{"data":{"id":"us/40-cfr-421.293","jurisdiction":"us","citation":"40 CFR 421.293","heading":"Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable.","body":"Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable:\n(a) Tin smelter SO2 scrubber.\nBAT Limitations 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.\nBAT Limitations 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.\nBAT Limitations 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.\nBAT Limitations 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.\nBAT Limitations 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.\nBAT Limitations 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.\nBAT Limitations 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 21.240\n(h) Tin hydroxide supernatant from plating solutions and sludges.\nBAT Limitations 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.\nBAT Limitations 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":"f352fcf592c9b5ae0b5112735e0083773efd4f139c85058e669b2dcaf9e50dd1","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-421.292","next":"us/40-cfr-421.294"},"notice":"GroundRules: Original legal text. Not legal advice."}