Nonattainment New Source Review (NNSR) Permits

The Nonattainment New Source Review (NNSR) program applies to the construction of new major stationary sources and to major modifications of existing major stationary sources where such new source or modification will be located in a nonattainment area for the regulated pollutant for which the source is major.  In other words, the source must be major for the same regulated pollutant for which the area is designated nonattainment (i.e., ambient concentrations of that pollutant are not compliant with its National Ambient Air Quality Standard (NAAQS)).  NNSR also applies to modifications of existing minor stationary sources if the modification itself would constitute a major source.

NNSR procedures are set forth in LAC 33:III.504.  Affected parishes, pollutants, and nonattainment classifications are provided in the following table.
Parish Nonattainment for Classification
St. Bernard SO2 N/A

NNSR Permits

Prior to commencement of construction of any project that would trigger NNSR, an NNSR “permit” must be obtained from the LDEQ.  An NNSR permit is not a stand-alone document; rather, NNSR provisions are incorporated in the source’s Title V permit.

A Single Project Can Trigger Both NNSR and PSD

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) would require that the VOC increase be evaluated in accordance with NNSR procedures, whereas the CO increase would be reviewed in accordance with Prevention of Significant Deterioration (PSD) regulations.

Offset Requirements in Specified Parishes

LDEQ has established state-only offset requirements under LAC 33:III.504.M for stationary sources located in the parishes of Ascension, East Baton Rouge, Iberville, Livingston, and West Baton Rouge when the parish's designation with respect to the 8-hour NAAQS for ozone is attainment, marginal nonattainment, or moderate nonattainment. 

Related Topics

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

  • NNSR Applicability;
  • NNSR Requirements;
  • Plantwide Applicability Limits (PALs);
  • Commencement of Construction; 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
      Emission Reduction Credits (ERC) Banking

      Louisiana Department of Environmental Quality 602 N. Fifth Street Baton Rouge, LA 70802
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