EWG's Tap Water Database — 2021 UPDATE



Revere Water Department (MWRA)

Dibromochloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Dibromochloromethane 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
20140.334 ppb2612ND - 0.960 ppb
20150.700 ppb154141ND - 1.38 ppb
20160.812 ppb130129ND - 1.09 ppb
20170.959 ppb1301300.630 ppb - 1.22 ppb
20180.980 ppb145144ND - 1.39 ppb
20190.906 ppb136135ND - 1.25 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.1 ppb

The EWG Health Guideline of 0.1 ppb for dibromochloromethane 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 Result