Approval of California Air Plan; Owens Valley Serious Area Plan for the 1987 24-Hour PM10

The Environmental Protection Agency (EPA) is proposing to approve a state implementation plan (SIP) revision submitted by the State of California and Great Basin Unified Air Pollution Control District (GBUAPCD or ``District'') to meet Clean Air Act (CAA or ``Act'') requirements applicable to the Owens Valley PM10 nonattainment area (NA). The Owens Valley PM10 NA is located in the southern portion of the Owens Valley in Inyo County, California. It is classified as a Serious nonattainment area for the national ambient air quality standards (NAAQS) for particulate matter of ten microns or less (PM10). The submitted SIP revision is the ``Great Basin Unified Air Pollution Control District 2016 Owens Valley Planning Area PM10 State Implementation Plan'' (``2016 PM10 Plan'' or ``Plan''). The GBUAPCD's obligation to submit the 2016 PM10 Plan was triggered by the EPA's 2007 finding that the Owens Valley PM10 NA had failed to meet its December 31, 2006, deadline to attain the PM10 NAAQS. The CAA requires a Serious PM10 nonattainment area that fails to meet its attainment deadline to submit a plan providing for attainment of the PM10 NAAQS and for an annual emission reduction in PM10 of not less than five percent until attainment of the PM10 NAAQS. The EPA is proposing to approve the 2016 PM10 Plan as meeting all relevant statutory and regulatory requirements.