An official website of the United States government.

Due to a lapse in appropriations, EPA websites will not be regularly updated. In the event of an environmental emergency imminently threatening the safety of human life or where necessary to protect certain property, the EPA website will be updated with appropriate information. Please note that all information on the EPA website may not be up to date, and transactions and inquiries submitted to the EPA website may not be processed or responded to until appropriations are enacted.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

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: