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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

Logan 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.

 

24

Samples

0

Samples exceeding legal limit (MCL)

7

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20120.350 ppb61ND - 2.10 ppb
20130.380 ppb53ND - 0.700 ppb
20140.700 ppb21ND - 1.40 ppb
2015ND60ND
20160.700 ppb31ND - 2.10 ppb
20171.40 ppb21ND - 2.80 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
2012-08-15ND
2012-08-15ND
2012-08-15ND
2012-08-152.10 ppb
2012-08-15ND
2012-08-15ND
2013-08-06ND
2013-08-06ND
2013-08-070.500 ppb
2013-10-090.700 ppb
2013-10-090.700 ppb
2014-08-191.40 ppb
2014-08-19ND
2015-07-29ND
2015-07-29ND
2015-07-29ND
2015-07-29ND
2015-08-13ND
2015-08-13ND
2016-02-26ND
2016-08-22ND
2016-08-222.10 ppb
2017-08-152.80 ppb
2017-08-15ND