In the spirit of the Superfund Basic Research Program’s (SBRP’s) mandate to develop mechanisms to deliver research findings to interested stakeholders, CROET and the SBRC recently sponsored a one-day scientific symposium entitled Trichloroethylene (TCE) from the ground up: Contaminated sites, health effects, and remediation strategies. The Symposium was held on May 21, 2004 in downtown Portland. The purpose of the symposium was to bring together experts from academia and government with the goal of understanding TCE’s impact in the region. Speakers represented both government agencies and academic institutions. Represented government agencies were EPA Region 10, Oregon Department of Environmental Quality, and Oregon Department of Human Services, while academic speakers were affiliated with Oregon Health & Science University/CROET, Oregon State University, and Washington State University. The symposium provided an ideal opportunity to bring together a diverse group of people who addressed Superfund issues from a variety of perspectives.

TCE is a nonflammable, colorless liquid that is used mainly as a solvent to remove grease from metal parts, but it is also an ingredient in adhesives, paint removers, typewriter correction fluids, and spot removers. TCE is not thought to occur naturally in the environment. However, it has been found in underground water sources and many surface waters as a result of its manufacture, use, and disposal (ATSDR, 1997). TCE is an important Superfund site contaminant, an important regional and national contaminant, and a key contaminant of concern in our SBRC. The specific focus of our SBRC is Superfund chemicals that produce neurotoxic effects, and TCE and several of its breakdown products are known to be neurotoxic (ATSDR, 1997). In addition, there is great public interest in the issue of TCE groundwater contamination at the former local View Master plant, a manufacturing plant that government agencies are involved in cleaning up.

TCE Contamination at RCRA and Superfund Sites in the Northwest: Howard Orlean, U.S. Environmental Protection Agency, Region 10. Mr. Orlean is the Corrective Action Coordinator for the RCRA (Resource Conservation and Recovery Act) Program at EPA Region 10. There are 23 Superfund sites in Washington and Oregon with TCE contamination. At all of these sites, TCE contamination is found in groundwater. Concentrations vary from below drinking water standards (5 parts per billion, ppb) up to 1000-2000 ppb. EPA is addressing this health risk by cleaning up sites to groundwater standards. Mr. Orlean subsequently illustrated this by detailing the risk management strategy for the Philip Services Corporation Georgetown facility in Seattle.

Oregon Environmental Cleanup Program: TCE Cleanup Approaches and Issues: Bruce Gilles, Oregon Department of Environmental Quality (DEQ). Mr. Gilles is a project manager with the Oregon DEQ’s Cleanup. Over the course of his career he has managed a number of investigation and cleanup projects throughout Oregon involving chlorinated solvents, and his talk presented the criteria and methods he uses to evaluate, investigate, and remediate TCE-contaminated sites. One case study of particular public interest involved the local former View Master plant, where TCE had been used for 30 years, and which now has extremely high levels of TCE in its former drinking water wells. The area has shallow groundwater contamination and high TCE levels in a deep basalt aquifer. DEQ’s risk assessment determined that there was an unacceptable risk to on-site and utility workers, as well as from future use of groundwater. Treatment has begun using chemical oxidation, air stripping, and carbon filtration. The cleanup will take 30 years.

TCE: Public Health Perspective: David Stone & Michael Heumann, Oregon Department of Human Services (DHS). Dr. Stone is a public health toxicologist who examines the public health implications of exposure to environmental contaminants. Mr. Heumann is an epidemiologist whose primary area of focus is occupational and environmental epidemiology. Together, they presented case studies involving TCE from a public health perspective. Mr. Heumann spoke about the View Master plant, a local former manufacturing plant that is now highly contaminated with TCE. TCE contamination was first found in the plant's drinking water well in 1998. DEQ has estimated that the well had been contaminated for over 20 years, resulting in a large number of workers exposed to TCE in the drinking water. The proposed public health response plan included recreating the cohort, designing public health outcome studies, and conducting dose and exposure reconstruction analysis. The first step was to review mortality data from Oregon and the US. Conclusions thus far indicate that the well contamination constitutes a past public health hazard, with proportional excesses of kidney and pancreatic cancer, and that a more thorough investigation of the impact of these data on the local community is needed.

Health Effects of TCE: Richard Bull, Washington State University. Dr. Bull, a retired toxicology professor, presented studies that primarily focused on the carcinogenic properties of TCE. There is data indicating that TCE causes kidney, liver, esophageal, and cervical cancer, as well as non-Hodgkin’s lymphoma, in humans. He also described several studies of TCE-induced liver cancer in mice.

Methods for Determining In-Situ Rates of Reductive Dechlorination in Groundwater: Jennifer Field, Oregon State University & Superfund Basic Research Center. Dr. Field is a professor of environmental and molecular toxicology who spoke about her SBRC-sponsored research. She stated that in-situ rate determining methods are necessary in order to assess the potential for intrinsic bioremediation, to design engineered bioremediation projects, and to monitor remediation progress. However, these rates can be difficult to obtain. Her research involves modifying the “push-pull” test, in which a prepared test solution containing tracer and a substrate is injected into a monitoring well and then samples are collected and analyzed for tracer, substrate, and product. Conclusions from these studies stated that using TCFE to measure in-situ reductive dechlorination rates is a cost-effective, simple method to obtain rate information, and can be effectively applied in the field.

Anaerobic Biological Processes and Abiotic Remediation: Lewis Semprini, Oregon State University & Superfund Basic Research Center. Dr. Semprini, professor of civil, construction, and environmental engineering, spoke about his research on biological processes for the treatment of hazardous wastes, and on the fate and transport of organic contaminants in the environment. He specializes in field, laboratory, and modeling studies. He spoke about his work identifying microorganisms that reductively dechlorinate TCE, using molecular biology techniques to identify bacteria and modeling studies to determine reductive dechlorination rates of TCE.