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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Valencia 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

 

314

Samples

0

Samples exceeding legal limit (MCL)

126

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.0611 ppb543ND - 1.10 ppb
20150.153 ppb536ND - 1.70 ppb
20160.552 ppb5418ND - 3.50 ppb
20171.25 ppb5332ND - 3.60 ppb
20181.78 ppb4631ND - 5.20 ppb
20192.20 ppb5436ND - 8.10 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
2014-01-139590-800-0850ND
2014-01-139590-801-1005ND
2014-01-139590-802-0916ND
2014-01-139590-803-1135ND
2014-01-139590-804-1335ND
2014-01-139590-805-13151.10 ppb
2014-01-139590-806-0945ND
2014-01-139590-807-0805ND
2014-02-269590-048-0915ND
2014-04-149590-800-1120ND
2014-04-149590-801-0928ND
2014-04-149590-802-0810ND
2014-04-149590-803-1320ND
2014-04-149590-804-1100ND
2014-04-149590-805-1335ND
2014-04-149590-806-1015ND
2014-04-149590-807-1130ND
2014-05-289590-048-0915ND
2014-07-149590-800-1300ND
2014-07-149590-801-1100ND
2014-07-149590-802-0815ND
2014-07-149590-803-1315ND
2014-07-149590-804-1230ND
2014-07-149590-805-1345ND
2014-07-149590-806-1000ND
2014-07-149590-807-14101.10 ppb
2014-08-289590-048-0940ND
2014-10-139590-800-1100ND
2014-10-139590-801-1400ND
2014-10-139590-802-0900ND
2014-10-139590-803-1400ND
2014-10-139590-804-1455ND
2014-10-139590-805-1415ND
2014-10-139590-806-1300ND
2014-10-139590-807-1545ND
2014-11-089590-021-0830ND
2014-11-089590-024-1135ND
2014-11-089590-052-0930ND
2014-11-089590-062-0815ND
2014-11-139590-005-0950ND
2014-11-139590-017-0940ND
2014-11-139590-018-0900ND
2014-11-139590-025-1050ND
2014-11-139590-026-0845ND
2014-11-139590-046-11001.10 ppb
2014-11-139590-049-0900ND
2014-11-139590-051-1010ND
2014-11-139590-058-0920ND
2014-11-139590-070-1025ND
2014-11-209590-003-1115ND
2014-11-209590-004-0930ND
2014-11-209590-047-1030ND
2014-11-209590-048-1015ND
2014-11-209590-073-0915ND
2015-01-129590-800-1040ND
2015-01-129590-801-1130ND
2015-01-129590-802-0840ND
2015-01-129590-803-0910ND
2015-01-129590-804-1120ND
2015-01-129590-805-0950ND
2015-01-129590-806-1100ND
2015-01-129590-807-1340ND
2015-02-199590-048-0950ND
2015-04-139590-800-13301.70 ppb
2015-04-139590-801-1450ND
2015-04-139590-802-1400ND
2015-04-139590-803-1030ND
2015-04-139590-804-13101.50 ppb
2015-04-139590-805-0940ND
2015-04-139590-806-1345ND
2015-04-139590-807-1420ND
2015-06-049590-048-1000ND
2015-07-139590-800-1311ND
2015-07-139590-801-1345ND
2015-07-139590-802-1245ND
2015-07-139590-803-1331ND
2015-07-139590-804-1302ND
2015-07-139590-805-1350ND
2015-07-139590-806-1330ND
2015-07-139590-807-1235ND
2015-08-279590-048-0918ND
2015-10-129590-800-11351.10 ppb
2015-10-129590-801-09301.40 ppb
2015-10-129590-802-08381.30 ppb
2015-10-129590-803-1315ND
2015-10-129590-804-0936ND
2015-10-129590-805-1307ND
2015-10-129590-806-10061.10 ppb
2015-10-129590-807-0750ND
2015-11-059590-005-0932ND
2015-11-059590-018-0951ND
2015-11-059590-021-0815ND
2015-11-059590-024-0854ND
2015-11-059590-026-0910ND
2015-11-059590-058-1012ND
2015-11-059590-062-0828ND
2015-11-129590-017-0950ND
2015-11-129590-025-0818ND
2015-11-129590-046-0907ND
