California Air Resources Board
January - June
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 6 1 4 0.136 0.106
1996 8 0 6 0.118 0.102
1997 6 0 3 0.105 0.092
1998** 1 0 0 0.10  0.076

Sacramento Sacramento-
Del Paso Manor
1995 6 2 5 0.132 0.103
1996 8 0 3 0.121 0.104
1997 3 0 0 0.097 0.083
1998** 0 0 0 0.09  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 22 2 13 0.146 0.122
1996 25 2 14 0.138 0.117
1997 12 0 6 0.109 0.093
1998** 1 0 1 0.105 0.089

San Diego Escondido-
Valley Parkway
1995 2 0 1 0.103 0.089
1996 7 0 7 0.119 0.099
1997 0 0 0 0.092 0.083
1998** 0 0 0 0.094 0.082

San Diego Otay Mesa-
Paseo International
1995 2 0 0 0.113 0.080
1996 5 0 1 0.111 0.089
1997 3 0 0 0.100 0.079
1998** 0 0 0 0.072 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 5 2 2 0.142 0.094
1996 7 2 3 0.131 0.099
1997 0 0 0 0.088 0.059
1998** 1 0 0 0.10 0.068

Contra Costa Concord-
2975 Treat Blvd
1995 2 1 1 0.128 0.087
1996 3 0 3 0.116 0.099
1997 0 0 0 0.087 0.060
1998** 0 0 0 0.089 0.069

Santa Clara San Jose-
935 Piedmont Road
1995 3 2 2 0.127 0.101
1996 4 0 0 0.118 0.083
1997 0 0 0 0.080 0.063
1998** 0 0 0 0.075 0.058
** 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 13 5 11 0.135 0.108
1996 10 3 12 0.126 0.110
1997 9 0 7 0.119 0.098
1998** 5 0 4 0.11  0.098

Fresno Parlier 1995 1 0 0 0.097 0.078
1996 18 4 12 0.136 0.103
1997 18 2 12 0.137 0.106
1998** 6 0 4 0.116 0.098

Kern Arvin-
Bear Mountain Blvd
1995 18 4 15 0.142 0.115
1996 31 8 30 0.139 0.123
1997 9 1 9 0.129 0.105
1998** 7 0 7 0.12  0.100

Kern Edison 1995 22 1 21 0.128 0.109
1996 20 2 18 0.136 0.118
1997 8 0 6 0.114 0.092
1998** 6 1 5 0.13  0.103
** 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 26 16 18 0.216 0.151
1996 34 17 21 0.197 0.150
1997 25 5 10 0.164 0.120
1998** 8 1 4 0.170 0.121

Riverside Riverside-
Rubidoux
1995 28 11 22 0.169 0.146
1996 36 11 33 0.203 0.162
1997 29 3 20 0.152 0.129
1998** 9 1 6 0.140 0.126

San Bernardino Lake Gregory 1995 33 14 28 0.173 0.132
1996 46 28 41 0.234 0.154
1997 28 9 20 0.147 0.123
1998** 24 8 26 0.210 0.167

San Bernardino San Bernardino-
4th Street
1995 29 11 20 0.187 0.150
1996 45 24 37 0.239 0.173
1997 45 16 32 0.157 0.126
1998** 11 4 6 0.170 0.145
** 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 July 2, 1998
 
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