Established in 1975, the air monitor at Watkins Mill State Park is one of the state's longest-running stations. The park lies about 40 miles northwest of the Kanas City line, and the monitor helps determine ozone exposure of a population segment in the Kansas City metropolitan statistical area. The state park is adjacent to the Watkins Woolen Mill State Historic Site. The park and historic site bear the name of entrepreneur Waltus Watkins. 


Ozone Pollutant

The primary National Ambient Air Quality Standard for ozone is 0.070 parts per million averaged over eight hours (annual fourth-highest daily maximum 8-hour concentration, averaged over three years). The federal ozone season for monitoring runs from March 1 to Oct. 31.

Departmental information about ozone (O3)

  • Description
  • Health effects
  • Tips to reduce ozone
  • 2008 and 2015 standards plus related documents
  • 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, 2021 and 2022
  • Daily maximum average eight-hour concentration for each site from beginning of season
  • Map of Missouri's ozone monitoring sites
Watkins Mill State Park Air Monitoring Site

Watkins Mill Road
Lawson, MO 64062
United States

Date Established
Pollutants Monitored
39.407419, -94.265142