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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Darbonne Ws North

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

 

70

Samples

0

Samples exceeding legal limit (MCL)

20

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20145.77 ppb64ND - 9.43 ppb
20155.25 ppb42ND - 10.5 ppb
20160.293 ppb86ND - 0.560 ppb
20170.166 ppb186ND - 0.640 ppb
20180.169 ppb186ND - 0.580 ppb
20190.0588 ppb162ND - 0.470 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
2014-07-0813156557.89 ppb
2014-07-0813156549.43 ppb
2014-07-0813156557.89 ppb
2014-07-0813156549.43 ppb
2014-12-01AE00107ND
2014-12-01AE00107ND
2015-07-071408338ND
2015-07-07140833710.5 ppb
2015-07-071408338ND
2015-07-07140833710.5 ppb
2016-08-151516442ND
2016-08-1515164430.260 ppb
2016-08-1515164430.260 ppb
2016-08-151516442ND
2016-11-0815397670.560 ppb
2016-11-0815397680.350 ppb
2016-11-0815397680.350 ppb
2016-11-0815397670.560 ppb
2017-02-0235292874003ND
2017-02-0235292874004ND
2017-02-0235292874004ND
2017-02-0235292874003ND
2017-05-1535312642002ND
2017-05-1535312642001ND
2017-05-1535312642001ND
2017-05-1535312642002ND
2017-08-1035329805004ND
2017-08-1035329805003ND
2017-08-1035329805004ND
2017-08-1035329805003ND
2017-11-15353491820030.640 ppb
2017-11-15353491820010.390 ppb
2017-11-15353491820020.460 ppb
2017-11-15353491820010.390 ppb
2017-11-15353491820020.460 ppb
2017-11-15353491820030.640 ppb
2018-02-26353765980030.510 ppb
2018-02-26353765980020.430 ppb
2018-02-2635376598001ND
2018-02-26353765980030.510 ppb
2018-02-26353765980020.430 ppb
2018-02-2635376598001ND
2018-05-29353952120020.580 ppb
2018-05-2935395212001ND
2018-05-29353952120020.580 ppb
2018-05-2935395212001ND
2018-08-1635412063002ND
2018-08-1635412063001ND
2018-08-1635412063002ND
2018-08-1635412063001ND
2018-11-1935432389002ND
2018-11-1935432389001ND
2018-11-1935432389001ND
2018-11-1935432389002ND
2019-02-25354509640020.470 ppb
2019-02-2535450964001ND
2019-02-2535450964001ND
2019-02-25354509640020.470 ppb
2019-05-2035470222002ND
2019-05-2035470222002ND
2019-05-2035470222001ND
2019-05-2035470222001ND
2019-08-1935492404002ND
2019-08-1935492404001ND
2019-08-1935492404001ND
2019-08-1935492404002ND
2019-11-1935514075001ND
2019-11-1935514075002ND
2019-11-1935514075001ND
2019-11-1935514075002ND