An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

New Source Review (NSR) Permitting

Project Aggregation

Date Title EPA Office Author
11/15/2018 Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NNSR): Aggregation; Reconsideration Administrator Wheeler, Andrew
06/17/1993 Applicability of NSR Review Circumvention Guidance to 3M - Maplewood, Minnesota SSCD Rasnic, John
08/08/1996 Honda Permits to Install 1 Year Aggregation Region 5 Newton, Cheryl
07/05/2005 Southwire Company "Splitting of Projects" Review Region 4

Worley, Gregg


Accumulation of De minimis Increases

Region 4 Wilburn, James

Net Emissions Increase Under PSD

OAQPS Meyers, Sheldon
08/29/2013 J.R. Simplot Company's Don Siding Plant and Issues Related to Aggregation, Debottlenecking and Projected Actual Emissions Region 10 Kelly, Kate

Related Topics: STEP 1: Emissions Increase Calculation (Project Emissions Increase) | Debottlenecked Sources

Return to Policy & Guidance Document Index

The “Relevant Guidance” index includes a collection of documents issued by EPA organized by topic area. These documents include memoranda, letters, orders, and other types of EPA actions that may provide guidance in one or more forms, such as an adjudication, statement of policy, interpretation of statutes or regulations, or technical information. Each collection is intended to be representative of EPA statements on the topic, but it may not be a complete listing of such statements. The collection does not reflect topic-specific statements that have been expressed by EPA though published rule preambles and Title V petition orders, nor does it include EAB decisions. Each document in the collection speaks for itself, and the inclusion or exclusion of a document in the collection is not intended by EPA to communicate anything more than what is expressed within each document. EPA makes no independent representations on this website as to the extent to which any document in the collection reflects EPA’s current views on the topic, is a final action by EPA, or has any legal effect or precedential weight. Readers are advised to review the documents in the collection and conduct their own assessment of such considerations based on the content of each document and other documents in the collection. Some of the information or views included in the documents may be affected by subsequent changes to the referenced statutory or regulatory language or by court decisions. In addition, many of the statements in these documents are based upon the federal regulations which may differ from rules that govern federally-approved programs. Permitting authorities are advised to consult with their EPA Regional Offices if there is a question as to the relevance of a particular statement to their NSR program.