DEQ was established by the Oregon Legislative Assembly in 1969 when it dissolved its predecessor, the Oregon State Sanitary Authority, which was created in 1938 in response to public outcry for cleanup of the Willamette River.
The Oregon Department of Environmental Quality (DEQ) originated in 1969, resulting from the disbanding of the earlier Oregon State Sanitary Authority, which was created in 1938 in response to community pressure to clean up the Willamette River.