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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

South Mesa Water Company

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

 

52

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
2015ND40ND
2016ND160ND
2017ND60ND
2018ND80ND
2019ND160ND

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
2014-08-053761-802-1030ND
2014-08-053761-801-1000ND
2015-08-033761-802-1050ND
2015-08-033761-801-1020ND
2015-12-013761-801-1140ND
2015-12-013761-802-1210ND
2016-03-093761-802-1205ND
2016-03-093761-801-1140ND
2016-06-023761-802-1210ND
2016-06-023761-801-1125ND
2016-08-023761-006-0830ND
2016-08-023761-008-0905ND
2016-08-023761-003-0750ND
2016-08-023761-004-0810ND
2016-08-023761-009-0920ND
2016-08-023761-013-0845ND
2016-08-023761-010-0945ND
2016-08-023761-022-1005ND
2016-09-013761-802-1200ND
2016-09-013761-801-1230ND
2016-12-023761-802-1015ND
2016-12-023761-801-0930ND
2017-03-033761-801-1110ND
2017-03-033761-802-1140ND
2017-09-113761-801-1000ND
2017-09-113761-802-1015ND
2017-12-043761-801-1145ND
2017-12-043761-802-1220ND
2018-03-143761-801-0910ND
2018-03-143761-802-0935ND
2018-06-053761-801-0850ND
2018-06-053761-802-0925ND
2018-09-113761-801-1120ND
2018-09-113761-802-1205ND
2018-12-063761-801-0840ND
2018-12-063761-802-0920ND
2019-03-083761-801-0850ND
2019-03-083761-802-0930ND
2019-06-143761-801-0940ND
2019-06-143761-802-1025ND
2019-08-123761-008-1020ND
2019-08-123761-003-0930ND
2019-08-123761-004-0945ND
2019-08-123761-006-1000ND
2019-08-123761-009-1030ND
2019-08-123761-013-1015ND
2019-08-123761-022-1110ND
2019-09-043761-802-0955ND
2019-09-043761-801-0925ND
2019-09-303761-010-1050ND
2019-12-053761-801-1000ND
2019-12-053761-802-1115ND