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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

Newhall Cwd-pinetree

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.

 

55

Samples

0

Samples exceeding legal limit (MCL)

27

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20120.133 ppb91ND - 1.20 ppb
20130.200 ppb112ND - 1.10 ppb
20140.670 ppb105ND - 1.80 ppb
20150.625 ppb83ND - 2.20 ppb
20161.56 ppb87ND - 3.70 ppb
20173.13 ppb991.50 ppb - 7.20 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
2012-01-129590-001-1030ND
2012-02-099590-003-1120ND
2012-02-099590-001-1155ND
2012-02-099590-008-1100ND
2012-05-109590-001-0916ND
2012-07-129590-800-1115ND
2012-07-129590-801-1200ND
2012-10-109590-801-10151.20 ppb
2012-10-109590-800-0945ND
2013-01-109590-801-1010ND
2013-01-109590-800-1025ND
2013-02-149590-003-1015ND
2013-02-149590-008-1034ND
2013-02-149590-001-1025ND
2013-04-119590-801-1020ND
2013-04-119590-800-0950ND
2013-07-119590-800-0930ND
2013-07-119590-801-1005ND
2013-10-109590-800-09481.10 ppb
2013-10-109590-801-10041.10 ppb
2014-01-169590-800-0920ND
2014-01-169590-801-0955ND
2014-02-139590-008-1300ND
2014-02-139590-003-1235ND
2014-04-109590-800-10501.20 ppb
2014-04-109590-801-11101.30 ppb
2014-07-179590-800-0827ND
2014-07-179590-801-08451.30 ppb
2014-10-169590-801-10351.10 ppb
2014-10-169590-800-10001.80 ppb
2015-01-159590-800-0900ND
2015-01-159590-801-09251.10 ppb
2015-04-239590-800-1320ND
2015-04-239590-801-1331ND
2015-07-169590-800-0900ND
2015-07-169590-801-1000ND
2015-10-159590-801-09052.20 ppb
2015-10-159590-800-08401.70 ppb
2016-01-149590-801-09101.20 ppb
2016-01-149590-800-08501.40 ppb
2016-04-079590-801-11301.50 ppb
2016-04-079590-800-11001.40 ppb
2016-07-219590-801-10301.20 ppb
2016-07-219590-800-1010ND
2016-10-069590-801-09123.70 ppb
2016-10-069590-800-08502.10 ppb
2017-01-199590-801-09003.50 ppb
2017-01-199590-800-08303.50 ppb
2017-04-069590-008-09357.20 ppb
2017-04-139590-801-14252.10 ppb
2017-04-139590-800-11502.00 ppb
2017-07-139590-801-09152.00 ppb
2017-07-139590-800-09311.50 ppb
2017-10-199590-800-11452.90 ppb
2017-10-199590-801-12203.50 ppb