{"data":{"id":"us/40-cfr-421.20","jurisdiction":"us","citation":"40 CFR 421.20","heading":"Applicability: description of the primary aluminum smelting subcategory.","body":"The provisions of this subpart are applicable to discharges resulting from the production of aluminum from alumina in the Hall-Heroult process.","path":["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 B—Primary Aluminum Smelting Subcategory"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"11be2872f1d3435b330d5954389d0f46c2e2bef851e2993e35134cd132c52538","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-421.16","next":"us/40-cfr-421.21"},"notice":"GroundRules: Original legal text. Not legal advice."}