Since 1993, Environmental Services and the Oregon Department of Environmental Quality (DEQ) have studied the Columbia Slough watershed and worked together to improve sediment quality.

Studies show widespread, low-level contamination throughout the slough's sediments with a few isolated areas of higher contamination. The city's cleanup approach includes controlling the source of the contaminants, cleaning up the most contaminated areas, and long-term monitoring.

Choose from the links below for more information about the Columbia Slough Sediment Program.