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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Midvale City Water System

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

 

125

Samples

0

Samples exceeding legal limit (MCL)

62

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20146.17 ppb3418ND - 45.2 ppb
201512.4 ppb2214ND - 42.6 ppb
20165.33 ppb147ND - 28.4 ppb
20179.22 ppb1910ND - 36.5 ppb
20188.52 ppb2010ND - 36.1 ppb
20194.73 ppb163ND - 28.9 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 Result
2014-01-097.90 ppb
2014-01-097.10 ppb
2014-01-096.20 ppb
2014-01-099.40 ppb
2014-01-140.900 ppb
2014-01-140.800 ppb
2014-01-140.800 ppb
2014-01-140.900 ppb
2014-04-020.600 ppb
2014-04-02ND
2014-04-02ND
2014-04-021.50 ppb
2014-05-01ND
2014-05-01ND
2014-05-01ND
2014-05-01ND
2014-07-154.10 ppb
2014-07-153.10 ppb
2014-07-157.60 ppb
2014-07-1517.3 ppb
2014-09-29ND
2014-09-29ND
2014-09-29ND
2014-09-29ND
2014-09-29ND
2014-09-29ND
2014-10-27ND
2014-10-27ND
2014-10-2729.7 ppb
2014-10-27ND
2014-10-27ND
2014-10-2745.2 ppb
2014-10-2728.7 ppb
2014-10-2737.9 ppb
2015-03-1711.4 ppb
2015-03-175.40 ppb
2015-03-176.90 ppb
2015-03-176.90 ppb
2015-03-26ND
2015-03-26ND
2015-05-0415.5 ppb
2015-05-0414.4 ppb
2015-05-047.70 ppb
2015-05-0416.5 ppb
2015-05-04ND
2015-05-04ND
2015-07-30ND
2015-07-30ND
2015-07-30ND
2015-07-30ND
2015-07-3018.5 ppb
2015-07-3011.2 ppb
2015-10-1442.0 ppb
2015-10-1442.4 ppb
2015-10-1431.0 ppb
2015-10-1442.6 ppb
2016-02-10ND
2016-02-10ND
2016-02-104.10 ppb
2016-02-107.20 ppb
2016-06-13ND
2016-06-13ND
2016-06-132.20 ppb
2016-06-136.20 ppb
2016-08-09ND
2016-08-091.10 ppb
2016-10-06ND
2016-10-06ND
2016-10-0625.4 ppb
2016-10-0628.4 ppb
2017-01-181.70 ppb
2017-01-181.80 ppb
2017-01-18ND
2017-01-18ND
2017-05-04ND
2017-05-08ND
2017-05-1011.6 ppb
2017-06-09ND
2017-06-1623.4 ppb
2017-06-164.40 ppb
2017-07-141.000 ppb
2017-07-19ND
2017-07-19ND
2017-07-19ND
2017-09-2034.1 ppb
2017-09-2036.5 ppb
2017-10-17ND
2017-10-1728.7 ppb
2017-10-1732.0 ppb
2018-01-11ND
2018-01-1136.1 ppb
2018-01-1115.3 ppb
2018-01-1116.5 ppb
2018-01-2422.5 ppb
2018-01-2421.6 ppb
2018-04-1010.4 ppb
2018-04-1018.2 ppb
2018-04-10ND
2018-04-10ND
2018-04-13ND
2018-04-13ND
2018-04-24ND
2018-04-24ND
2018-06-14ND
2018-07-05ND
2018-07-05ND
2018-07-058.10 ppb
2018-07-0512.3 ppb
2018-12-139.40 ppb
2019-03-15ND
2019-03-15ND
2019-03-15ND
2019-03-15ND
2019-03-25ND
2019-03-25ND
2019-06-12ND
2019-06-12ND
2019-06-1225.6 ppb
2019-06-1221.2 ppb
2019-07-10ND
2019-07-1028.9 ppb
2019-07-10ND
2019-07-10ND
2019-10-10ND
2019-10-10ND