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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Eureka

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

 

67

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND140ND
2015ND100ND
2016ND110ND
2017ND130ND
20180.190 ppb91ND - 1.71 ppb
2019ND100ND

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
2014-01-28AC17703ND
2014-01-28AC17702ND
2014-01-28AC17704ND
2014-04-30AC22515ND
2014-04-30AC22517ND
2014-04-30AC22516ND
2014-07-30AC30062ND
2014-07-30AC30063ND
2014-07-30AC30064ND
2014-08-20AC33710ND
2014-09-26AC35755ND
2014-10-28AC37317ND
2014-10-28AC37318ND
2014-10-28AC37319ND
2015-01-30AC41366ND
2015-01-30AC41365ND
2015-04-29AC45798ND
2015-04-29AC45799ND
2015-08-19AC58580ND
2015-08-19AC58581ND
2015-09-24AC59646ND
2015-09-29AC60323ND
2015-10-29AC62083ND
2015-10-29AC62082ND
2016-01-29AC65842ND
2016-01-29AC65841ND
2016-04-28AC70156ND
2016-04-28AC70157ND
2016-08-03AC80845ND
2016-08-03AC80846ND
2016-08-24AC81708ND
2016-10-24AC86077ND
2016-10-24AC86078ND
2016-11-14AC87964ND
2016-11-14AC87963ND
2017-01-23AC89907ND
2017-01-23AC89908ND
2017-04-26AC95128ND
2017-04-26AC95129ND
2017-07-26AD02414ND
2017-07-26AD02413ND
2017-08-15AD04262ND
2017-08-15AD04260ND
2017-08-15AD04261ND
2017-09-26AD06621ND
2017-09-26AD06620ND
2017-10-30AD08623ND
2017-10-30AD08622ND
2018-01-22AD12091ND
2018-01-22AD12092ND
2018-05-08AD18727ND
2018-05-08AD18728ND
2018-07-12AD29644ND
2018-07-12AD29645ND
2018-09-14AD338751.71 ppb
2018-09-21AD33070ND
2018-09-21AD33071ND
2019-01-16AD38511ND
2019-01-16AD38512ND
2019-04-17AD46829ND
2019-04-17AD46830ND
2019-07-18AD52843ND
2019-07-18AD52844ND
2019-09-25AD55375ND
2019-09-25AD55376ND
2019-10-24AD57534ND
2019-10-24AD57535ND