Toxics Cleanup Program |
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Lower Duwamish
Toxics Cleanup Program |
Sites |
Site Information |
Lower Duwamish
Combined Sewer Overflow (CSO): Wastewater collection system overflows of stormwater and wastewater. This occurs when flows exceed the carrying capacity of the wastewater collection system, such as during heavy rain events.
Contamination: The introduction of substances harmful or potentially harmful to human health and the environment.
Dredge: A device for mechanically removing layers of sediment, rock, debris, and sand from a waterbody. Used to clear channels and for cleanup work.
Mercury: A heavy, toxic and volatile silvery metal which is liquid at room temperature. Most people associate mercury with thermometers and barometers, but it is also used as an industrial chemical in a number of processes.
PAHs: Polycyclic (or Polynuclear) Aromatic Hydrocarbons are a group of petroleum-derived compounds. PAHs are formed by burning organic material and are commonly found in the environment. Many PAHs are known or suspected carcinogens.
PCBs: Polychlorinated biphenyls are toxic, persistent chemicals. Due to their non-flammability, chemical stability, high boiling point and electrical insulating properties, PCBs were used in hundreds of industrial and commercial applications including electrical equipment; plasticizers (substances added to plastics to increase their flexibility). PCBs are a serious threat to public health because they have been proven to cause cancer in animals. In 1977 they were made illegal to produce in the United States, yet they still remain in the environment.
Phthalates: A class of chemical compounds that are mainly used as plasticizers. They are chiefly used to turn polyvinyl chloride from a hard plastic into a flexible plastic and they are also used in many other products (such as detergents, cosmetics) and industrial processes. Due to the pervasiveness in products, phthalates are a very widespread class of pollutants. These chemicals may have adverse effects on humans and the environment.
Sediments: The accumulated layers of silt, mud, and stones, on the bottom of a body of water.
Source Control: The process of identifying and managing sources of contamination to waterway sediments. For sources to the Lower Duwamish Waterway Superfund Site, this process is explained in the Lower Duwamish Waterway Source Control Strategy.
VOCs: Volatile Organic Compounds include a variety of chemicals that become a gas at room temperature, such as benzene, toluene, methylene chloride, and methyl chloroform. Due to their low water solubility and persistence, once released into the environment they can last for decades.
This page last updated 09/15/2008