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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Cedarburg L & W Commission

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

 

148

Samples

0

Samples exceeding legal limit (MCL)

12

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.153 ppb152ND - 1.20 ppb
20150.127 ppb264ND - 2.10 ppb
20160.107 ppb252ND - 1.80 ppb
20170.0511 ppb272ND - 0.750 ppb
20180.138 ppb263ND - 1.90 ppb
20190.383 ppb293ND - 9.50 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
2014-03-04772846ND
2014-03-04772841ND
2014-03-04772844ND
2014-05-12785096ND
2014-05-12785091ND
2014-05-12785094ND
2014-08-19811812ND
2014-08-19811810ND
2014-08-19811816ND
2014-08-19811815ND
2014-08-198118091.10 ppb
2014-08-198118081.20 ppb
2014-12-01833295ND
2014-12-01833292ND
2014-12-01833297ND
2015-03-10847454ND
2015-03-10847452ND
2015-03-10847447ND
2015-03-10847449ND
2015-03-10847457ND
2015-03-10847450ND
2015-06-01862720ND
2015-06-01862719ND
2015-06-01862715ND
2015-06-01862716ND
2015-06-01862717ND
2015-06-01862718ND
2015-07-28873580ND
2015-07-28873576ND
2015-07-28873577ND
2015-07-28873579ND
2015-07-28873578ND
2015-07-288735810.250 ppb
2015-07-288735830.770 ppb
2015-07-288735822.10 ppb
2015-10-05887228ND
2015-10-05887224ND
2015-10-05887225ND
2015-10-05887226ND
2015-10-05887227ND
2015-10-058872290.170 ppb
2016-03-08908903ND
2016-03-08908901ND
2016-03-08908895ND
2016-03-08908897ND
2016-03-08908899ND
2016-03-08908898ND
2016-05-16921447ND
2016-05-16921446ND
2016-05-16921443ND
2016-05-16921445ND
2016-05-16921444ND
2016-08-15939240ND
2016-08-15939239ND
2016-08-15939235ND
2016-08-15939236ND
2016-08-15939237ND
2016-08-15939238ND
2016-08-159392420.870 ppb
2016-08-159392411.80 ppb
2016-10-17953742ND
2016-10-17953741ND
2016-10-17953737ND
2016-10-17953738ND
2016-10-17953739ND
2016-10-17953740ND
2017-01-16969880ND
2017-01-16969877ND
2017-01-16969906ND
2017-01-16969884ND
2017-01-16969904ND
2017-01-16969905ND
2017-01-16969887ND
2017-04-12982954ND
2017-04-12982952ND
2017-04-12982948ND
2017-04-12982949ND
2017-04-12982951ND
2017-04-12982950ND
2017-07-241006158ND
2017-07-241006157ND
2017-07-241006154ND
2017-07-241006155ND
2017-07-241006159ND
2017-07-241006156ND
2017-07-2410061600.630 ppb
2017-07-2410061610.750 ppb
2017-11-131029331ND
2017-11-131029330ND
2017-11-131029326ND
2017-11-131029327ND
2017-11-131029328ND
2017-11-131029329ND
2018-01-111036953ND
2018-01-111036949ND
2018-01-111036950ND
2018-01-111036952ND
2018-01-111036951ND
2018-01-1110369540.290 ppb
2018-04-161050258ND
2018-04-161050257ND
2018-04-161050253ND
2018-04-161050254ND
2018-04-161050256ND
2018-04-161050255ND
2018-07-311070622ND
2018-07-311070621ND
2018-07-311070617ND
2018-07-311070618ND
2018-07-311070619ND
2018-07-311070620ND
2018-07-3110706241.40 ppb
2018-07-3110706231.90 ppb
2018-11-061091353ND
2018-11-061091352ND
2018-11-061091348ND
2018-11-061091349ND
2018-11-061091351ND
2018-11-061091350ND
2019-01-081100042ND
2019-01-081100041ND
2019-01-081100040ND
2019-01-081100039ND
2019-01-081100043ND
2019-01-081100044ND
2019-06-031124606ND
2019-06-031124605ND
2019-06-031124603ND
2019-06-0311246040.320 ppb
2019-06-241130092ND
2019-06-241130093ND
2019-07-231136373ND
2019-08-191141967ND
2019-08-191141966ND
2019-08-191141962ND
2019-08-191141963ND
2019-08-191141965ND
2019-08-191141964ND
2019-08-1911419681.30 ppb
2019-08-1911419699.50 ppb
2019-09-091146111ND
2019-10-211156361ND
2019-11-051159255ND
2019-11-051159254ND
2019-11-051159251ND
2019-11-051159253ND
2019-11-051159252ND
2019-12-101165212ND