Regulations last checked for updates: May 18, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
§ 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
Chromium0.0330.014
Zinc0.1090.046
Ammonia9.954.37
Fluoride4.441.97

(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
Chromium0.1270.052
Zinc0.4220.177
Ammonia38.517.0
Fluoride17.27.63

(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
Chromium0.0020.0007
Zinc0.0060.003
Ammonia0.5320.234
Fluoride0.2380.106

(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
Chromiun1.740.711
Zinc5.772.41
Ammonia527232
Fluoride235105

(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
Chromiun0.2050.084
Zinc0.6810.285
Ammonia62.127.3
Fluoride27.812.3

(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
Chromiun0.8320.340
Zinc2.761.16
Ammonia252111
Fluoride11349.9

(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
Chromiun0.0090.004
Zinc0.0290.012
Ammonia2.601.15
Fluoride1.160.515

(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
Chromium0.2730.112
Zinc0.9040.378
Ammonia8.2536.3
Fluoride36.916.4
[50 FR 34270, Aug. 23, 1985; 51 FR 2884, Jan. 22, 1986]
authority: Secs. 301, 304(b), (c), (e), and (g), 306(b) and (c), 307, 308, and 501 of the Clean Water Act (the Federal Water Pollution Control Act Amendments of 1972 as amended by the Clean Water Act of 1977) (the “Act”); 33 U.S.C. 1311,1314,c,e,and, 1316(b) andc,and; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217
source: 50 FR 34270, Aug. 23, 1985, unless otherwise noted.
cite as: 40 CFR 471.24