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 Cortland County, New York, and

Delaware County, New York, give the percentage contributions from specific air pollution sources.  The Cortland County Seat is Cortland, New York, and the Delaware County Seat is Delhi, New York.