The Clean Water Act (CWA) started with the Federal Water Pollution Control Act which was enacted in 1948. In 1972, the Act was significantly reorganized and expanded and became known as the “Clean Water Act.”
Today, the Act establishes guidelines for regulating discharges of pollutants into U.S. waters and regulates quality standards for surface waters. Building off of the framework that the act set, pollution control programs for wastewater have been implemented and national water quality criteria recommendations have been developed.
More information: U.S. Environmental Protection Agency