40 CFR § 146.21 - Applicability.

---
identifier: "/us/cfr/t40/s146.21"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 146.21 - Applicability."
title_number: 40
title_name: "Protection of Environment"
section_number: "146.21"
section_name: "Applicability."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "D"
subchapter_name: "WATER PROGRAMS"
part_number: "146"
part_name: "UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA AND STANDARDS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Safe Drinking Water Act, 42 U.S.C. 300f  Resource Conservation and Recovery Act, 42 U.S.C. 6901"
regulatory_source: "45 FR 42500, June 24, 1980, unless otherwise noted."
cfr_part: "146"
---


# 146.21 Applicability.

This subpart establishes criteria and standards for underground injection control programs to regulate Class II wells.