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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Roslyn WD

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

 

115

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND300ND
2015ND80ND
2016ND140ND
2017ND160ND
2018ND250ND
2019ND220ND

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
2014-01-081401261-002-POCSND
2014-02-111402494-002-POCSND
2014-03-271403J26-002-POCSND
2014-04-141404A24-002-POCSND
2014-05-081405607-002-POCSND
2014-05-161405C18-002-POCSND
2014-05-161405C18-003-POCSND
2014-05-161405C18-005-POCSND
2014-05-161405C18-004-POCSND
2014-06-051406390-002-POCSND
2014-06-121406931-002-POCSND
2014-06-171406B96-002-POCSND
2014-06-241406H35-002-POCSND
2014-07-081407453-002-POCSND
2014-07-211407E33-002-POCSND
2014-07-231407G36-002-POCSND
2014-07-301407L12-002-POCSND
2014-08-051408195-002-POCSND
2014-08-121408739-002-POCSND
2014-08-131408868-002-POCSND
2014-08-211408F37-002-POCSND
2014-08-251408H19-002-POCSND
2014-09-041409267-002-POCSND
2014-09-111409890-002-POCSND
2014-09-181409E16-001-POCSND
2014-10-091410647-002-POCSND
2014-10-221410E31-002-POCSND
2014-11-101411665-002-POCSND
2014-11-211411E96-002-POCSND
2014-12-051412410-002-POCSND
2015-01-151501871-002-POCSND
2015-02-101502633-001-POCSND
2015-04-161504C10-002-POCSND
2015-04-231504I52-001-POCSND
2015-04-231504I52-002-POCSND
2015-05-011505031-002-POCSND
2015-05-281505K32-002-POCSND
2015-06-091506722-002-POCSND
2016-01-131604L15-001ND
2016-02-111602918-002ND
2016-02-111602918-001ND
2016-05-031605147-001ND
2016-06-221606L82-001ND
2016-07-181607D67-002ND
2016-07-191607E94-002ND
2016-08-161608E60-002ND
2016-08-231608L92-002ND
2016-09-201609F92-001ND
2016-09-291609P72-001ND
2016-10-11701661001ND
2016-11-15704522005-POCND
2016-12-14706837002ND
2017-01-04708255003-POCND
2017-02-157011343003ND
2017-04-067015144002ND
2017-04-197016340004ND
2017-04-197016340004-POCND
2017-05-107018231002ND
2017-05-127018516002-POCND
2017-06-067020424002-POCND
2017-07-217024907002-POCND
2017-08-167027363002-POCND
2017-08-287028346002-POCND
2017-09-287031248001-POCND
2017-11-137035525002-POCND
2017-11-167035924002-POCND
2017-12-017036957002-POCND
2017-12-017036961002-POCND
2018-01-117040222002-POCND
2018-01-197040884002-POCND
2018-02-087042437002ND
2018-02-277043967002-POCND
2018-03-087044819001ND
2018-03-137045126002ND
2018-04-057047399001-POCND
2018-05-077050698002ND
2018-05-307053122001ND
2018-06-127054579002ND
2018-06-277056403002ND
2018-07-177058450002ND
2018-07-197058782002-POCND
2018-07-267059540002-POCND
2018-08-037060299002-POCND
2018-08-077060662002-POCND
2018-08-097060947002-POCND
2018-09-177065090001ND
2018-09-197065305001ND
2018-10-177068227002ND
2018-10-257069045002ND
2018-11-157071210002ND
2018-11-287072146002ND
2018-12-047072741002ND
2018-12-127073713001ND
2019-01-087075818002ND
2019-01-237077366001ND
2019-02-147079548002ND
2019-02-157079807002ND
2019-03-047081159002ND
2019-04-117085552002ND
2019-04-257087227002ND
2019-05-077088362002ND
2019-06-047092008002ND
2019-06-137093546002ND
2019-06-147093737003ND
2019-07-117097203001ND
2019-07-257098830002-POCND
2019-08-0670100015002-POCND
2019-08-1470101279002ND
2019-09-1070104226002ND
2019-09-1270104647001ND
2019-09-2470106023002ND
2019-10-0970107824002-POCND
2019-10-1670108611002ND
2019-11-1370111657002ND
2019-11-1470111831002ND