Dibromochloromethane

Rio Waterworks

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.

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	0.118 ppb	5	1	ND - 0.590 ppb
2015	0.420 ppb	3	2	ND - 0.790 ppb
2016	0.270 ppb	3	1	ND - 0.810 ppb
2017	ND	4	0	ND
2018	1.33 ppb	3	2	ND - 2.00 ppb
2019	1.07 ppb	3	2	ND - 2.10 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	Lab ID	Result
2014-07-28	147663002	ND
2014-08-04	148747001	ND
2014-08-04	148748001	ND
2014-09-09	155868001	0.590 ppb
2014-09-09	155866001	ND
2015-02-09	178688001	ND
2015-08-12	211381001	0.470 ppb
2015-08-12	211382001	0.790 ppb
2016-07-21	267709001	ND
2016-08-31	274996001	0.810 ppb
2016-08-31	274994001	ND
2017-08-08	902547	ND
2017-08-08	902549	ND
2017-09-19	923296	ND
2017-09-19	923305	ND
2018-07-10	393175001	ND
2018-08-15	401207001	2.00 ppb
2018-08-15	401204001	2.00 ppb
2019-02-19	431942001	ND
2019-08-12	462739001	1.10 ppb
2019-08-12	462737001	2.10 ppb