40 CFR § 421.275 - Pretreatment standards for existing sources.

§ 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
Hexachlorobenzene 0.042 0.042
Chromium (total) 1.544 0.626
Lead 1.168 0.542
Nickel 2.295 1.544

(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
Hexachlorobenzene 0.007 0.007
Chromium (total) 0.272 0.110
Lead 0.206 0.095
Nickel 0.404 0.272

(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
Hexachlorobenzene 0.094 0.094
Chromium (total) 3.474 1.409
Lead 2.629 1.221
Nickel 5.165 3.474

(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
Hexachlorobenzene 0.000 0.000
Chromium (total) 0.000 0.000
Lead 0.000 0.000
Nickel 0.000 0.000

(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
Hexachlorobenzene 0.004 0.004
Chromium (total) 0.134 0.054
Lead 0.101 0.047
Nickel 0.199 0.134