{"data":{"id":"us/40-cfr-471.31","jurisdiction":"us","citation":"40 CFR 471.31","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 125.30-125.32, any existing point source sub-\nject 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 C—BPT. There shall be no discharge of process wastewater pollutants.\n(b) Rolling spent emulsions.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt rolled with emulsions\nChromium 0.075 0.031\nNickel 0.327 0.216\nFluoride 10.1 4.49\nOil and grease 3.4 2.04\nTSS 6.97 3.32\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(c) Rolling contact cooling water.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt rolled with water\nChromium 1.66 0.679\nNickel 7.24 4.79\nFluoride 225 99.6\nOil and grease 75.4 45.3\nTSS 155 73.5\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(d) Tube Reducing Spent Lubricant—subpart C—BPT. (1) There shall be no discharge of process wastewater pollutants except as provided under paragraph (d)(2) of this section.\n(2) Process wastewater pollutants may be discharged, with no allowance for any pollutants discharged, provided the facility owner or operator demonstrates, on the basis of analytical methods set forth in or approved pursuant to 40 CFR part 136, that the concentrations of nitrosamine compounds in the wastewater discharged from the tube reducing process do not exceed 0.050 mg/l of N-nitrosodimethylamine, 0.020 mg/l of N-nitrosodiphenylamine, and 0.020 mg/l of N-nitrosodi-n-propylamine.\n(3) The demonstration required under paragraph (d)(2) of this section shall be made once per month until the demonstration has been made for all three nitrosamine compounds for six consecutive months, after which time the demonstration may be made once per quarter. If a sample is found to contain any of the foregoing nitrosamine compounds at concentrations greater than those specified in paragraph (d)(2) of this section, the actions described in paragraph (d)(4) of this section shall be taken, and the demonstration required under paragraph (d)(2) of this section shall be made once per month until it has been made for all three nitrosamine compounds for six consecutive months.\n(4) If sampling results show that any of the foregoing nitrosamine compounds is present in the process wastewater at concentrations greater than those specified in paragraph (d)(2) of this section, the facility owner or operator shall ensure that, within thirty days of receiving written notification of the sampling results, there is no further discharge of tube reducing spent lubricant wastewater until the owner or operator:\n(i) Performs a subsequent analysis which demonstrates that the concentrations of the foregoing nitrosamine compounds do not exceed the levels specified in paragraph (d)(2) of this section; or\n(ii) Substitutes a new tube reducing lubricant and thereafter complies with the requirements of paragraph (d)(3) of this section; or\n(iii) Determines the source of the pollutant whose concentration exceeded the level specified in paragraph (d)(2) of this section and demonstrates to the satisfaction of the NPDES issuing authority that such source has been eliminated.\n(5) The concentration limits specified in paragraph (d)(2) of this section apply at the point of discharge from the tube reducing process. However, sampling after the tube reducing wastewater has been commingled with other wastewaters is permitted if:\n(i) Any dilution caused by the other wastewaters is taken into account in determining the appropriate (i.e., lower) allowable discharge concentration; and\n(ii) An analytical method of sufficient sensitivity is used to measure the levels of each of the foregoing nitrosamine compounds in the wastewaters being sampled.\n(e) Drawing spent neat oils—subpart C—BPT. There shall be no discharge of process wastewater pollutants\n(f) Drawing spent emulsions.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt drawn with emulsions\nChromium 0.042 0.017\nNickel 0.183 0.121\nFluoride 5.68 2.52\nOil and grease 1.91 1.15\nTSS 3.91 1.86\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(g) Extrusion spent lubricants—subpart C—BPT. There shall be no discharge of process wastewater pollutants.\n(h) Extrusion press or solution heat treatment contact cooling water.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt heat treated\nChromium 0.037 0.015\nNickel 0.160 0.106\nFluoride 4.95 2.20\nOil and grease 1.67 0.999\nTSS 3.41 1.63\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(i) Extrusion press hydraulic fluid leakage.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt extruded\nChromium 0.102 0.042\nNickel 0.446 0.295\nFluoride 13.8 6.13\nOil and grease 4.64 2.79\nTSS 9.51 4.53\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(j) Forging equipment cleaning wastewater.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt forged\nChromium 0.018 0.007\nNickel 0.077 0.051\nFluoride 2.38 1.06\nOil and grease 0.800 0.480\nTSS 1.640 0.780\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(k) Forging contact cooling water.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of forged nickel-cobalt cooled with water\nChromium 0.209 0.086\nNickel 0.910 0.602\nFluoride 28.2 12.5\nOil and grease 9.48 5.69\nTSS 19.5 9.25\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(l) Forging press hydraulic fluid leakage.