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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

Centerville 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.

 

79

Samples

0

Samples exceeding legal limit (MCL)

42

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20122.23 ppb95ND - 10.5 ppb
20132.80 ppb43ND - 8.70 ppb
20142.72 ppb176ND - 19.5 ppb
20159.86 ppb147ND - 56.0 ppb
20165.51 ppb147ND - 40.1 ppb
201710.1 ppb2114ND - 63.4 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
2012-01-10ND
2012-01-10ND
2012-07-020.600 ppb
2012-07-02ND
2012-07-021.80 ppb
2012-10-016.60 ppb
2012-10-01ND
2012-10-010.600 ppb
2012-10-0110.5 ppb
2013-07-010.700 ppb
2013-07-011.80 ppb
2013-07-01ND
2013-07-018.70 ppb
2014-01-06ND
2014-01-06ND
2014-01-06ND
2014-01-061.60 ppb
2014-01-06ND
2014-01-060.700 ppb
2014-01-06ND
2014-04-072.30 ppb
2014-04-073.40 ppb
2014-07-0719.5 ppb
2014-07-07ND
2014-07-07ND
2014-07-07ND
2014-07-07ND
2014-07-0718.7 ppb
2014-08-10ND
2014-08-10ND
2015-01-055.90 ppb
2015-01-051.60 ppb
2015-04-0628.2 ppb
2015-04-06ND
2015-04-10ND
2015-07-0643.5 ppb
2015-07-060.600 ppb
2015-07-21ND
2015-07-21ND
2015-07-22ND
2015-07-22ND
2015-07-22ND
2015-10-052.30 ppb
2015-10-0556.0 ppb
2016-01-113.60 ppb
2016-01-11ND
2016-04-0423.0 ppb
2016-04-04ND
2016-06-15ND
2016-06-151.40 ppb
2016-07-05ND
2016-07-054.30 ppb
2016-07-05ND
2016-07-05ND
2016-10-03ND
2016-10-0340.1 ppb
2016-10-031.40 ppb
2016-10-033.40 ppb
2017-01-091.50 ppb
2017-01-094.40 ppb
2017-01-093.10 ppb
2017-01-091.40 ppb
2017-01-10ND
2017-01-10ND
2017-01-10ND
2017-02-22ND
2017-04-0337.9 ppb
2017-04-03ND
2017-04-030.700 ppb
2017-04-03ND
2017-04-030.600 ppb
2017-07-062.00 ppb
2017-07-061.10 ppb
2017-07-06ND
2017-07-0663.4 ppb
2017-10-0220.2 ppb
2017-10-0217.8 ppb
2017-10-0218.1 ppb
2017-10-0238.9 ppb