2007 Four Highest Maximum 8-hour Ozone Averages by Monitor
Based on Information Received by East-West Gateway Measured in Parts Per Billion
Monitor
First Highest
Second Highest
Third Highest
Fourth Highest
MISSOURI
April 1-July 31, 2007
Arnold
91
81
82
80
West Alton
94
88
87
84
Orchard Farm
95
89
83
83
Maryland Heights
103
101
93
92
Sunset Hills
94
86
85
83
Pacific
93
89
89
85
Blair St.
92
97
80
78
Margaretta
91
91
88
83
Foley *
98
96
89
88
Bonne Terre *
91
91
87
85
ILLINOIS
April 30-July 31, 2007
Wood River
90
87
85
85
Maryville
91
87
79
78
Alton
85
83
81
79
East St. Louis
74
72
6069
69
Jerseyville
85
75
72
72
Nilwood *
75
73
73
72
Houston *
78
77
75
74
*Monitors are outside the St. Louis 8-hour ozone non-attainment area
8-hour ozone standard is 85 parts per billion (ppb) Exceedances of the standard are in bold.
To attain the eight-hour ozone standard, the three year average of the annual fourth highest daily maximum eight-hour ozone concentration as measured at each monitor has to be less than or equal to 85
ppb.
Source: Missouri Department of Natural Resources and Illinois Environmental Protection Agency. Information is preliminary and has not been quality assured
East-West Gateway Council of Governments One Memorial Dr., Ste 1600
St. Louis, MO 63102 phone: (314) 421-4220 or (618) 274-2750 fax: (314) 231-6120 e-mail: webmaster@ewgateway.org
