The Orchard Farm air monitoring station is located downwind of St. Louis. It helps to characterize ozone concentrations downwind of the St. Louis area and determine exposure to ozone of the population of the St. Louis Metropolitan Statistical Area. The station monitors attainment of the National Ambient Air Quality Standards (NAAQS).
To learn about other air monitoring sites the department operates as part of the state's ambient air monitoring network, visit Air Monitoring Sites.
Pollutants
Ozone Pollutant
The primary National Ambient Air Quality Standard (NAAQS) for ozone is 0.070 parts per million (ppm) averaged over eight hours (annual fourth-highest daily maximum 8-hour concentration, averaged over three years). The federal ozone monitoring season runs from March 1 to Oct. 31.
*All times listed in reports reflect Central Standard Time (CST).
- Eight-hour ozone design values
- Four highest eight-hour ozone values from beginning of ozone season
- Running list of sites with exceedances from beginning of season
- Monthly number of exceedances
- Daily maximum average eight-hour concentration for each site from beginning of season
- Map of Missouri's ozone monitoring sites
Additional information about Ozone State Planning efforts
Technical issues can affect ability to deliver quality data. Access a table of symbols with explanation of the problems they represent.
- "P" stands for primary monitor
- "S" stands for secondary monitor
- Data from 10 days ago through current date
2165 Highway V
St. Charles, MO 63301
United States
Air Pollution Control Program
Division of Environmental Quality
P.O. Box 176
Jefferson City, MO 65102-0176
United States