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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

Pico 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.

 

115

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND130ND
2013ND80ND
2014ND240ND
2015ND230ND
2016ND240ND
20170.174 ppb233ND - 1.90 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
2012-03-139588-004-0925ND
2012-03-139588-006-0940ND
2012-03-139588-009-0950ND
2012-03-149588-002-0930ND
2012-03-149588-011-0945ND
2012-05-099588-002-0945ND
2012-08-179588-006-0914ND
2012-08-179588-009-0927ND
2012-08-179588-011-0858ND
2012-08-219588-004-0810ND
2012-12-129588-004-1132ND
2012-12-129588-009-0937ND
2012-12-129588-011-1019ND
2013-03-219588-006-0930ND
2013-03-219588-009-0942ND
2013-03-269588-002-1040ND
2013-03-269588-004-1140ND
2013-03-269588-011-0955ND
2013-06-269588-011-0900ND
2013-12-069588-011-1320ND
2013-12-139588-006-1015ND
2014-01-069588-011-0745ND
2014-02-119588-800-0823ND
2014-02-119588-801-0953ND
2014-02-119588-802-1118ND
2014-02-119588-803-1044ND
2014-03-209588-002-0930ND
2014-03-209588-004-0936ND
2014-03-209588-006-1000ND
2014-03-209588-009-1008ND
2014-05-139588-800-0817ND
2014-05-139588-801-0843ND
2014-05-139588-802-1115ND
2014-05-139588-803-1038ND
2014-06-209588-011-0950ND
2014-08-139588-800-1313ND
2014-08-139588-801-1233ND
2014-08-139588-802-1137ND
2014-08-139588-803-1056ND
2014-08-229588-011-1005ND
2014-10-239588-011-0940ND
2014-11-129588-800-0825ND
2014-11-129588-801-0857ND
2014-11-129588-802-1221ND
2014-11-129588-803-1111ND
2015-02-109588-800-0750ND
2015-02-109588-801-0910ND
2015-02-109588-802-1055ND
2015-02-109588-803-1010ND
2015-03-189588-004-0831ND
2015-03-189588-006-0819ND
2015-03-189588-009-0806ND
2015-03-189588-011-0755ND
2015-05-129588-800-1351ND
2015-05-129588-801-0938ND
2015-05-129588-802-1212ND
2015-05-129588-803-1028ND
2015-06-229588-011-0837ND
2015-08-109588-800-0748ND
2015-08-109588-801-0832ND
2015-08-109588-802-1210ND
2015-08-109588-803-1027ND
2015-08-269588-011-0957ND
2015-11-099588-800-1258ND
2015-11-099588-801-1114ND
2015-11-099588-802-0958ND
2015-11-099588-803-1016ND
2015-12-239588-011-0823ND
2016-02-109588-800-0758ND
2016-02-109588-801-0943ND
2016-02-109588-802-1248ND
2016-02-109588-803-1043ND
2016-02-259588-011-0800ND
2016-03-149588-009-0915ND
2016-03-239588-004-0802ND
2016-03-239588-006-0816ND
2016-05-099588-011-0828ND
2016-05-249588-800-0748ND
2016-05-249588-801-0925ND
2016-05-249588-802-1241ND
2016-05-249588-803-1148ND
2016-08-109588-011-0825ND
2016-08-179588-800-0728ND
2016-08-179588-801-0932ND
2016-08-179588-802-1239ND
2016-08-179588-803-1300ND
2016-11-089588-800-0746ND
2016-11-089588-801-0930ND
2016-11-089588-802-1305ND
2016-11-089588-803-1336ND
2016-11-309588-011-0800ND
2016-12-229588-011-0837ND
2017-02-149588-800-0859ND
2017-02-149588-801-1058ND
2017-02-149588-802-13181.10 ppb
2017-02-149588-803-12381.90 ppb
2017-02-239588-011-0840ND
2017-03-209588-004-1000ND
2017-03-209588-006-0920ND
2017-03-209588-009-09101.000 ppb
2017-05-089588-011-0815ND
2017-05-099588-800-0754ND
2017-05-099588-801-0848ND
2017-05-099588-802-1035ND
2017-05-099588-803-0911ND
2017-08-079588-800-1430ND
2017-08-079588-801-1306ND
2017-08-079588-802-1118ND
2017-08-079588-803-1214ND
2017-08-249588-011-0924ND
2017-11-149588-800-1126ND
2017-11-149588-801-1254ND
2017-11-149588-802-1034ND
2017-11-149588-803-0901ND
2017-11-229588-011-0850ND