Prevention of Significant Deterioration (PSD) is intended maintain air quality in areas that meet or exceed National Ambient Air Quality Standards. PSD is intended to protect public health and welfare, maintain the air quality of class on areas, and assure that economic growth occurs carefully, after and evaluation of potential impacts to air quality.
To build a new facility, or modify an existing one, PSD requires that there be an air quality analysis, additional impact analysis, public involvement, and the use of the best available control technology (BACT) (defined elsewhere in Smokepedia).
Based upon PSD, air pollution in the area may only increase by a set increment, when that increment is exceeded significant deterioration occurs.
Source: U.S. Environmental Protection Agency.2011. "Prevention of Significant Deterioration (PSD) Basic Information". New Source Review (NSR). 2007. Accessed 28 May 2008. Available at http://www.epa.gov