California Air Resources Board California Map with County Boundaries
Ozone Data Summaries (1980-1998)
Placer County Portion
of the Mountain Counties Air Basin
Year Number of Days Standard Exceeded Ozone Concentrations in ppm
1 hour 8 hour
State
1hr
Federal
1hr
Federal
8hr
Max
1hr
3 Year
4th High*
EPDC*
Max
8hr
3 Year Avg
4th High*
1997 2 0 2 0.10 0.11 0.111 0.097 0.086
1996 4 0 5 0.11 0.12   0.091 0.091
1995 16 1 11 0.13 0.12   0.100 0.092
1994 15 0 12 0.12 0.12   0.107 0.092
1993 9 0 4 0.12 0.11   0.097 0.092
1992 17 1 12 0.13 0.11   0.098 0.092
1991 0 0 0 0.06 0.10   0.035 0.063
1990 0 0 0 0.09 0.14   0.078 0.089
1989 24 0 22 0.12 0.14   0.101 0.102
1988 39 7 35 0.16 0.14   0.138 0.108
* The 3 year 4th high, 3 year average 4th high, and Expected Peak Day Concentration (EPDC) are calculated based on data for 3 successive years, listed by the last year of the three year period.  The EPDC represents the ozone concentration expected to occur once per year.
   

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This page last revised on March 26, 1999

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