Trichloroethylene (TCE) is a common industrial solvent mostly used for metal degreasing. Due to its wide use in industries, there have been several incidences of waste TCE leaking into aquifers and contaminating groundwaters. Due to their similar industrial uses, areas contaminated with mainly TCE may also be contaminated with tetrachloroethylene in smaller amounts.
Background The first known report of TCE in groundwater was given in 1949 by two English public chemists who described two separate instances of well contamination by industrial releases of TCE. Exposure to TCE occurs mainly through contaminated drinking water. With a specific gravity greater than 1 (denser than water), trichloroethylene can be present as a dense non-aqueous phase liquid (DNAPL) if sufficient quantities are introduced into the environment. Another significant source of vapor exposure in Superfund sites that has contaminated groundwater, such as at the Twin Cities Army Ammunition Plant, was by showering. TCE readily volatilizes out of hot water and into the air. Long, hot showers would then volatilize more TCE into the air. In a home closed tightly to conserve the cost of heating and cooling, these vapors would then recirculate. Based on available federal and state surveys, between 9% and 34% of the drinking water supply sources tested in the U.S. may have some TCE contamination, though EPA has reported that most water supplies are in compliance with the maximum contaminant level (MCL) of 5 ppb. In addition, a growing concern in recent years at sites with TCE contamination in soil or groundwater has been vapor intrusion in buildings, which has resulted in indoor air exposures, such is in a recent case in the McCook Field neighborhood of Dayton, Ohio, United States. Trichloroethylene has been detected in 852 Superfund sites across the United States, according to the Agency for Toxic Substances and Disease Registry (ATSDR). Under the Safe Drinking Water Act of 1974, and as amended annual water quality testing is required for all public drinking water distributors. The EPA'S current guidelines for TCE are online. The EPA's table of "TCE Releases to Ground" is dated 1987 to 1993, thereby omitting one of the largest Superfund cleanup sites in the nation, the North IBW in Scottsdale, Arizona. Earlier, TCE was dumped here, and was subsequently detected in the municipal drinking water wells in 1982, prior to the study period. Marine Corps Base Camp Lejeune in North Carolina may be the largest TCE contamination site in the United States. Legislation could force the EPA to establish a health advisory and a national public drinking water regulation to limit trichloroethylene. The 1998 film A Civil Action dramatizes the EPA lawsuit Anne Anderson, et al., v. Cryovac, Inc. concerning trichloroethylene contamination that occurred in Woburn, Massachusetts in the 1970s and 1980s.
1980s Between 1975 and 1985, the water supply of Marine Corps Base Camp Lejeune was contaminated with trichloroethylene and other volatile organic compounds. In 1986, and later again in 2009, 2 plumes containing trichloroethylene was found on Long Island, New York due to Northrop Grumman's Bethpage factories that worked in conjunction with the United States Navy during the 1930s and 1940s. In 1988, the EPA discovered tons of TCE that had been leaked or dumped into the ground by the United States military and semiconductor industry (companies including Fairchild Semiconductor, Intel Corporation, and Raytheon Company) just outside NASA Ames in Moffett Field, Mountain View, California. In 1987, Hill Air Force Base, in Layton, Utah, was declared a Superfund site in 1987 and added to the U.S. Environmental Protection Agency's National Priorities List. Contamination of TCE has been detected in the groundwater throughout Weber County, Utah.
1990s In 1990, Fort Ord, California was added to the EPA's National Priorities List. Veterans have linked trichloroethylene as the underlying cause for high incidence rates of multiple myeloma. In 1992, Lockformer conducted soil sampling on their property and found TCE in the soil at levels as high as 680 parts per million (ppm). During the summer of 2000, a group of residents hired legal counsel, and on October 11, 2000, these residents had their private well water tested by a private environmental consultant. The group owned homes south of the Lockformer property in the suspected path of groundwater flow. The consultant collected a second round of well water samples on November 10, 2000, and TCE was detected in some of the wells sampled. Beginning in December 2000, Illinois EPA collected about 350 more private well water samples north and south of the Lockformer property. For over 20 years of operation, RCA Corporation had been pouring toxic wastewater into a well in its Taoyuan City, Taiwan facility. The pollution from the plant was not revealed until 1994, when former workers brought it to light. Investigation by the Taiwan Environmental Protection Administration confirmed that RCA had been dumping chlorinated organic solvents into a secret well and caused contamination to the soil and groundwater surrounding the plant site. High levels of TCE and tetrachloroethylene can be found in groundwater drawn as far as two kilometers from the site. In 1998, the View-Master factory supply well in Beaverton, Oregon was found to have been contaminated with high levels of TCE. It was estimated that 25,000 factory workers had been exposed to it from 1950 to 2001. In the case of Lisle, Illinois, releases of trichloroethylene had allegedly occurred on the Lockformer property beginning in 1968 and continuing for an undetermined period. The company used TCE in the past as a degreaser to clean metal parts. Contamination at the Lockformer site is presently under investigation by the U.S. Environmental Protection Agency and Illinois EPA.
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