California Air Resources Board
January - July
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 12 3 10 0.136 0.109
1996 24 4 17 0.130 0.113
1997 12 1 6 0.125 0.092
1998** 8 2 7 0.15  0.136

Sacramento Sacramento-
Del Paso Manor
1995 12 5 11 0.154 0.121
1996 16 0 8 0.123 0.104
1997 4 0 0 0.097 0.083
1998** 3 1 2 0.15  0.130
* 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 37 5 23 0.146 0.122
1996 31 2 19 0.138 0.117
1997 20 1 10 0.136 0.112
1998** 16 4 12 0.164 0.141

San Diego Escondido-
Valley Parkway
1995 5 1 2 0.154 0.107
1996 9 0 8 0.119 0.099
1997 3 0 2 0.112 0.090
1998** 3 0 2 0.122 0.089

San Diego Otay Mesa-
Paseo International
1995 3 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 0.094 0.077
** 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 11 4 6 0.155 0.115
1996 14 5 7 0.133 0.112
1997 0 0 0 0.088 0.065
1998** 5 1 2 0.143 0.108

Contra Costa Concord-
2975 Treat Blvd
1995 6 2 4 0.152 0.114
1996 5 1 4 0.127 0.099
1997 1 0 0 0.095 0.070
1998** 2 0 1 0.115 0.098

Santa Clara San Jose-
935 Piedmont Road
1995 10 3 5 0.145 0.109
1996 5 0 0 0.118 0.083
1997 0 0 0 0.080 0.063
1998** 1 1 0 0.129 0.083
** 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 24 8 22 0.140 0.117
1996 30 6 28 0.143 0.110
1997 17 0 15 0.121 0.101
1998** 19 5 22 0.15  0.117

Fresno Parlier 1995 2 0 0 0.103 0.079
1996 39 8 28 0.145 0.109
1997 35 4 28 0.137 0.106
1998** 29 5 25 0.145 0.108

Kern Arvin-
Bear Mountain Blvd
1995 35 9 29 0.151 0.124
1996 58 19 55 0.139 0.123
1997 28 2 26 0.129 0.112
1998** 32 1 30 0.13  0.116

Kern Edison 1995 44 9 35 0.156 0.123
1996 45 9 39 0.137 0.118
1997 19 1 15 0.131 0.106
1998** 31 7 27 0.17  0.136
** 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 54 33 40 0.216 0.158
1996 56 29 34 0.197 0.150
1997 37 10 15 0.170 0.130
1998** 21 10 19 0.222 0.171

Riverside Riverside-
Rubidoux
1995 52 26 39 0.213 0.146
1996 57 20 50 0.203 0.162
1997 50 6 33 0.165 0.129
1998** 24 11 24 0.193 0.170

San Bernardino Lake Gregory 1995 59 34 52 0.205 0.170
1996 75 46 69 0.234 0.164
1997 56 19 43 0.205 0.138
1998** 48 25 51 0.244 0.206

San Bernardino San Bernardino-
4th Street
1995 54 29 44 0.203 0.165
1996 70 40 59 0.239 0.173
1997 66 23 45 0.197 0.137
1998** 27 16 21 0.214 0.180
** 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 August 4, 1998
 
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