New Source Performance Standards (NSPS)
and
Prevention of Significant Deterioration (PSD)

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In addition to the basic framework and procedural aspects of the old Clean Air Act after the passage of the 1990 Amendments, two major sections of the old Act have
remained substantially unchanged. The first is the provision for standards of performance for new stationary sources (New Source Performance Standards or NSPS). The second is the provision for the Prevention of Significant Deterioration (PSD) in those areas which have high air quality and are in compliance with the national primary and secondary air quality standards.

New Source Performance Standards (NSPS)

The New Source Performance Standards process requires the EPA to list categories of stationary sources which "cause, or contribute significantly to, air pollution which may resonably be anticipated to endanger public health or welfare." The NSPS program sets uniform emission limitations for industrial categories or sub-categories of sources. The standards generally must be stated in terms of maximum amounts of emissions. These standards apply to all pollutants emitted by the source category. However, for many sources, the EPA has only regulated the criteria pollutants.

"New Source" is defined broadly to include newly constructed factories or furnaces as well as any modification of existing sources, including changes in the way sources are operated that increase emissions or add a new pollutant to emissions.

If the EPA finds that a stationary source is violating a national primary or secondary ambient air quality standard, the EPA can enforce the standards. However, if the EPA finds that the state's procedure for enforcing the standards is adequate, the EPA may delegate to such state all enforcement authority rendered to it under the Clean Air Act. A listing of what New Source Performance Standards have been delegated to particular states is contained in the regulations.

Prevention of Significant Deterioration (PSD)

The Prevention of Significant Deterioration process requires states in their SIP's to ensure that areas already in compliance with the national ambient air quality standards do not deteriorate to or above those standards at too rapid a pace. Such areas, depending upon the quality of their air in a baseline year, must control the emissions of certain pollutants such that the concentration of those pollutants increases no more than the allowable increment as set forth in the Act. Before any new source may be built or any existing source may be modified, such sources must apply for and be issued a PSD permit which demonstrates that they will be in compliance with the PSD program.

While these two programs have survived the 1990 amendments, several programs have been substantially modified, including the enforcement provisions, and the regulations pertaining to hazardous pollutants, emissions by motor vehicles, and non-attainment areas for the six criteria pollutants. In addition, three totally new sections have been added. The first is designed to control acid rain, the second to protect the stratospheric ozone through the regulation of chlorofluorocarbons and hydrochlorofluorocarbons, and the third sets forth the permit procedures under the Act. Because these new and modified sections represent such a significant change in environmental law in this country, this document will address in detail the seven titles of the Clean Air Amendments of 1990 wherein they are set forth.