{"data":{"id":"us/40-cfr-471.41","jurisdiction":"us","citation":"40 CFR 471.41","heading":"Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).","body":"Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations for the process operations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT):\n(a) Rolling spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.\n(b) Rolling spent emulsions.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals rolled with emulsions\nChromium 0.026 0.012\nCopper 0.147 0.077\nCyanide 0.023 0.010\nSilver 0.032 0.013\nOil and grease 1.54 0.925\nTSS 3.16 1.51\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(c) Drawing spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.\n(d) Drawing spent emulsions.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals drawn with emulsions\nCadmium 0.016 0.007\nCopper 0.091 0.048\nCyanide 0.014 0.006\nSilver 0.020 0.008\nOil and grease 0.950 0.570\nTSS 1.95 0.926\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(e) Drawing spent soap solutions.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals drawn with soap solutions\nCadmium 0.001 0.0005\nCopper 0.006 0.003\nCyanide 0.0009 0.0004\nSilver 0.001 0.0006\nOil and grease 0.063 0.038\nTSS 0.128 0.061\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(f) Metal powder production wet atomization wastewater.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals powder wet atomized\nCadmium 2.27 1.00\nCopper 12.7 6.70\nCyanide 1.94 0.802\nSilver 2.70 1.14\nOil and grease 134 80.2\nTSS 274 130\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(g) Heat treatment contact cooling water.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of extruded precious metals heat treated\nCadmium 1.42 0.626\nCopper 7.93 4.17\nCyanide 1.21 0.501\nSilver 1.71 0.709\nOil and grease 83.4 50.1\nTSS 171 81.3\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(h) Semi-continuous or continuous casting contact cooling water.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals cast by the semi-continuous or continuous method\nCadmium 3.50 1.55\nCopper 19.6 10.3\nCyanide 2.99 1.24\nSilver 4.23 1.75\nOil and grease 206 124\nTSS 423 209\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(i) Stationary casting contact cooling water—subpart D—BPT. There shall be no discharge of process wastewater pollutants.\n(j) Direct chill casting contact cooling water.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals cast by the direct chill method\nCadmium 3.67 1.62\nCopper 20.5 10.8\nCyanide 3.13 1.30\nSilver 4.43 1.84\nOil and grease 216 130\nTSS 443 211\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(k) Shot casting contact cooling water.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals shot cast\nCadmium 1.25 0.551\nCopper 6.98 3.67\nCyanide 1.07 0.441\nSilver 1.51 0.624\nOil and grease 73.4 44.1\nTSS 151 71.6\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(l) Wet air pollution control scrubber blowdown—subpart D—BPT. There shall be no discharge of process wastewater pollutants.\n(m) Pressure bonding contact cooling water.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals and base metal pressure bonded\nCadmium 0.029 0.013\nCopper 0.159 0.084\nCyanide 0.024 0.010\nSilver 0.034 0.014\nOil and grease 1.67 1.00\nTSS 3.43 1.63\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(n) Surface treatment spent baths.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals surface treated\nCadmium 0.033 0.015\nCopper 0.183 0.097\nCyanide 0.028 0.012\nSilver 0.040 0.017\nOil and grease 1.93 1.16\nTSS 3.95 1.88\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(o) Surface treatment rinse.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals surface treated\nCadmium 2.10 0.924\nCopper 11.7 5.16\nCyanide 1.79 0.739\nSilver 2.53 1.05\nOil and grease 123 73.9\nTSS 253 120\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(p) Alkaline cleaning spent baths.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals alkaline cleaned\nCadmium 0.021 0.009\nCopper 0.114 0.060\nCyanide 0.018 0.007\nSilver 0.025 0.010\nOil and grease 1.20 0.720\nTSS 2.46 1.170\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(q) Alkaline cleaning rinse.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals alkaline cleaned\nCadmium 3.81 1.68\nCopper 21.3 11.2\nCyanide 3.25 1.35\nSilver 4.59 1.91\nOil and grease 224 135\nTSS 459 219\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(r) Alkaline cleaning prebonding wastewater.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals and base metal cleaned prior to bonding\nCadmium 3.95 1.74\nCopper 22.1 11.6\nCyanide 3.37 1.39\nSilver 4.76 1.97\nOil and grease 232 139\nTSS 476 226\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(s) Tumbling or burnishing wastewater.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals tumbled or burnished\nCadmium 4.12 1.82\nCopper 23.0 12.1\nCyanide 3.51 1.45\nSilver 4.96 2.06\nOil and grease 242 145\nTSS 496 236\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(t) Sawing or grinding spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.\n(u) Sawing or grinding spent emulsions.\nSubpart D—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of precious metals sawed or ground with emulsions\nCadmium 0.032 0.014\nCopper 0.178 0.094\nCyanide 0.027 0.011\nSilver 0.039 0.016\nOil and grease 1.87 1.12\nTSS 3.83 1.82\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(v) Degreasing spent solvents—subpart D—BPT. There shall be no discharge of process wastewater pollutants.","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 D—Precious Metals 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":"ac7c45b464a79f57dafdf6a1b64c5ebbc5d8fafc31f76707da6de90399108426","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-471.40","next":"us/40-cfr-471.42"},"notice":"GroundRules: Original legal text. Not legal advice."}