Final rule · 2025-09997

Clean Data Determination and Approval of Base Year Emissions Inventory; California; Los Angeles-South Coast Air Basin; 189(d) Plan for the 2006 24-Hour PM2.5 NAAQS

The Environmental Protection Agency (EPA) is making a clean data determination (CDD) for the Los Angeles-South Coast Air Basin ("South Coast") air quality planning area in California based on our determination that the area is attaining the 2006 24-hour fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standards (NAAQS). As a result of this CDD, certain Clean Air Act (CAA) requirements that have applied to California will be suspended for so long as the area continues to meet the 2006 24-hour PM<INF>2.5</INF> NAAQS. The EPA is also approving a revision to California's state implementation plan (SIP) consisting of the 2018 base year emissions inventory for the South Coast PM<INF>2.5</INF> nonattainment area, submitted by the California Air Resources Board (CARB) on December 29, 2020.