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt forged\nChromium 0.083 0.034\nNickel 0.359 0.238\nFluoride 11.2 4.94\nOil and grease 3.74 2.25\nTSS 7.67 3.65\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(m) Forging spent lubricants—subpart C—BPT. There shall be no discharge of process wastewater pollutants.\n(n) Stationary casting contact cooling water.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt cast with stationary casting methods\nChromium 5.33 2.18\nNickel 23.3 15.4\nFluoride 720 320\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(o) Vacuum melting steam condensate—subpart C—BPT. There shall be no allowance for the discharge of process wastewater pollutants.\n(p) Metal powder production atomization wastewater.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt metal powder atomized\nChromium 1.16 0.472\nNickel 5.03 3.33\nFluoride 156 69.2\nOil and grease 52.4 31.5\nTSS 108 51.1\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(q) Annealing and solution heat treatment contact cooling water—subpart C—BPT. There shall be no allowance for the discharge of process wastewater pollutants.\n(r) Wet air pollution control scrubber blowdown.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt formed\nChromium 0.357 0.146\nNickel 1.56 1.03\nFluoride 48.2 21.4\nOil and grease 16.2 9.72\nTSS 33.2 15.8\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(s) Surface treatment spent baths.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt surface treated\nChromium 0.412 0.169\nNickel 1.80 1.19\nFluoride 55.7 24.7\nOil and grease 18.7 11.2\nTSS 38.4 18.3\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(t) Surface treatment rinse.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt surface treated\nChromium 10.4 4.25\nNickel 45.3 30.0\nFluoride 1410 623\nOil and grease 472 283\nTSS 968 460\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(u) Alkaline cleaning spent baths.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt alkaline cleaned\nChromium 0.015 1.52\nNickel 16.2 10.7\nFluoride 502 223\nOil and grease 169 101\nTSS 346 165\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(v) Alkaline cleaning rinse.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt alkaline cleaned\nChromium 1.03 0.420\nNickel 4.48 2.96\nFluoride 139 61.5\nOil and grease 46.6 28.0\nTSS 95.6 45.5\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(w) Molten salt rinse.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt treated with molten salt\nChromium 3.72 1.52\nNickel 16.2 10.7\nFluoride 502 223\nOil and grease 169 101\nTSS 346 165\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(x) Ammonia rinse.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt treated with ammonia solution\nChromium 0.007 0.003\nNickel 0.029 0.019\nFluoride 0.881 0.391\nOil and grease 0.296 0.178\nTSS 0.607 0.289\npH (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(y) Sawing or grinding spent emulsions.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt sawed or ground with emulsions\nChromium 0.018 0.007\nNickel 0.076 0.050\nFluoride 2.35 1.04\nOil and grease 0.788 0.473\nTSS 1.62 0.769\npH (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(z) Sawing or grinding rinse.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of sawed or ground nickel-cobalt rinsed\nChromium 0.797 0.326\nNickel 3.48 2.30\nFluoride 108 47.8\nOil and grease 36.2 21.7\nTSS 74.2 35.3\npH (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(aa) Steam Cleaning Condensate.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt steam cleaned\nChromium 0.013 0.006\nNickel 0.058 0.039\nFluoride 1.79 0.795\nOil and grease 0.602 0.361\nTSS 1.24 0.587\npH (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(bb) Hydrostatic tube testing and ultrasonic testing wastewater—subpart C—BPT. There shall be no allowance for the discharge of process wastewater pollutants.\n(cc) Degreasing spent solvents—subpart C—BPT. There shall be no discharge of process wastewater pollutants.\n(dd) Dye penetrant testing wastewater.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt tested with dye penetrant method\nChromium 0.094 0.039\nNickel 0.409 0.271\nFluoride 12.7 5.63\nOil and grease 4.26 2.56\nTSS 8.74 4.16\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(ee) Electrocoating rinse.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt electrocoated\nChromium 1.48 0.607\nNickel 6.47 4.28\nFluoride 201 89.0\nOil and grease 67.4 40.5\nTSS 138 65.7\npH (1) (1)\n1 Within the range of 7.5 to 10.0 at all times.\n(ff) Miscellaneous wastewater sources.\nSubpart C—BPT\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/off-kg (pounds per million off-pounds) of nickel-cobalt formed\nChromium 0.108 0.044\nNickel 0.473 0.313\nFluoride 14.7 6.50\nOil and grease 4.92 2.95\nTSS 10.1 4.80\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 471—NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY","Subpart C—Nickel-Cobalt 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":"bdd41bcb3797fc1ca89c603b3b77d56be8b302e658548778a08d53f55c3b52e9","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-471.30","next":"us/40-cfr-471.32"},"notice":"GroundRules: Original legal text. Not legal advice."}