Because the NSR program relies on this principle, it minimizes emissions from new sources while maximizing opportunities for additional industrial and economic growth. It's a simple concept that has been working in the NSR program for almost a quarter-century, protecting our nation's air resources, and making up a critical component of our total air quality program. Background The NSR provisions of the Clean Air Act combine air quality planning, air pollution technology requirements, and stakeholder participation. NSR is a preconstruction permitting program. If new construction or making a major modification will increase emissions by an amount large enough to trigger NSR requirements, then the source must obtain a permit before it can begin construction.
States are key partners in the program.
Under the Act, states have the primary responsibility for issuing permits, and they can customize their NSR programs within the limits of EPA regulations. EPA's role is to approve state programs, to review, comment on, and take any other necessary actions on draft permits, and to assure consistency with EPA's rules, the state's implementation plan, and the Clean Air Act. Citizens also play a role in the permitting decision, and must be afforded an opportunity to comment on each construction permit before it is issued. In attainment areas, PSD sources typically do not need to obtain offsets. However, PSD does require an air quality modeling analysis of the impact of the construction project, and if the analysis finds that the project contributes to ambient air pollution that exceeds allowable levels, this impact must be mitigated.