Permit Review Process

Steps for the Federal Land Manager’s prevention of significant deterioration (PSD) permit review process.

One of the ways U.S. law protects clean air is through pre-construction review of major air pollution sources. Groups wishing to build new, or significantly modify existing, major facilities in clean air regions must obtain a prevention of significant deterioration (PSD) permit from the appropriate authority (state, tribe, or EPA) and meet requirements that minimize air quality deterioration. Sources located in an area that does not meet the National Ambient Air Quality Standard (NAAQS) for one or more criteria pollutants must obtain a nonattainment New Source Review permit for the pollutant that is violating the NAAQS.

Project proponents submit a PSD permit application to the permitting authority. Within 30 days of receipt applications are sent to the National Park Service (NPS) Air Resources Division for review if they “may affect” air quality or air quality related values (AQRVs) in a Class I area. PSD permit applicants must use the best available control technology for all pollutants emitted in "significant" amounts, and demonstrate that their emissions will not cause a violation of the national ambient air quality standards or a PSD increment.

The PSD permit review process for the NPS and other federal land managers consists of three main analyses:

1. a best available control technology (BACT) analysis to ensure that the emission increases from the proposed facility are minimized;
2. an air quality analysis to ensure that the pollutant levels do not exceed national ambient air quality standards and PSD increments; and
3. an air quality related values (AQRV) analysis to ensure that the Class I area resources are not adversely affected by the proposed emissions.

Applications are reviewed to determine if NPS area ecosystems and visibility will be impacted by the proposed emission increases from the new or modified facility. This is done by looking at what resources (plants, animals, water, soils, etc.) exist in the park or refuge and which ones are susceptible to certain levels of pollutants. Potential impacts on visibility are also an analysis requirement.

Modeling software is used to predict how much emissions from the new facility will reach affected parks. Cumulative emissions from other sites as well as from the proposed facility are considered in making the final impact determination for the park or wilderness. If this "loading" reaches a level that negatively affects resources or visibility in the park, then an "adverse impact determination" may be made in these cases. In such cases, the NPS may recommend that the state deny the permit application. Compromises are always explored and the NPS seeks to recommend solutions to reduce or control emissions so that park resources will not be significantly affected.

Visit the Resources for Permit Applicants page to learn more.