{"data":{"id":"us/40-cfr-421.295","jurisdiction":"us","citation":"40 CFR 421.295","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 secondary tin process wastewater introduced into a POTW must not exceed the following values:\n(a) Tin smelter SO2 scrubber.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of crude tapped tin produced\nArsenic 12.790 5.703\nLead 2.575 1.196\nIron 11.040 5.611\nTin 3.495 2.024\n(b) Dealuminizing rinse.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of dealuminized scrap produced\nLead 0.010 0.005\nCyanide (total) 0.007 0.003\nFluoride 1.225 0.697\nTin 0.013 0.008\n(c) Tin mud acid neutralization filtrate.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of neutralized dewatered tin mud produced\nLead 1.413 0.656\nCyanide (total) 1.009 0.404\nFluoride 176.600 100.400\nTin 1.918 1.110\n(d) Tin hydroxide wash.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tin hydroxide washed\nLead 3.347 1.554\nCyanide (total) 2.391 0.956\nFluoride 418.400 237.900\nTin 4.542 2.630\n(e) Spent electrowinning solution from new scrap.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of cathode tin produced\nLead 4.704 2.184\nCyanide (total) 3.360 1.344\nFluoride 588.000 334.300\nTin 6.384 3.696\n(f) Spent electrowinning solution from municipal solid waste.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of MSW scrap used as raw material\nLead 0.033 0.015\nCyanide (total) 0.024 0.010\nFluoride 4.165 2.368\nTin 0.045 0.026\n(g) Tin hydroxide supernatant from scrap.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tin metal recovered from scrap\nLead 15.580 7.233\nCyanide (total) 11.130 4.451\nFluoride 1,947.000 1,107.000\nTin 21.140 12.240\n(h) Tin hydroxide supernatant from plating solutions and sludges.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tin metal recovered from plating solutions and sludges\nLead 32.20 14.95\nCyanide (total) 23.00 9.20\nFluoride 4,025.00 2,289.00\nTin 43.70 25.30\n(i) Tin hydroxide filtrate.\nPSES for the Secondary Tin Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tin metal produced\nLead 7.012 3.256\nCyanide (total) 5.009 2.004\nFluoride 876.500 498.400\nTin 9.517 5.510","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 AA—Secondary Tin 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":"97e435de7142b73b8e93cc7da6f02b3632427e7c39ec01e993c1b3b38c930f84","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-421.294","next":"us/40-cfr-421.296"},"notice":"GroundRules: Original legal text. Not legal advice."}