Which legislation allows the EPA to set air pollution limits?

The Clean Air Act is the legislation that specifically empowers the Environmental Protection Agency (EPA) to establish and enforce air quality standards, including limits on air pollutants. Enacted in 1963 and amended several times since, this act has been instrumental in regulating the emission of pollutants from various sources, such as factories and vehicles, to protect public health and the environment.

The authority granted by the Clean Air Act enables the EPA to identify and categorize harmful air pollutants, set National Ambient Air Quality Standards (NAAQS), and ensure that states implement plans to achieve and maintain these standards. This legislation is key to the federal government's efforts in combating air pollution and improving air quality across the United States.

Other options, while significant in their own right, do not specifically address air pollution limits. The Clean Water Act focuses on water quality and regulating discharges into navigable waters, the National Environmental Policy Act relates to environmental impact assessments for federal actions, and the Environmental Protection Act is not a standalone act that establishes such powers related to air pollution.