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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

Magna Water District

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.

 

102

Samples

0

Samples exceeding legal limit (MCL)

75

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20127.65 ppb1210ND - 22.0 ppb
20136.30 ppb1814ND - 18.6 ppb
201412.0 ppb1613ND - 31.2 ppb
201514.9 ppb1611ND - 35.6 ppb
20167.53 ppb1711ND - 21.3 ppb
20177.49 ppb2316ND - 23.4 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
2012-05-298.03 ppb
2012-05-2910.7 ppb
2012-05-297.31 ppb
2012-05-29ND
2012-08-2816.6 ppb
2012-08-2822.0 ppb
2012-08-281.50 ppb
2012-08-28ND
2012-11-2611.8 ppb
2012-11-266.20 ppb
2012-11-265.70 ppb
2012-11-261.90 ppb
2013-02-080.600 ppb
2013-02-080.600 ppb
2013-02-269.63 ppb
2013-02-2610.1 ppb
2013-02-266.50 ppb
2013-02-26ND
2013-05-287.88 ppb
2013-05-2811.6 ppb
2013-05-28ND
2013-05-284.67 ppb
2013-08-268.66 ppb
2013-08-2610.1 ppb
2013-08-264.69 ppb
2013-08-26ND
2013-11-2511.0 ppb
2013-11-2518.6 ppb
2013-11-258.69 ppb
2013-11-25ND
2014-02-2510.8 ppb
2014-02-2513.1 ppb
2014-02-259.83 ppb
2014-02-25ND
2014-05-2024.4 ppb
2014-05-2031.2 ppb
2014-05-207.98 ppb
2014-05-20ND
2014-08-2514.7 ppb
2014-08-2514.2 ppb
2014-08-2510.4 ppb
2014-08-25ND
2014-11-1818.1 ppb
2014-11-1821.1 ppb
2014-11-1815.6 ppb
2014-11-180.595 ppb
2015-02-2316.2 ppb
2015-02-2420.9 ppb
2015-02-2423.6 ppb
2015-02-24ND
2015-05-2629.5 ppb
2015-05-2621.4 ppb
2015-05-2617.0 ppb
2015-05-26ND
2015-08-2617.7 ppb
2015-08-2620.5 ppb
2015-08-26ND
2015-08-26ND
2015-11-2334.9 ppb
2015-11-2335.6 ppb
2015-11-230.900 ppb
2015-11-23ND
2016-01-26ND
2016-02-2317.1 ppb
2016-02-230.700 ppb
2016-02-231.000 ppb
2016-02-23ND
2016-05-3114.2 ppb
2016-05-3113.7 ppb
2016-05-31ND
2016-05-31ND
2016-08-230.510 ppb
2016-08-23ND
2016-08-2319.0 ppb
2016-08-2321.3 ppb
2016-11-2119.5 ppb
2016-11-219.66 ppb
2016-11-21ND
2016-11-2111.4 ppb
2017-02-16ND
2017-02-226.80 ppb
2017-02-2214.7 ppb
2017-02-2211.6 ppb
2017-02-221.91 ppb
2017-02-27ND
2017-05-10ND
2017-05-101.70 ppb
2017-05-2220.7 ppb
2017-05-2221.9 ppb
2017-05-22ND
2017-05-2223.4 ppb
2017-07-111.10 ppb
2017-08-07ND
2017-08-07ND
2017-08-210.760 ppb
2017-08-2115.2 ppb
2017-08-2116.1 ppb
2017-08-218.23 ppb
2017-11-209.68 ppb
2017-11-208.41 ppb
2017-11-20ND
2017-11-209.98 ppb