Missouri Department of Natural Resources (MDNR) has released the draft 2019 Monitoring Network Plan. This plan describes the ambient air monitoring stations used to determine compliance with National Ambient Air Quality Standards (NAAQS). Missouri's ambient monitoring network includes 43 monitoring stations, primarily located in the St. Louis and Kansas City areas.
The largest change from previous years is the proposed addition of a Photochemical Assessment Monitoring Station (PAMS) to St. Louis City beginning in 2021. PAMS data is used for enhanced ozone monitoring, and is especially useful in areas of ozone nonattainment.