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EWG's Tap Water Database — 2021 UPDATE

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Bromoform

Walnut Creek SUD

Bromoform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromoform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

 

102

Samples

0

Samples exceeding legal limit (MCL)

64

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20144.38 ppb17172.70 ppb - 5.90 ppb
20150.818 ppb174ND - 3.70 ppb
2016ND170ND
20171.32 ppb179ND - 2.95 ppb
20183.14 ppb17171.97 ppb - 4.86 ppb
20192.32 ppb17171.48 ppb - 3.64 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.5 ppb

The EWG Health Guideline of 0.5 ppb for bromoform 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
2014-02-26Q14063680013.30 ppb
2014-02-26Q14063680022.70 ppb
2014-02-26Q14063680033.60 ppb
2014-02-26Q14063680043.06 ppb
2014-05-29Q14184040015.90 ppb
2014-05-29Q14184040023.70 ppb
2014-05-29Q14184040035.60 ppb
2014-05-29Q14184040045.20 ppb
2014-09-03Q14411340014.23 ppb
2014-09-03Q14411340035.40 ppb
2014-09-03Q14411340045.30 ppb
2014-09-03Q14411340055.30 ppb
2014-09-03Q14411340065.00 ppb
2014-12-01Q14577460014.20 ppb
2014-12-01Q14577460023.60 ppb
2014-12-01Q14577460034.30 ppb
2014-12-01Q14577460044.10 ppb
2015-03-03Q15079400033.50 ppb
2015-03-03Q15079400043.70 ppb
2015-03-03Q15079400053.60 ppb
2015-03-03Q15079400063.10 ppb
2015-06-02Q1520361001ND
2015-06-02Q1520361002ND
2015-06-02Q1520361003ND
2015-06-02Q1520361004ND
2015-09-15Q1535843002ND
2015-09-15Q1535843003ND
2015-09-15Q1535843004ND
2015-09-15Q1535843005ND
2015-09-15Q1535843006ND
2015-12-14Q1549778001ND
2015-12-14Q1549778002ND
2015-12-14Q1549778003ND
2015-12-14Q1549778004ND
2016-02-29Q1608183009ND
2016-02-29Q1608183010ND
2016-02-29Q1608183011ND
2016-02-29Q1608183012ND
2016-05-31Q1621276001ND
2016-05-31Q1621276002ND
2016-05-31Q1621276003ND
2016-05-31Q1621276004ND
2016-09-26Q1640029001ND
2016-09-26Q1640029003ND
2016-09-26Q1640029004ND
2016-09-26Q1640029005ND
2016-09-26Q1640029006ND
2016-12-14Q1654569001ND
2016-12-14Q1654569003ND
2016-12-14Q1654569002ND
2016-12-14Q1654569004ND
2017-02-13Q1706085002ND
2017-02-13Q1706085003ND
2017-02-13Q1706085006ND
2017-02-13Q1706085004ND
2017-05-22Q1720856001ND
2017-05-22Q1720856002ND
2017-05-22Q1720856003ND
2017-05-22Q1720856004ND
2017-08-28Q17387590032.25 ppb
2017-08-28Q17387590042.42 ppb
2017-08-28Q17387590061.74 ppb
2017-08-28Q17387590012.45 ppb
2017-08-28Q17387590052.58 ppb
2017-11-07Q17569500032.79 ppb
2017-11-07Q17569500012.57 ppb
2017-11-07Q17569500042.95 ppb
2017-11-07Q17569500022.69 ppb
2018-02-15Q18066650052.17 ppb
2018-02-15Q18066650062.33 ppb
2018-02-15Q18066650072.29 ppb
2018-02-15Q18066650081.97 ppb
2018-04-23Q18163860012.18 ppb
2018-04-23Q18163860032.27 ppb
2018-04-23Q18163860022.54 ppb
2018-05-02Q18177560012.20 ppb
2018-07-23Q18290230022.94 ppb
2018-07-23Q18290230054.58 ppb
2018-07-23Q18290230034.38 ppb
2018-07-23Q18290230064.86 ppb
2018-07-23Q18290230044.14 ppb
2018-10-16Q18410600013.46 ppb
2018-10-16Q18410600023.85 ppb
2018-10-16Q18410600033.76 ppb
2018-10-16Q18410600043.38 ppb
2019-01-22Q19030730071.94 ppb
2019-01-22Q19030730082.14 ppb
2019-01-22Q19030730091.96 ppb
2019-01-22Q19030730101.71 ppb
2019-04-23Q19162480032.68 ppb
2019-04-23Q19162480012.74 ppb
2019-04-23Q19162480042.59 ppb
2019-04-23Q19162480022.41 ppb
2019-08-22Q19584730011.53 ppb
2019-08-22Q19584730031.48 ppb
2019-08-22Q19584730042.22 ppb
2019-08-22Q19584730051.68 ppb
2019-08-22Q19584730061.58 ppb
2019-11-18Q19771200013.13 ppb
2019-11-18Q19771200023.64 ppb
2019-11-18Q19771200033.31 ppb
2019-11-18Q19771200042.66 ppb