EWG's Tap Water Database — 2021 UPDATE



Hampton Water Association

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.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20142.05 ppb221.000 ppb - 3.10 ppb
20151.50 ppb221.20 ppb - 1.80 ppb
20160.850 ppb41ND - 3.40 ppb
20175.65 ppb221.60 ppb - 9.70 ppb
20182.40 ppb222.20 ppb - 2.60 ppb
20192.40 ppb112.40 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
2019-07-092.40 ppb