2015-11-129590-049-0932ND
2015-11-129590-051-1015ND
2015-11-129590-070-0838ND
2015-11-309590-003-0903ND
2015-11-309590-004-1014ND
2015-11-309590-047-1006ND
2015-11-309590-048-0920ND
2015-11-309590-073-0845ND
2016-01-119590-800-0900ND
2016-01-119590-801-10101.10 ppb
2016-01-119590-802-1050ND
2016-01-119590-803-1310ND
2016-01-119590-804-1400ND
2016-01-119590-805-1330ND
2016-01-119590-806-0940ND
2016-01-119590-807-1110ND
2016-02-259590-048-0928ND
2016-03-039590-052-0910ND
2016-04-189590-800-0928ND
2016-04-189590-801-10402.10 ppb
2016-04-189590-802-11001.40 ppb
2016-04-189590-803-12551.50 ppb
2016-04-189590-804-13451.10 ppb
2016-04-189590-805-1320ND
2016-04-189590-806-10101.20 ppb
2016-04-189590-807-1120ND
2016-05-269590-048-0959ND
2016-07-189590-800-10121.20 ppb
2016-07-189590-801-0858ND
2016-07-189590-802-08301.000 ppb
2016-07-189590-803-1042ND
2016-07-189590-804-09191.30 ppb
2016-07-189590-805-1120ND
2016-07-189590-806-09241.000 ppb
2016-07-189590-807-0810ND
2016-10-179590-800-09102.10 ppb
2016-10-179590-801-10002.00 ppb
2016-10-179590-802-08351.40 ppb
2016-10-179590-803-11302.60 ppb
2016-10-179590-804-11003.50 ppb
2016-10-179590-805-11451.50 ppb
2016-10-179590-806-09352.00 ppb
2016-10-179590-807-1025ND
2016-11-039590-005-1000ND
2016-11-039590-018-1030ND
2016-11-039590-021-0820ND
2016-11-039590-024-0940ND
2016-11-039590-026-0950ND
2016-11-039590-052-0920ND
2016-11-039590-058-1040ND
2016-11-039590-062-0900ND
2016-11-099590-017-1036ND
2016-11-099590-025-0926ND
2016-11-099590-046-10071.80 ppb
2016-11-099590-049-0910ND
2016-11-099590-051-1054ND
2016-11-099590-070-0943ND
2016-11-179590-003-0922ND
2016-11-179590-004-0954ND
2016-11-179590-047-0943ND
2016-11-179590-048-1006ND
2016-11-179590-073-0903ND
2017-01-179590-800-10152.00 ppb
2017-01-179590-801-10453.40 ppb
2017-01-179590-802-11003.60 ppb
2017-01-179590-803-09302.10 ppb
2017-01-179590-805-09451.20 ppb
2017-01-179590-806-10302.80 ppb
2017-01-179590-807-08351.40 ppb
2017-02-239590-048-0948ND
2017-04-179590-800-10002.00 ppb
2017-04-179590-801-10401.70 ppb
2017-04-179590-802-10551.90 ppb
2017-04-179590-803-09151.70 ppb
2017-04-179590-804-11301.80 ppb
2017-04-179590-805-09351.80 ppb
2017-04-179590-806-10202.00 ppb
2017-04-179590-807-11101.80 ppb
2017-07-189590-800-09051.90 ppb
2017-07-189590-801-09352.30 ppb
2017-07-189590-802-09551.20 ppb
2017-07-189590-803-10453.40 ppb
2017-07-189590-804-10202.60 ppb
2017-07-189590-805-11003.30 ppb
2017-07-189590-806-09201.30 ppb
2017-07-189590-807-08351.30 ppb
2017-08-249590-048-0915ND
2017-10-169590-800-10051.50 ppb
2017-10-169590-801-10302.50 ppb
2017-10-169590-802-09501.70 ppb
2017-10-169590-803-11253.10 ppb
2017-10-169590-804-11001.80 ppb
2017-10-169590-805-11302.00 ppb
2017-10-169590-806-10151.80 ppb
2017-10-169590-807-1045ND
2017-10-269590-048-0900ND
2017-11-029590-005-1005ND
2017-11-029590-018-0940ND
2017-11-029590-021-0855ND
2017-11-029590-024-1020ND
2017-11-029590-026-1215ND
2017-11-029590-052-0920ND
2017-11-029590-058-0955ND
2017-11-029590-062-0905ND
2017-11-169590-017-1130ND
2017-11-169590-025-1010ND
2017-11-169590-046-10301.60 ppb
2017-11-169590-049-1115ND
2017-11-169590-051-1150ND
2017-11-169590-070-1050ND
