Regulations last checked for updates: Jun 02, 2024

Title 40 - Protection of Environment last revised: May 30, 2024
§ 421.190 - Applicability: Description of the secondary indium subcategory.

The provisions of this subpart are applicable to discharges resulting from the production of indium at secondary indium facilities processing spent electrolyte solutions and scrap indium metal raw materials.

§ 421.191 - Specialized definitions.

For the purpose of this subpart the general definitions, abbreviations, and methods of analysis set forth in 40 CFR part 401 shall apply to this subpart.

§§ 421.192-421.193 - §[Reserved]
§ 421.194 - Standards of performance for new sources.

Any new source subject to this subpart shall achieve the following new source performance standards:

(a) Displacement Supernatant.

NSPS for the Secondary Indium Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of indium metal produced
Cadmium2.1050.929
Lead2.6001.238
Zinc9.0373.776
Indium2.7241.114
Total suspended solids253.800120.700
pH( 1)( 1)

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

(b) Spent Electrolyte.

NSPS for the Secondary Indium Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of cathode indium produced
Cadmium12.1705.370
Lead15.0407.160
Zinc52.27021.840
Indium15.7506.444
Total suspended solids1,468.000698.100
pH( 1)( 1)

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

§ 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

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of indium metal produced
Cadmium2.1050.929
Lead2.6001.238
Zinc9.0373.776
Indium2.7241.114

(b) Spent Electrolyte.

PSES for the Secondary Indium Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of cathode indium produced
Cadmium12.1705.370
Lead15.0407.160
Zinc52.27021.840
Indium15.7506.444
§ 421.196 - Pretreatment standards for new sources.

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. The mass of wastewater pollutants in secondary indium process wastewater introduced into a POTW should not exceed the following values:

(a) Displacement Supernatant.

PSNS for the Secondary Indium Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of indium metal produced
Cadimum2.1050.929
Lead2.6001.238
Zinc9.0373.776
Indium2.7241.114

(b) Spent Electrolyte.

PSNS for the Secondary Indium Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of cathode indium produced
Cadmium12.1705.370
Lead15.0407.160
Zinc52.27021.840
Indium15.7506.444
§ 421.197 - [Reserved]
authority: Secs. 301, 304 (b), (c), (e), and (g), 306 (b) and (c), 307 (b) and (c), 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) and the Water Quality Act of 1987 (the “Act”); 33 U.S.C. 1311,1314,c,e,and, 1316 (b) andc, 1317 (b) andc,1318; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217; 101 Stat. 7, Pub. L. 100-4
source: 49 FR 8790, Mar. 8, 1984, unless otherwise noted.
cite as: 40 CFR 421.194