DEQ's Western Region encompasses 12 counties (Benton, Coos, Curry, Douglas, Jackson, Josephine, Lane, Lincoln, Linn, Marion, Polk and Yamhill) and has regional offices in Coos Bay, Eugene, Grants Pass, Medford and Salem.

Western Region staff issue permits regulating water discharges, air emissions and hazardous and solid waste disposal. They also conduct a range of activities to clean up and protect Oregon's environment and support community involvement in environmental protection.