---
kind: "unit"
title: "40"
title_heading: "Protection of Environment"
key: "chI/subchD/part142"
level: "part"
label: "Part 142"
heading: "National Primary Drinking Water Regulations Implementation"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/40/chI-subchD-part142"
sections_count: 63
---

# Part 142 — National Primary Drinking Water Regulations Implementation

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-part142-subpartA.md)
- [Subpart B — Primary Enforcement Responsibility](/cfr/40/chI-subchD-part142-subpartB.md)
- [Subpart C — Review of State-Issued Variances and Exemptions](/cfr/40/chI-subchD-part142-subpartC.md)
- [Subpart D — Federal Enforcement](/cfr/40/chI-subchD-part142-subpartD.md)
- [Subpart E — Variances Issued by the Administrator Under Section 1415(a) of the Act](/cfr/40/chI-subchD-part142-subpartE.md)
- [Subpart F — Exemptions Issued by the Administrator](/cfr/40/chI-subchD-part142-subpartF.md)
- [Subpart G — Identification of Best Technology, Treatment Techniques or Other Means Generally Available](/cfr/40/chI-subchD-part142-subpartG.md)
- [Subpart H — Indian Tribes](/cfr/40/chI-subchD-part142-subpartH.md)
- [Subpart I — Administrator's Review of State Decisions that Implement Criteria Under Which Filtration Is Required](/cfr/40/chI-subchD-part142-subpartI.md)
- [Subpart J — Subpart J [Reserved]](/cfr/40/chI-subchD-part142-subpartJ.md)
- [Subpart K — Variances for Small System](/cfr/40/chI-subchD-part142-subpartK.md)