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 This website is no longer updated and links to external websites and some internal pages may not work.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 »

Clean Air Markets

NODA for EPA's Updated Ozone Transport Modeling

On July 23, 2015, EPA provided a Notice of Data Availability for EPA’s updated ozone transport modeling data for the 2008 ozone National Ambient Air Quality Standard (NAAQS). A list of the associated files and documents can be found below. Several of the documents released as part of this NODA also pertain to the proposed CSAPR Update Rule and can be found in the list of technical support documents.

Additional Information: