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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Mustang SUD

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

 

118

Samples

0

Samples exceeding legal limit (MCL)

96

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201420.0 ppb1716ND - 31.4 ppb
201519.9 ppb2016ND - 41.9 ppb
201615.8 ppb2016ND - 35.5 ppb
20179.76 ppb2116ND - 17.1 ppb
201812.4 ppb2016ND - 22.6 ppb
201912.4 ppb2016ND - 25.8 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
2014-01-16Q1401487002ND
2014-03-28Q141024600114.4 ppb
2014-03-28Q141024600214.7 ppb
2014-03-28Q141024600315.5 ppb
2014-03-28Q141024600419.3 ppb
2014-06-04Q141937401124.3 ppb
2014-06-04Q141937401222.3 ppb
2014-06-04Q141937401323.0 ppb
2014-06-04Q141937400123.8 ppb
2014-07-22Q142987900126.5 ppb
2014-07-22Q142987900227.6 ppb
2014-07-22Q142987900331.4 ppb
2014-07-22Q142987900430.6 ppb
2014-10-07Q145206100117.6 ppb
2014-10-07Q145206100215.0 ppb
2014-10-07Q145206100318.4 ppb
2014-10-07Q145206100415.6 ppb
2015-02-02Q150383000217.8 ppb
2015-02-02Q150383000317.5 ppb
2015-02-02Q150383000417.1 ppb
2015-02-02Q150383000516.3 ppb
2015-04-07Q1512608009ND
2015-04-07Q1512608012ND
2015-04-07Q151260800519.6 ppb
2015-04-07Q151260800619.2 ppb
2015-04-07Q151260800728.5 ppb
2015-04-07Q151260800821.0 ppb
2015-07-06Q1525681009ND
2015-07-06Q1525681012ND
2015-07-06Q152568100135.6 ppb
2015-07-06Q152568100241.9 ppb
2015-07-06Q152568100340.0 ppb
2015-07-06Q152568100439.0 ppb
2015-10-07Q153945500119.3 ppb
2015-10-07Q153945500222.5 ppb
2015-10-07Q153945500321.3 ppb
2015-10-07Q153945500421.8 ppb
2016-01-07Q1600448014ND
2016-01-07Q1600448010ND
2016-01-07Q1600448011ND
2016-01-07Q1600448016ND
2016-01-07Q160044800121.0 ppb
2016-01-07Q160044800223.6 ppb
2016-01-07Q160044800324.0 ppb
2016-01-07Q160044800424.6 ppb
2016-04-06Q161360800218.9 ppb
2016-04-06Q161360800327.5 ppb
2016-04-06Q161360800435.5 ppb
2016-04-06Q161360800526.0 ppb
2016-07-05Q162680000113.5 ppb
2016-07-05Q162680000212.7 ppb
2016-07-05Q162680000313.8 ppb
2016-07-05Q162680000415.2 ppb
2016-10-06Q164241400113.8 ppb
2016-10-06Q164241400215.6 ppb
2016-10-06Q164241400314.4 ppb
2016-10-06Q164241400416.2 ppb
2017-01-12Q17016670047.64 ppb
2017-01-12Q17016670017.60 ppb
2017-01-12Q17016670037.66 ppb
2017-01-12Q17016670026.98 ppb
2017-03-22Q1712369002ND
2017-03-22Q1712369004ND
2017-03-22Q1712369006ND
2017-03-22Q1712369008ND
2017-04-06Q171436200312.7 ppb
2017-04-06Q171436200114.3 ppb
2017-04-06Q171436200413.4 ppb
2017-04-06Q171436200214.2 ppb
2017-07-06Q172763800215.6 ppb
2017-07-06Q172763800114.0 ppb
2017-07-06Q172763800316.3 ppb
2017-07-06Q172763800412.0 ppb
2017-10-04Q1749048001ND
2017-10-04Q174904800817.1 ppb
2017-10-04Q174904800914.8 ppb
2017-10-04Q174904801017.1 ppb
2017-10-04Q174904801113.6 ppb
2018-01-30Q180350400115.7 ppb
2018-01-30Q180350400319.5 ppb
2018-01-30Q180350400219.2 ppb
2018-01-30Q180350400418.4 ppb
2018-04-05Q181417800110.1 ppb
2018-04-05Q181417800413.4 ppb
2018-04-05Q181417800216.2 ppb
2018-04-05Q181417800516.4 ppb
2018-07-10Q1827459002ND
2018-07-10Q1827459004ND
2018-07-10Q1827459006ND
2018-07-10Q1827459007ND
2018-07-10Q182745902222.6 ppb
2018-07-10Q182745902319.3 ppb
2018-07-10Q182745902416.5 ppb
2018-07-10Q182745902517.3 ppb
2018-10-03Q18397150026.89 ppb
2018-10-03Q183971500310.8 ppb
2018-10-03Q183971500414.3 ppb
2018-10-03Q183971500112.3 ppb
2019-01-08Q1900592007ND
2019-01-08Q1900592017ND
2019-01-08Q1900592008ND
2019-01-08Q1900592020ND
2019-01-08Q190059200419.0 ppb
2019-01-08Q190059201520.0 ppb
2019-01-08Q190059200518.1 ppb
2019-01-08Q190059201617.9 ppb
2019-04-09Q19145030023.29 ppb
2019-04-09Q19145030033.44 ppb
2019-04-09Q19145030043.40 ppb
2019-04-09Q19145030012.82 ppb
2019-08-05Q195072300425.3 ppb
2019-08-05Q195072300125.8 ppb
2019-08-05Q195072300225.2 ppb
2019-08-05Q195072300322.8 ppb
2019-10-02Q197111100216.9 ppb
2019-10-02Q197111100314.6 ppb
2019-10-02Q197111100415.4 ppb
2019-10-02Q197111100513.8 ppb