Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Chloroform

Hudson Waterworks

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

 

90

Samples

0

Samples exceeding legal limit (MCL)

40

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.296 ppb73ND - 1.30 ppb
20150.681 ppb97ND - 2.30 ppb
20160.874 ppb1613ND - 2.80 ppb
20170.260 ppb2110ND - 0.960 ppb
20180.327 ppb1811ND - 1.20 ppb
20190.474 ppb1912ND - 1.60 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
2014-03-26776786ND
2014-03-26776789ND
2014-03-267767920.290 ppb
2014-03-31777341ND
2014-06-16797090ND
2014-08-188112130.480 ppb
2014-08-188112121.30 ppb
2015-02-04841974ND
2015-09-15883174ND
2015-09-158831720.210 ppb
2015-09-158831712.30 ppb
2015-09-158831731.20 ppb
2015-12-148979370.330 ppb
2015-12-148979361.000 ppb
2015-12-148979380.590 ppb
2015-12-148979390.500 ppb
2016-03-16910638ND
2016-03-169106372.00 ppb
2016-03-169106360.310 ppb
2016-03-169106350.630 ppb
2016-06-139265412.00 ppb
2016-06-139265420.270 ppb
2016-06-13926540ND
2016-06-139265390.480 ppb
2016-09-129448060.310 ppb
2016-09-129448071.10 ppb
2016-09-129448051.70 ppb
2016-09-129448042.80 ppb
2016-12-12965935ND
2016-12-129659320.750 ppb
2016-12-129659340.780 ppb
2016-12-129659330.860 ppb
2017-03-149778960.520 ppb
2017-03-149778990.440 ppb
2017-03-149778980.360 ppb
2017-03-14977897ND
2017-04-03980874ND
2017-04-03980878ND
2017-04-03980883ND
2017-04-04981146ND
2017-04-05981439ND
2017-06-13997246ND
2017-06-13997248ND
2017-06-139972450.420 ppb
2017-06-139972470.630 ppb
2017-09-111017337ND
2017-09-1110173350.670 ppb
2017-09-111017336ND
2017-09-111017334ND
2017-12-1210331210.260 ppb
2017-12-1210331190.490 ppb
2017-12-1210331200.720 ppb
2017-12-1210331180.960 ppb
2018-03-1910457260.290 ppb
2018-03-1910457290.500 ppb
2018-03-1910457270.210 ppb
2018-03-191045728ND
2018-06-1810620060.380 ppb
2018-06-1810620050.610 ppb
2018-06-1810620031.20 ppb
2018-06-181062004ND
2018-06-2510636500.550 ppb
2018-09-1110794370.420 ppb
2018-09-1110794380.470 ppb
2018-09-111079439ND
2018-09-111079436ND
2018-10-231088635ND
2018-12-111097181ND
2018-12-1110971830.330 ppb
2018-12-111097184ND
2018-12-1910984600.920 ppb
2019-02-261106795ND
2019-03-1911104090.320 ppb
2019-03-1911104070.340 ppb
2019-03-1911104080.700 ppb
2019-03-1911104100.710 ppb
2019-05-081119849ND
2019-06-181128939ND
2019-06-1811289370.770 ppb
2019-06-1811289380.760 ppb
2019-06-181128940ND
2019-08-061139065ND
2019-09-171148789ND
2019-09-1711487900.310 ppb
2019-09-1711487870.530 ppb
2019-09-1711487881.20 ppb
2019-12-091165055ND
2019-12-1611657590.360 ppb
2019-12-1611657601.40 ppb
2019-12-1611657611.60 ppb