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EWG's Tap Water Database

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Chloroform

Grants Way

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.

 

21

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2010ND30ND
2011ND40ND
2012ND40ND
2013ND20ND
2014ND40ND
2015ND40ND

ppb = parts per billion.

State and national drinking water standards and health guidelines

Health Guideline 0.4 ppb

The 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.

EPA Maximum Contaminant
Level Goal (MCLG)70.0 ppb

A non-enforceable federal health guideline. For cancer-causing chemicals, these health goals are typically set to zero.

ppb = parts per billion.

All test results

Date Lab ID Result
2010-04-14S73115ND
2010-09-13A10090774-02ND
2010-10-19S254798ND
2011-01-26S227888ND
2011-04-25S227921ND
2011-07-26S201364ND
2011-10-21S196634ND
2012-01-26S313461ND
2012-04-26S313584ND
2012-07-24S366444ND
2012-10-19S382326ND
2013-01-14S382342ND
2013-08-28L4744306-1ND
2014-01-30S438321ND
2014-04-23S479078ND
2014-07-23L5171337-1ND
2014-10-15S257742ND
2015-01-15S504601ND
2015-04-21S580497ND
2015-08-24S612406ND
2015-10-20S614751ND