California Air Resources Board
January - April
Year-to-Date Ozone Summary
for Selected California Monitoring Sites
   

Sacramento Valley Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Sacramento Folsom-
50 Natoma Street*
1995 0 0 0 0.078 0.064
1996 0 0 0 0.088 0.072
1997 0 0 0 0.082 0.075
1998** 0 0 0 0.07  0.065

Sacramento Sacramento-
Del Paso Manor
1995 0 0 0 0.087 0.075
1996 1 0 0 0.102 0.080
1997 0 0 0 0.092 0.082
1998** 0 0 0 0.08  0.072
* The 50 Natoma Street site replaced the Folsom-City Corporation Yard site in 1997.
** All 1998 data are preliminary and subject to further review.  
 
San Diego Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
San Diego Alpine-
Victoria Drive
1995 5 0 2 0.116 0.085
1996 2 0 1 0.108 0.097
1997 2 0 1 0.102 0.086
1998** 0 0 0 0.092 0.084

San Diego Escondido-
Valley Parkway
1995 0 0 0 0.087 0.075
1996 1 0 1 0.097 0.085
1997 0 0 0 0.088 0.076
1998** 0 0 0 0.094 0.082

San Diego Otay Mesa-
Paseo International
1995 2 0 0 0.113 0.078
1996 2 0 1 0.111 0.089
1997 1 0 0 0.096 0.078
1998** 0 0 0 0.068 0.060
** All 1998 data are preliminary and subject to further review.  
 
San Francisco Bay Area Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Alameda Livermore-
Old 1st Street
1995 0 0 0 0.070 0.062
1996 0 0 0 0.089 0.080
1997 0 0 0 0.074 0.054
1998** 0 0 0 0.087 0.062

Contra Costa Concord-
2975 Treat Blvd
1995 0 0 0 0.068 0.059
1996 1 0 1 0.109 0.089
1997 0 0 0 0.071 0.055
1998** 0 0 0 0.089 0.069

Santa Clara San Jose-
935 Piedmont Road
1995 0 0 0 0.072 0.061
1996 0 0 0 0.087 0.064
1997 0 0 0 0.056 0.043
1998** 0 0 0 0.051 0.047
** All 1998 data are preliminary and subject to further review.  
 
San Joaquin Valley Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Fresno Fresno-
1st Street
1995 1 0 0 0.105 0.078
1996 0 0 0 0.090 0.079
1997 0 0 0 0.092 0.084
1998** 1 0 1 0.10  0.087

Fresno Parlier 1995 0 0 0 0.082 0.063
1996 2 1 1 0.125 0.102
1997 2 0 0 0.097 0.079
1998** 0 0 0 0.094 0.083

Kern Arvin-
Bear Mountain Blvd
1995 0 0 0 0.085 0.078
1996 4 0 2 0.106 0.093
1997 0 0 0 0.094 0.081
1998** 0 0 0 0.09  0.077

Kern Edison 1995 2 0 2 0.102 0.086
1996 1 0 1 0.098 0.087
1997 1 0 0 0.098 0.083
1998** 0 0 0 0.09  0.077
** All 1998 data are preliminary and subject to further review.  
 
South Coast Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Los Angeles Glendora-
Laurel
1995 4 1 1 0.130 0.097
1996 8 3 3 0.139 0.109
1997 1 0 0 0.097 0.071
1998** 2 0 0 0.110 0.079

Riverside Riverside-
Rubidoux
1995 4 1 2 0.125 0.097
1996 7 1 7 0.126 0.109
1997 4 0 1 0.108 0.086
1998** 1 0 1 0.100 0.086

San Bernardino Lake Gregory 1995 4 0 2 0.110 0.098
1996 6 2 3 0.154 0.104
1997 2 0 1 0.108 0.098
1998** 6 0 4 0.120 0.098

San Bernardino San Bernardino-
4th Street
1995 2 0 1 0.120 0.091
1996 6 1 3 0.139 0.107
1997 4 0 1 0.108 0.089
1998** 3 0 0 0.100 0.084
** All 1998 data are preliminary and subject to further review.  
 
 
Please send questions or comments to:
aqdweb@arb.ca.gov
 
This page last revised on May 5, 1998
 
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