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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Acton MUD

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

 

179

Samples

0

Samples exceeding legal limit (MCL)

32

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.618 ppb186ND - 2.40 ppb
20150.861 ppb349ND - 6.51 ppb
20160.834 ppb326ND - 9.42 ppb
20170.615 ppb324ND - 8.99 ppb
20180.150 ppb333ND - 2.10 ppb
20190.188 ppb304ND - 1.56 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
2014-02-26Q14064460021.52 ppb
2014-02-26Q14064460031.71 ppb
2014-02-26Q1406446004ND
2014-02-26Q1406446001ND
2014-04-16Q1412086003ND
2014-04-16Q1412086055ND
2014-04-16Q1412086056ND
2014-04-16Q1412086057ND
2014-04-16Q1412086058ND
2014-04-17Q1412419006ND
2014-08-18Q14374170032.20 ppb
2014-08-18Q14374170042.40 ppb
2014-08-18Q14374170051.70 ppb
2014-08-18Q1437417006ND
2014-10-22Q14535020011.60 ppb
2014-10-22Q1453502002ND
2014-10-22Q1453502003ND
2014-10-22Q1453502004ND
2015-02-09Q1504919003ND
2015-02-09Q1504919005ND
2015-02-09Q1504919007ND
2015-02-09Q1504919001ND
2015-02-09Q1504919009ND
2015-02-09Q1504919012ND
2015-02-09Q1504919014ND
2015-02-09Q1504919015ND
2015-02-09Q1504919017ND
2015-02-09Q1504919020ND
2015-02-09Q1504919022ND
2015-02-09Q1504919023ND
2015-02-09Q15049190574.90 ppb
2015-02-09Q15049190581.60 ppb
2015-02-09Q1504919059ND
2015-02-09Q1504919060ND
2015-06-23Q15235400032.18 ppb
2015-06-23Q1523540004ND
2015-06-23Q1523540005ND
2015-06-23Q1523540006ND
2015-06-23Q1523540002ND
2015-08-06Q15308810015.36 ppb
2015-08-06Q15308810026.51 ppb
2015-08-06Q15308810032.94 ppb
2015-08-06Q15308810042.92 ppb
2015-08-06Q15308810051.85 ppb
2015-10-27Q1542356001ND
2015-10-27Q1542356003ND
2015-10-27Q1542356006ND
2015-10-27Q1542356007ND
2015-10-27Q1542356011ND
2015-10-27Q15423560121.000 ppb
2015-10-27Q1542356013ND
2015-10-27Q1542356014ND
2016-01-19Q1602084002ND
2016-01-19Q1602084003ND
2016-01-19Q1602084006ND
2016-01-19Q1602084007ND
2016-01-19Q1602084010ND
2016-01-19Q1602084011ND
2016-01-19Q1602084014ND
2016-01-19Q1602084016ND
2016-01-19Q1602084018ND
2016-01-19Q1602084019ND
2016-01-19Q1602084021ND
2016-01-19Q1602084029ND
2016-01-19Q1602084051ND
2016-01-19Q16020840523.09 ppb
2016-01-19Q1602084053ND
2016-01-19Q1602084054ND
2016-03-16Q1610933006ND
2016-05-31Q16213090016.23 ppb
2016-05-31Q16213090029.42 ppb
2016-05-31Q16213090031.40 ppb
2016-05-31Q1621309004ND
2016-05-31Q1621309006ND
2016-07-28Q1630951001ND
2016-07-28Q16309510021.84 ppb
2016-07-28Q1630951003ND
2016-07-28Q1630951004ND
2016-07-28Q1630951006ND
2016-11-30Q1652001001ND
2016-11-30Q16520010074.70 ppb
2016-11-30Q1652001002ND
2016-11-30Q1652001003ND
2016-11-30Q1652001010ND
2017-02-16Q17068090028.26 ppb
2017-02-16Q17068090038.99 ppb
2017-02-16Q1706809004ND
2017-02-16Q1706809005ND
2017-05-08Q1718746002ND
2017-05-08Q1718746003ND
2017-05-08Q1718746004ND
2017-05-08Q1718746005ND
2017-07-17Q1729214001ND
2017-07-17Q17292140021.02 ppb
2017-07-17Q1729214003ND
2017-07-17Q1729214004ND
2017-08-31Q1740574037ND
2017-08-31Q1740574002ND
2017-08-31Q1740574039ND
2017-08-31Q1740574003ND
2017-08-31Q1740574040ND
2017-08-31Q1740574006ND
2017-08-31Q1740574043ND
2017-08-31Q1740574033ND
2017-10-05Q1749124025ND
2017-10-05Q1749124030ND
2017-10-05Q1749124028ND
2017-10-05Q1749124032ND
2017-10-05Q1749124023ND
2017-10-05Q1749124050ND
2017-10-05Q1749124051ND
2017-10-05Q1749124018ND
2017-10-05Q1749124052ND
2017-10-05Q1749124053ND
2017-10-18Q17537610131.41 ppb
2017-10-18Q1753761012ND
2018-02-15Q1806602001ND
2018-02-15Q1806602002ND
2018-02-15Q1806602003ND
2018-02-15Q1806602004ND
2018-03-28Q1812936001ND
2018-03-28Q1812936004ND
2018-03-28Q1812936005ND
2018-03-28Q1812936008ND
2018-03-28Q1812936010ND
2018-03-28Q1812936012ND
2018-03-28Q1812936013ND
2018-03-28Q1812936016ND
2018-03-28Q1812936018ND
2018-03-28Q1812936019ND
2018-03-28Q1812936021ND
2018-05-01Q1817372001ND
2018-05-01Q1817372003ND
2018-05-01Q1817372005ND
2018-05-01Q1817372007ND
2018-05-01Q1817372009ND
2018-05-01Q1817372022ND
2018-05-01Q1817372023ND
2018-05-01Q1817372024ND
2018-05-01Q1817372025ND
2018-07-23Q1829049003ND
2018-07-23Q18290490011.04 ppb
2018-07-23Q1829049002ND
2018-07-23Q1829049004ND
2018-12-11Q1850865005ND
2018-12-11Q18508650062.10 ppb
2018-12-11Q18508650021.81 ppb
2018-12-11Q1850865007ND
2018-12-11Q1850865003ND
2019-01-10Q1901506003ND
2019-01-10Q1901506008ND
2019-01-10Q19015060011.28 ppb
2019-01-10Q1901506013ND
2019-01-10Q1901506007ND
2019-01-10Q1901506014ND
2019-03-26Q1912275021ND
2019-03-26Q1912275023ND
2019-03-26Q1912275026ND
2019-03-26Q1912275027ND
2019-03-26Q1912275029ND
2019-03-26Q1912275032ND
2019-03-26Q1912275033ND
2019-03-26Q1912275036ND
2019-03-26Q1912275038ND
2019-03-26Q1912275040ND
2019-04-18Q1915698002ND
2019-04-18Q1915698004ND
2019-04-18Q1915698006ND
2019-04-18Q1915698007ND
2019-04-18Q1915698008ND
2019-05-15Q1925754001ND
2019-09-04Q1962165001ND
2019-09-04Q19621650021.43 ppb
2019-09-04Q1962165003ND
2019-09-04Q1962165004ND
2019-10-29Q19743660011.36 ppb
2019-10-29Q19743660021.56 ppb
2019-10-29Q1974366003ND
2019-10-29Q1974366004ND