Abstract: The Environmental Protection Agency (EPA) compiles data on emission tonnages of air pollutants for US counties.  US Air Quality Gradebook ("AirGrades") source sheets give the percentage contributions from specific air pollution sources.  This source sheet is for

Union County, Oregon; Wallowa County, Oregon; and Wasco County, Oregon.  The Union County Seat is La Grande, Oregon; the Wallowa County Seat is Enterprise, Oregon; and the Wasco County Seat is The Dalles, Oregon.