What is “contaminated” sediment and how bad is it?
Sediment is the often-mucky material found at the bottom of water bodies. It s where many natural and man-made chemicals tend to build up. If exposure to sediment chemicals causes no or only minor problems, it is considered safe to dispose of it at open water disposal sites already established in Puget Sound. If chemicals reach high enough levels, the sediment can cause harm to aquatic plants and animals and is considered “contaminated”. Exposure to contaminated sediment can cause severe harm. Studies conducted during the 1970s and 1980s found an unusual number of bottom fish like English sole with major tissue lesions, organ damage and tumors. Fish and shellfish have also been found to accumulate and concentrate certain sediment chemicals in their tissues. If eaten regularly, these fish and shellfish may pose an unacceptable risk to public health. When sediment causes serious harm to aquatic life and/or too high a risk to human health, then it needs to be properly managed. This can me
