40 CFR § 421.190 - Applicability: Description of the secondary indium subcategory.
---identifier: "/us/cfr/t40/s421.190"source: "ecfr"legal_status: "authoritative_unofficial"title: "40 CFR § 421.190 - Applicability: Description of the secondary indium subcategory."title_number: 40title_name: "Protection of Environment"section_number: "421.190"section_name: "Applicability: Description of the secondary indium subcategory."chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"subchapter_number: "N"subchapter_name: "EFFLUENT GUIDELINES AND STANDARDS"part_number: "421"part_name: "NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY"positive_law: falsecurrency: "2026-04-05"last_updated: "2026-04-05"format_version: "1.1.0"generator: "[email protected]"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 (b), (c), (e), and (g), 1316 (b) and (c), 1317 (b) and (c), 1318 and 1361; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217; 101 Stat. 7, Pub. L. 100-4."regulatory_source: "49 FR 8790, Mar. 8, 1984, unless otherwise noted."cfr_part: "421"---
Identifier
/us/cfr/t40/s421.190
Currency
2026-04-05
Positive Law
No
Updated
2026-04-05
Chapter
Environmental Protection Agency
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 A... 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 (b), (c), (e), and (g), 1316 (b) and (c), 1317 (b) and (c), 1318 and 1361; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217; 101 Stat. 7, Pub. L. 100-4.
# 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.