A detailed discussion of the U.S. regulatory system and the difference between law and regulations is first presented. The chapter is highlighted with the multimedia laws that exist for controlling water pollution in the U.S. The U.S. Environmental Protection Agency works with the states and local governments to develop and implement comprehensive environmental programs. Federal laws such as the Clean Air Act, the Safe Drinking Water Act, the Resource Conservation and Recovery Act, and the Comprehensive Environmental Response, Compensation, and Liability Act, all mandate involvement by state and local government in the details of implementation. This chapter provides an overview of eight key environmental laws and subsequent regulations that affect the environment in the United States. The applications section provides six Illustrative Examples related to the general subject of environmental regulations.