Air monitoring is required under the federal Clean Air Act (CAA). The State of Missouri operates a network of about 50 ambient air monitoring sites. This network is used to determine whether areas in Missouri are meeting the primary National Ambient Air Quality Standards (NAAQS) and help develop information on air quality for the citizens of Missouri.
Under Code of Federal Regulations, 40 C.F.R. Part 58.10(d), each state is required to perform an assessment of their air quality monitoring network every five years. The assessment helps the state determine whether the network meets the monitoring objectives defined in 40 C.F.R. Part 58 - Appendix D, whether new sites are needed, whether existing sites are no longer needed, and whether new technologies are appropriate for incorporation into the monitoring network. Recent changes or proposed changes in the NAAQS must be considered in assessing the air quality monitoring network.
These assessments are submitted to the U.S. Environmental Protection Agency (EPA). The assessment discusses Missouri population, climate and new emission sources that are used to evaluate the network for monitoring of each of the following air pollutants: carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), particulate matter smaller than 10 micrometers (PM10), ozone (O3), particulate matter smaller than 2.5 micrometers (PM2.5) and lead.
Listed below are the two most recent assessments. For copies of older assessments, please submit an Open Records/ Sunshine Law Request.