---
kind: "unit"
title: "40"
title_heading: "Protection of Environment"
key: "chI/subchD/part146"
level: "part"
label: "Part 146"
heading: "Underground Injection Control Program: Criteria and Standards"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/40/chI-subchD-part146"
sections_count: 53
---

# Part 146 — Underground Injection Control Program: Criteria and Standards

Title 40 C.F.R. — Protection of Environment › Chapter I — Environmental Protection Agency › Subchapter D — Water Programs

## Contents

- [Subpart A — General Provisions](/cfr/40/chI-subchD-part146-subpartA.md)
- [Subpart B — Criteria and Standards Applicable to Class I Wells](/cfr/40/chI-subchD-part146-subpartB.md)
- [Subpart C — Criteria and Standards Applicable to Class II Wells](/cfr/40/chI-subchD-part146-subpartC.md)
- [Subpart D — Criteria and Standards Applicable to Class III Wells](/cfr/40/chI-subchD-part146-subpartD.md)
- [Subpart E — Criteria and Standards Applicable to Class IV Injection Wells [Reserved]](/cfr/40/chI-subchD-part146-subpartE.md)
- [Subpart F — Criteria and Standards Applicable to Class V Injection Wells](/cfr/40/chI-subchD-part146-subpartF.md)
- [Subpart G — Criteria and Standards Applicable to Class I Hazardous Waste Injection Wells](/cfr/40/chI-subchD-part146-subpartG.md)
- [Subpart H — Criteria and Standards Applicable to Class VI Wells](/cfr/40/chI-subchD-part146-subpartH.md)