Chapter 5 Statewide Table 5-21 Diesel PM County Air Basin tons/year Percent Los Angeles South Coast 4490 18% Orange South Coast 1670 7% San Diego San Diego 1527 6% Fresno San Joaquin Valley 1006 4% Riverside South Coast 996 4% Alameda San Francisco Bay Area 914 4% Santa Clara San Francisco Bay Area 904 4% San Bernardino South Coast 795 3% San Francisco San Francisco Bay Area 764 3% Kern San Joaquin Valley 749 3%