Ozone Standard Exceedance Days in the South San Joaquin Valley

Jan De Leeuw, Shuojun Wang
This note analyzes ozone standard exceedance days in Bakersfield, Arvin, Oildale, and Shafter since 1989. We have plotted violations of both one-hour and eight-hour federal and state standards (data from CARB monitoring stations). We have also drawn linear regression lines to estimate trend. They show a modest long term improvement (around 20%) in violations of one-hour state standards, but generally a smaller increase in violations of eight-hour state standards. They also show larger improvement in urban Bakersfield than in the rural areas.
2007-09-01