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 designations are provided in the following table.

  Parish [1] Nonattainment for Designation
  Ascension 8-hour Ozone Marginal
  East Baton Rouge 8-hour Ozone Marginal
  Iberville 8-hour Ozone Marginal
  Livingston 8-hour Ozone Marginal
  West Baton Rouge 8-hour Ozone Marginal

VOC is regulated as a surrogate for ozone.  On December 20, 2001 (upon the promulgation of amendments to §504), the Baton Rouge Nonattainment Area’s Clean Air Act Section 182(f) NOX exemption was effectively rescinded.[2]  Therefore, both VOC and NOX are regulated as nonattainment pollutants because both have been determined to contribute to tropospheric ozone formation.  However, ambient concentrations of particulate, SO2, NOX, and CO are in compliance with their respective NAAQS; therefore, emissions of these pollutants are evaluated pursuant to Prevention of Significant Deterioration (PSD) regulations.

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, East Baton Rouge (EBR) Parish is in attainment with the NAAQS for all criteria pollutants except ozone.  Therefore, a permit application proposing a significant net emissions increase of both VOC (a nonattainment pollutant in EBR Parish) 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.

Related Topics

For extended discussions on the following topics, see LDEQ’s Air Permit Procedures Manual. 

  • NNSR Applicability;
  • NNSR Requirements;
  • Plantwide Applicability Limits (PALs);
  • Commencement of Construction;
  • NNSR, PSD, and NOX Increases in the Baton Rouge Nonattainment Area;
  • Transition from the 1-Hour Ozone NAAQS to the 8-Hour Ozone NAAQS; and
  • EPA’s Equipment Replacement Rule and Routine Maintenance, Repair, and Replacement.

    Other Online Resources

    In addition to the Air Permit Procedures Manual, other resources include:
    EPA’s NSR Website
    EPA’s New Source Review Policy and Guidance Database
    Emission Reduction Credits (ERC) Banking 

    [1] These parishes are collectively referred to as the Baton Rouge Nonattainment Area (BRNA).
    [2] EPA finalized its May 7, 2002, proposal to rescind the BRNA’s Section 182(f) & 182(b)(1) NOX exemptions at 68 FR 23597 (May 5, 2003), effective June 4, 2003.

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