NPL Site Narrative for East Multnomah County Ground Water Contamination EAST MULTNOMAH COUNTY GROUND WATER CONTAMINATION Multnomah County, Oregon 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. The other two documented sources are Cascade Corp. and Swift Adhesives (a division of Reichhold Chemicals, Inc.), both upgradient of the Boeing plant. Chlorinated organic solvents have been detected in soils and ground water at both plants, as well as in downgradient ground water. Because the Boeing plant is regulated under RCRA, it is not part of the NPL site, although its cleanup will be coordinated with any CERCLA action. Soil gas studies indicate that potential sources may exist at Norwest Paper, Firestone, Opticraft, Northwest Retreader, and an area near Parker & Grantz Automotive. The Oregon Department of Environmental Quality has started preliminary investigations at the Norwest Paper and Opticraft facilities. In addition to the EPA investigations, the companies, either independently or under State enforcement orders, have also conducted investigations. Recent studies by Swift Adhesives found that a well upgradient of its plant is showing increased levels of organic solvents, suggesting a previously unidentified source. An estimated 280,000 people (including 267,500 in Portland and vicinity) use the affected ground water for standby wells. For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet at ATSDR - ToxFAQs (http://www.atsdr.cdc.gov/toxfaqs/index.asp) or by telephone at 1-888-42-ATSDR or 1-888-422-8737. ------- |