Code of Federal Regulations (alpha)

CFR /  Title 40  /  Part 471  /  Sec. 471.21 Effluent limitations representing the degree of effluent reduction

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.

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 0.014Zinc........................................ 0.109 0.046Ammonia..................................... 9.95 4.37Fluoride.................................... 4.440 1.97Oil and grease.............................. 1.49 0.895TSS......................................... 3.06 1.46pH.......................................... ............ (\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 0.520Zinc........................................ 4.22 1.77Ammonia..................................... 385 170Fluoride.................................... 172 76.3Oil and grease.............................. 57.8 34.7TSS......................................... 119 56.4pH.......................................... ............ (\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 0.007Zinc.......................................... 0.059 0.025Ammonia....................................... 5.32 2.34Fluoride...................................... 2.38 1.06Oil and grease................................ 0.798 0.479TSS........................................... 1.64 0.778pH............................................ ........... (\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 0.711Zinc........................................ 5.77 2.41Ammonia..................................... 527 232Fluoride.................................... 235 105Oil and grease.............................. 79.0 47.4TSS......................................... 162 77.1pH.......................................... ............ (\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 0.084Zinc........................................ 0.681 0.285Ammonia..................................... 62.1 27.3Fluoride.................................... 27.8 12.3Oil and grease.............................. 9.32 5.59TSS......................................... 19.1 9.09pH.......................................... ............ (\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 3.4Zinc........................................ 27.6 11.5Ammonia..................................... 2520 1110Fluoride.................................... 1130 499Oil and grease.............................. 378 227TSS......................................... 775 369pH.......................................... ............ (\1\)------------------------------------------------------------------------\1\ Within the range of 7.5 to 10.0 at all times.

(h) Sawing or grinding spent emulsions.

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 0.004Zinc........................................ 0.029 0.012Ammonia..................................... 2.60 1.15Fluoride.................................... 1.16 0.515Oil and grease.............................. 0.390 0.234TSS......................................... 0.800 0.381pH.......................................... ............ (\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 0.112Zinc........................................ 0.904 0.378Ammonia..................................... 82.5 36.3Fluoride.................................... 36.9 16.4Oil and grease.............................. 12.4 7.43TSS......................................... 25.4 12.1pH.......................................... ............ (\1\)------------------------------------------------------------------------\1\ Within the range of 7.5 to 10.0 at all times.