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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Benbrook Water Authority

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

 

150

Samples

0

Samples exceeding legal limit (MCL)

112

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20148.74 ppb1816ND - 20.3 ppb
20158.56 ppb2921ND - 33.0 ppb
20167.43 ppb2617ND - 26.2 ppb
20176.06 ppb2619ND - 19.5 ppb
20184.55 ppb2617ND - 19.1 ppb
20197.69 ppb2522ND - 24.6 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
2014-03-14Q14084240018.30 ppb
2014-03-14Q14084240025.90 ppb
2014-03-14Q14084240032.00 ppb
2014-03-14Q1408424004ND
2014-06-23Q142342500120.3 ppb
2014-06-23Q142342500215.2 ppb
2014-06-23Q14234250039.00 ppb
2014-06-23Q1423425004ND
2014-08-14Q143687400510.6 ppb
2014-08-14Q14368740073.37 ppb
2014-08-14Q143687400916.5 ppb
2014-08-14Q143687401010.8 ppb
2014-08-14Q14368740117.90 ppb
2014-08-14Q14368740128.50 ppb
2014-10-28Q145431100115.3 ppb
2014-10-28Q145431100211.0 ppb
2014-10-28Q14543110038.60 ppb
2014-10-28Q14543110044.00 ppb
2015-02-04Q1504394006ND
2015-02-04Q1504394001ND
2015-02-04Q1504394004ND
2015-02-04Q15043940072.05 ppb
2015-02-04Q1504394010ND
2015-02-04Q15043940114.40 ppb
2015-02-04Q15043940132.36 ppb
2015-02-04Q15043940295.00 ppb
2015-02-04Q15043940302.90 ppb
2015-02-04Q15043940317.60 ppb
2015-02-04Q15043940321.30 ppb
2015-04-30Q1515940001ND
2015-04-30Q15159400031.95 ppb
2015-04-30Q1515940006ND
2015-04-30Q151594001316.8 ppb
2015-04-30Q151594001415.5 ppb
2015-04-30Q15159400157.22 ppb
2015-04-30Q15159400162.44 ppb
2015-09-08Q153461700110.6 ppb
2015-09-08Q153461700333.0 ppb
2015-09-08Q153461700430.0 ppb
2015-09-08Q153461700531.0 ppb
2015-09-08Q1534617006ND
2015-09-08Q15346170079.76 ppb
2015-11-02Q154289800119.1 ppb
2015-11-02Q154289800216.3 ppb
2015-11-02Q154289800325.1 ppb
2015-11-02Q1542898004ND
2015-11-02Q15428980064.00 ppb
2016-01-21Q1602764001ND
2016-01-21Q1602764003ND
2016-01-21Q16027640229.15 ppb
2016-01-21Q16027640234.99 ppb
2016-01-21Q16027640249.67 ppb
2016-01-21Q1602764025ND
2016-05-04Q1617499002ND
2016-05-04Q1617499003ND
2016-05-04Q16174990051.51 ppb
2016-05-04Q1617499008ND
2016-05-04Q1617499009ND
2016-05-04Q161749902023.7 ppb
2016-05-04Q161749902116.7 ppb
2016-05-04Q161749902226.2 ppb
2016-05-04Q16174990235.40 ppb
2016-09-28Q16409820035.51 ppb
2016-09-28Q164098200525.9 ppb
2016-09-28Q164098200621.2 ppb
2016-09-28Q164098200116.1 ppb
2016-09-28Q1640982002ND
2016-11-21Q16508810065.86 ppb
2016-11-21Q16508810025.33 ppb
2016-12-12Q16538720037.94 ppb
2016-12-12Q16538720015.29 ppb
2016-12-12Q16538720042.75 ppb
2016-12-12Q1653872002ND
2017-01-31Q17042610021.32 ppb
2017-01-31Q17042610157.01 ppb
2017-01-31Q17042610165.24 ppb
2017-01-31Q17042610078.77 ppb
2017-01-31Q1704261017ND
2017-05-23Q172107000210.4 ppb
2017-05-23Q172107000314.3 ppb
2017-05-23Q172107000412.9 ppb
2017-05-23Q17210700051.20 ppb
2017-08-01Q1731488036ND
2017-08-01Q1731488011ND
2017-08-01Q1731488013ND
2017-08-01Q17314880162.94 ppb
2017-08-01Q17314880174.06 ppb
2017-08-01Q173148800514.5 ppb
2017-08-01Q173148800817.3 ppb
2017-08-01Q173148802319.5 ppb
2017-08-01Q1731488028ND
2017-08-02Q1732390008ND
2017-11-08Q17574590103.72 ppb
2017-11-08Q1757459019ND
2017-11-08Q17574590113.96 ppb
2017-11-08Q17574590288.13 ppb
2017-11-08Q17574590046.37 ppb
2017-11-08Q17574590297.51 ppb
2017-11-08Q17574590058.42 ppb
2018-02-01Q1804024015ND
2018-02-01Q1804024017ND
2018-02-01Q18040240021.27 ppb
2018-02-01Q1804024019ND
2018-02-01Q1804024004ND
2018-02-01Q18040240114.58 ppb
2018-02-01Q18040240252.57 ppb
2018-02-01Q18040240123.52 ppb
2018-02-01Q1804024026ND
2018-04-12Q1815334014ND
2018-04-12Q1815334007ND
2018-04-12Q1815334005ND
2018-04-12Q18153340129.00 ppb
2018-04-12Q18153340036.69 ppb
2018-04-12Q18153340155.35 ppb
2018-04-12Q18153340044.09 ppb
2018-07-19Q18287700022.01 ppb
2018-07-19Q18287700042.44 ppb
2018-07-19Q182877000811.0 ppb
2018-07-19Q182877000910.8 ppb
2018-07-19Q18287700018.96 ppb
2018-07-19Q1828770010ND
2018-10-31Q184368500419.1 ppb
2018-10-31Q184368500114.5 ppb
2018-10-31Q184368500210.9 ppb
2018-10-31Q18436850031.48 ppb
2019-01-29Q19040880092.41 ppb
2019-01-29Q1904088004ND
2019-01-29Q19040880101.29 ppb
2019-01-29Q19040880051.43 ppb
2019-01-29Q190408803113.0 ppb
2019-01-29Q19040880198.14 ppb
2019-01-29Q19040880326.19 ppb
2019-01-29Q19040880201.83 ppb
2019-05-20Q1926717001ND
2019-05-20Q1926717003ND
2019-05-20Q19267170051.46 ppb
2019-05-20Q192671701124.6 ppb
2019-05-20Q192671701223.0 ppb
2019-05-20Q192671701312.4 ppb
2019-05-20Q19267170141.32 ppb
2019-09-05Q19625920018.15 ppb
2019-09-05Q19625920036.78 ppb
2019-09-05Q196259200619.4 ppb
2019-09-05Q196259200720.7 ppb
2019-09-05Q196259200814.3 ppb
2019-09-05Q19625920091.44 ppb
2019-12-05Q19791610036.18 ppb
2019-12-05Q19791610045.45 ppb
2019-12-05Q19791610013.91 ppb
2019-12-05Q19791610028.97 ppb