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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Oak Park Water Service

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

 

100

Samples

0

Samples exceeding legal limit (MCL)

75

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20141.66 ppb1611ND - 3.90 ppb
20153.20 ppb2017ND - 5.60 ppb
20160.806 ppb167ND - 2.50 ppb
20172.18 ppb1614ND - 3.10 ppb
20182.37 ppb1610ND - 6.00 ppb
20191.29 ppb16161.000 ppb - 1.70 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
2014-01-079588-004-08091.20 ppb
2014-01-079588-002-0856ND
2014-01-079588-003-08231.20 ppb
2014-01-079588-005-08351.10 ppb
2014-04-019588-005-08422.50 ppb
2014-04-019588-004-07422.50 ppb
2014-04-019588-003-08282.80 ppb
2014-04-019588-002-08122.40 ppb
2014-07-089588-005-08252.90 ppb
2014-07-089588-004-07253.20 ppb
2014-07-089588-003-08052.90 ppb
2014-07-089588-002-07503.90 ppb
2014-10-079588-004-0818ND
2014-10-079588-003-0754ND
2014-10-079588-005-0810ND
2014-10-079588-002-0742ND
2015-01-079588-005-0945ND
2015-01-079588-004-1035ND
2015-01-079588-003-0925ND
2015-01-079588-002-09002.20 ppb
2015-04-079588-005-10483.30 ppb
2015-04-079588-004-10153.80 ppb
2015-04-079588-002-08453.30 ppb
2015-04-079588-003-10483.20 ppb
2015-07-079588-003-13573.50 ppb
2015-07-079588-002-14433.60 ppb
2015-07-079588-005-14103.90 ppb
2015-07-079588-004-13463.40 ppb
2015-10-069588-003-09505.30 ppb
2015-10-069588-002-10355.00 ppb
2015-10-069588-005-09305.60 ppb
2015-10-069588-004-11455.40 ppb
2015-12-019588-003-10363.40 ppb
2015-12-019588-002-09082.90 ppb
2015-12-019588-005-10513.20 ppb
2015-12-019588-004-11242.90 ppb
2016-01-059588-003-09001.000 ppb
2016-01-059588-002-09201.000 ppb
2016-01-059588-005-1000ND
2016-01-059588-004-08401.40 ppb
2016-04-059588-003-1230ND
2016-04-059588-002-1215ND
2016-04-059588-005-1245ND
2016-04-059588-004-1155ND
2016-07-059588-002-1155ND
2016-07-059588-004-1047ND
2016-07-059588-005-1255ND
2016-07-059588-003-1240ND
2016-10-049588-003-09502.30 ppb
2016-10-049588-002-09252.30 ppb
2016-10-049588-004-09002.40 ppb
2016-10-049588-005-10102.50 ppb
2017-01-039588-005-11181.90 ppb
2017-01-039588-002-09492.50 ppb
2017-01-039588-003-10212.30 ppb
2017-01-039588-004-10522.50 ppb
2017-04-049588-005-13253.00 ppb
2017-04-049588-003-13103.00 ppb
2017-04-049588-002-12453.00 ppb
2017-04-049588-004-11552.90 ppb
2017-07-119588-005-09071.20 ppb
2017-07-119588-002-1019ND
2017-07-119588-004-08351.40 ppb
2017-07-119588-003-0920ND
2017-10-039588-004-10202.80 ppb
2017-10-039588-005-11033.10 ppb
2017-10-039588-002-11523.00 ppb
2017-10-039588-003-10482.30 ppb
2018-01-039588-004-11202.50 ppb
2018-01-039588-005-11523.50 ppb
2018-01-039588-002-12373.50 ppb
2018-01-039588-003-11352.90 ppb
2018-04-119588-005-09566.00 ppb
2018-04-119588-002-10305.50 ppb
2018-04-119588-003-10105.90 ppb
2018-04-119588-004-09305.90 ppb
2018-07-109588-004-10591.20 ppb
2018-07-109588-005-0930ND
2018-07-109588-003-1029ND
2018-07-109588-002-1007ND
2018-10-029588-005-1540ND
2018-10-029588-004-15401.000 ppb
2018-10-029588-003-1540ND
2018-10-029588-002-1540ND
2019-01-089588-005-08331.40 ppb
2019-01-089588-002-09391.20 ppb
2019-01-089588-003-08511.20 ppb
2019-01-089588-004-10351.30 ppb
2019-04-099588-002-08361.10 ppb
2019-04-099588-004-11191.20 ppb
2019-04-099588-005-10041.20 ppb
2019-04-099588-003-09271.000 ppb
2019-07-099588-004-10351.40 ppb
2019-07-099588-002-08501.10 ppb
2019-07-099588-005-09551.30 ppb
2019-07-099588-003-09301.10 ppb
2019-10-089588-004-00001.70 ppb
2019-10-089588-003-00001.60 ppb
2019-10-089588-002-00001.20 ppb
2019-10-089588-005-00001.60 ppb