Well, kind of. To be more specific, the "Muskie Act" extension, passed on Sept. 14, 1970, has hit the top of the hill (the original Clean Air Act was passed in 1963). The 1970 amendments, passed just months after the first Earth Day, created the basic provisions that have come to define air pollutant regulation for two generations.

The enactment of the Clean Air Act of 1970 resulted in a major shift in the federal government's role in air pollution control. This legislation authorized the development of comprehensive federal and state regulations to limit emissions from both stationary (industrial) sources and mobile sources. Four major regulatory programs affecting stationary sources were initiated: the National Ambient Air Quality Standards (NAAQS), State Implementation Plans (SIPs), New Source Performance Standards (NSPS), and National Emission Standards for Hazardous Air Pollutants (NESHAPs). Furthermore, the enforcement authority was substantially expanded.

The adoption of this legislation occurred the same year as the National Environmental Policy Act that established the EPA. The EPA was created on May 2, 1971 in order to implement the various requirements included in the Clean Air Act of 1970.

As part of the activities commemorating the EPA's 40th anniversary, the agency is highlighting progress made under the 40 years of the Clean Air Act (CAA) at a conference in Washington, D.C. The agency highlighted the enormous success it has had in the last four decades in controlling the law's six "criteria" pollutants: CO, NO₂, ozone, SO₂, particulate matter (at the time: PM10), and lead.

More information on the Clean Air Act's 40th birthday: http://epa.gov/oar/caa/40th.html

SOURCE: EPA Press Release