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State of California California Air Resources Board
January 1st - September 9th
Year 2001 Ozone Summary
for Selected California Monitoring Sites and Regions
The tables below include ozone summary statistics for 2001 through the date given above. For comparison, the 1998, 1999, and 2000 summary statistics are for the full year. To view the 1998, 1999, and 2000 summary statistics through the date given above, click on Year-to-Date.

Previous Ozone Summaries

Greater Sacramento Planning Area
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
1998 31 10 26 0.15 0.14
1999 22 4 18 0.15 0.13
2000 17 1 15 0.13 0.10
2001** 31 3 24 0.14 0.11

Sacramento Sacramento-
Del Paso Manor
1998 19 5 10 0.16 0.13
1999 12 1 6 0.13 0.11
2000 13 0 9 0.12 0.10
2001** 12 1 9 0.14 0.11

Sacramento Sloughhouse 1998 27 8 24 0.15 0.12
1999 27 4 19 0.15 0.11
2000 22 3 18 0.14 0.11
2001** 23 0 20 0.12 0.10
Region* Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Greater Sacramento Planning Area
Summary
1998 47 13 34 0.16 0.14
1999 56 7 48 0.16 0.13
2000 45 7 37 0.14 0.11
2001** 48 4 42 0.15 0.11
* For the Regional summary statistics, the number of exceedance days equals the number of distinct days on which the relevant standard was exceeded at any monitoring site in the area.  If the standard was exceeded at more than one site on a given day, it only counts as one exceedance day for the broader area.  
** All 2001 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
1998 47 8 32 0.16 0.14
1999 21 0 15 0.12 0.10
2000 19 0 12 0.12 0.11
2001** 18 1 13 0.14 0.12

San Diego Escondido-
Valley Parkway
1998 9 0 5 0.12 0.09
1999 1 0 0 0.10 0.08
2000 6 0 3 0.12 0.11
2001** 2 0 0 0.11 0.08

San Diego Otay Mesa-
Paseo International
1998 0 0 0 0.09 0.08
1999 1 0 0 0.10 0.08
2000 0 0 0 0.09 0.06
2001** 0 0 0 0.08 0.07
Region* Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
San Diego Air Basin Summary 1998 54 9 35 0.16 0.14
1999 27 0 16 0.12 0.10
2000 24 0 16 0.12 0.11
2001** 22 1 13 0.14 0.12
* For the Regional summary statistics, the number of exceedance days equals the number of distinct days on which the relevant standard was exceeded at any monitoring site in the area.  If the standard was exceeded at more than one site on a given day, it only counts as one exceedance day for the broader area.  
** All 2001 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-
Rincon¹
1998 21 6 10 0.15 0.11
1999 14 2 5 0.15 0.12
2000 7 1 2 0.15 0.11
2001** 7 0 2 0.11 0.09

Contra Costa Concord-
2975 Treat Blvd
1998 13 2 6 0.15 0.11
1999 8 2 6 0.16 0.12
2000 2 1 1 0.14 0.10
2001** 6 1 1 0.13 0.09

Santa Clara San Jose-
935 Piedmont Road
1998 5 1 0 0.13 0.08
1999 2 0 0 0.12 0.08
2000 1 0 0 0.10 0.07
2001** 0 0 0 0.09 0.06
Region* Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
San Francisco Bay Area Air Basin
Summary
1998 29 8 16 0.15 0.11
1999 20 3 9 0.16 0.12
2000 12 3 4 0.15 0.11
2001** 13 1 6 0.13 0.10
¹ The new Livermore-Rincon site, which is a replacement for the Livermore-Old 1st Street site, started operating at the begining of 2000.
* For the Regional summary statistics, the number of exceedance days equals the number of distinct days on which the relevant standard was exceeded at any monitoring site in the area.  If the standard was exceeded at more than one site on a given day, it only counts as one exceedance day for the broader area.  
** All 2001 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
1998 65 26 62 0.17 0.13
1999 56 5 49 0.14 0.12
2000 49 8 44 0.15 0.13
2001** 51 6 44 0.15 0.12

