{"data":{"id":"us/40-cfr-421.312","jurisdiction":"us","citation":"40 CFR 421.312","heading":"Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.","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 practicable technology currently available:\n(a) Tungsten detergent wash and rinse.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tungsten scrap washed\nCopper 0.371 0.195\nNickel 0.374 0.248\nAmmonia (as N) 25.990 11.430\nCobalt 0.768 0.337\nTungsten 1.357 0.542\nOil and grease 3.900 2.340\nTotal suspended solids 7.995 3.803\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(b) Tungsten leaching acid.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tungsten produced\nCopper 4.885 2.571\nNickel 4.937 3.265\nAmmonia (as N) 342.700 150.700\nCobalt 10.130 4.448\nTungsten 17.890 7.147\nOil and grease 51.420 30.850\nTotal suspended solids 105.400 50.140\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(c) Tungsten post-leaching wash and rinse.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tungsten produced\nCopper 9.772 5.143\nNickel 9.875 6.532\nAmmonia (as N) 685.600 301.400\nCobalt 20.263 8.897\nTungsten 35.800 14.300\nOil and grease 102.900 61.720\nTotal suspended solids 210.900 100.300\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(d) Synthetic scheelite filtrate.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of synthetic scheelite produced\nCopper 31.660 16.660\nNickel 31.990 21.160\nAmmonia (as N) 2,221.000 976.300\nCobalt 65.644 28.824\nTungsten 116.000 46.320\nOil and grease 333.200 200.000\nTotal suspended solids 683.100 324.900\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(e) Tungsten carbide leaching wet air pollution control.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tungsten carbide scrap leached\nCopper 3.327 1.751\nNickel 3.362 2.224\nAmmonia (as N) 233.400 102.600\nCobalt 6.899 3.029\nTungsten 12.190 4.868\nOil and grease 35.020 21.010\nTotal suspended solids 71.790 34.150\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(f) Tungsten carbide wash water.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of tungsten carbide produced\nCopper 15.830 8.333\nNickel 16.000 10.580\nAmmonia (as N) 1,111.000 488.300\nCobalt 32.832 14.416\nTungsten 58.000 23.170\nOil and grease 166.700 100.000\nTotal suspended solids 341.700 162.500\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(g) Cobalt sludge leaching wet air pollution control.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of cobalt produced from cobalt sludge\nCopper 67.990 35.780\nNickel 68.700 45.440\nAmmonia (as N) 4,770.000 2,097.000\nCobalt 140.977 61.901\nTungsten 249.000 99.470\nOil and grease 715.600 429.400\nTotal suspended solids 1,467.000 697.700\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(h) Crystallization decant.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of cobalt produced\nCopper 79.140 41.650\nNickel 79.970 52.900\nAmmonia (as N) 5,552.000 2,441.000\nCobalt 164.101 72.055\nTungsten 289.900 115.800\nOil and grease 833.000 499.800\nTotal suspended solids 1,708.000 812.200\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(i) Acid wash decant.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of cobalt produced\nCopper 36.220 19.060\nNickel 36.600 24.210\nAmmonia (as N) 2,541.000 1,117.000\nCobalt 75.104 32.977\nTungsten 132.700 52.990\nOil and grease 381.300 228.800\nTotal suspended solids 781.600 371.700\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(j) Cobalt hydroxide filtrate.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of cobalt produced\nCopper 107.600 56.650\nNickel 108.800 71.940\nAmmonia (as N) 7,551.000 3,320.000\nCobalt 223.189 97.999\nTungsten 394.300 157.500\nOil and grease 1,133.000 679.800\nTotal suspended solids 2,323.000 1,105.000\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(k) Cobalt hydroxide filter cake wash.\nBPT Limitations for the Secondary Tungsten and Cobalt Subcategory\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/kg (pounds per million pounds) of cobalt produced\nCopper 207.200 109.100\nNickel 209.400 138.500\nAmmonia (as N) 14,530.000 6,389.000\nCobalt 429.598 188.631\nTungsten 758.900 303.100\nOil and grease 2,181.000 1,309.000\nTotal suspended solids 4,471.000 2,126.000\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.","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 AC—Secondary Tungsten and Cobalt 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":"8ee289c87b58b686182b25cf8b4b95b5af872d302c5e6d6d0a7fbd1aeac46fa3","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-421.311","next":"us/40-cfr-421.313"},"notice":"GroundRules: Original legal text. Not legal advice."}