About Us Sac Metro Air District is designated by EPA as part of the Sacramento Federal Ozone Nonattainment Area (SFNA), which is comprised of all of Sacramento and Yolo Counties, the eastern portion of Solano County,  the southern portion of Sutter County, the western slopes of El Dorado and Placer Counties up to the Sierra crest, and includes four other local air districts. Sac Metro Air District is responsible for monitoring air pollution within the Basin and for developing and administering programs to reduce air pollution levels below the health-based standards established by the state and federal governments.