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 Sarpy County, Nebraska, and

Saunders County, Nebraska, give the percentage contributions from specific air pollution sources.  The Sarpy County Seat is Papillion, Nebraska, and the Saunders County Seat is Wahoo, Nebraska.