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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Cassatt Water Kershaw-lee Company RWA

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.

MORE ABOUT THIS CONTAMINANT

 

96

Samples

0

Samples exceeding legal limit (MCL)

16

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.334 ppb162ND - 3.17 ppb
20150.153 ppb162ND - 1.32 ppb
20160.329 ppb162ND - 3.02 ppb
20170.273 ppb163ND - 2.13 ppb
20180.379 ppb163ND - 2.60 ppb
20190.567 ppb164ND - 3.90 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
2014-02-182140221-7ND
2014-02-182140221-8ND
2014-02-182140221-9ND
2014-02-182140221-10ND
2014-05-062140508-29ND
2014-05-062140508-30ND
2014-05-062140508-31ND
2014-05-062140508-32ND
2014-08-052140807-17ND
2014-08-052140807-18ND
2014-08-052140807-193.17 ppb
2014-08-052140807-20ND
2014-11-132141114-26ND
2014-11-132141114-28ND
2014-11-132141114-272.17 ppb
2014-11-132141114-25ND
2015-02-102150212-17ND
2015-02-102150212-18ND
2015-02-102150212-191.12 ppb
2015-02-102150212-20ND
2015-05-042150508-101.32 ppb
2015-05-042150508-7ND
2015-05-042150508-8ND
2015-05-042150508-9ND
2015-08-122150814-35ND
2015-08-122150814-37ND
2015-08-122150814-36ND
2015-08-122150814-34ND
2015-11-182151119-7ND
2015-11-182151119-8ND
2015-11-182151119-9ND
2015-11-182151119-10ND
2016-02-092160210-24ND
2016-02-092160210-22ND
2016-02-092160210-21ND
2016-02-092160210-23ND
2016-05-112160513-29ND
2016-05-112160513-31ND
2016-05-112160513-30ND
2016-05-112160513-32ND
2016-08-092160812-173.02 ppb
2016-08-092160812-15ND
2016-08-092160812-162.25 ppb
2016-08-092160812-18ND
2016-11-092161111-27ND
2016-11-092161111-25ND
2016-11-092161111-26ND
2016-11-092161111-28ND
2017-02-062170210-18ND
2017-02-062170210-17ND
2017-02-062170210-15ND
2017-02-062170210-16ND
2017-05-162170519-151.23 ppb
2017-05-162170519-16ND
2017-05-162170519-17ND
2017-05-162170519-18ND
2017-08-302170901-62ND
2017-08-302170901-61ND
2017-08-302170901-60ND
2017-08-302170901-592.13 ppb
2017-11-162171117-271.01 ppb
2017-11-162171117-28ND
2017-11-162171117-29ND
2017-11-162171117-30ND
2018-03-142180316-18ND
2018-03-142180316-17ND
2018-03-142180316-16ND
2018-03-142180316-15ND
2018-05-092180510-332.60 ppb
2018-05-092180510-30ND
2018-05-092180510-31ND
2018-05-092180510-32ND
2018-08-152180817-42ND
2018-08-152180817-411.18 ppb
2018-08-152180817-40ND
2018-08-152180817-39ND
2018-11-072181109-172.29 ppb
2018-11-072181109-18ND
2018-11-072181109-19ND
2018-11-072181109-20ND
2019-02-192190222-17ND
2019-02-192190222-18ND
2019-02-192190222-19ND
2019-02-192190222-20ND
2019-05-082190510-171.64 ppb
2019-05-082190510-20ND
2019-05-082190510-19ND
2019-05-082190510-18ND
2019-08-122190814-18ND
2019-08-122190814-20ND
2019-08-122190814-191.80 ppb
2019-08-122190814-173.90 ppb
2019-11-202191122-20ND
2019-11-202191122-19ND
2019-11-202191122-18ND
2019-11-202191122-171.73 ppb