Air Plan Revisions; Arizona; Maricopa County Air Quality Department

The Environmental Protection Agency (EPA) is finalizing a limited approval and limited disapproval of revisions to the Maricopa County Air Quality Department (MCAQD or "County") portion of the Arizona State Implementation Plan (SIP). These revisions concern emissions of volatile organic compounds (VOCs) from loading of organic liquids and gasoline. Under the authority of the Clean Air Act (CAA or "Act"), this action simultaneously approves local rules that regulate these emission sources and directs Arizona to correct rule deficiencies. We are also finalizing a disapproval of MCAQD's reasonably available control technology (RACT) demonstration for the source categories associated with these rules for the 2008 8-hour ozone national ambient air quality standard (NAAQS) in the Phoenix-Mesa ozone nonattainment area.