Stage of Clean-up: Construction Underway
The East Multnomah County Ground Water Contamination site covers 3 square miles in Multnomah County east of Portland, Oregon. Current studies indicate that the site involves plumes of ground water contaminated with chlorinated organic solvents. The plumes are from individual sources and are mixing together. EPA learned that TRICHLOROETHENE (TCE) and two of its degradation products, 1,1-DICHLOROETHENE and 1,1-DICHLOROETHANE, were contaminating ground water in 1986 when the Boeing Co. Portland Plant was closing a surface impoundment under Subtitle C of the Resource Conservation and Recovery Act (RCRA). A subsequent investigation by Boeing found ground water contamination upgradient of the plant. During 1987-1991, EPA inventoried local businesses (many of which use TCE as a solvent) and investigated the area extensively, including sampling wells and conducting an area-wide soil gas survey. The results documented three sources of ground water plumes, including the Boeing plant, identified five potential sources requiring further investigation, and suggested still more sources may be identified. More...