---
kind: "unit"
title: "40"
title_heading: "Protection of Environment"
key: "chI/subchD"
level: "subchap"
label: "Subchapter D"
heading: "Water Programs"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/40/chI-subchD"
sections_count: 1152
---

# Subchapter D — Water Programs

Title 40 C.F.R. — Protection of Environment › Chapter I — Environmental Protection Agency

## Contents

- [Part 100-103 — Parts 100-103 [reserved]](/cfr/40/chI-subchD-part100-103.md)
- [Part 104 — Public Hearings on Effluent Standards for Toxic Pollutants](/cfr/40/chI-subchD-part104.md)
- [Part 105 — Recognition Awards under the Clean Water Act](/cfr/40/chI-subchD-part105.md)
- [Part 108 — Employee Protection Hearings](/cfr/40/chI-subchD-part108.md)
- [Part 109 — Criteria for State, Local and Regional Oil Removal Contingency Plans](/cfr/40/chI-subchD-part109.md)
- [Part 110 — Discharge of Oil](/cfr/40/chI-subchD-part110.md)
- [Part 112 — Oil Pollution Prevention](/cfr/40/chI-subchD-part112.md)
- [Part 113 — Liability Limits for Small Onshore Storage Facilities](/cfr/40/chI-subchD-part113.md)
- [Part 116 — Designation of Hazardous Substances](/cfr/40/chI-subchD-part116.md)
- [Part 117 — Determination of Reportable Quantities for Hazardous Substances](/cfr/40/chI-subchD-part117.md)
- [Part 118 — Clean Water Act Hazardous Substances Facility Response Plans](/cfr/40/chI-subchD-part118.md)
- [Part 120 — Definition of Waters of the United States](/cfr/40/chI-subchD-part120.md)
- [Part 121 — State Certification of Activities Requiring a Federal License or Permit](/cfr/40/chI-subchD-part121.md)
- [Part 122 — Epa Administered Permit Programs: the National Pollutant Discharge Elimination System](/cfr/40/chI-subchD-part122.md)
- [Part 123 — State Program Requirements](/cfr/40/chI-subchD-part123.md)
- [Part 124 — Procedures for Decisionmaking](/cfr/40/chI-subchD-part124.md)
- [Part 125 — Criteria and Standards for the National Pollutant Discharge Elimination System](/cfr/40/chI-subchD-part125.md)
- [Part 127 — Npdes Electronic Reporting](/cfr/40/chI-subchD-part127.md)
- [Part 129 — Toxic Pollutant Effluent Standards](/cfr/40/chI-subchD-part129.md)
- [Part 130 — Water Quality Planning and Management](/cfr/40/chI-subchD-part130.md)
- [Part 131 — Water Quality Standards](/cfr/40/chI-subchD-part131.md)
- [Part 132 — Water Quality Guidance for the Great Lakes System](/cfr/40/chI-subchD-part132.md)
- [Part 133 — Secondary Treatment Regulation](/cfr/40/chI-subchD-part133.md)
- [Part 135 — Prior Notice of Citizen Suits](/cfr/40/chI-subchD-part135.md)
- [Part 136 — Guidelines Establishing Test Procedures for the Analysis of Pollutants](/cfr/40/chI-subchD-part136.md)
- [Part 139 — Discharges Incidental to the Normal Operation of Vessels](/cfr/40/chI-subchD-part139.md)
- [Part 140 — Marine Sanitation Device Standard](/cfr/40/chI-subchD-part140.md)
- [Part 141 — National Primary Drinking Water Regulations](/cfr/40/chI-subchD-part141.md)
- [Part 142 — National Primary Drinking Water Regulations Implementation](/cfr/40/chI-subchD-part142.md)
- [Part 143 — Other Safe Drinking Water Act Regulations](/cfr/40/chI-subchD-part143.md)
- [Part 144 — Underground Injection Control Program](/cfr/40/chI-subchD-part144.md)
- [Part 145 — State Uic Program Requirements](/cfr/40/chI-subchD-part145.md)
- [Part 146 — Underground Injection Control Program: Criteria and Standards](/cfr/40/chI-subchD-part146.md)
- [Part 147 — State, Tribal, and Epa-Administered Underground Injection Control Programs](/cfr/40/chI-subchD-part147.md)
- [Part 148 — Hazardous Waste Injection Restrictions](/cfr/40/chI-subchD-part148.md)
- [Part 149 — Sole Source Aquifers](/cfr/40/chI-subchD-part149.md)