Although state and tribal agencies actually measure the air pollutants, EPA maintains an active role through extensive oversight and routinely provides monitoring agencies with technical support.
Oversight includes review and approval of the monitoring locations and monitoring methods.
Technical support includes sampler designations, monitoring experience, and liaison with EPA headquarters regarding technical issues. The table below highlights some of the important activities. States and tribes review their air monitoring networks every year. States and tribes communicate with EPA about the progress of changes in the air monitoring network. EPA participates in the network review by reviewing state and tribal written reports.