmonia 527 232\nFluoride 235 105\n(f) Surface treatment spent baths.\nSubpart B—PSES\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of magnesium surface treated\nChromiun 0.205 0.084\nZinc 0.681 0.285\nAmmonia 62.1 27.3\nFluoride 27.8 12.3\n(g) Surface treatment rinse.\nSubpart B—PSES\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of magnesium surface treated\nChromiun 0.832 0.340\nZinc 2.76 1.16\nAmmonia 252 111\nFluoride 113 49.9\n(h) Sawing or grinding spent emulsions.\nSubpart B—PSES\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of magnesium sawed or ground\nChromiun 0.009 0.004\nZinc 0.029 0.012\nAmmonia 2.60 1.15\nFluoride 1.16 0.515\n(i) Degreasing Spent Solvents—subpart B—PSES. There shall be no discharge of process wastewater pollutants.\n(j) Wet air pollution control scrubber blowdown.\nSubpart B—PSES\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of magnesium sanded and repaired or forged\nChromium 0.273 0.112\nZinc 0.904 0.378\nAmmonia 8.25 36.3\nFluoride 36.9 16.4","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER N—EFFLUENT GUIDELINES AND STANDARDS","PART 471—NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY","Subpart B—Magnesium Forming 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":"876e38dfaf68b0022f6c9bc7fe6264f3909bd3d30e3bb208db70bf525948ac22","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-471.23","next":"us/40-cfr-471.25"},"notice":"GroundRules: Original legal text. Not legal advice."}