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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Maywood Mutual Water Company #3

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

 

80

Samples

0

Samples exceeding legal limit (MCL)

32

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20142.43 ppb149ND - 9.30 ppb
20151.10 ppb135ND - 4.30 ppb
20161.08 ppb145ND - 5.70 ppb
20170.762 ppb135ND - 3.00 ppb
20180.715 ppb135ND - 3.60 ppb
20190.862 ppb133ND - 7.70 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
2014-01-213761-801-13302.10 ppb
2014-01-213761-800-14002.50 ppb
2014-01-249588-004-1412ND
2014-01-249588-009-1340ND
2014-04-033761-801-09004.60 ppb
2014-04-033761-800-09204.90 ppb
2014-04-229588-004-0913ND
2014-07-103761-801-08553.90 ppb
2014-07-103761-800-09059.30 ppb
2014-07-179588-004-1010ND
2014-10-083761-801-10202.40 ppb
2014-10-083761-800-10002.10 ppb
2014-11-259588-009-1445ND
2014-12-109588-004-09242.20 ppb
2015-01-093761-801-0845ND
2015-01-093761-800-08304.30 ppb
2015-01-279588-009-0930ND
2015-01-279588-004-0943ND
2015-04-079588-004-1212ND
2015-04-093761-801-13452.70 ppb
2015-04-093761-800-13303.00 ppb
2015-07-083761-801-0830ND
2015-07-083761-800-0845ND
2015-07-289588-004-0942ND
2015-10-083761-801-09202.20 ppb
2015-10-083761-800-09002.10 ppb
2015-10-279588-004-0947ND
2016-01-143761-801-1130ND
2016-01-143761-800-11102.70 ppb
2016-03-239588-009-1027ND
2016-03-239588-004-1014ND
2016-04-183761-801-1500ND
2016-04-183761-800-15152.60 ppb
2016-05-049588-009-0952ND
2016-05-049588-004-1010ND
2016-07-073761-800-08451.80 ppb
2016-07-073761-801-08155.70 ppb
2016-08-169588-004-0951ND
2016-10-063761-801-1340ND
2016-10-063761-800-14002.30 ppb
2016-10-119588-004-1010ND
2017-01-123761-801-1150ND
2017-01-123761-800-12503.00 ppb
2017-01-139588-009-0955ND
2017-01-139588-004-0940ND
2017-04-059588-004-0930ND
2017-04-063761-801-11302.40 ppb
2017-04-063761-800-11102.20 ppb
2017-07-053761-801-0920ND
2017-07-053761-800-0850ND
2017-07-119588-004-0946ND
2017-10-053761-801-09341.000 ppb
2017-10-053761-800-09151.30 ppb
2017-10-129588-004-0935ND
2018-01-123761-801-0940ND
2018-01-123761-800-09551.10 ppb
2018-01-259588-004-0930ND
2018-01-259588-009-0945ND
2018-04-053761-801-0810ND
2018-04-053761-800-08301.000 ppb
2018-04-109588-004-0950ND
2018-07-053761-801-0945ND
2018-07-053761-800-10002.10 ppb
2018-07-279588-004-0900ND
2018-10-033761-801-14053.60 ppb
2018-10-033761-800-14151.50 ppb
2018-10-309588-004-0939ND
2019-01-103761-801-13457.70 ppb
2019-01-103761-800-1400ND
2019-01-299588-009-0940ND
2019-01-299588-004-1030ND
2019-04-183761-801-15402.00 ppb
2019-04-183761-800-1520ND
2019-05-039588-004-0910ND
2019-07-103761-801-13151.50 ppb
2019-07-103761-800-1340ND
2019-07-169588-004-0945ND
2019-10-023761-801-1325ND
2019-10-023761-800-1400ND
2019-10-299588-004-1020ND