DefinitionTrichloroethylene (TCE) concentrations (in micrograms of TCE per liter of water or mcg/L) in community drinking water systems (CWS) are combined with information about each CWS (such as service population) to generate the following measures shown in this report: 1) statewide TCE concentration distribution in CWSs by mean and maximum over time, 2) annual distribution of mean and maximum TCE concentration for persons served by CWS and 3) annual distribution of mean and maximum TCE concentration by CWS.
EPHT data queries -- https://nmtracking.org/dataportal/query/selection/water/WaterSelection.html -- provide detailed results by year for
1) mean TCE concentration by CWS for a select year,
2) maximum TCE concentration by CWS for a select year,
3) mean TCE concentration and the number of CWS by year,
4) maximum TCE concentration and the number of CWS by year,
5) mean TCE concentration and the number of persons served by year or
6) maximum TCE concentration and the number of persons served by year.
Additionally, users may query the number of persons served and the number of CWS in the state for a select year.
A CWS is a public water system (PWS) that serves year-round residents of a community, subdivision, or mobile home park that has at least 15 service connections or an average of at least 25 residents. These CWSs are a subset of all New Mexico PWSs.
To measure TCE concentration in CWS, drinking water samples are usually taken at entry points to the distribution system or representative sampling points after water treatment has occurred.
NumeratorConcentration of TCE.
Data Interpretation IssuesTo measure the TCE concentration in CWS, drinking water samples are usually taken at entry points to the distribution system or representative sampling points after water treatment has occurred.
Measures do not account for the variability in sampling, number or sampling repeats, etc. Furthermore, concentrations in drinking water cannot be directly converted to exposure because water consumption varies by climate, level of physical activity, and between persons. Due to potential errors in estimating service population, the measures may overestimate or underestimate the number of potentially affected people. In addition, the older data (i.e., 1999 through 2004) may be of poor quality that could results in over- or underestimated TCE concentration in CWS drinking water during 1999-2004.
Why Is This Important?Trichloroethylene (TCE) is a volatile organic compound known as a chlorinated solvent and is widely used for cleaning and degreasing metal parts. TCE is used as an anesthetic and in veterinary medicine, a heat transfer medium, an extraction solvent for fats and oils, in textile processing industry to scour fabrics (e.g., cotton and wool), in dry-cleaning operations, and an intermediate for production of other chemicals (e.g., hydrofluorocarbons, pharmaceuticals, or insecticides). However, since January 2012, it has no longer been manufactured for domestic use in the U.S.1 TCE is present in the environment from its past industrial releases or other uses. It has been found in soil, ground water and surface water as a result of its use in manufacture, consumer products and disposal practices. People who live near facilities that use TCE or near hazardous waste sites containing TCE may have a higher exposure to TCE. It readily separates from contaminated soil and water into the air. However, it is expected to remain in ground water for long periods of time, because it cannot readily evaporate from groundwater as it would from surface waters.
For the general public, TCE-contaminated drinking water and air are the most important sources of exposure to this solvent. Inhalation of airborne TCE is the primary exposure route for workers? exposure. TCE may enter indoor air from contaminated soils or shallow ground water through cracks in the foundation of a building or from household uses of TCE-containing water, including from dishwashing, bathing, showering, or flushing toilets.
Ingestion of TCE-containing drinking water and inhalation of TCE-contaminated air are the major routes of exposure for the general population. It is well absorbed into the human body from the lungs, gastrointestinal tract, and skin. Exposure to moderate to high amounts of TCE are associated with a number of adverse health effects, including central nervous system (CNS) depression, autoimmune system disorders (such as scleroderma), immune system dysfunction (such as immunosuppression or hypersensitivity dermatitis), and adverse birth outcomes (such as spontaneous abortions, congenital heart defects, orofacial clefts, neural tube defects, or hypospadias)2
Trichloroethylene is also known to be a human carcinogen. The International Agency for Research on Cancer (IARC) has determined that there is sufficient evidence in humans for the carcinogenicity of TCE and thus classified TCE as a Group 1 carcinogen3. TCE causes cancer of the kidney, non-Hodgkin lymphoma, and cancer of the liver.
2. http://www.atsdr.cdc.gov/toxprofiles/index.asp; http://monographs.iarc.fr/ENG/Monographs/vol106/mono106.pdf.
Other ObjectivesCDC Environmental Public Health Tracking, Nationally Consistent Data and Measures (EPHT NCDM)
Environmental Health Epidemiology Bureau, Environmental Public Health Tracking Program, New Mexico Department of Health, 1190 S. Saint Francis Drive, Suite 1320, Santa Fe, NM 87505, Heidi Krapfl, Chief, (505) 476-3577, firstname.lastname@example.org, or Brian Woods, Environmental Epidemiologist, (505) 827-2868, email@example.com
What Is Being Done?In 2014, TCE levels in drinking water from CWS in New Mexico were below the Environmental Protection Agency (EPA)-established drinking water standard or Maximum Contaminant Level (MCL) for TCE of 5 micrograms per liter (5 mcg/L) or 5 parts per billion (5 ppb) (Safe Drinking Water Act (SDWA). This MCL is the highest level of TCE, which is allowed in drinking water and it is the enforceable standard. Community systems' drinking water is routinely monitored and tested for TCE by CWS to comply with the 5 mcg/L EPA standard for TCE. Every year, CWS send to their customers a consumer confidence report (also called a water quality report) that lists any levels of TCE measured. EPA also requires all CWS to give their customers public notice when their water supply violates the TCE standard. This would include information about what is being done to correct the situation. However, people who use their private wells water for drinking are solely responsible for testing the water for TCE (for information about laboratories certified to test drinking water and certified home treatment units visit https://nmtracking.org/environment/water/private_wells/Testing.html). Some people who use water containing TCE in excess of EPA's standard for drinking water and other household uses (such as bathing, showering, and dishwashing) over many years may experience adverse health effects, such as CNS depression, immune system depression or hypersensitivity dermatitis, and may develop certain cancers (such as kidney cancer or non-Hodgkin lymphoma).