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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Hope Water Light Comm.

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

 

124

Samples

0

Samples exceeding legal limit (MCL)

68

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201420.2 ppb2216ND - 80.5 ppb
201539.2 ppb1914ND - 130.0 ppb
201612.1 ppb239ND - 77.4 ppb
201718.6 ppb189ND - 99.2 ppb
201830.4 ppb1911ND - 147.0 ppb
201913.4 ppb239ND - 84.4 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
2014-01-07140100037021.20 ppb
2014-01-07140100039021.000 ppb
2014-01-07140100038021.20 ppb
2014-01-0714010004102ND
2014-04-0114094001302ND
2014-04-0114094000902ND
2014-04-011409400120250.0 ppb
2014-04-011409400100280.5 ppb
2014-05-2114142008902ND
2014-05-21141420086027.70 ppb
2014-05-211414200850266.9 ppb
2014-05-211414200870261.5 ppb
2014-07-021418401370249.3 ppb
2014-07-02141840136023.50 ppb
2014-07-0214184013902ND
2014-07-021418401350223.7 ppb
2014-08-19142330090011.02 ppb
2014-10-0114276000902ND
2014-10-01142760005021.80 ppb
2014-10-011427600080249.3 ppb
2014-10-01142760006026.20 ppb
2014-10-291430300270140.1 ppb
2015-01-05150080020021.70 ppb
2015-01-05150080019022.30 ppb
2015-01-0515008002302ND
2015-01-05150080022025.20 ppb
2015-04-061510000100227.2 ppb
2015-04-0615100001302ND
2015-04-061510000090240.3 ppb
2015-04-06151000012027.30 ppb
2015-07-0815190002101ND
2015-07-0815190003502123.0 ppb
2015-07-0815190003602ND
2015-07-0815190003202126.0 ppb
2015-07-0815190003302130.0 ppb
2015-10-051528200050272.7 ppb
2015-10-05152820006021.30 ppb
2015-10-051528200030261.3 ppb
2015-10-0515282000402107.0 ppb
2015-10-081528200560139.1 ppb
2015-10-2015296000401ND
2016-01-0616008010302ND
2016-01-0616008010202ND
2016-01-0616008010102ND
2016-01-06160080100023.50 ppb
2016-04-0416098011602ND
2016-04-0416098011502ND
2016-04-0416098011402ND
2016-04-04160980113021.30 ppb
2016-07-05161890104027.30 ppb
2016-07-051618901050277.4 ppb
2016-07-05161890106023.30 ppb
2016-07-0516189010702ND
2016-07-0516189010801ND
2016-07-0516189010901ND
2016-07-0516189011001ND
2016-07-0516189011101ND
2016-07-0516189011201ND
2016-07-0516189011301ND
2016-10-051628000930243.8 ppb
2016-10-051628000940250.0 ppb
2016-10-0516280009502ND
2016-10-051628000920259.3 ppb
2016-10-051628000890132.5 ppb
2017-01-0417005004802ND
2017-01-0417005004702ND
2017-01-041700500460218.0 ppb
2017-01-04170050045022.90 ppb
2017-04-051709600920225.8 ppb
2017-04-051709600930261.8 ppb
2017-04-0517096009402ND
2017-04-05170960095021.70 ppb
2017-07-0517187003602ND
2017-07-0517187003502ND
2017-07-0517187003702ND
2017-07-051718700380288.5 ppb
2017-07-1817200003901ND
2017-10-031727800210129.2 ppb
2017-10-041727800390299.2 ppb
2017-10-0417278003602ND
2017-10-0417278003802ND
2017-10-04172780037027.50 ppb
2018-01-0318004006502ND
2018-01-0318004006602ND
2018-01-0318004006702116.0 ppb
2018-01-0318004006402ND
2018-04-041809500890237.9 ppb
2018-04-04180950091021.20 ppb
2018-04-04180950090027.80 ppb
2018-04-0418095009202ND
2018-07-031818600600271.8 ppb
2018-07-0318186005902103.0 ppb
2018-07-031818600580230.2 ppb
2018-07-0318186005702ND
2018-07-2418207000701ND
2018-10-031827700650210.1 ppb
2018-10-0318277006402147.0 ppb
2018-10-031827700630232.8 ppb
2018-10-0318277006602ND
2018-10-031827700620120.0 ppb
2018-12-0418340005501ND
2019-01-0919010009002ND
2019-01-0919010009202ND
2019-01-0919010009102ND
2019-01-091901000930231.2 ppb
2019-04-021909400400245.4 ppb
2019-04-02190940042021.000 ppb
2019-04-0219094004302ND
2019-04-0219094004102ND
2019-07-09191910037024.60 ppb
2019-07-091919100350274.3 ppb
2019-07-0919191003802ND
2019-07-0919191003602ND
2019-08-0519220002801ND
2019-08-0519220002301ND
2019-08-0519220002701ND
2019-08-0519220002901ND
2019-08-0519220002501ND
2019-08-0519220002601ND
2019-10-0219276003902ND
2019-10-021927600360284.4 ppb
2019-10-02192760037021.10 ppb
2019-10-021927600380230.4 ppb
2019-10-291930400070135.1 ppb