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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Sulphur Water System

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

 

196

Samples

0

Samples exceeding legal limit (MCL)

178

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.872 ppb3624ND - 1.50 ppb
20151.27 ppb32320.940 ppb - 1.80 ppb
20161.67 ppb32321.20 ppb - 2.20 ppb
20171.35 ppb3226ND - 2.40 ppb
20181.56 ppb32321.20 ppb - 2.20 ppb
20191.57 ppb32321.30 ppb - 2.20 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
2014-05-21L0043246-011.40 ppb
2014-05-21L0043246-021.40 ppb
2014-05-21L0043246-031.50 ppb
2014-05-21L0043246-041.30 ppb
2014-05-21L0043246-011.40 ppb
2014-05-21L0043246-021.40 ppb
2014-05-21L0043246-031.50 ppb
2014-05-21L0043246-041.30 ppb
2014-07-21AD93894ND
2014-07-21AD93895ND
2014-07-21AD93896ND
2014-07-21AD93897ND
2014-07-21AD93894ND
2014-07-21AD93895ND
2014-07-21AD93896ND
2014-07-21AD93897ND
2014-08-13L0046638-011.000 ppb
2014-08-13L0046638-021.10 ppb
2014-08-13L0046638-031.40 ppb
2014-08-13L0046638-041.40 ppb
2014-08-13L0046638-011.000 ppb
2014-08-13L0046638-021.10 ppb
2014-08-13L0046638-031.40 ppb
2014-08-13L0046638-041.40 ppb
2014-10-06AD98325ND
2014-10-06AD98326ND
2014-10-06AD98325ND
2014-10-06AD98326ND
2014-11-18L0050771-011.40 ppb
2014-11-18L0050771-021.10 ppb
2014-11-18L0050771-031.50 ppb
2014-11-18L0050771-041.20 ppb
2014-11-18L0050771-011.40 ppb
2014-11-18L0050771-021.10 ppb
2014-11-18L0050771-031.50 ppb
2014-11-18L0050771-041.20 ppb
2015-02-12LA3487-11.30 ppb
2015-02-12LA3487-20.980 ppb
2015-02-12LA3487-31.30 ppb
2015-02-12LA3487-40.980 ppb
2015-02-12LA3487-11.30 ppb
2015-02-12LA3487-20.980 ppb
2015-02-12LA3487-31.30 ppb
2015-02-12LA3487-40.980 ppb
2015-05-21LA7268-10.940 ppb
2015-05-21LA7268-20.960 ppb
2015-05-21LA7268-31.30 ppb
2015-05-21LA7268-41.20 ppb
2015-05-21LA7268-10.940 ppb
2015-05-21LA7268-20.960 ppb
2015-05-21LA7268-31.30 ppb
2015-05-21LA7268-41.20 ppb
2015-09-09LA11381-11.70 ppb
2015-09-09LA11381-21.50 ppb
2015-09-09LA11381-31.40 ppb
2015-09-09LA11381-41.80 ppb
2015-09-09LA11381-11.70 ppb
2015-09-09LA11381-21.50 ppb
2015-09-09LA11381-31.40 ppb
2015-09-09LA11381-41.80 ppb
2015-12-03LA14715-11.20 ppb
2015-12-03LA14715-21.40 ppb
2015-12-03LA14715-31.10 ppb
2015-12-03LA14715-41.30 ppb
2015-12-03LA14715-11.20 ppb
2015-12-03LA14715-21.40 ppb
2015-12-03LA14715-31.10 ppb
2015-12-03LA14715-41.30 ppb
2016-02-23LA17652-11.40 ppb
2016-02-23LA17652-21.20 ppb
2016-02-23LA17652-31.30 ppb
2016-02-23LA17652-41.20 ppb
2016-02-23LA17652-11.40 ppb
2016-02-23LA17652-21.20 ppb
2016-02-23LA17652-31.30 ppb
2016-02-23LA17652-41.20 ppb
2016-05-17LA20834-12.20 ppb
2016-05-17LA20834-22.00 ppb
2016-05-17LA20834-32.00 ppb
2016-05-17LA20834-42.00 ppb
2016-05-17LA20834-12.20 ppb
2016-05-17LA20834-22.00 ppb
2016-05-17LA20834-32.00 ppb
2016-05-17LA20834-42.00 ppb
2016-08-16LA24340-11.40 ppb
2016-08-16LA24340-21.70 ppb
2016-08-16LA24340-31.90 ppb
2016-08-16LA24340-42.20 ppb
2016-08-16LA24340-11.40 ppb
2016-08-16LA24340-21.70 ppb
2016-08-16LA24340-31.90 ppb
2016-08-16LA24340-42.20 ppb
