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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

California Water Service Company-Lancaster

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.

 

39

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND20ND
2013ND10ND
2014ND60ND
2015ND100ND
20160.0580 ppb101ND - 0.580 ppb
2017ND100ND

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
2012-12-185810-005-1220ND
2012-12-185810-001-1230ND
2013-06-195701-005-1030ND
2014-05-135701-801-0942ND
2014-05-135701-800-1009ND
2014-05-205701-001-1000ND
2014-06-245701-005-1112ND
2014-07-235701-801-1011ND
2014-07-235701-800-0953ND
2015-02-035701-800-1307ND
2015-02-035701-801-1238ND
2015-05-125701-801-0809ND
2015-05-125701-800-0808ND
2015-05-195701-001-0937ND
2015-06-165701-005-1347ND
2015-08-115701-800-0949ND
2015-08-115701-801-0950ND
2015-11-095810-801-1641ND
2015-11-095810-800-1650ND
2016-02-095701-801-0908ND
2016-02-095701-800-0908ND
2016-05-105701-800-0919ND
2016-05-105701-801-0919ND
2016-05-245701-001-1342ND
2016-06-285701-005-1145ND
2016-08-095701-801-0945ND
2016-08-095701-800-0945ND
2016-11-155701-801-08440.580 ppb
2016-11-155701-800-0844ND
2017-02-145701-801-0941ND
2017-02-145701-800-0940ND
2017-05-095701-801-0956ND
2017-05-095701-800-0956ND
2017-05-095701-001-1025ND
2017-06-205701-005-1501ND
2017-08-155810-801-1452ND
2017-08-155810-800-1423ND
2017-11-135810-801-1500ND
2017-11-135810-800-1406ND