Clean Water Act: Permits, Standards and Who Enforces Them

33 U.S.C. § 1251 et seq.

U.S. Code home

1972

modern statutory structure

Section 402

NPDES permits

Section 404

dredge and fill permits

2026

proposed WOTUS rulemaking pending

Section 505

citizen-suit provision

Federal Environmental Laws > Clean Water Act

This page belongs to the Federal Environmental Laws collection. It reads the Clean Water Act as a statute in force, not as a general history of water policy. For the broader collection frame, see Federal Environmental Laws.

Why the Clean Water Act still matters

The Clean Water Act is the main federal statute for surface water pollution control in the United States. The first Federal Water Pollution Control Act dates to 1948, but the modern structure comes from Public Law 92-500, signed Oct. 18, 1972.

Congress stated the Act’s objective in Section 101(a): restore and maintain the chemical, physical, and biological integrity of the Nation’s waters, now codified at 33 U.S.C. § 1251(a). The operating rule is in Section 301: without statutory authorization, the discharge of a pollutant is unlawful, 33 U.S.C. § 1311(a).

Three definitions do much of the work: pollutant, 33 U.S.C. § 1362(6); point source, 33 U.S.C. § 1362(14); and navigable waters, defined as waters of the United States, 33 U.S.C. § 1362(7). The Act is not the Safe Drinking Water Act, and it does not reach every wet area, drainage feature, or local water complaint.

Clean Water Act properties

The permit programs matter, but the covered-waters question comes first. If the water is outside the Act’s reach, the federal permit analysis never starts.

The two permit programs side by side

A pipe discharge points first to Section 402. A fill in a wetland or stream points first to Section 404. Neither answer replaces the threshold question: is the water within the Clean Water Act’s covered waters under the statute, controlling court decisions, and the operative regulatory regime? For the permit side in more detail, see Water and Wetlands.

What waters are covered after Sackett

Sackett v. EPA, 598 U.S. 651, decided May 25, 2023, is the current Supreme Court limit that many summaries still understate. The Court rejected the significant nexus approach as enough for wetlands jurisdiction. Covered wetlands must be, as a practical matter, indistinguishable from waters of the United States because they have a continuous surface connection with such waters.

The agencies issued a conforming rule on Sept. 8, 2023, at 88 Fed. Reg. 61964. Where that amended 2023 rule is operative, the definitions appear in 40 C.F.R. § 120.2 and 33 C.F.R. § 328.3. Where the January 2023 rule is enjoined, the agencies apply the pre-2015 regime consistent with Sackett. Proposed rules published on Nov. 20, 2025, and Sept. 9, 2026, had not replaced the final rule as of the sources checked here.

We do not treat a wet map spot as coverage. The law does not. That is the line, and it is narrower than summaries that still rely on pre-Sackett habits.

Who enforces what

Clean Water Act enforcement is split. EPA sits at the center, but states can be the front-line NPDES permitting authority when EPA has approved their program. The Corps is central for Section 404 permits. Citizens have a statutory tool, but Section 505 is a defined cause of action with procedural limits, not an open-ended invitation to sue over every water problem.

Water quality standards and effluent limits

Permits are only one part of the Act. Section 303, 33 U.S.C. § 1313, uses water quality standards: state standards, subject to federal review, that identify uses for a water body and criteria to protect those uses. Section 301, 33 U.S.C. § 1311, prohibits unauthorized pollutant discharges and supports effluent limitations, which restrict what a source may discharge.

That structure matters because a permit is not the whole legal picture. A source must meet the conditions written into the permit and any applicable water quality standard. A Clean Water Act summary that lists only permits misses the statute’s second half: technology-based controls, water quality standards, and permit limits working together.

Common misreadings

First, the Clean Water Act is not separate from the Federal Water Pollution Control Act. It is the common name for the Act after the 1972 amendments, codified at 33 U.S.C. § 1251 et seq.

Second, the Act does not cover all water in the United States. After Sackett, coverage depends on the legal definition of waters of the United States and on the operative regulatory regime.

Third, a permit does not solve every Clean Water Act issue. It covers defined activities, discharges, limits, and conditions.

Fourth, the Clean Water Act is not the Safe Drinking Water Act. The Clean Water Act focuses on covered waters and surface water quality programs. Drinking water regulation is a separate federal statute.

Fifth, point source and nonpoint source pollution are not treated the same way. The NPDES trigger depends on a point source discharge into covered waters. For the neighboring federal review statute, see National Environmental Policy Act (NEPA): What It Requires After 2025.

Neighbor statutes and water tools

NEPA governs environmental review for federal actions. The Clean Air Act uses a different structure for air pollution control.

The closest water page is the broader Water and Wetlands page, which takes the permit and jurisdiction questions further. This page keeps the Clean Water Act in the common statute grid: what it covers, which permits it creates, who enforces it, and what changed after Sackett.