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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Sbcwd - Lessalt

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

 

97

Samples

0

Samples exceeding legal limit (MCL)

11

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20142.97 ppb32ND - 5.70 ppb
20150.183 ppb122ND - 1.10 ppb
2016ND120ND
20170.550 ppb164ND - 4.30 ppb
20180.0462 ppb261ND - 1.20 ppb
20190.139 ppb282ND - 2.50 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
2014-01-085810-002-11503.20 ppb
2014-04-085810-002-07005.70 ppb
2014-12-235810-002-0915ND
2015-01-065810-002-0925ND
2015-02-035810-002-0830ND
2015-04-065810-002-0900ND
2015-05-045810-002-1000ND
2015-06-035810-002-1000ND
2015-07-065810-002-0910ND
2015-08-045810-002-08301.10 ppb
2015-08-245810-002-07401.10 ppb
2015-09-035810-002-0855ND
2015-10-085810-002-0810ND
2015-11-055810-002-0915ND
2015-12-025810-002-0935ND
2016-01-075810-002-0815ND
2016-02-025810-002-0820ND
2016-03-095810-002-0845ND
2016-04-065810-002-0820ND
2016-05-025810-002-1130ND
2016-06-085810-002-0910ND
2016-07-055810-002-0830ND
2016-08-225810-002-0910ND
2016-09-085810-002-1020ND
2016-10-065810-002-0905ND
2016-11-015810-002-0900ND
2016-12-085810-002-0815ND
2017-01-055810-002-0850ND
2017-02-015810-002-0835ND
2017-03-015810-002-0910ND
2017-04-055810-002-0845ND
2017-05-035810-002-0915ND
2017-06-065810-002-0840ND
2017-07-065810-002-0905ND
2017-08-295810-002-08101.10 ppb
2017-09-075810-002-1010ND
2017-09-075810-004-10402.20 ppb
2017-10-045810-002-09201.20 ppb
2017-10-045810-004-0945ND
2017-11-085810-002-0825ND
2017-11-085810-004-09004.30 ppb
2017-12-065810-002-0855ND
2017-12-065810-004-1030ND
2018-01-095810-002-1000ND
2018-01-095810-004-0930ND
2018-02-075810-006-0915ND
2018-02-075810-005-1030ND
2018-02-085810-002-0950ND
2018-02-085810-004-1015ND
2018-03-075810-002-1025ND
2018-03-075810-004-1025ND
2018-04-055810-002-0945ND
2018-04-055810-004-1115ND
2018-05-035810-004-0930ND
2018-05-035810-002-0900ND
2018-06-075810-004-1030ND
2018-06-075810-002-0845ND
2018-07-105810-004-1000ND
2018-07-105810-002-0915ND
2018-08-285810-004-0900ND
2018-08-285810-002-0900ND
2018-09-115810-004-10101.20 ppb
2018-09-115810-002-0930ND
2018-10-035810-004-0910ND
2018-10-035810-002-0845ND
2018-11-085810-002-0840ND
2018-11-085810-004-0905ND
2018-12-055810-002-0755ND
2018-12-055810-004-0955ND
2019-01-105810-002-1015ND
2019-01-105810-004-0945ND
2019-01-175810-005-1400ND
2019-01-175810-006-1315ND
2019-02-065810-002-1055ND
2019-02-065810-004-1020ND
2019-03-065810-002-0900ND
2019-03-065810-004-0925ND
2019-04-045810-004-1010ND
2019-04-045810-002-0830ND
2019-05-085810-002-0925ND
2019-05-085810-004-1000ND
2019-06-065810-004-0940ND
2019-06-065810-002-0915ND
2019-07-105810-004-0935ND
2019-07-105810-002-0910ND
2019-08-075810-004-0800ND
2019-08-075810-004-1010ND
2019-08-285810-004-13252.50 ppb
2019-08-285810-002-1350ND
2019-09-055810-004-0855ND
2019-09-055810-002-0940ND
2019-10-025810-004-10201.40 ppb
2019-10-025810-002-0820ND
2019-11-065810-004-1050ND
2019-11-065810-002-1030ND
2019-12-055810-004-0835ND
2019-12-055810-002-0805ND