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New Source Review (NSR) Permitting

Draft Guidance: Revised Policy on Exclusions from “Ambient Air”

EPA is providing an opportunity for interested stakeholders to comment on the draft guidance titled, Revised Policy on Exclusions from “Ambient Air”.   In this draft guidance, EPA is revising its 1980 policy on the exclusion of certain areas from the scope of “ambient air” under the Clean Air Act and EPA’s regulations, while still maintaining public health protection. The regulatory definition of ambient air, remains as “that portion of the atmosphere, external to buildings, to which the general public has access.”

EPA will accept public comment on the draft guidance through January 11, 2019. 

Read the draft guidance:  Revised Policy on Exclusions from “Ambient Air”


Comment on the Draft Guidance

You may submit your comments using the form below. EPA will consider the comments received and complete a revised version of the guidance. 

If you have files you would like to submit as part of your comments, please direct them to the following email address: Ambient_Air_Guidance@epa.gov.