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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Suez Water Delaware

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

 

168

Samples

0

Samples exceeding legal limit (MCL)

168

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201420.6 ppb35351.08 ppb - 53.4 ppb
201527.7 ppb323210.3 ppb - 60.2 ppb
201625.5 ppb24247.90 ppb - 49.7 ppb
201723.7 ppb28285.60 ppb - 61.0 ppb
201828.3 ppb33334.60 ppb - 70.2 ppb
201924.0 ppb16163.90 ppb - 54.2 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
2014-03-0610749530019.10 ppb
2014-03-0610749530023.60 ppb
2014-03-0610749530035.20 ppb
2014-03-0610749530049.60 ppb
2014-03-0610749530059.90 ppb
2014-03-0610749530064.30 ppb
2014-03-0610749530072.20 ppb
2014-03-0610749530084.40 ppb
2014-06-112013111001 TTHM30.0 ppb
2014-06-112013111002 TTHM17.6 ppb
2014-06-112013111003 TTHM26.3 ppb
2014-06-112013111004 TTHM31.2 ppb
2014-06-112013111005 TTHM20.8 ppb
2014-06-112013111006 TTHM25.1 ppb
2014-06-112013111007 TTHM30.9 ppb
2014-06-112013111008 TTHM27.1 ppb
2014-09-09202898300145.2 ppb
2014-09-09202898300246.6 ppb
2014-09-09202898300332.4 ppb
2014-09-09202898300452.4 ppb
2014-09-09202898300550.7 ppb
2014-09-09202898300647.5 ppb
2014-09-09202898300739.1 ppb
2014-09-09202898300853.4 ppb
2014-12-18204252007-TTHM4.40 ppb
2014-12-18204625200118.3 ppb
2014-12-182046252002-TTHM7.20 ppb
2014-12-182046252003-TTHM12.6 ppb
2014-12-182046252004-TTHM21.6 ppb
2014-12-182046252005-TTHM11.4 ppb
2014-12-182046252006-TTHM5.80 ppb
2014-12-182046252008-TTHM11.8 ppb
2014-12-22S6039011.39 ppb
2014-12-22S6039021.08 ppb
2014-12-22S6039031.92 ppb
2015-03-112059081001 TTHM30.7 ppb
2015-03-112059081002 TTHM23.3 ppb
2015-03-112059081003 TTHM22.5 ppb
2015-03-112059081004 TTHM22.7 ppb
2015-03-112059081005 TTHM44.2 ppb
2015-03-112059081006 TTHM29.7 ppb
2015-03-112059081007 TTHM31.3 ppb
2015-03-112059081008 TTHM34.3 ppb
2015-06-082075686001 TTHM60.2 ppb
2015-06-082075686002 TTHM36.6 ppb
2015-06-082075686003 TTHM28.1 ppb
2015-06-082075686004 TTHM43.7 ppb
2015-06-082075686005 TTHM41.3 ppb
2015-06-082075686006 TTHM37.2 ppb
2015-06-082075686007 TTHM27.9 ppb
2015-06-082075686008 TTHM29.7 ppb
2015-09-032093960002 TTHM19.7 ppb
2015-09-032093960003 TTHM23.1 ppb
2015-09-032093960004 TTHM35.8 ppb
2015-09-032093960005 TTHM27.5 ppb
2015-09-032093960006 TTHM27.0 ppb
2015-09-032093960007 TTHM17.5 ppb
2015-09-032093960008 TTHM30.8 ppb
2015-12-07L5949833-1 TTHM30.5 ppb
2015-12-07L5949833-2 TTHM16.4 ppb
2015-12-07L5949833-3 TTHM10.3 ppb
2015-12-07L5949833-4 TTHM24.8 ppb
2015-12-07L5949833-6 TTHM17.9 ppb
2015-12-07L5949833-7 TTHM17.6 ppb
2015-12-07L5949833-8 TTHM10.9 ppb
2015-12-07L594983395 TTHM22.6 ppb
2015-12-30S62496910.8 ppb
2016-06-102151332001 TTHM37.8 ppb
2016-06-102151332002 TTHM28.3 ppb
2016-06-102151332003 TTHM15.6 ppb
2016-06-102151332004 TTHM49.7 ppb
2016-06-102151332005 TTHM31.2 ppb
2016-06-102151332006 TTHM31.0 ppb
2016-06-102151332007 TTHM20.4 ppb
2016-06-102151332008 TTHM25.9 ppb
2016-09-082173721001 TTHM30.3 ppb
2016-09-082173721002-TTHM23.6 ppb
