Regulations last checked for updates: May 18, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
§ 471.23 - New source performance standards (NSPS).

Any new source subject to this subpart must achieve the following new source performance standards. The mass of pollutants in the magnesium forming process wastewater shall not exceed the following values:

(a) Rolling spent emulsions.

Subpart B—NSPS

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
Chromium0.0280.011
Zinc0.0760.032
Ammonia9.954.37
Fluoride4.441.97
Oil and grease0.7460.746
TSS1.120.895
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

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

(c) Forging contact cooling water.

Subpart B—NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off/kg (pounds per million off-pounds) of forged magnesium cooled with water
Chromium0.1070.044
Zinc0.2950.122
Ammonia38.517.0
Fluoride17.27.63
Oil and grease2.892.89
TSS4.343.47
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(d) Forging equipment cleaning wastewater.

Subpart B—NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off/kg (pounds per million off-pounds) of magnesium forged
Chromium0.0020.0006
Zinc0.0040.002
Ammonia0.5320.234
Fluoride0.2380.106
Oil and grease0.0400.040
TSS0.0600.048
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(e) Direct chill casting contact cooling water.

Subpart B—NSPS

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
Chromium1.460.593
Zinc4.031.66
Ammonia527232
Fluoride235105
Oil and grease39.539.5
TSS59.347.4
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(f) Surface treatment spent baths.

Subpart B—NSPS

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
Chromium0.1730.070
Zinc0.4760.196
Ammonia62.127.3
Fluoride27.812.3
Oil and grease4.664.66
TSS6.995.60
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times

(g) Surface treatment rinse.

Subpart B—NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/off-kg (pound pers million off-pounds) of magnesium surface treated
Chromium0.7000.284
Zinc1.930.794
Ammonia252111
Fluoride11349
Oil and grease18.918.9
TSS28.422.7
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times

(h) Sawing or grinding spent emulsions.

Subpart B—NSPS

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
Chromium0.0070.003
Zinc0.0200.008
Ammonia2.601.15
Fluoride1.160.515
Oil and grease0.1950.195
TSS0.2930.234
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

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

(j) Wet air pollution control scrubber blowdown.

Subpart B—NSPS

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
Chromium0.2290.093
Zinc0.6320.260
Ammonia82.536.3
Fluoride36.916.4
Oil and grease6.196.19
TSS9.297.43
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

[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 471.23