California Air Resources Board California Map with District Boundaries
Ozone Data Summaries (1980-1998)
Imperial County APCD
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*
1998 40 3 16 0.14 0.14 0.142 0.104 0.093
1997 69 10 50 0.16 0.16 0.157 0.120 0.103
1996 69 10 34 0.18 0.18 0.155 0.117 0.103
1995 83 22 49 0.23 0.18 0.163 0.116 0.105
1994 75 8 47 0.18 0.15 0.154 0.116 0.104
1993 50 16 24 0.21 0.15 0.120 0.128 0.095
1992 46 8 24 0.15 0.15 0.110 0.117 0.090
1991 9 3 3 0.18 0.12 0.108 0.135 0.078
1990 6 0 0 0.11 0.11 0.117 0.082 0.076
1989 4 0 1 0.11 0.11 0.110 0.088 0.075
1988 17 0 3 0.12 0.11 0.110 0.098 0.073
1987 0 0 0 0.09 0.09   0.081 0.069
1986 0 0 0 0.09 0.12   0.080 0.071
1985 16 1 10 0.13 0.12   0.102 0.067
1984 0 0 0 0.05 0.10   0.031 0.059
1983 3 0 0 0.11 0.11 0.114 0.080 0.078
1982 2 0 0 0.10 0.12 0.117 0.081 0.083
1981 15 1 5 0.18 0.12 0.121 0.110 0.088
1980 47 9 32 0.15 0.13 0.116 0.113 0.105
* 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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