The Environmental Protection Agency (EPA) finalized a proposed amendment to nitrogen oxides (NOx) SIP Call regulations that was published on September 27, 2018. This amendment allows covered states (including Alabama) to amend their State Implementation Plans (SIPs), for NOx SIP Call purposes only, to establish alternate emissions monitoring requirements for certain emission sources. Certain sources subject to emissions monitoring requirements for purposes of the NOx SIP call could be impacted, if Alabama chooses to implement these revisions.

The final rule went into effect March 8, 2019, and finalized the amendment generally as proposed, as well as included several minor revisions to remove obsolete provisions of the NOx SIP Call regulations.

The March 8, 2019 Federal Register notice is available on the U.S. Government Publishing Office's website.