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 Montcalm County, Michigan, and

Montmorency County, Michigan, give the percentage contributions from specific air pollution sources.  The Montcalm County Seat is Stanton, Michigan, and the Montmorency County Seat is Atlanta, Michigan.