Air Plan Approval; California; Mammoth Lakes; Redesignation Request; PM10

The Environmental Protection Agency (EPA) is proposing to approve, as a revision to the California State Implementation Plan (SIP), California's request to redesignate the Mammoth Lakes nonattainment area to attainment for the 1987 National Ambient Air Quality Standard (NAAQS) for particulate matter of ten microns or less (PM10). EPA is also proposing to approve the maintenance plan for the Mammoth Lakes area and the associated motor vehicle emissions budgets for use in transportation conformity determinations. Finally, EPA is proposing to approve the attainment year emissions inventory. EPA is proposing these actions because the SIP revision meets the requirements of the Clean Air Act and EPA guidance for maintenance plans and motor vehicle emissions budgets.