Clean Water Act, United States

Source: Encyclopedia of Earth

Increasing public interest in protecting America’s waters from pollution pushed Congress to enact the Federal Water Pollution Control Act, popularly known as the Clean Water Act (CWA), in 1972. As amended in 1977, this law became commonly known as the Clean Water Act. The Act established the basic structure for regulating discharges of pollutants into the waters of the United States. Its principle intent was to ". . .restore and maintain the chemical, physical, and biological integrity of the Nation's waters" (Section 101). To accomplish that objective, the act aimed to attain a level of water quality that "provides for the protection and propagation of fish, shellfish, and wildlife, and provides for recreation in and on the water" by 1983 and to eliminate the discharge of pollutants into navigable waters by 1985.

The CWA gave the Environmental Protection Agency (EPA) the authority to implement pollution control programs such as setting wastewater standards for industry. The Clean Water Act also continued requirements to set water quality standards for all contaminants in surface waters. The Act made it unlawful for any person to discharge any pollutant from a point source into navigable waters, unless a permit was obtained under its provisions. It also funded the construction of sewage treatment plants under the construction grants program and recognized the need for planning to address the critical problems posed by nonpoint source pollution. The CWA has five main elements: (1) a system of minimum national effluent standards for each industry, (2) water quality standards, (3) a discharge permit program that translates these standards into enforceable limits, (4) provisions for special problems such as toxic chemicals and oil spills, and (5) a revolving construction loan program (formerly a grant program) for publicly-owned treatment works (POTWs).

The CWA requires the EPA to establish effluent limitations for the amounts of specific pollutants that may be discharged by municipal sewage plants and industrial facilities. The two-step approach to setting the standards includes: (1) establishing a nationwide, base-level treatment through an assessment of what is technologically and economically achievable for a particular industry and (2) requiring more stringent levels of treatment for specific plants if necessary to achieve water quality objectives for the particular body of water into which that plant discharges. For example, EPA sets limits based on water quality to control pollution in waters designated by the states for drinking, swimming, or fishing.

The primary method by which the act imposes limitations on pollutant discharges is the nationwide permit program established under Section 402 and referred to as the National Pollutant Discharge Elimination System (NPDES). Under the NPDES program any person responsible for the discharge of a pollutant or pollutants into any waters of the United States from any point source must apply for and obtain a permit.

Under the Clean Water Act, it is unlawful for any person to discharge any substance classified as a pollutant from a point source into navigable waters. Some significant amendments succeeding the Clean Water Act include revisions in 1977, 1987, and 1990. The Clean Water Act of 1977 restructured the 1972 Act while adding new control programs for toxic water pollutants. Revisions in 1981 streamlined the municipal construction grants process, improving the capabilities of treatment plants built under the program. Changes in 1987 phased out the construction grants program, replacing it with the State Water Pollution Control Revolving Fund, more commonly known as the Clean Water State Revolving Fund. This new funding strategy addressed water quality needs by building on EPA-State partnerships.

Over the years, many other laws have changed parts of the Clean Water Act. Title I of the Great Lakes Critical Programs Act of 1990, for example, put into place parts of the Great Lakes Water Quality Agreement of 1978, signed by the U.S. and Canada, where the two nations agreed to reduce certain toxic pollutants in the Great Lakes. That law required EPA to establish water quality criteria for the Great Lakes addressing 29 toxic pollutants with maximum levels that are safe for humans, wildlife, and aquatic life. It also required EPA to help the States implement the criteria on a specific schedule. The Oil Pollution Act of 1990 tightened regulations concerning the discharge of oil and hazardous substances. The Great Lakes Critical Program Act of 1990 focused on protecting the integrity of the Great Lakes; both Canada and the U.S. agreed to reduce discharge of certain toxic pollutants contaminating the Great Lakes at the time.

For many years following the passage of CWA in 1972, EPA, states, and Indian tribes focused mainly on the chemical aspects water pollution. Recently, more attention has been given to physical and biological integrity. Also, in the early decades of the Act's implementation, efforts focused on regulating discharges from traditional "point source" facilities, such as municipal sewage plants and industrial facilities, with little attention paid to runoff from streets, construction sites, farms, and other "wet-weather" sources.

Starting in the late 1980s, efforts to address polluted runoff have increased significantly. For "nonpoint" runoff, voluntary programs, including cost-sharing with landowners are the key tool. For "wet weather point sources" like urban storm sewer systems and construction sites, a regulatory approach is being employed.

Evolution of CWA programs over the last decade has also included something of a shift from a program-by-program, source-by-source, pollutant-by-pollutant approach to more holistic watershed-based strategies. Under the watershed approach equal emphasis is placed on protecting healthy waters and restoring impaired ones. A full array of issues are addressed, not just those subject to CWA regulatory authority. Involvement of stakeholder groups in the development and implementation of strategies for achieving and maintaining state water quality and other environmental goals is another hallmark of this approach.

Further Reading

Kenney, Robyn (Lead Author); Richard Rich (Topic Editor). 2008. "Clean Water Act, United States." In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth October 4, 2006; Last revised July 21, 2008; Retrieved September 17, 2008]. <,_United_States>


(2008). Clean Water Act, United States. Retrieved from


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Cliff Lyon wrote: 09-26-2008 11:04:39

It should be noted that the Clean Water Act was one of the great successes of the Nixon Administration, back in the day when real scientists and true policy experts held leadership positions in Federal Agencies. One can only hope, that the coming transition in national leadership will include a return to the days when professionals shaped our environmental (and other) policy and led federal agencies.