The Environmental Protection Agency (EPA) is taking final action to approve four permitting rules submitted as a revision to the San Diego County Air Pollution Control District (SDAPCD 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 section 110(a)(2)(C) and part D of title I of the Clean Air Act (CAA or ``Act''). This action will update the District's applicable SIP with rules revised to address a deficiency identified in our September 16, 2020 limited disapproval action. On May 12, 2022, we made an interim final determination that deferred the imposition of CAA sanctions associated with our September 16, 2020 limited disapproval action. This final approval stops all sanction and federal implementation plan clocks started by our September 16, 2020 limited approval and limited disapproval. This action also finalizes regulatory text to clarify that San Diego County is not subject to the Federal Implementation Plan related to protection of visibility from sources in nonattainment areas.