Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Chloroform

Chino Basin Desalter Authority - Desalter 2

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

 

186

Samples

0

Samples exceeding legal limit (MCL)

42

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.271 ppb164ND - 1.20 ppb
20150.530 ppb208ND - 1.60 ppb
20160.437 ppb278ND - 1.90 ppb
20170.332 ppb378ND - 2.10 ppb
20180.328 ppb439ND - 2.40 ppb
20190.353 ppb435ND - 4.20 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
2014-04-084790-001-1312ND
2014-04-084790-001-1314ND
2014-04-084790-003-11171.10 ppb
2014-04-084790-004-11520.940 ppb
2014-04-084790-010-1118ND
2014-07-084790-001-1325ND
2014-07-084790-002-0945ND
2014-07-084790-003-14301.20 ppb
2014-07-084790-004-11551.10 ppb
2014-07-084790-005-1135ND
2014-07-084790-007-1115ND
2014-07-084790-008-1055ND
2014-07-084790-009-1015ND
2014-07-084790-010-1030ND
2014-10-064790-001-1100ND
2014-10-064790-010-1000ND
2015-01-284790-001-1210ND
2015-01-284790-003-09400.990 ppb
2015-01-284790-004-10451.20 ppb
2015-01-284790-010-0950ND
2015-04-214790-001-1225ND
2015-04-214790-003-09051.10 ppb
2015-04-214790-004-10201.60 ppb
2015-04-214790-010-0905ND
2015-08-124790-001-1300ND
2015-08-124790-002-1000ND
2015-08-124790-003-11251.10 ppb
2015-08-124790-004-12001.60 ppb
2015-08-124790-005-1015ND
2015-08-124790-007-1200ND
2015-08-124790-009-1130ND
2015-08-124790-010-1100ND
2015-08-134790-008-0900ND
2015-08-274790-004-14251.50 ppb
2015-08-274790-004-14451.50 ppb
2015-11-054790-001-1115ND
2016-01-204790-001-1125ND
2016-01-204790-003-09251.30 ppb
2016-01-204790-004-10101.90 ppb
2016-01-204790-010-1100ND
2016-04-134790-001-1140ND
2016-04-134790-003-08451.40 ppb
2016-04-134790-004-09401.40 ppb
2016-04-134790-010-1100ND
2016-04-194790-009-1140ND
2016-08-104790-001-0900ND
2016-08-104790-002-0945ND
2016-08-104790-003-10201.60 ppb
2016-08-104790-004-10501.30 ppb
2016-08-104790-005-1120ND
2016-08-104790-007-1315ND
2016-08-104790-008-1145ND
2016-08-104790-009-1210ND
2016-08-104790-010-1340ND
2016-10-124790-001-1220ND
2016-10-124790-002-0925ND
2016-10-124790-003-11001.50 ppb
2016-10-124790-004-11301.40 ppb
2016-10-124790-005-1020ND
2016-10-124790-007-1055ND
2016-10-124790-008-1035ND
2016-10-124790-009-0930ND
2016-10-124790-010-1005ND
2017-01-184790-001-1110ND
2017-01-184790-002-0845ND
2017-01-184790-003-09351.30 ppb
2017-01-184790-004-10201.30 ppb
2017-01-184790-005-1000ND
2017-01-184790-007-1030ND
2017-01-184790-008-1105ND
2017-01-184790-009-0850ND
2017-01-184790-010-0925ND
2017-04-194790-001-1045ND
2017-04-194790-002-0835ND
2017-04-194790-003-09151.40 ppb
2017-04-194790-004-09501.30 ppb
2017-04-194790-005-1000ND
2017-04-194790-007-0850ND
2017-04-194790-009-1115ND
2017-04-194790-010-0930ND
2017-04-214790-008-0955ND
2017-07-264790-001-1105ND
2017-08-154790-001-1040ND
2017-08-154790-002-0830ND
2017-08-154790-004-09051.80 ppb
2017-08-154790-005-0950ND
2017-08-154790-008-0915ND
2017-08-154790-009-0945ND
2017-08-154790-010-0820ND
2017-08-164790-007-1045ND
2017-08-224790-003-10002.10 ppb
2017-10-174790-001-1050ND
2017-10-174790-002-0825ND
2017-10-174790-003-09151.30 ppb
2017-10-174790-004-10051.80 ppb
2017-10-174790-005-0840ND
2017-10-174790-007-0920ND
2017-10-174790-008-1050ND
2017-10-174790-009-1130ND
2017-10-174790-010-1010ND
2018-01-104790-008-1030ND
2018-01-104790-009-1145ND
2018-01-104790-010-0900ND
2018-01-174790-001-1045ND
2018-01-174790-002-1150ND
2018-01-174790-003-10501.30 ppb
2018-01-174790-004-09102.10 ppb
2018-01-174790-005-1145ND
2018-01-174790-007-09200.500 ppb
2018-03-284790-015-0905ND
2018-03-284790-016-1000ND
2018-04-104790-007-1040ND
2018-04-104790-008-0830ND
2018-04-104790-009-1155ND
2018-04-104790-010-0945ND
2018-04-114790-001-1030ND
2018-04-114790-002-0845ND
2018-04-114790-003-10301.10 ppb
2018-04-114790-004-11301.80 ppb
2018-04-114790-005-0845ND
2018-06-224790-015-1030ND
2018-06-224790-016-0850ND
2018-07-104790-001-1045ND
2018-07-104790-002-0805ND
2018-07-104790-003-09001.30 ppb
2018-07-104790-004-09452.30 ppb
2018-07-104790-005-0820ND
2018-07-104790-007-0930ND
2018-07-104790-008-0850ND
2018-07-104790-010-1015ND
2018-07-194790-016-1145ND
2018-08-144790-009-0835ND
2018-10-104790-001-1100ND
2018-10-104790-002-0805ND
2018-10-104790-003-08501.30 ppb
2018-10-104790-004-09302.40 ppb
2018-10-104790-005-1015ND
2018-10-104790-007-1045ND
2018-10-104790-008-1020ND
2018-10-104790-009-0945ND
2018-10-104790-010-0915ND
2018-10-104790-016-1125ND
2018-12-124790-015-1055ND
2019-02-124790-001-1030ND
2019-02-124790-002-0915ND
2019-02-124790-003-08301.20 ppb
2019-02-124790-004-10552.60 ppb
2019-02-124790-005-1155ND
2019-02-124790-015-0950ND
2019-02-124790-016-0850ND
2019-02-154790-007-0815ND
2019-02-154790-008-1000ND
2019-02-154790-009-0725ND
2019-02-154790-010-0900ND
2019-06-194790-001-1020ND
2019-06-194790-004-11003.80 ppb
2019-06-194790-005-1200ND
2019-06-194790-007-0935ND
2019-06-194790-008-0815ND
2019-06-194790-009-0845ND
2019-06-194790-015-1000ND
2019-06-194790-016-0840ND
2019-06-204790-003-0915ND
2019-06-204790-010-1030ND
2019-08-074790-004-12054.20 ppb
2019-08-074790-005-1045ND
2019-08-074790-008-1120ND
2019-08-074790-009-1150ND
2019-08-084790-001-1255ND
2019-08-084790-015-1200ND
2019-08-084790-016-1105ND
2019-08-154790-003-1130ND
2019-08-154790-007-0900ND
2019-08-154790-010-1030ND
2019-10-084790-002-1220ND
2019-10-174790-001-1210ND
2019-10-174790-002-1105ND
2019-10-174790-003-0950ND
2019-10-174790-004-08303.40 ppb
2019-10-174790-005-0910ND
2019-10-174790-007-1120ND
2019-10-174790-008-1035ND
2019-10-174790-009-0955ND
2019-10-174790-010-0900ND
2019-10-174790-015-1210ND
2019-10-174790-016-1300ND