U.S. Code of Federal Regulations

Regulations most recently checked for updates: Oct 08, 2024

§ 421.275 - Pretreatment standards for existing sources.

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 achieve the following pretreatment standards for existing sources. The mass of wastewater pollutants in primary rare earth metals process wastewater introduced into a POTW must not exceed the following values:

(a) Dryer vent water quench scrubber.

PSES for the Primary Rare Earth Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mischmetal produced from wet rare earth chlorides
Hexachlorobenzene0.0420.042
Chromium (total)1.5440.626
Lead1.1680.542
Nickel2.2951.544

(b) Dryer vent caustic wet air pollution control.

PSES for the Primary Rare Earth Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mischmetal produced from wet rare earth chlorides
Hexachlorobenzene0.0070.007
Chromium (total)0.2720.110
Lead0.2060.095
Nickel0.4040.272

(c) Electrolytic cell water quench and scrubber.

PSES for the Primary Rare Earth Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of total mischmetal produced
Hexachlorobenzene0.0940.094
Chromium (total)3.4741.409
Lead2.6291.221
Nickel5.1653.474

(d) Electrolytic cell caustic wet air pollution control.

PSES for the Primary Rare Earth Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of total mischmetal produced
Hexachlorobenzene0.0000.000
Chromium (total)0.0000.000
Lead0.0000.000
Nickel0.0000.000

(e) Sodium hypochlorite filter backwash.

PSES for the Primary Rare Earth Metals Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of total mischmetal produced
Hexachlorobenzene0.0040.004
Chromium (total)0.1340.054
Lead0.1010.047
Nickel0.1990.134