California Air Resources Board
January - September
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 32 7 27 0.156 0.128
1996 35 7 23 0.157 0.126
1997 19 1 8 0.125 0.101
1998** 30 10 26 0.15  0.136

Sacramento Sacramento-
Del Paso Manor
1995 29 7 23 0.154 0.121
1996 26 3 13 0.150 0.110
1997 6 0 1 0.108 0.094
1998** 18 5 12 0.16  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 68 7 39 0.146 0.122
1996 44 2 27 0.138 0.117
1997 27 1 11 0.136 0.112
1998** 41 8 29 0.164 0.141

San Diego Escondido-
Valley Parkway
1995 7 1 2 0.154 0.107
1996 12 0 9 0.119 0.099
1997 4 0 2 0.112 0.090
1998** 8 0 5 0.122 0.092

San Diego Otay Mesa-
Paseo International
1995 7 1 0 0.162 0.081
1996 6 0 1 0.111 0.089
1997 6 0 0 0.122 0.081
1998** 0 0 0 0.094 0.078
** 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 20 7 11 0.155 0.115
1996 22 8 10 0.138 0.112
1997 3 0 0 0.114 0.084
1998** 20 6 10 0.143 0.108

Contra Costa Concord-
2975 Treat Blvd
1995 9 3 6 0.152 0.114
1996 11 1 4 0.127 0.099
1997 2 0 0 0.099 0.081
1998** 13 2 7 0.147 0.109

Santa Clara San Jose-
935 Piedmont Road
1995 15 3 6 0.145 0.109
1996 5 0 0 0.118 0.083
1997 1 0 0 0.095 0.071
1998** 5 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 Clovis-
N Villa Avenue
1995 49 7 42 0.152 0.114
1996 65 16 56 0.146 0.122
1997 68 9 63 0.147 0.127
1998** 63 26 61 0.169  0.13

Fresno Fresno-
1st Street
1995 57 14 52 0.173 0.126
1996 54 15 46 0.146 0.123
1997 30 1 23 0.128 0.107
1998** 46 14 46 0.15 0.117

Fresno Parlier 1995 34 9 23 0.143 0.111
1996 75 16 54 0.151 0.112
1997 63 9 46 0.137 0.112
1998** 63 13 51 0.162 0.118

Kern Arvin-
Bear Mountain Blvd
1995 75 19 67 0.151 0.124
1996 104 33 99 0.164 0.137
1997 55 7 45 0.134 0.112
1998** 70 11 65 0.15  0.125

Kern Edison 1995 89 34 77 0.168 0.134
1996 83 22 72 0.165 0.131
1997 48 3 29 0.146 0.118
1998** 71 22 60 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 105 69 81 0.216 0.158
1996 84 46 50 0.205 0.150
1997 63 18 24 0.170 0.130
1998** 51 25 36 0.222 0.171

Riverside Riverside-
Rubidoux
1995 96 51 77 0.213 0.146
1996 85 34 70 0.203 0.162
1997 85 13 52 0.187 0.129
1998** 59 27 55 0.195 0.169

San Bernardino Lake Gregory 1995 108 63 89 0.256 0.203
1996 112 62 97 0.234 0.164
1997 89 29 64 0.205 0.138
1998** 90 50 91 0.244 0.206

San Bernardino San Bernardino-
4th Street
1995 103 60 84 0.203 0.165
1996 107 62 85 0.239 0.173
1997 99 32 61 0.197 0.137
1998** 56 33 46 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 October 2, 1998
 
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