The Environmental Protection Agency (EPA) is finalizing an approval and a limited approval and limited disapproval of revisions to the Antelope Valley Air Quality Management District (AVAQMD or ``District'') portion of the California State Implementation Plan (SIP). These revisions concern the District's New Source Review (NSR) permitting program for new and modified sources of air pollution under part D of title I of the Clean Air Act (CAA or ``Act''). This action updates the District's portion of the California SIP with nine revised rules. Under the authority of the CAA, this action simultaneously approves local rules that regulate emission sources and directs the District to correct rule deficiencies.