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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Dona Ana MDWCA

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

 

84

Samples

0

Samples exceeding legal limit (MCL)

19

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND120ND
20150.126 ppb162ND - 1.60 ppb
20160.192 ppb166ND - 1.60 ppb
20170.288 ppb123ND - 1.90 ppb
20180.636 ppb128ND - 2.50 ppb
20191.21 ppb1614ND - 4.40 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
2014-03-311404082-001AND
2014-03-311404055-001AND
2014-03-311404083-001AND
2014-03-311404081-001AND
2014-08-201408C33-001AND
2014-08-201408C17-001AND
2014-08-201408C35-001AND
2014-09-241409C74-001AND
2014-12-161412986-001AND
2014-12-161412985-001AND
2014-12-161412984-001AND
2014-12-161412987-001AND
2015-03-241503C67-001AND
2015-03-241503C16-001AND
2015-03-241503C69-001AND
2015-03-241503C68-001AND
2015-06-102015017185ND
2015-06-102015017187ND
2015-06-102015017186ND
2015-06-102015017184ND
2015-09-012015026201ND
2015-09-012015026199ND
2015-09-0120150262020.410 ppb
2015-09-012015026200ND
2015-12-1420150365851.60 ppb
2015-12-142015036582ND
2015-12-142015036584ND
2015-12-142015036583ND
2016-03-0820160068340.520 ppb
2016-03-0820160068320.190 ppb
2016-03-082016006833ND
2016-03-082016006835ND
2016-06-0920160164630.160 ppb
2016-06-092016016465ND
2016-06-092016016464ND
2016-06-0920160164620.1000 ppb
2016-09-1420160269720.500 ppb
2016-09-142016026974ND
2016-09-142016026973ND
2016-09-142016026971ND
2016-12-062016035276ND
2016-12-062016035278ND
2016-12-0620160352771.60 ppb
2016-12-062016035279ND
2017-03-3020170092100.350 ppb
2017-03-302017009212ND
2017-03-302017009213ND
2017-03-302017009211ND
2017-06-1320170173191.20 ppb
2017-06-132017017317ND
2017-06-132017017318ND
2017-06-222017018392ND
2017-09-062017025773ND
2017-09-062017025772ND
2017-09-062017025771ND
2017-09-1220170264401.90 ppb
2018-03-0720180067881.50 ppb
2018-03-0720180067870.200 ppb
2018-03-0720180067860.260 ppb
2018-03-0720180067850.230 ppb
2018-06-1220180163242.50 ppb
2018-06-122018016321ND
2018-06-122018016322ND
2018-06-122018016323ND
2018-12-042018033613ND
2018-12-0420180336140.280 ppb
2018-12-0420180336150.260 ppb
2018-12-0420180336272.40 ppb
2019-03-0620190056322.10 ppb
2019-03-0620190056330.260 ppb
2019-03-062019005634ND
2019-03-0620190056370.370 ppb
2019-06-0520190155551.20 ppb
2019-06-052019015556ND
2019-06-0520190155570.320 ppb
2019-06-0520190155582.20 ppb
2019-09-0920190253160.410 ppb
2019-09-0920190253180.640 ppb
2019-09-0920190253174.40 ppb
2019-09-0920190253150.530 ppb
2019-12-1220190351353.90 ppb
2019-12-1220190351340.240 ppb
2019-12-1220190351332.50 ppb
2019-12-1220190351320.340 ppb