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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

City of Orange

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

 

107

Samples

0

Samples exceeding legal limit (MCL)

68

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.731 ppb1611ND - 1.30 ppb
20150.972 ppb1815ND - 1.80 ppb
20160.328 ppb185ND - 1.30 ppb
20170.950 ppb1813ND - 1.70 ppb
20181.92 ppb1816ND - 13.0 ppb
20190.558 ppb198ND - 2.10 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
2014-02-11AC421761.10 ppb
2014-02-11AC42189ND
2014-02-11AC421711.000 ppb
2014-02-11AC422101.10 ppb
2014-04-09AC500311.000 ppb
2014-04-09AC50032ND
2014-04-09AC50027ND
2014-04-09AC500281.000 ppb
2014-09-16AC671291.10 ppb
2014-09-16AC671341.000 ppb
2014-09-16AC671281.30 ppb
2014-09-16AC671381.10 ppb
2014-11-24AC727591.000 ppb
2014-11-24AC72760ND
2014-11-24AC727631.000 ppb
2014-11-24AC72761ND
2015-01-21AC770791.000 ppb
2015-01-21AC770730.800 ppb
2015-01-21AC771841.000 ppb
2015-01-21AC771821.10 ppb
2015-01-21AC771861.20 ppb
2015-01-21AC772111.10 ppb
2015-04-09AC878231.10 ppb
2015-04-09AC87824ND
2015-04-09AC878301.30 ppb
2015-04-09AC878261.10 ppb
2015-09-02AD053141.20 ppb
2015-09-02AD05300ND
2015-09-02AD053041.10 ppb
2015-09-02AD053151.30 ppb
2015-10-27AD11824ND
2015-10-27AD118251.20 ppb
2015-10-27AD118281.80 ppb
2015-10-27AD118261.20 ppb
2016-03-03AD26879ND
2016-03-03AD26851ND
2016-03-03AD268801.10 ppb
2016-03-03AD26878ND
2016-05-18AD37514ND
2016-05-18AD37522ND
2016-05-18AD37435ND
2016-05-18AD37445ND
2016-05-18AD374441.20 ppb
2016-05-18AD37442ND
2016-09-27AD51390ND
2016-09-27AD513721.30 ppb
2016-09-27AD51391ND
2016-09-27AD51377ND
2016-10-20AD54059ND
2016-10-20AD54060ND
2016-10-20AD540321.20 ppb
2016-10-20AD540711.10 ppb
2017-02-22AD717571.000 ppb
2017-02-22AD71743ND
2017-02-22AD71722ND
2017-02-22AD71715ND
2017-02-22AD717231.30 ppb
2017-02-22AD717181.10 ppb
2017-05-22AD852181.30 ppb
2017-05-22AD852221.20 ppb
2017-05-22AD852241.60 ppb
2017-05-22AD852271.60 ppb
2017-08-15AD930631.10 ppb
2017-08-15AD93065ND
2017-08-15AD93062ND
2017-08-15AD930641.10 ppb
2017-11-01AE031791.30 ppb
2017-11-01AE031651.60 ppb
2017-11-01AE031781.70 ppb
2017-11-01AE031641.20 ppb
2018-01-10AE0863713.0 ppb
2018-01-10AE08641ND
2018-01-10AE086061.10 ppb
2018-01-10AE085941.000 ppb
2018-01-10AE08596ND
2018-01-10AE086071.000 ppb
2018-04-04AE211671.10 ppb
2018-04-04AE211661.20 ppb
2018-04-04AE211681.30 ppb
2018-04-04AE211801.20 ppb
2018-07-05AE323781.50 ppb
2018-07-05AE323931.90 ppb
2018-07-05AE324062.60 ppb
2018-07-05AE323801.60 ppb
2018-10-09AE429291.20 ppb
2018-10-09AE429321.50 ppb
2018-10-09AE429302.10 ppb
2018-10-09AE429311.20 ppb
2019-02-12AE54144ND
2019-02-12AE54140ND
2019-02-12AE54064ND
2019-02-12AE540591.10 ppb
2019-02-12AE540621.50 ppb
2019-02-12AE54058ND
2019-06-13AE70555ND
2019-06-13AE70572ND
2019-06-13AE70570ND
2019-06-13AE705731.000 ppb
2019-07-15AE74376ND
2019-07-15AE743801.90 ppb
2019-07-15AE743822.10 ppb
2019-07-15AE74407ND
2019-10-30AE879821.000 ppb
2019-10-30AE87979ND
2019-10-30AE879801.000 ppb
2019-10-30AE87978ND
2019-10-30AE879981.000 ppb