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 Redwood County, Minnesota, and

Renville County, Minnesota, give the percentage contributions from specific air pollution sources.  The Redwood County Seat is Redwood Falls, Minnesota, and the Renville County Seat is Olivia, Minnesota.