40 CFR 471.24: Pretreatment standards for existing sources (PSES).

Except as provided in 40 CFR 403.7 and 403.13, any existing source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and by August 23, 1988 achieve the following pretreatment standards for existing sources (PSES). The mass of wastewater pollutants in magnesium forming process wastewater introduced into a POTW shall not exceed the following values:

(a) Rolling spent emulsions.

Subpart B—PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

mg/off-kg (pounds per million off-pounds) of magnesium rolled with emulsions

Chromium 0.033 0.014

Zinc 0.109 0.046

Ammonia 9.95 4.37

Fluoride 4.44 1.97

(b) Forging spent lubricants—subpart B—PSE. There shall be no discharge of process wastewater pollutants.

(c) Forging contact cooling water.

Subpart B—PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

mg/off-kg (pounds per million off-pounds) of magnesium cooled with water

Chromium 0.127 0.052

Zinc 0.422 0.177

Ammonia 38.5 17.0

Fluoride 17.2 7.63

(d) Forging equipment cleaning wastewater.

Subpart B—PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

mg/off-kg (pounds per million off-pounds) of magnesium forged

Chromium 0.002 0.0007

Zinc 0.006 0.003

Ammonia 0.532 0.234

Fluoride 0.238 0.106

(e) Direct chill casting contact cooling water.

Subpart B—PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

mg/off-kg (pounds per million off-pounds) of magnesium cast with direct chill methods

Chromiun 1.74 0.711

Zinc 5.77 2.41

Ammonia 527 232

Fluoride 235 105

(f) Surface treatment spent baths.

Subpart B—PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

mg/off-kg (pounds per million off-pounds) of magnesium surface treated

Chromiun 0.205 0.084

Zinc 0.681 0.285

Ammonia 62.1 27.3

Fluoride 27.8 12.3

(g) Surface treatment rinse.

Subpart B—PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

mg/off-kg (pounds per million off-pounds) of magnesium surface treated

Chromiun 0.832 0.340

Zinc 2.76 1.16

Ammonia 252 111

Fluoride 113 49.9

(h) Sawing or grinding spent emulsions.

Subpart B—PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average

mg/off-kg (pounds per million off-pounds) of magnesium sawed or ground

Chromiun 0.009 0.004

Zinc 0.029 0.012

Ammonia 2.60 1.15

Fluoride 1.16 0.515

(i) Degreasing Spent Solvents—subpart B—PSES. There shall be no discharge of process wastewater pollutants.

(j) Wet air pollution control scrubber blowdown.

Subpart B—PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly 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 8.25 36.3

Fluoride 36.9 16.4