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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

Lafayette

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.

 

132

Samples

0

Samples exceeding legal limit (MCL)

88

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20121.67 ppb3422ND - 6.70 ppb
20131.45 ppb2618ND - 4.50 ppb
20141.04 ppb189ND - 3.30 ppb
20151.48 ppb1814ND - 3.10 ppb
20161.51 ppb1812ND - 2.90 ppb
20171.46 ppb1813ND - 4.20 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
2012-02-15AH53445ND
2012-02-15AH534463.00 ppb
2012-02-15AH534471.20 ppb
2012-02-15AH534484.10 ppb
2012-02-15AH534491.70 ppb
2012-02-15AH534502.30 ppb
2012-02-15AH534511.70 ppb
2012-02-15AH534521.70 ppb
2012-05-08AH59995ND
2012-05-08AH59996ND
2012-05-30AH65611ND
2012-05-30AH656125.60 ppb
2012-05-30AH65613ND
2012-05-30AH656141.80 ppb
2012-05-30AH65615ND
2012-05-30AH656162.50 ppb
2012-05-30AH65617ND
2012-05-30AH65618ND
2012-08-27AH75892ND
2012-08-27AH758931.80 ppb
2012-08-27AH758943.40 ppb
2012-08-27AH758952.40 ppb
2012-08-27AH75896ND
2012-08-27AH758974.50 ppb
2012-08-27AH75898ND
2012-08-27AH758991.20 ppb
2012-11-15AH842032.00 ppb
2012-11-15AH842041.30 ppb
2012-11-15AH842052.50 ppb
2012-11-15AH842061.80 ppb
2012-11-15AH84207ND
2012-11-15AH842086.70 ppb
2012-11-15AH842092.30 ppb
2012-11-15AH842101.20 ppb
2013-03-12AH907371.40 ppb
2013-03-12AH907381.40 ppb
2013-03-12AH907391.10 ppb
2013-03-12AH907402.40 ppb
2013-03-12AH90741ND
2013-03-12AH907423.70 ppb
2013-03-12AH90743ND
2013-03-12AH907441.30 ppb
2013-05-14AI01532ND
2013-05-14AI015332.50 ppb
2013-05-14AI015341.20 ppb
2013-05-14AI015353.50 ppb
2013-05-14AI015361.70 ppb
2013-05-14AI015374.50 ppb
2013-05-14AI015381.60 ppb
2013-05-14AI015392.40 ppb
2013-05-21AI020500.790 ppb
2013-05-21AI02051ND
2013-09-18AI16140ND
2013-09-18AI161411.80 ppb
2013-09-18AI161422.00 ppb
2013-09-18AI161432.00 ppb
2013-12-19AI254672.30 ppb
2013-12-19AI25468ND
2013-12-19AI25469ND
2013-12-19AI25470ND
2014-03-20AI364851.80 ppb
2014-03-20AI364862.10 ppb
2014-03-20AI36487ND
2014-03-20AI36488ND
2014-05-14AI40538ND
2014-05-14AI40539ND
2014-06-16AI433203.00 ppb
2014-06-16AI433211.70 ppb
2014-06-16AI43322ND
2014-06-16AI43323ND
2014-09-16AI540373.30 ppb
2014-09-16AI540381.50 ppb
2014-09-16AI540392.20 ppb
2014-09-16AI540402.00 ppb
2014-12-17AI617321.20 ppb
2014-12-17AI61733ND
2014-12-17AI61734ND
2014-12-17AI61735ND
2015-03-18AI69326ND
2015-03-18AI693271.20 ppb
2015-03-18AI693281.50 ppb
2015-03-18AI693291.20 ppb
2015-04-07AI74279ND
2015-04-07AI74280ND
2015-06-16AI799193.10 ppb
2015-06-16AI799201.60 ppb
2015-06-16AI799212.90 ppb
2015-06-16AI799221.90 ppb
2015-09-15AI898112.40 ppb
2015-09-15AI89812ND
2015-09-15AI898132.30 ppb
2015-09-15AI898141.80 ppb
2015-12-15AJ029451.30 ppb
2015-12-15AJ029461.60 ppb
2015-12-15AJ029472.40 ppb
2015-12-15AJ029481.40 ppb
2016-03-15AJ082002.10 ppb
2016-03-15AJ082012.60 ppb
2016-03-15AJ082022.50 ppb
2016-03-15AJ082032.20 ppb
2016-05-11AJ12002ND
2016-05-11AJ12003ND
2016-06-14AJ141462.90 ppb
2016-06-14AJ141472.00 ppb
2016-06-14AJ141482.10 ppb
2016-06-14AJ141491.90 ppb
2016-09-21AJ284812.30 ppb
2016-09-21AJ284821.60 ppb
2016-09-21AJ284832.50 ppb
2016-09-21AJ28484ND
2016-12-20AJ372442.40 ppb
2016-12-20AJ37245ND
2016-12-20AJ37246ND
2016-12-20AJ37247ND
2017-03-20AJ483472.20 ppb
2017-03-20AJ483481.30 ppb
2017-03-20AJ483491.50 ppb
2017-03-20AJ483501.10 ppb
2017-06-21AJ58195ND
2017-06-21AJ58196ND
2017-06-21AJ582134.20 ppb
2017-06-21AJ582142.70 ppb
2017-06-21AJ582152.10 ppb
2017-06-21AJ582162.10 ppb
2017-09-18AJ682943.00 ppb
2017-09-18AJ682951.60 ppb
2017-09-18AJ682961.80 ppb
2017-09-18AJ682971.40 ppb
2017-12-18AJ75637ND
2017-12-18AJ756381.20 ppb
2017-12-18AJ75639ND
2017-12-18AJ75640ND