TITLE 40 - PROTECTION OF ENVIRONMENT

CHAPTER I - ENVIRONMENTAL PROTECTION AGENCY

SUBCHAPTER N - EFFLUENT GUIDELINES AND STANDARDS

PART 421 - NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY

subpart q - SECONDARY INDIUM SUBCATEGORY

421.195 - 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 secondary indium process wastewater introduced into a POTW must not exceed the following values: (a) Displacement Supernatant.

PSES for the Secondary Indium Subcategory ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/kg (pounds per million pounds) of indium metal produced ------------------------- Cadmium....................................... 2.105 0.929 Lead.......................................... 2.600 1.238 Zinc.......................................... 9.037 3.776 Indium........................................ 2.724 1.114 ------------------------------------------------------------------------ (b) Spent Electrolyte.

PSES for the Secondary Indium Subcategory ------------------------------------------------------------------------ Maximum for Pollutant or pollutant property Maximum for monthly any 1 day average ------------------------------------------------------------------------ mg/kg (pounds per million pounds) of cathode indium produced ------------------------- Cadmium....................................... 12.170 5.370 Lead.......................................... 15.040 7.160 Zinc.......................................... 52.270 21.840 Indium........................................ 15.750 6.444 ------------------------------------------------------------------------