Prevention of Significant Deterioration (PSD) Permits

The Prevention of Significant Deterioration (PSD) program applies to the construction of new major stationary sources and to major modifications of existing stationary sources.  PSD also applies to modifications of existing minor stationary sources if the modification itself would constitute a major source.

The basic goals of the PSD program are to:

  • ensure that economic growth will occur in harmony with the preservation of existing clean air resources;
  • protect the public health and welfare from any adverse effects that might occur, even at air pollution levels better than the NAAQS; and
  • preserve, protect, and enhance the air quality in areas of special natural, recreational, scenic or historic value, such as national parks and wilderness areas (Class I Areas).

Because PSD is pollutant-specific, a significant net emissions increase of one pollutant subjects an affected source to PSD for that pollutant only.  It is important to note that a source that is major for one pollutant can trigger PSD requirements due to a significant net emissions increase of any regulated NSR pollutant.  For example, if NOx and CO emissions exceed 250 TPY, a 15 TPY net emissions increase in PM10 is subject to PSD review, even if facility-wide PM10 emissions are below the PSD major stationary source threshold.  PSD procedures are set forth in LAC 33:III.509.

PSD Permits
Prior to commencement of construction of any project that would trigger PSD, a PSD permit must be obtained from the LDEQ.

A Single Project Can Trigger Both PSD and NNSR
Because New Source Review (which encompasses both NNSR and PSD) is pollutant-specific, it is important to note that a permit application may require both NNSR and PSD reviews.  For example, in an ozone nonattainment area, a permit application proposing a significant net emissions increase of both VOC (a nonattainment pollutant) and CO (an attainment pollutant in Louisiana) would require that the VOC increase be evaluated in accordance with NNSR procedures, whereas the CO increase would be reviewed in accordance with PSD regulations.

Notification of the Federal Land Manager

Related Topics
For extended discussions on the following topics, see LDEQ’s Louisiana Guidance for Air Permitting Actions.

  • PSD Applicability;
  • PSD Requirements;
  • Plantwide Applicability Limits (PALs);
  • Commencement of Construction;
  • How LAC 33:III.509 Differs from the Federal PSD Rule (at 40 CFR 51.166); and
  • Routine Maintenance, Repair, and Replacement (RMRR).

Other Online Resources
In addition to the Louisiana Guidance for Air Permitting Actions, other resources include:

EPA’s NSR Website
EPA’s New Source Review Policy and Guidance Database