This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.
Interpretation of Ambient Air (PDF)(2 pp, 14 K)
This document is part of the NSR Policy and Guidance Database.