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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

Waukesha Water Utility

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.

 

42

Samples

0

Samples exceeding legal limit (MCL)

31

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20122.00 ppb109ND - 3.90 ppb
20131.20 ppb550.290 ppb - 3.30 ppb
20141.21 ppb97ND - 3.80 ppb
20151.10 ppb64ND - 3.60 ppb
20163.85 ppb223.70 ppb - 4.00 ppb
20171.92 ppb105ND - 6.96 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
2012-03-206550590.490 ppb
2012-03-206550570.500 ppb
2012-05-22664036ND
2012-08-026762001.10 ppb
2012-08-026762031.70 ppb
2012-08-026762062.50 ppb
2012-08-026762022.90 ppb
2012-08-026762013.40 ppb
2012-08-026762053.50 ppb
2012-08-026762043.90 ppb
2013-02-207062180.290 ppb
2013-02-207062200.770 ppb
2013-02-207062220.460 ppb
2013-08-277401511.20 ppb
2013-08-277401523.30 ppb
2014-03-267767550.430 ppb
2014-03-267767530.570 ppb
2014-05-07784419ND
2014-05-077844220.670 ppb
2014-05-077844250.900 ppb
2014-06-117961031.10 ppb
2014-06-11796100ND
2014-08-128105253.40 ppb
2014-08-128105263.80 ppb
2015-03-108478530.470 ppb
2015-03-108478510.640 ppb
2015-03-11847855ND
2015-08-318796121.90 ppb
2015-08-318796113.60 ppb
2015-09-29886380ND
2016-07-149333764.00 ppb
2016-07-149333773.70 ppb
2017-03-28980078ND
2017-03-289800840.850 ppb
2017-03-289800811.70 ppb
2017-05-02986361ND
2017-05-02986364ND
2017-05-31994537ND
2017-05-31994540ND
2017-07-031707308-002A3.79 ppb
2017-07-031707308-001A6.96 ppb
2017-10-1110239345.90 ppb