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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Belforest Water System

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

 

21

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.0689 ppb92ND - 0.320 ppb
2015ND10ND
2016ND40ND
20170.268 ppb21ND - 0.535 ppb
2018ND20ND
2019ND30ND

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
2014-01-13AA88295ND
2014-01-16AA88294ND
2014-04-15AA89084ND
2014-07-16AA90617ND
2014-07-17AA90616ND
2014-10-14AA92211ND
2014-10-16AA922140.300 ppb
2014-10-16AA92212ND
2014-10-16AA922130.320 ppb
2015-10-15AB08451ND
2016-10-03AB15822ND
2016-10-13AB15823ND
2016-10-13AB15821ND
2016-10-13AB15824ND
2017-10-11AB236650.535 ppb
2017-10-12AB23664ND
2018-10-11AB30933ND
2018-10-11AB30934ND
2019-12-09AB40553ND
2019-12-09AB40552ND
2019-12-09AB40551ND