Bromodichloromethane

Waterworks District 7

Bromodichloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromodichloromethane 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	ND	4	0	ND
2015	ND	4	0	ND
2016	0.965 ppb	4	4	0.540 ppb - 1.39 ppb
2017	0.715 ppb	4	4	0.700 ppb - 0.730 ppb
2018	1.32 ppb	4	4	0.930 ppb - 1.70 ppb
2019	0.460 ppb	4	2	ND - 0.920 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.06 ppb

The EWG Health Guideline of 0.06 ppb for bromodichloromethane 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
2014-08-05	1323129	ND
2014-08-05	1323128	ND
2014-08-05	1323129	ND
2014-08-05	1323128	ND
2015-06-25	1405769	ND
2015-06-25	1405769	ND
2015-06-25	1405770	ND
2015-06-25	1405770	ND
2016-05-05	1489002	0.540 ppb
2016-05-05	1489003	1.39 ppb
2016-05-05	1489003	1.39 ppb
2016-05-05	1489002	0.540 ppb
2017-05-05	35311308031	0.700 ppb
2017-05-05	35311308031	0.700 ppb
2017-05-05	35311308030	0.730 ppb
2017-05-05	35311308030	0.730 ppb
2018-05-10	35392006002	0.930 ppb
2018-05-10	35392006001	1.70 ppb
2018-05-10	35392006001	1.70 ppb
2018-05-10	35392006002	0.930 ppb
2019-05-01	35465767001	0.920 ppb
2019-05-01	35465767002	ND
2019-05-01	35465767001	0.920 ppb
2019-05-01	35465767002	ND