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

Okanogan County, Washington; Pacific County, Washington; and Pend Oreille County, Washington.  The Okanogan County Seat is Okanogan, Washington; the Pacific County Seat is South Bend, Washington; and the Pend Oreille County Seat is Newport, Washington.