Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Chloroform

Foxcroft School

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.

 

36

Samples

0

Samples exceeding legal limit (MCL)

10

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.400 ppb52ND - 1.10 ppb
20150.388 ppb82ND - 2.50 ppb
20160.445 ppb115ND - 1.90 ppb
2017ND80ND
2018ND10ND
20190.267 ppb31ND - 0.800 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
2014-01-28E1312055160.900 ppb
2014-04-10E140302161ND
2014-07-28E1406021321.10 ppb
2014-10-27E140904165ND
2014-10-27E140904166ND
2015-01-14VA010-DCLSND
2015-01-14VA010-DCLSND
2015-04-15VA010-DCLSND
2015-04-28VA010-DCLSND
2015-08-03VA010-DCLS2.50 ppb
2015-08-26VA010-DCLSND
2015-10-13VA010-DCLS0.600 ppb
2015-10-13VA010-DCLSND
2016-02-03E1601008280.600 ppb
2016-02-03E1601008240.700 ppb
2016-04-06E160203382ND
2016-04-06E1602033780.900 ppb
2016-07-25E1606015791.90 ppb
2016-07-25E160601592ND
2016-07-27E160601580ND
2016-10-19E160903973ND
2016-10-19E160903970ND
2016-10-19E160903980ND
2016-10-19E1609039810.800 ppb
2017-02-01E161200822ND
2017-02-01E161200819ND
2017-05-15E170203789ND
2017-05-15E170203793ND
2017-08-15E170503920ND
2017-08-15E170503922ND
2017-11-28E170903299ND
2017-11-28E170903294ND
2018-03-26E171203487ND
2019-03-26E181206035ND
2019-09-10E1907063900.800 ppb
2019-09-10E190706394ND