2016-09-082173721003-TTHM18.3 ppb
2016-09-082173721004-TTHM46.8 ppb
2016-09-082173721005-TTHM33.6 ppb
2016-09-082173721006-TTHM27.6 ppb
2016-09-082173721007-TTHM19.0 ppb
2016-09-082173721008-TTHM26.8 ppb
2016-12-082194964001 TTHM18.2 ppb
2016-12-082194964002 TTHM11.4 ppb
2016-12-082194964003 TTHM7.90 ppb
2016-12-082194964004 TTHM30.6 ppb
2016-12-082194964005 TTHM19.0 ppb
2016-12-082194964006 TTHM32.6 ppb
2016-12-082194964007 TTHM9.50 ppb
2016-12-082194964008 TTHM17.4 ppb
2017-03-082214632001 TTHM15.0 ppb
2017-03-082214632002 TTHM6.40 ppb
2017-03-082214632003 TTHM5.60 ppb
2017-03-082214632004 TTHM20.5 ppb
2017-03-082214632005 TTHM11.4 ppb
2017-03-082214632006 TTHM18.1 ppb
2017-03-082214632007 TTHM7.30 ppb
2017-03-082214632008 TTHM7.80 ppb
2017-06-092239424001 TTHM26.4 ppb
2017-06-092239424002 TTHM16.1 ppb
2017-06-092239424003 TTHM16.3 ppb
2017-06-092239424004 TTHM31.9 ppb
2017-06-092239424005 TTHM23.0 ppb
2017-06-092239424006 TTHM34.0 ppb
2017-06-092239424007 TTHM17.4 ppb
2017-06-092239424008 TTHM21.8 ppb
2017-09-072260181001 TTHM61.0 ppb
2017-09-072260181002 TTHM44.1 ppb
2017-09-072260181003 TTHM30.7 ppb
2017-09-072260181004 TTHM47.4 ppb
2017-09-072260181005 TTHM40.7 ppb
2017-09-072260181006 TTHM58.8 ppb
2017-09-072260181007 TTHM24.4 ppb
2017-09-072260181008 TTHM32.7 ppb
2017-12-072282095001 TTHM8.30 ppb
2017-12-072282095002 TTHM11.5 ppb
2017-12-072282095003 TTHM15.5 ppb
2017-12-072282095005 TTHM9.40 ppb
2018-03-0823008790014.60 ppb
2018-03-082300879002 TTHM28.1 ppb
2018-03-082300879003 TTHM10.7 ppb
2018-03-082300879004 TTHM18.4 ppb
2018-03-082300879005 TTHM6.40 ppb
2018-03-082300879006 TTHM6.80 ppb
2018-03-082300879007 TTHM13.8 ppb
2018-03-082300879008 TTHM22.1 ppb
2018-06-072319771001 TTHM23.6 ppb
2018-06-072319771002 TTHM34.4 ppb
2018-06-072319771003 TTHM37.8 ppb
2018-06-072319771004 TTHM39.1 ppb
2018-06-072319771005 TTHM41.8 ppb
2018-06-072319771006 TTHM29.4 ppb
2018-06-072319771007 TTHM17.1 ppb
2018-06-072319771008 TTHM50.5 ppb
2018-09-078092132-01 TTHM46.3 ppb
2018-09-078092132-02 TTHM67.1 ppb
2018-09-078092132-03 THM62.7 ppb
2018-09-078092132-04 TTHM22.3 ppb
2018-09-078092132-05 TTHM70.2 ppb
2018-09-078092132-06 TTHM55.4 ppb
2018-09-078092132-07 TTHM32.1 ppb
2018-09-078092132-08 TTHM30.8 ppb
2018-12-078122168-01 TTHM15.9 ppb
2018-12-078122168-02 TTHM9.30 ppb
2018-12-078122168-03 TTHM9.30 ppb
2018-12-078122168-04 TTHM24.8 ppb
2018-12-078122168-05 TTHM33.3 ppb
2018-12-078122168-06 TTHM13.0 ppb
2018-12-078122168-07 TTHM41.2 ppb
2018-12-078122168-08 TTHM9.80 ppb
2018-12-31S8169105.50 ppb
2019-06-079062660-01 TTHM33.3 ppb
2019-06-079062660-02 TTHM22.2 ppb
2019-06-079062660-03 TTHM20.6 ppb
2019-06-079062660-04 TTHM44.0 ppb
2019-06-079062660-05 TTHM46.2 ppb
2019-06-079062660-06 TTHM25.3 ppb
2019-06-079062660-07 TTHM54.2 ppb
2019-06-079062660-08 TTHM38.9 ppb
2019-12-099122405-01 TTHM15.0 ppb
2019-12-099122405-02 TTHM7.20 ppb
2019-12-099122405-03 TTHM3.90 ppb
2019-12-099122405-04 TTHM6.30 ppb
2019-12-099122405-05 TTHM16.4 ppb
2019-12-099122405-06 TTHM4.70 ppb
2019-12-099122405-07 TTHM25.3 ppb
2019-12-099122405-08 TTHM20.2 ppb