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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

San Gabriel County WD

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.

 

129

Samples

0

Samples exceeding legal limit (MCL)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND210ND
2013ND220ND
20140.0696 ppb231ND - 1.60 ppb
20150.105 ppb212ND - 1.10 ppb
20160.152 ppb213ND - 1.20 ppb
2017ND210ND

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
2012-02-073761-001-1005ND
2012-04-189588-007-1100ND
2012-04-239588-800-1145ND
2012-04-239588-801-1230ND
2012-04-239588-802-1210ND
2012-04-239588-803-1250ND
2012-05-013761-001-1135ND
2012-07-033761-001-1040ND
2012-07-179588-009-0915ND
2012-07-179588-010-0930ND
2012-07-179588-011-1015ND
2012-07-269588-800-0855ND
2012-07-269588-801-1135ND
2012-07-269588-802-1120ND
2012-07-269588-803-1155ND
2012-08-073761-001-0000ND
2012-10-239588-800-0945ND
2012-10-239588-801-1315ND
2012-10-239588-802-1350ND
2012-10-239588-803-1255ND
2012-11-073761-001-1120ND
2013-01-239588-800-1300ND
2013-01-239588-801-1230ND
2013-01-239588-802-1250ND
2013-01-239588-803-1105ND
2013-04-109588-007-0915ND
2013-04-239588-800-0910ND
2013-04-239588-801-1230ND
2013-04-239588-802-0905ND
2013-04-239588-803-1100ND
2013-05-243761-020-1125ND
2013-07-159588-009-0950ND
2013-07-159588-010-1005ND
2013-07-249588-800-1445ND
2013-07-249588-801-1415ND
2013-07-249588-802-1430ND
2013-07-249588-803-1400ND
2013-08-139588-001-1015ND
2013-08-139588-011-0945ND
2013-10-239588-800-0850ND
2013-10-239588-801-1245ND
2013-10-239588-802-0840ND
2013-10-239588-803-1155ND
2014-01-239588-800-0900ND
2014-01-239588-801-1300ND
2014-01-239588-802-0845ND
2014-01-239588-803-1225ND
2014-04-089588-007-0940ND
2014-04-229588-800-0840ND
2014-04-229588-801-1200ND
2014-04-229588-802-0830ND
2014-04-229588-803-1045ND
2014-06-173761-020-1020ND
2014-07-149588-009-0900ND
2014-07-149588-010-0915ND
2014-07-149588-011-0945ND
2014-07-159588-001-1000ND
2014-07-239588-800-0820ND
2014-07-239588-801-0845ND
2014-07-239588-802-0830ND
2014-07-239588-803-0905ND
2014-10-239588-800-0905ND
2014-10-239588-801-1215ND
2014-10-239588-802-0850ND
2014-10-239588-803-12001.60 ppb
2014-12-059588-020-0910ND
2015-01-239588-800-0830ND
2015-01-239588-801-1205ND
2015-01-239588-802-0820ND
2015-01-239588-803-1130ND
2015-03-179588-020-1050ND
2015-04-229588-800-0830ND
2015-04-229588-801-1135ND
2015-04-229588-802-0815ND
2015-04-229588-803-1120ND
2015-06-119588-007-0905ND
2015-07-169588-001-0940ND
2015-07-169588-010-1000ND
2015-07-169588-011-1020ND
2015-07-239588-800-0835ND
2015-07-239588-801-1205ND
2015-07-239588-802-0820ND
2015-07-239588-803-11401.10 ppb
2015-10-269588-800-0830ND
2015-10-269588-801-11501.10 ppb
2015-10-269588-802-0820ND
2015-10-269588-803-1135ND
2016-01-269588-800-0850ND
2016-01-269588-801-12101.000 ppb
2016-01-269588-802-0840ND
2016-01-269588-803-1155ND
2016-04-139588-007-0940ND
2016-04-229588-800-0840ND
2016-04-229588-801-12101.000 ppb
2016-04-229588-802-0820ND
2016-04-229588-803-1135ND
2016-07-189588-009-0925ND
2016-07-189588-010-0935ND
2016-07-189588-011-0950ND
2016-07-269588-800-0835ND
2016-07-269588-801-1125ND
2016-07-269588-802-0825ND
2016-07-269588-803-1110ND
2016-09-159588-020-0910ND
2016-10-269588-800-0900ND
2016-10-269588-801-12051.20 ppb
2016-10-269588-802-0845ND
2016-10-269588-803-1150ND
2017-01-249588-800-0850ND
2017-01-249588-801-1210ND
2017-01-249588-802-0835ND
2017-01-249588-803-1150ND
2017-04-139588-007-0925ND
2017-04-249588-800-1355ND
2017-04-249588-801-1330ND
2017-04-249588-802-1345ND
2017-04-249588-803-1315ND
2017-07-179588-009-0905ND
2017-07-179588-010-0925ND
2017-07-179588-011-0945ND
2017-07-179588-020-1025ND
2017-07-279588-800-1405ND
2017-07-279588-801-1330ND
2017-07-279588-802-1345ND
2017-07-279588-803-1315ND
2017-10-249588-800-0840ND
2017-10-249588-801-1210ND
2017-10-249588-802-0830ND
2017-10-249588-803-1145ND