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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Valencia Heights Water Company

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

 

65

Samples

0

Samples exceeding legal limit (MCL)

42

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20142.73 ppb112ND - 16.0 ppb
20158.04 ppb108ND - 17.0 ppb
20166.48 ppb118ND - 15.0 ppb
201711.7 ppb118ND - 25.0 ppb
20186.31 ppb118ND - 16.0 ppb
20196.90 ppb118ND - 18.0 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
2014-01-249588-801-1100ND
2014-01-249588-800-1115ND
2014-04-239588-801-1020ND
2014-04-239588-800-1035ND
2014-07-119588-012-1120ND
2014-07-119588-010-1105ND
2014-07-119588-005-1140ND
2014-07-249588-801-1415ND
2014-07-249588-800-1425ND
2014-10-279588-801-110016.0 ppb
2014-10-279588-800-111514.0 ppb
2015-01-289588-801-104510.00 ppb
2015-01-289588-800-11003.40 ppb
2015-04-239588-800-103015.0 ppb
2015-04-239588-801-10154.80 ppb
2015-07-169588-012-0730ND
2015-07-169588-010-0745ND
2015-07-279588-801-122515.0 ppb
2015-07-279588-800-124017.0 ppb
2015-10-289588-801-07306.70 ppb
2015-10-289588-800-07458.50 ppb
2016-01-259588-800-13107.20 ppb
2016-01-259588-801-12559.00 ppb
2016-04-069588-005-0810ND
2016-04-279588-800-111010.00 ppb
2016-04-279588-801-10555.70 ppb
2016-07-159588-012-0840ND
2016-07-159588-010-0830ND
2016-07-259588-800-124015.0 ppb
2016-07-259588-801-122515.0 ppb
2016-10-259588-800-13004.90 ppb
2016-10-259588-801-12404.50 ppb
2017-01-279588-800-10454.60 ppb
2017-01-279588-801-10307.40 ppb
2017-04-189588-005-0910ND
2017-04-259588-800-125024.0 ppb
2017-04-259588-801-123525.0 ppb
2017-07-129588-010-0850ND
2017-07-129588-012-0840ND
2017-07-259588-800-083521.0 ppb
2017-07-259588-801-082016.0 ppb
2017-10-279588-801-104019.0 ppb
2017-10-279588-800-105512.0 ppb
2018-01-269588-800-111016.0 ppb
2018-01-269588-801-105512.0 ppb
2018-04-259588-800-122011.0 ppb
2018-04-259588-801-12107.30 ppb
2018-06-269588-005-0745ND
2018-07-139588-012-0825ND
2018-07-139588-010-0840ND
2018-07-279588-801-09256.60 ppb
2018-07-279588-800-09406.40 ppb
2018-10-249588-801-09504.70 ppb
2018-10-249588-800-09355.40 ppb
2019-01-239588-801-10104.10 ppb
2019-01-239588-800-10205.30 ppb
2019-04-099588-005-0710ND
2019-04-249588-801-10157.10 ppb
2019-04-249588-800-10308.50 ppb
2019-07-129588-012-0725ND
2019-07-129588-010-0705ND
2019-07-249588-801-103518.0 ppb
2019-07-249588-800-105016.0 ppb
2019-10-259588-801-12107.60 ppb
2019-10-259588-800-12309.30 ppb