2016-11-29LA28117-11.50 ppb
2016-11-29LA28117-21.60 ppb
2016-11-29LA28118-11.40 ppb
2016-11-29LA28118-21.70 ppb
2016-11-29LA28117-11.50 ppb
2016-11-29LA28117-21.60 ppb
2016-11-29LA28118-11.40 ppb
2016-11-29LA28118-21.70 ppb
2017-02-10352945740011.40 ppb
2017-02-1035294574002ND
2017-02-1035294574003ND
2017-02-1035294574004ND
2017-02-10352945740011.40 ppb
2017-02-1035294574002ND
2017-02-1035294574003ND
2017-02-1035294574004ND
2017-05-12353121270051.60 ppb
2017-05-12353121270062.40 ppb
2017-05-12353121270071.50 ppb
2017-05-12353121270082.00 ppb
2017-05-12353121270051.60 ppb
2017-05-12353121270062.40 ppb
2017-05-12353121270071.50 ppb
2017-05-12353121270082.00 ppb
2017-08-04353283600011.40 ppb
2017-08-04353283600021.90 ppb
2017-08-04353283600031.40 ppb
2017-08-04353283600042.10 ppb
2017-08-04353283600011.40 ppb
2017-08-04353283600021.90 ppb
2017-08-04353283600031.40 ppb
2017-08-04353283600042.10 ppb
2017-11-02353461800011.20 ppb
2017-11-02353461800021.70 ppb
2017-11-02353461800031.20 ppb
2017-11-02353461800041.80 ppb
2017-11-02353461800011.20 ppb
2017-11-02353461800021.70 ppb
2017-11-02353461800031.20 ppb
2017-11-02353461800041.80 ppb
2018-02-09353740530011.20 ppb
2018-02-09353740530021.60 ppb
2018-02-09353740530031.20 ppb
2018-02-09353740530041.60 ppb
2018-02-09353740530011.20 ppb
2018-02-09353740530021.60 ppb
2018-02-09353740530031.20 ppb
2018-02-09353740530041.60 ppb
2018-05-02353903190011.60 ppb
2018-05-02353903190021.80 ppb
2018-05-02353903190031.40 ppb
2018-05-02353903190041.40 ppb
2018-05-02353903190011.60 ppb
2018-05-02353903190021.80 ppb
2018-05-02353903190031.40 ppb
2018-05-02353903190041.40 ppb
2018-08-08354099080011.60 ppb
2018-08-08354099080021.60 ppb
2018-08-08354099080031.70 ppb
2018-08-08354099080042.00 ppb
2018-08-08354099080011.60 ppb
2018-08-08354099080021.60 ppb
2018-08-08354099080031.70 ppb
2018-08-08354099080042.00 ppb
2018-11-08354304280012.20 ppb
2018-11-08354304280021.50 ppb
2018-11-08354304280031.20 ppb
2018-11-08354304280041.30 ppb
2018-11-08354304280012.20 ppb
2018-11-08354304280021.50 ppb
2018-11-08354304280031.20 ppb
2018-11-08354304280041.30 ppb
2019-02-06354470770011.40 ppb
2019-02-06354470770021.60 ppb
2019-02-06354470770031.30 ppb
2019-02-06354470770041.50 ppb
2019-02-06354470770011.40 ppb
2019-02-06354470770021.60 ppb
2019-02-06354470770031.30 ppb
2019-02-06354470770041.50 ppb
2019-05-02354661360011.30 ppb
2019-05-02354661360021.50 ppb
2019-05-02354661360031.50 ppb
2019-05-02354661360041.50 ppb
2019-05-02354661360011.30 ppb
2019-05-02354661360021.50 ppb
2019-05-02354661360031.50 ppb
2019-05-02354661360041.50 ppb
2019-08-08354890160011.70 ppb
2019-08-08354890160022.20 ppb
2019-08-08354890160031.40 ppb
2019-08-08354890160041.70 ppb
2019-08-08354890160011.70 ppb
2019-08-08354890160022.20 ppb
2019-08-08354890160031.40 ppb
2019-08-08354890160041.70 ppb
2019-11-14355128570011.70 ppb
2019-11-14355128570021.60 ppb
2019-11-14355128570031.50 ppb
2019-11-14355128570041.70 ppb
2019-11-14355128570011.70 ppb
2019-11-14355128570021.60 ppb
2019-11-14355128570031.50 ppb
2019-11-14355128570041.70 ppb