Dibromochloromethane

Duncan, Village of

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	ND	4	0	ND
2015	1.20 ppb	4	2	ND - 3.70 ppb
2016	0.161 ppb	5	1	ND - 0.805 ppb
2017	0.465 ppb	4	2	ND - 0.960 ppb
2018	0.195 ppb	4	1	ND - 0.780 ppb
2019	1.33 ppb	5	5	0.620 ppb - 3.45 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
2014-01-21	278561	ND
2014-04-07	293558	ND
2014-07-07	309828	ND
2014-10-06	328707	ND
2015-01-05	343430	ND
2015-04-06	353686	ND
2015-07-06	372092	3.70 ppb
2015-10-05	392382	1.10 ppb
2016-01-20		0.805 ppb
2016-04-04		ND
2016-07-05		ND
2016-09-19		ND
2016-10-11		ND
2017-03-06		0.960 ppb
2017-06-12		ND
2017-09-05		ND
2017-10-16		0.900 ppb
2018-01-02	530843	0.780 ppb
2018-04-03	542883	ND
2018-07-09	560193	ND
2018-10-15	577046	ND
2019-01-14	590577	1.09 ppb
2019-04-01	602878	0.890 ppb
2019-07-08	621137	0.620 ppb
2019-09-09	630435	3.45 ppb
2019-10-21	638589	0.620 ppb