Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Chloroform

Riverside Highland Water Company

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

 

79

Samples

0

Samples exceeding legal limit (MCL)

42

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.407 ppb116ND - 0.870 ppb
20150.408 ppb106ND - 0.980 ppb
20160.503 ppb1811ND - 1.20 ppb
20170.546 ppb136ND - 1.60 ppb
20180.562 ppb128ND - 1.40 ppb
20190.580 ppb155ND - 1.90 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
2014-01-064790-011-0848ND
2014-07-024790-604-13340.830 ppb
2014-07-024790-601-1314ND
2014-07-024790-603-1300ND
2014-07-024790-602-13560.700 ppb
2014-07-074790-008-0830ND
2014-10-064790-604-14400.780 ppb
2014-10-064790-010-10410.870 ppb
2014-10-064790-601-13200.790 ppb
2014-10-064790-602-1400ND
2014-10-064790-603-14190.510 ppb
2015-01-064790-601-09360.570 ppb
2015-01-064790-604-10130.510 ppb
2015-01-064790-603-0906ND
2015-01-064790-602-1036ND
2015-04-014790-003-1000ND
2015-04-024790-601-08530.980 ppb
2015-10-024790-601-12210.910 ppb
2015-10-024790-604-12430.590 ppb
2015-10-024790-603-1319ND
2015-10-024790-602-13040.520 ppb
2016-01-054790-603-0749ND
2016-01-054790-604-08390.690 ppb
2016-01-054790-602-0814ND
2016-01-054790-601-0906ND
2016-04-054790-602-1112ND
2016-04-054790-601-10530.520 ppb
2016-04-054790-604-13020.650 ppb
2016-04-054790-603-1245ND
2016-07-064790-009-0945ND
2016-07-074790-604-10340.530 ppb
2016-07-074790-602-10051.000 ppb
2016-07-074790-603-1021ND
2016-07-074790-601-09501.20 ppb
2016-10-044790-012-08251.000 ppb
2016-10-054790-601-10410.920 ppb
2016-10-054790-604-09550.800 ppb
2016-10-054790-603-09300.640 ppb
2016-10-054790-602-10091.10 ppb
2017-01-054790-011-1030ND
2017-04-054790-601-08461.20 ppb
2017-04-054790-602-08310.580 ppb
2017-04-054790-603-0813ND
2017-04-054790-604-09010.920 ppb
2017-07-055810-603-0850ND
2017-07-055810-602-10411.40 ppb
2017-07-055810-604-1055ND
2017-07-055810-601-09551.60 ppb
2017-10-045810-601-09371.40 ppb
2017-10-045810-604-1058ND
2017-10-045810-603-1012ND
2017-10-045810-602-0955ND
2018-01-055810-601-10391.10 ppb
2018-01-055810-604-1231ND
2018-01-055810-603-0946ND
2018-01-055810-602-1016ND
2018-07-104790-604-13001.40 ppb
2018-07-104790-602-10410.590 ppb
2018-07-104790-601-12360.640 ppb
2018-07-104790-603-10100.540 ppb
2018-10-094790-601-10191.30 ppb
2018-10-094790-602-10360.620 ppb
2018-10-094790-603-1057ND
2018-10-094790-604-09560.550 ppb
2019-01-034790-603-1055ND
2019-01-034790-602-1033ND
2019-01-034790-601-10101.80 ppb
2019-04-084790-603-1309ND
2019-04-084790-604-14561.60 ppb
2019-04-084790-601-14161.80 ppb
2019-04-084790-602-1348ND
2019-07-034790-604-1441ND
2019-07-034790-603-1310ND
2019-07-034790-601-1353ND
2019-07-034790-602-1339ND
2019-10-024790-604-12461.60 ppb
2019-10-024790-603-0931ND
2019-10-024790-601-10241.90 ppb
2019-10-024790-602-1000ND