California Air Resources Board California Map with District Boundaries
Ozone Data Summaries (1980-1998)
Butte County AQMD
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 2 0 1 0.11 0.10 0.091 0.090 0.072
1997 0 0 0 0.09 0.09 0.091 0.072 0.072
1996 2 0 0 0.11 0.10 0.095 0.084 0.077
1995 1 0 1 0.11 0.10 0.098 0.086 0.078
1994 3 0 2 0.10 0.10 0.096 0.091 0.078
1993 1 0 0 0.10 0.09 0.091 0.083 0.075
1992 0 0 0 0.09 0.09 0.094 0.077 0.076
1991 1 0 1 0.10 0.10 0.098 0.085 0.077
1990 2 1 1 0.13 0.10 0.103 0.095 0.080
1989 4 0 1 0.10 0.10 0.105 0.087 0.082
1988 8 0 3 0.10 0.10 0.103 0.092 0.081
1987 5 0 3 0.11 0.10 0.102 0.088 0.082
1986 2 0 1 0.11 0.10 0.097 0.087 0.078
1985 4 0 4 0.10 0.10 0.094 0.093 0.074
1984 0 0 0 0.09 0.08 0.086 0.075 0.069
1983 0 0 0 0.08 0.09 0.087 0.068 0.068
1982 0 0 0 0.09 0.10 0.094 0.076 0.070
1981 1 0 0 0.10 0.10 0.099 0.078 0.072
1980 4 0 0 0.11 0.10 0.103 0.078 0.074
* 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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