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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Elon

Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Read More.

In addition to tap water disinfection, chloroform pollution in the environment also comes from industrial discharges from pulp and paper mills, and from urban wastewater effluent. Human studies show that chloroform damages the kidneys, liver and central nervous system. In animals, chloroform causes infertility, birth defects and cancer.

Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

 

86

Samples

0

Samples exceeding legal limit (MCL)

86

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201458.0 ppb8844.0 ppb - 82.0 ppb
201555.2 ppb141431.0 ppb - 85.0 ppb
201640.9 ppb161627.0 ppb - 66.0 ppb
201749.1 ppb161637.0 ppb - 61.0 ppb
201849.6 ppb161641.0 ppb - 65.0 ppb
201932.8 ppb161626.0 ppb - 41.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.4 ppb

The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

ppb = parts per billion

All test results

Date Lab ID Result
2014-02-119218936600255.0 ppb
2014-02-119218936600154.0 ppb
2014-05-2992203302001TTH72.0 ppb
2014-05-2992203302002TTH82.0 ppb
2014-08-1992214112009TTH56.0 ppb
2014-08-1992214112010TTH56.0 ppb
2014-11-1892226246001TTH45.0 ppb
2014-11-1892226246002TTH44.0 ppb
2015-02-2531.0 ppb
2015-02-2532.0 ppb
2015-05-2083.0 ppb
2015-05-2083.0 ppb
2015-05-2083.0 ppb
2015-05-2085.0 ppb
2015-08-2441.0 ppb
2015-08-2442.0 ppb
2015-08-2441.0 ppb
2015-08-2444.0 ppb
2015-11-1754.0 ppb
2015-11-1751.0 ppb
2015-11-1750.0 ppb
2015-11-1753.0 ppb
2016-02-1692286793002TTH41.0 ppb
2016-02-1692286793003TTH42.0 ppb
2016-02-1692286793004TTH46.0 ppb
2016-02-1692286793001TTH42.0 ppb
2016-05-2492298939001TTH36.0 ppb
2016-05-2492298939003TTH36.0 ppb
2016-05-2492298939004TTH65.0 ppb
2016-05-2492298939005TTH66.0 ppb
2016-08-2292309970011TTH38.0 ppb
2016-08-2292309970014TTH39.0 ppb
2016-08-2292309970013TTH35.0 ppb
2016-08-3092310689001TTH45.0 ppb
2016-11-1592319857001TTH27.0 ppb
2016-11-1592319857002TTH27.0 ppb
2016-11-1592319857003TTH35.0 ppb
2016-11-1592319857004TTH35.0 ppb
2017-02-1492329991001TTH41.0 ppb
2017-02-1492329991003TTH37.0 ppb
2017-02-1492329991004TTH39.0 ppb
2017-02-1492329991002TTH43.0 ppb
2017-05-1692340947003TTH55.0 ppb
2017-05-1692340947002TTH53.0 ppb
2017-05-1692340947001TTH54.0 ppb
2017-05-1692340947004TTH52.0 ppb
2017-08-2392352713001TTH59.0 ppb
2017-08-2392352713002TTH60.0 ppb
2017-08-2392352713003TTH61.0 ppb
2017-08-2392352713004TTH59.0 ppb
2017-11-1492363453001TTH41.0 ppb
2017-11-1492363453002TTH43.0 ppb
2017-11-1492363453003TTH45.0 ppb
2017-11-1492363453004TTH44.0 ppb
2018-02-2692374989004TTH 50.0 ppb
2018-02-2692374989003TTH 50.0 ppb
2018-02-2692374989002TTH 52.0 ppb
2018-02-2692374989001TTH 50.0 ppb
2018-05-2292385734004TTH 47.0 ppb
2018-05-2292385734001TTH 47.0 ppb
2018-05-2292385734002TTH 51.0 ppb
2018-05-2292385734003TTH 48.0 ppb
2018-08-2892397713004TTH 43.0 ppb
2018-08-2892397713003TTH 43.0 ppb
2018-08-2892397713002TTH 41.0 ppb
2018-08-2892397713001TTH 41.0 ppb
2018-11-2692408354001TTH 52.0 ppb
2018-11-2692408354002TTH 54.0 ppb
2018-11-2692408354003TTH 60.0 ppb
2018-11-2692408354004TTH 65.0 ppb
2019-02-1992418331001_377035.0 ppb
2019-02-1992418331003_377036.0 ppb
2019-02-1992418331004_377039.0 ppb
2019-02-1992418331005_377038.0 ppb
2019-05-2192430102001_377036.0 ppb
2019-05-2192430102005_377038.0 ppb
2019-05-2192430102003_377041.0 ppb
2019-05-2192430102002_377038.0 ppb
2019-08-2692443067002_377028.0 ppb
2019-08-2692443067004_377026.0 ppb
2019-08-2692443067003_377028.0 ppb
2019-08-2692443067001_377028.0 ppb
2019-11-1992454503004_377031.0 ppb
2019-11-1992454503003_377026.0 ppb
2019-11-1992454503002_377027.0 ppb
2019-11-1992454503001_377030.0 ppb