Fresno Fresno-
1st Street
1998 46 15 44 0.15 0.12
1999 53 4 45 0.14 0.12
2000 48 5 41 0.14 0.11
2001** 43 4 34 0.14 0.11

Fresno Parlier 1998 64 13 54 0.16 0.12
1999 81 15 68 0.16 0.11
2000 81 17 66 0.17 0.12
2001** 67 7 54 0.15 0.12

Kern Arvin-
Bear Mountain Blvd
1998 71 12 64 0.15 0.12
1999 94 9 85 0.13 0.11
2000 82 9 73 0.15 0.12
2001** 67 13 61 0.13 0.12

Kern Edison 1998 71 22 61 0.17 0.14
1999 68 5 55 0.14 0.11
2000 72 9 58 0.15 0.12
2001** 47 6 44 0.14 0.11
Region* Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
San Joaquin Valley Air Basin Summary 1998 90 39 84 0.17 0.14
1999 123 28 117 0.16 0.12
2000 114 30 103 0.17 0.13
2001** 87 23 81 0.15 0.12
* For the Regional summary statistics, the number of exceedance days equals the number of distinct days on which the relevant standard was exceeded at any monitoring site in the area.  If the standard was exceeded at more than one site on a given day, it only counts as one exceedance day for the broader area.  
** All 2001 data are preliminary and subject to further review.  
 
South Coast Air Quality Management District
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Los Angeles Glendora-
Laurel
1998 61 28 37 0.22 0.17
1999 25 3 7 0.14 0.10
2000 39 11 21 0.17 0.15
2001** 54 14 30 0.19 0.14

Riverside Riverside-
Rubidoux
1998 70 32 57 0.20 0.17
1999 38 3 22 0.14 0.11
2000 42 3 26 0.14 0.11
2001** 38 6 32 0.14 0.12

San Bernardino Crestline 1998 97 57 86 0.24 0.21
1999 93 30 82 0.17 0.14
2000 85 18 64 0.18 0.15
2001** 83 27 75 0.17 0.14

San Bernardino Rim High School¹ 1998 100 52 96 0.24 0.20
1999 106 28 112 0.17 0.15
2000 102 29 89 0.19 0.16
2001** 68 24 67 0.16 0.14

San Bernardino San Bernardino-
4th Street
1998 65 39 47 0.21 0.18
1999 45 14 30 0.16 0.13
2000 48 7 23 0.15 0.13
2001** 53 17 37 0.18 0.14
Region* Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
South Coast Air Quality Management District Summary 1998 107 60 93 0.24 0.21
1999 111 39 93 0.17 0.14
2000 115 33 94 0.18 0.15
2001** 104 35 90 0.19 0.14
¹ The Rim High School site is a Children Health Study site, and not a South Coast SLAMS or NAMS site.
* For the Regional summary statistics, the number of exceedance days equals the number of distinct days on which the relevant standard was exceeded at any monitoring site in the area.  If the standard was exceeded at more than one site on a given day, it only counts as one exceedance day for the broader area.  
** All 2001 data are preliminary and subject to further review.  
 
Ventura County1
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Ventura Ojai-Ojai Road 1998 13 0 10 0.11 0.10
1999 7 0 7 0.11 0.10
2000 15 0 14 0.11 0.10
2001** 13 1 10 0.13 0.11

Ventura Simi Valley-
Cochran Street
1998 37 4 29 0.17 0.15
1999 31 2 22 0.13 0.11
2000 31 1 27 0.13 0.11
2001** 28 2 15 0.13 0.11
Region* Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Ventura County Summary 1998 40 5 30 0.17 0.15
1999 32 2 23 0.13 0.11
2000 38 1 30 0.13 0.11
2001** 30 2 20 0.13 0.11
* For the Regional summary statistics, the number of exceedance days equals the number of distinct days on which the relevant standard was exceeded at any monitoring site in the area.  If the standard was exceeded at more than one site on a given day, it only counts as one exceedance day for the broader area.  
** All 2001 data are preliminary and subject to further review.  
1 Ventura data have not been available since late August, 2001.  
 
 
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aqdweb@cleanair.arb.ca.gov
 
This page last revised on September 12, 2001
 
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