Bromoform

Watertown Waterworks

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

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	0.122 ppb	5	3	ND - 0.230 ppb
2015	ND	3	0	ND
2016	0.0360 ppb	5	1	ND - 0.180 ppb
2017	0.105 ppb	4	1	ND - 0.420 ppb
2018	ND	5	0	ND
2019	0.0720 ppb	5	2	ND - 0.220 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
2014-05-05	783793	ND
2014-05-05	783790	0.230 ppb
2014-05-05	783787	ND
2014-08-25	813450	0.160 ppb
2014-08-25	813451	0.220 ppb
2015-04-20	855197	ND
2015-07-06	869382	ND
2015-07-06	869383	ND
2016-05-02	918945	ND
2016-05-02	918949	ND
2016-05-02	918947	0.180 ppb
2016-07-25	935614	ND
2016-07-25	935613	ND
2017-05-03	986655	ND
2017-05-03	986659	ND
2017-08-09	1010343	ND
2017-08-09	1010342	0.420 ppb
2018-02-12	1040467	ND
2018-04-09	1049313	ND
2018-04-09	1049315	ND
2018-08-06	1071630	ND
2018-08-06	1071631	ND
2019-03-20	1110824	ND
2019-03-20	1110828	ND
2019-03-20	1110826	0.140 ppb
2019-08-07	1139755	ND
2019-08-07	1139754	0.220 ppb