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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Colchester Commons

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.

 

20

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND80ND
2015ND30ND
2016ND20ND
2017ND20ND
2018ND30ND
2019ND20ND

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
2014-02-19BG10471VOC1ND
2014-02-19BG10470VOC1ND
2014-04-18BG34476VOC1ND
2014-04-18BG34477VOC1ND
2014-07-29BG83659VOC1ND
2014-07-29BG83661VOC1ND
2014-10-16BH28215VOC1ND
2014-10-16BH28216VOC1ND
2015-04-24BJ07685VOC1ND
2015-04-24BJ07684VOC1ND
2015-04-24BJ07683VOC1ND
2016-03-24BK87904VOC1ND
2016-03-24BK87906VOC1ND
2017-04-07BY00694VOC1ND
2017-10-10BZ18334VOC1ND
2018-04-27CA37955VOC1ND
2018-04-27CA37956VOC1ND
2018-04-27CA37957VOC1ND
2019-10-21CE44554ND
2019-10-21CE44556ND