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 Seneca County, New York, and

St. Lawrence County, New York, give the percentage contributions from specific air pollution sources.  The Seneca County Seat is Waterloo, New York, and the St. Lawrence County Seat is Canton, New York.