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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

California Water Service (CWS) - Selma

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

 

121

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND200ND
2015ND180ND
2016ND220ND
2017ND200ND
2018ND180ND
2019ND230ND

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
2014-01-075701-901-1336ND
2014-01-075701-902-1432ND
2014-01-075701-903-1420ND
2014-01-075701-904-1445ND
2014-02-195701-038-1330ND
2014-04-085701-901-1200ND
2014-04-085701-902-1430ND
2014-04-085701-903-1440ND
2014-04-085701-904-1419ND
2014-04-165701-005-0908ND
2014-04-165701-013-0926ND
2014-07-085701-901-1425ND
2014-07-085701-902-1325ND
2014-07-085701-903-1340ND
2014-07-085701-904-1310ND
2014-10-075701-901-1438ND
2014-10-075701-902-1415ND
2014-10-075701-903-1403ND
2014-10-075701-904-1520ND
2014-10-215701-014-1053ND
2015-01-065701-901-1509ND
2015-01-065701-902-1546ND
2015-01-065701-903-1534ND
2015-01-065701-904-1556ND
2015-01-275701-021-0959ND
2015-04-085701-901-0809ND
2015-04-085701-902-0809ND
2015-04-085701-903-0809ND
2015-04-085701-904-0809ND
2015-07-075701-901-0948ND
2015-07-075701-902-0948ND
2015-07-075701-903-0948ND
2015-07-075701-904-0948ND
2015-10-065810-901-1505ND
2015-10-065810-902-1401ND
2015-10-065810-903-1420ND
2015-10-065810-904-1345ND
2015-10-209590-004-1110ND
2016-01-075810-901-1128ND
2016-01-075810-902-1203ND
2016-01-075810-903-1153ND
2016-01-075810-904-1214ND
2016-04-055701-901-0836ND
2016-04-055701-902-0836ND
2016-04-055701-903-0836ND
2016-04-055701-904-0836ND
2016-04-195701-018-1020ND
2016-04-195701-023-0956ND
2016-07-065701-901-0817ND
2016-07-065701-902-0817ND
2016-07-065701-903-0817ND
2016-07-065701-904-0817ND
2016-07-265701-001-0914ND
2016-07-265701-022-0941ND
2016-09-275701-036-1010ND
2016-10-045701-901-0841ND
2016-10-045701-902-0841ND
2016-10-045701-903-0841ND
2016-10-045701-904-0841ND
2016-11-095701-010-1030ND
2017-01-035701-901-0957ND
2017-01-035701-902-0957ND
2017-01-035701-903-0957ND
2017-01-035701-904-0957ND
2017-03-075810-038-1041ND
2017-04-045701-901-0944ND
2017-04-045701-902-0944ND
2017-04-045701-903-0944ND
2017-04-045701-904-0944ND
2017-04-115701-005-1030ND
2017-04-115701-013-1046ND
2017-07-065810-901-1127ND
2017-07-065810-902-1441ND
2017-07-065810-903-1424ND
2017-07-065810-904-1501ND
2017-10-035810-901-1036ND
2017-10-035810-902-1322ND
2017-10-035810-903-1246ND
2017-10-035810-904-1357ND
2017-10-245701-014-1122ND
2018-01-045810-901-0957ND
2018-01-045810-902-1123ND
2018-01-045810-903-1046ND
2018-01-045810-904-1210ND
2018-01-235701-021-0908ND
2018-04-035701-901-0821ND
2018-04-035701-902-0821ND
2018-04-035701-903-0821ND
2018-04-035701-904-0821ND
2018-07-055810-901-1250ND
2018-07-055810-902-1350ND
2018-07-055810-903-1325ND
2018-07-055810-904-1432ND
2018-10-095701-901-0914ND
2018-10-095701-902-0914ND
2018-10-095701-903-0914ND
2018-10-095701-904-0914ND
2018-10-165810-004-0947ND
2019-01-035701-901-0959ND
2019-01-035701-902-0959ND
2019-01-035701-903-0959ND
2019-01-035701-904-0959ND
2019-04-025701-902-0909ND
2019-04-025701-903-0909ND
2019-04-025701-904-0909ND
2019-04-095810-901-1355ND
2019-04-235701-018-1100ND
2019-04-235701-023-1046ND
2019-07-055701-901-1015ND
2019-07-055701-902-1104ND
2019-07-055701-903-1056ND
2019-07-055701-904-1113ND
2019-07-175701-022-0943ND
2019-10-015701-901-1308ND
2019-10-015701-902-1031ND
2019-10-015701-903-1229ND
2019-10-015701-904-1414ND
2019-10-085701-018-1105ND
2019-10-085701-023-1048ND
2019-10-175701-010-1051ND
2019-10-215701-036-1030ND