Which environmental law is focused on pollution control in U.S. waterways?

The Clean Water Act is the primary piece of legislation in the United States that specifically addresses pollution control in waterways. Enacted in 1972, this law aims to restore and maintain the integrity of the nation's waters by preventing point and nonpoint source pollution. It establishes the regulatory framework for discharging pollutants into U.S. waters and sets water quality standards for the protection of aquatic ecosystems and human health.

The other laws mentioned serve different purposes: The Water Quality Act enhances provisions related to water quality but is essentially a part of the Clean Water Act and does not independently serve as the main regulatory framework. The National Environmental Policy Act focuses on environmental impact assessments for federal projects rather than specifically on water pollution. The Safe Drinking Water Act is concerned with the quality of drinking water and does not primarily regulate aquatic pollution in waterways. Thus, the Clean Water Act is the most relevant law for direct pollution control in U.S. waterways.