• Part 100–103 - PARTS 100–103 [RESERVED]

• Part 104 [§ 104.1 - § 104.16] - PART 104—PUBLIC HEARINGS ON EFFLUENT STANDARDS FOR TOXIC POLLUTANTS

• Part 105 [§ 105.1 - § 105.16] - PART 105—RECOGNITION AWARDS UNDER THE CLEAN WATER ACT

• Part 108 [§ 108.1 - § 108.7] - PART 108—EMPLOYEE PROTECTION HEARINGS

• Part 109 [§ 109.1 - § 109.6] - PART 109—CRITERIA FOR STATE, LOCAL AND REGIONAL OIL REMOVAL CONTINGENCY PLANS

• Part 110 [§ 110.1 - § 110.6] - PART 110—DISCHARGE OF OIL

• Part 112 [§ 112.1 - § 112.21] - PART 112—OIL POLLUTION PREVENTION

• Part 113 [§ 113.1 - § 113.6] - PART 113—LIABILITY LIMITS FOR SMALL ONSHORE STORAGE FACILITIES

• Part 116 [§ 116.1 - § 116.4] - PART 116—DESIGNATION OF HAZARDOUS SUBSTANCES

• Part 117 [§ 117.1 - § 117.23] - PART 117—DETERMINATION OF REPORTABLE QUANTITIES FOR HAZARDOUS SUBSTANCES

• Part 120 [§ 120.1 - § 120.2] - PART 120—DEFINITION OF WATERS OF THE UNITED STATES

• Part 121 [§ 121.1 - § 121.16] - PART 121—STATE CERTIFICATION OF ACTIVITIES REQUIRING A FEDERAL LICENSE OR PERMIT

• Part 122 [§ 122.1 - § 122.64] - PART 122—EPA ADMINISTERED PERMIT PROGRAMS: THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM

• Part 123 [§ 123.1 - § 123.64] - PART 123—STATE PROGRAM REQUIREMENTS

• Part 124 [§ 124.1 - § 124.214] - PART 124—PROCEDURES FOR DECISIONMAKING

• Part 125 [§ 125.1 - § 125.139] - PART 125—CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM

• Part 127 [§ 127.1 - § 127.27] - PART 127—NPDES ELECTRONIC REPORTING

• Part 129 [§ 129.1 - § 129.105] - PART 129—TOXIC POLLUTANT EFFLUENT STANDARDS

• Part 130 [§ 130.0 - § 130.16] - PART 130—WATER QUALITY PLANNING AND MANAGEMENT

• Part 131 [§ 131.1 - § 131.47] - PART 131—WATER QUALITY STANDARDS

• Part 132 [§ 132.1 - § 132.6] - PART 132—WATER QUALITY GUIDANCE FOR THE GREAT LAKES SYSTEM

• Part 133 [§ 133.100 - § 133.105] - PART 133—SECONDARY TREATMENT REGULATION

• Part 135 [§ 135.1 - § 135.13] - PART 135—PRIOR NOTICE OF CITIZEN SUITS