EWG's Tap Water Database — 2021 UPDATE


Bromodichloroacetic acid

Emma PWS

Bromodichloroacetic acid is formed when chlorine or other disinfectants are used to treat drinking water. Bromodichloroacetic acid and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20147.17 ppb226.85 ppb - 7.49 ppb
20156.81 ppb442.43 ppb - 10.6 ppb
20164.17 ppb441.92 ppb - 5.77 ppb
20173.22 ppb442.18 ppb - 4.34 ppb
20183.88 ppb441.11 ppb - 5.51 ppb
20193.30 ppb87ND - 6.43 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.04 ppb

The EWG Health Guideline of 0.04 ppb for bromodichloroacetic acid was defined in a peer-reviewed scientific study by EWG and represents a on-in-a-million lifetime cancer risk level. This health guideline protects against cancer.

ppb = parts per billion

All test results

Date Lab ID Result
2014-07-23AC305136.85 ppb
2014-10-21AC375857.49 ppb
2015-01-20AC403097.53 ppb
2015-05-07AC449936.67 ppb
2015-07-14AC541962.43 ppb
2015-10-13AC6115210.6 ppb
2016-01-06AC649573.83 ppb
2016-04-12AC693165.77 ppb
2016-09-06AC837321.92 ppb
2016-10-17AC862265.14 ppb
2017-01-09AC890383.82 ppb
2017-04-05AC944052.52 ppb
2017-07-10AD013124.34 ppb
2017-10-09AD078412.18 ppb
2018-01-18AD112854.20 ppb
2018-04-24AD179564.70 ppb
2018-07-08AD290921.11 ppb
2018-10-16AD343645.51 ppb
2019-01-09AD376753.02 ppb
2019-04-10AD460955.87 ppb
2019-06-05AD497535.28 ppb
2019-07-17AD517086.43 ppb
2019-07-17AD517092.25 ppb
2019-10-10AD566782.24 ppb
2019-10-10AD566791.27 ppb