[Code of Federal Regulations] [Title 40, Volume 27] [Revised as ofJuly 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR471.21] [Page 697-699] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 471--NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY--Table of Contents Subpart B--Magnesium Forming Subcategory Sec. 471.21 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). 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): (a) Rolling spent emulsions. [[Page 698]] Subpart B--BPT ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/off-kg (pounds per million off-pounds) of magnesium rolled with emulsions --------------- Chromiun.................................... 0.033 0.014 Zinc........................................ 0.109 0.046 Ammonia..................................... 9.95 4.37 Fluoride.................................... 4.440 1.97 Oil and grease.............................. 1.49 0.895 TSS......................................... 3.06 1.46 pH.......................................... ............ (\1\) ------------------------------------------------------------------------ \1\ Within the range of 7.5 to 10.0 at all times. (b) Forging spent lubricants--Subpart B--BPT. There shall be no discharge of process wastewater pollutants. (c) Forging contact cooling water. Subpart B--BPT ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/off-kg (pounds per million off-pounds) of forged magnesium cooled with water --------------- Chromium.................................... 1.27 0.520 Zinc........................................ 4.22 1.77 Ammonia..................................... 385 170 Fluoride.................................... 172 76.3 Oil and grease.............................. 57.8 34.7 TSS......................................... 119 56.4 pH.......................................... ............ (\1\) ------------------------------------------------------------------------ \1\ Within the range of 7.5 to 10.0 at all times. (d) Forging equipment cleaning wastewater. Subpart B--BPT ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/off-kg (pounds per million off-pounds) of magnesium forged -------------- Chromium...................................... 0.018 0.007 Zinc.......................................... 0.059 0.025 Ammonia....................................... 5.32 2.34 Fluoride...................................... 2.38 1.06 Oil and grease................................ 0.798 0.479 TSS........................................... 1.64 0.778 pH............................................ ........... (\1\) ------------------------------------------------------------------------ \1\ Within the range of 7.5 to 10.0 at all times. (e) Direct chill casting contact cooling water. Subpart B--BPT ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/off-kg (pounds per million off-pounds) of magnesium cast with direct chill methods --------------- Chromium.................................... 1.74 0.711 Zinc........................................ 5.77 2.41 Ammonia..................................... 527 232 Fluoride.................................... 235 105 Oil and grease.............................. 79.0 47.4 TSS......................................... 162 77.1 pH.......................................... ............ (\1\) ------------------------------------------------------------------------ \1\ Within the range of 7.5 to 10.0 at all times. (f) Surface treatment spent baths. Subpart B--BPT ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/off-kg (pounds per million off-pounds) of magnesium surface treated --------------- Chromium.................................... 0.205 0.084 Zinc........................................ 0.681 0.285 Ammonia..................................... 62.1 27.3 Fluoride.................................... 27.8 12.3 Oil and grease.............................. 9.32 5.59 TSS......................................... 19.1 9.09 pH.......................................... ............ (\1\) ------------------------------------------------------------------------ \1\ Within the range of 7.5 to 10.0 at all times. (g) Surface treatment rinse. Subpart B--BPT ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/off-kg (pounds per million off-pounds) of magnesium surface treated --------------- Chromium.................................... 8.32 3.4 Zinc........................................ 27.6 11.5 Ammonia..................................... 2520 1110 Fluoride.................................... 1130 499 Oil and grease.............................. 378 227 TSS......................................... 775 369 pH.......................................... ............ (\1\) ------------------------------------------------------------------------ \1\ Within the range of 7.5 to 10.0 at all times. (h) Sawing or grinding spent emulsions. [[Page 699]] Subpart B--BPT ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/off-kg (pounds per million off-pounds) of magnesium sawed or ground --------------- Chromium.................................... 0.009 0.004 Zinc........................................ 0.029 0.012 Ammonia..................................... 2.60 1.15 Fluoride.................................... 1.16 0.515 Oil and grease.............................. 0.390 0.234 TSS......................................... 0.800 0.381 pH.......................................... ............ (\1\) ------------------------------------------------------------------------ \1\ Within the range of 7.5 to 10.0 at all times. (i) Degreasing spent solvents--Subpart B--BPT. There shall be no discharge of process wastewater pollutants. (j) Wet air pollution control scrubber blowdown. Subpart B--BPT ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/off-kg (pounds per million off-pounds) of magnesium sanded and repaired or forged --------------- Chromium.................................... 0.273 0.112 Zinc........................................ 0.904 0.378 Ammonia..................................... 82.5 36.3 Fluoride.................................... 36.9 16.4 Oil and grease.............................. 12.4 7.43 TSS......................................... 25.4 12.1 pH.......................................... ............ (\1\) ------------------------------------------------------------------------ \1\ Within the range of 7.5 to 10.0 at all times.