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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Conroe Resort

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.

 

14

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND10ND
2015ND30ND
2016ND30ND
20170.333 ppb31ND - 1.000 ppb
2018ND20ND
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
2014-09-15AC66968ND
2015-07-21AD00439ND
2015-07-21AD00415ND
2015-07-21AD00358ND
2016-09-27AD51403ND
2016-10-18AD53570ND
2016-12-15AD62400ND
2017-07-19AD89905ND
2017-11-21AE05590ND
2017-11-21AE056021.000 ppb
2018-08-07AE35978ND
2018-08-07AE35966ND
2019-09-24AE84427ND
2019-09-24AE84385ND