CFR › Title 40 › Part 409 › §409.5140 CFR §409.51Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkFor the purpose of this subpart:(a)Except as provided below, the general definitions, abbreviations and methods of analysis set forth in 40 CFR part 401 shall apply to this subpart.(b)[Reserved]