National Drinking Water Database
Tetrachloroethylene in Connecticut
Tetrachloroethylene (perc) is a common soil and groundwater contaminant used in dry cleaning and as a solvent in automotive and metalworking factories and other industries. [read more]
Tetrachloroethylene (Perchloroethylene or perc)
Tetrachloroethylene, also called perchloroethylene or perc for short, is used as a solvent for dry cleaning, metal degreasing and textile processing. Tetrachloroethylene is a High Production Volume (HPV) chemical, with over 500 million pounds of this chemical produced annually in the United States (Hazardous Substances Data Bank (HSDB) 2003e; U.S. Environmental Protection Agency (USEPA) 2008d).
Tetrachloroethylene can enter drinking water sources from its release onto land and water by the metals, chemicals, leather tanning, transportation equipment, ammunition and petroleum refining industries. The compound can also be found in drinking water from its use in dry cleaning establishments, garages and machine shops, which are poorly regulated and geographically dispersed (Aschengrau 1998). Every year, U.S. industrial facilities release millions of pounds of tetrachloroethylene into the environment, over 93 percent of which was into the air (USEPA 2002s). The industrial release volumes reported to EPA underestimate the total amount of tetrachloroethylene contamination in the environment, since smaller commercial users such as dry cleaning stores and machine shops do not report pollutant releases.
Industrial discharges of tetrachloroethylene can lead to high concentrations in groundwater where tetrachloroethylene may degrade to more toxic compounds, including vinyl chloride (World Health Organization (WHO) 2004a). According to EPA, long-term exposure to tetrachloroethylene in drinking water above the Maximum Contaminant Level (MCL) may cause detrimental effects to liver, kidney and central nervous system, and has the potential to cause cancer (USEPA 2002s).
The National Toxicology Program (NTP) classifies tetrachloroethylene as "reasonably anticipated" to be a human carcinogen. Tumors of the liver have been noted in laboratory mice that ingest tetrachloroethylene. Breathing the chemical causes leukemia and tumors of the liver and kidney in rats or mice. In people, occupational exposure to tetrachloroethylene has been linked with non-Hodgkin's lymphoma and cancers of the esophagus and cervix (NTP 2002a).
Recently, high levels of tetrachloroethylene in drinking water have been linked with increased incidence of cancers of the lung, breast and possible cancers of the colon-rectum in residents in Cape Code, Massachusetts who were exposed for 20 years to high concentrations of tetrachloroethylene in their drinking water (Aschengrau 1998, 2003; Paulu 1999). Residents were exposed to the compound starring in 1960 when 660 miles of asbestos cement water distribution pipes were coated with a vinyl resin containing tetrachloroethylene. The engineers assumed that the tetrachloroethylene had evaporated from the resin during its initial drying process, but in 1980 they discovered that it had been leaching into the drinking water for 20 years. Follow-up studies also suggested a link between tetrachloroethylene-contaminated drinking water and the risk of congenital anomalies such as neural tube defects and oral clefts (Aschengrau 2009).
Occupational exposure to tetrachloroethylene has been linked with menstrual disorders and spontaneous abortions in women, and abnormal sperm quality in men. Other worker studies have linked exposure to infertility, damage to the lung and kidney, loss of color vision, mood changes, muscle discoordination, forgetfulness, dizziness, headaches, difficulty in speaking and sleepiness (Agency for Toxic Substances and Disease Registry (ATSDR) 1997b; Schreiber 2002).
Developmental exposure to tetrachloroethylene in laboratory animals has been shown to cause eye damage, reduced growth and viability, and delayed skeletal development. Mice and rats exposed to tetrachloroethylene early in life tend to be hyperactive later in life, indicating that the developing nervous system is affected by tetrachloroethylene (ATSDR 1997b).
The Most Polluted Communities in Connecticut
19 water utilities reported detecting Tetrachloroethylene in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies
Ranked by highest average Tetrachloroethylene level
|Rank||System||Population Served||Positive test results of total reported tests||Average Level|
|1||Meriden Water Division|
|58,441||20 of 29||3.9 ppb|
(0 to 15 ppb)
|2||Valley Water Systems, Inc.|
|17,078||15 of 16||2.24 ppb|
(0 to 12.85 ppb)
|3||Hill Hollow Association|
|48||1 of 4||1.68 ppb|
(0 to 6.7 ppb)
|4||East Hampton Wpca - Village Center|
East Hampton, CT
|366||1 of 11||0.99 ppb|
(0 to 10.9 ppb)
|5||Connecticut Correctional Institute|
|5,460||1 of 19||0.79 ppb|
(0 to 15 ppb)
|6||Southington Water Department|
|40,408||6 of 18||0.68 ppb|
(0 to 3.05 ppb)
|646||6 of 9||0.65 ppb|
(0 to 1.3 ppb)
|8||Olmstead Water Supply Co-Possum Ridge|
|320||2 of 3||0.4 ppb|
(0 to 0.8 ppb)
|135||4 of 10||0.39 ppb|
(0 to 1.3 ppb)
|10||Sandy Lane Village Condominium Assn|
|318||1 of 4||0.33 ppb|
(0 to 1.3 ppb)
Health Based Limits for Tetrachloroethylene
|Maximum Contaminant Limit Goal (MCLG)||A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.||0 ppb|
|California Public Health Goals||Defined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.||0.06 ppb|
|EPA Human Health Water Quality Criteria||Water quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.||0.69 ppb|
|Maximum Contaminant Limit (MCL)||The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.||5 ppb|
|Lifetime health-based limit, non-cancer risk||Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.||10 ppb|
|Drinking Water Equivalent Level||A lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.||500 ppb|
|Children's health-based limit for 1-day exposure||Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.||2000 ppb|
|Children's health-based limit for 10-day exposure||Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.||2000 ppb|
Violation Summary for Tetrachloroethylene in Connecticut
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Connecticut since 2004
|Violation Type||Number of Violations|
|Failure to monitor regularly||75|