2017-11-309590-003-1000ND
2017-11-309590-004-0900ND
2017-11-309590-047-08501.50 ppb
2017-11-309590-048-0945ND
2017-11-309590-073-0920ND
2018-01-169590-800-09032.40 ppb
2018-01-169590-801-09322.40 ppb
2018-01-169590-802-09452.50 ppb
2018-01-169590-803-08261.90 ppb
2018-01-169590-804-10212.60 ppb
2018-01-169590-805-0840ND
2018-01-169590-806-09171.90 ppb
2018-01-169590-807-1000ND
2018-04-169590-800-08403.50 ppb
2018-04-169590-801-09055.20 ppb
2018-04-169590-802-09252.90 ppb
2018-04-169590-803-08104.60 ppb
2018-04-169590-804-10051.70 ppb
2018-04-169590-805-08203.50 ppb
2018-04-169590-806-08552.40 ppb
2018-04-169590-807-09452.00 ppb
2018-07-169590-800-08452.80 ppb
2018-07-169590-801-09252.70 ppb
2018-07-169590-802-09451.80 ppb
2018-07-169590-803-08104.50 ppb
2018-07-169590-804-10202.60 ppb
2018-07-169590-806-09051.90 ppb
2018-07-169590-807-10001.40 ppb
2018-07-269590-805-16361.50 ppb
2018-10-159590-800-08352.90 ppb
2018-10-159590-801-08003.70 ppb
2018-10-159590-802-08502.80 ppb
2018-10-159590-803-09453.10 ppb
2018-10-159590-804-11102.20 ppb
2018-10-159590-805-09201.70 ppb
2018-10-159590-806-08152.70 ppb
2018-10-159590-807-11351.90 ppb
2018-11-072104-005-0923ND
2018-11-072104-018-0941ND
2018-11-072104-021-0830ND
2018-11-072104-025-0857ND
2018-11-072104-026-0909ND
2018-11-072104-052-0910ND
2018-11-072104-058-0954ND
2018-11-072104-062-0845ND
2018-11-142104-017-1005ND
2018-11-142104-025-0940ND
2018-11-142104-046-08552.40 ppb
2018-11-142104-049-0950ND
2018-11-142104-051-1030ND
2018-11-142104-070-0920ND
2019-01-149590-800-09103.00 ppb
2019-01-149590-801-10004.90 ppb
2019-01-149590-802-10152.30 ppb
2019-01-149590-803-08353.90 ppb
2019-01-149590-804-11001.50 ppb
2019-01-149590-805-08452.10 ppb
2019-01-149590-806-09353.10 ppb
2019-01-149590-807-10301.50 ppb
2019-02-122104-003-0900ND
2019-02-122104-004-0830ND
2019-02-122104-047-08401.10 ppb
2019-02-122104-073-0950ND
2019-04-159590-800-09356.10 ppb
2019-04-159590-801-10205.90 ppb
2019-04-159590-802-10405.40 ppb
2019-04-159590-803-08407.70 ppb
2019-04-159590-804-11254.70 ppb
2019-04-159590-805-09008.10 ppb
2019-04-159590-806-10006.10 ppb
2019-04-159590-807-11006.30 ppb
2019-07-159590-800-09202.00 ppb
2019-07-159590-801-10301.60 ppb
2019-07-159590-802-10501.70 ppb
2019-07-159590-803-08352.60 ppb
2019-07-159590-804-12001.30 ppb
2019-07-159590-805-09001.90 ppb
2019-07-159590-806-09552.00 ppb
2019-07-159590-807-11251.90 ppb
2019-10-149590-800-11253.40 ppb
2019-10-149590-801-08153.10 ppb
2019-10-149590-802-08353.60 ppb
2019-10-149590-803-10403.90 ppb
2019-10-149590-804-09352.00 ppb
2019-10-149590-805-11002.40 ppb
2019-10-149590-806-12103.30 ppb
2019-10-149590-807-09051.10 ppb
2019-11-062104-018-0825ND
2019-11-062104-021-0926ND
2019-11-062104-026-0900ND
2019-11-062104-052-0840ND
2019-11-062104-058-1000ND
2019-11-062104-062-0908ND
2019-11-142104-017-1100ND
2019-11-142104-025-0935ND
2019-11-142104-046-08402.70 ppb
2019-11-142104-049-0915ND
2019-11-142104-051-0940ND
2019-11-142104-070-0920ND
2019-11-202104-003-0900ND
2019-11-202104-004-09401.20 ppb
2019-11-202104-047-09203.50 ppb
2019-11-202104-073-0930ND
2019-11-219590-048-1120ND
2019-11-252104-005-1030ND