Abstract: The Environmental Protection Agency (EPA) compiles data on emission tonnages of air pollutants for US counties.  US Air Quality Gradebook ("AirGrades") source sheets such as this one for St. Clair County, Alabama, and

Sumter County, Alabama, give the percentage contributions from specific air pollution sources.  The St. Clair County Seat is Ashville, Alabama, and the Sumter County Seat is Livingston, Alabama.