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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Olivehurst Public UD

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

 

62

Samples

0

Samples exceeding legal limit (MCL)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
201413.5 ppb21ND - 27.0 ppb
2015ND90ND
2016ND70ND
20170.0775 ppb161ND - 1.24 ppb
20180.0900 ppb161ND - 1.44 ppb
20190.326 ppb123ND - 1.73 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
2014-03-052236-001-090027.0 ppb
2014-08-211233-023-0752ND
2015-06-251610-023-0836ND
2015-06-251610-026-0849ND
2015-06-251610-025-0913ND
2015-06-251610-024-0905ND
2015-09-031610-023-0823ND
2015-09-031610-026-0818ND
2015-09-031610-025-0809ND
2015-09-031610-024-0801ND
2015-12-221610-023-1359ND
2016-03-021610-023-1403ND
2016-06-071610-023-1412ND
2016-09-191610-026-1423ND
2016-09-191610-023-1343ND
2016-09-191610-023-1458ND
2016-09-191610-024-1423ND
2016-12-131610-023-1341ND
2017-03-081610-026-1418ND
2017-03-081610-025-1448ND
2017-03-081610-023-1426ND
2017-03-081610-024-1439ND
2017-06-121610-025-13291.24 ppb
2017-06-121610-026-1336ND
2017-06-121610-023-1344ND
2017-06-121610-024-1319ND
2017-09-111610-024-1420ND
2017-09-111610-026-1410ND
2017-09-111610-025-1432ND
2017-09-111610-023-1402ND
2017-12-131610-024-1356ND
2017-12-131610-023-1336ND
2017-12-131610-026-1344ND
2017-12-131610-025-1406ND
2018-03-121610-024-1401ND
2018-03-121610-023-1341ND
2018-03-121610-025-1411ND
2018-03-121610-026-1347ND
2018-06-111610-025-1355ND
2018-06-111610-026-1402ND
2018-06-111610-024-1413ND
2018-06-111610-023-1347ND
2018-09-191610-026-14101.44 ppb
2018-09-191610-025-1354ND
2018-09-191610-024-1346ND
2018-09-191610-023-1403ND
2018-12-121610-023-1200ND
2018-12-121610-026-1211ND
2018-12-121610-025-1146ND
2018-12-121610-024-1138ND
2019-03-111610-023-14221.10 ppb
2019-03-111610-025-1411ND
2019-03-111610-024-1402ND
2019-03-111610-026-1430ND
2019-09-161610-023-1403ND
2019-09-161610-025-13501.73 ppb
2019-09-161610-026-1412ND
2019-09-161610-024-1337ND
2019-12-041610-024-14231.08 ppb
2019-12-041610-025-1436ND
2019-12-041610-026-1404ND
2019-12-041610-023-1355ND