Regulations last checked for updates: May 18, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
§ 471.25 - Pretreatment standards for new sources (PSNS).

Except as provided in 40 CFR 403.7, any new source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and achieve the following pretreatment standards for new sources (PSNS). 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—PSNS

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

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

(c) Forging contact cooling water.

Subpart B—PSNS

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

(d) Forging equipment cleaning wastewater.

Subpart B—PSNS

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

(e) Direct chill casting contact cooling water.

Subpart B—PSNS

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

(f) Surface treatment spent baths.

Subpart B—PSNS

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

(g) Surface treatment rinse.

Subpart B—PSNS

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
Chromium0.7000.284
Zinc1.930.794
Ammonia252111
Fluoride11349.9

(h) Sawing or grinding spent emulsions.

Subpart B—PSNS

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

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

(j) Wet air pollution control scrubber blowdown.

Subpart B—PSNS

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
[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 471.25