Dibromochloromethane

Midway W/a #1

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	1	0	ND
2015	0.368 ppb	8	2	ND - 1.50 ppb
2016	ND	8	0	ND
2017	ND	4	0	ND
2018	N/A	0	0	N/A
2019	ND	5	0	ND

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
2014-07-03	140704-002TH	ND
2015-03-11	150312-020TH	ND
2015-03-11	150312-019TH	ND
2015-06-24	150625-024TH	ND
2015-06-24	150625-023TH	ND
2015-09-16	150917-008TH	ND
2015-09-16	150917-007TH	ND
2015-12-09	151210-018TH	1.50 ppb
2015-12-09	151210-017TH	1.44 ppb
2016-03-16	160317-008TH	ND
2016-03-16	160317-007TH	ND
2016-06-09	160610-005TH	ND
2016-06-09	160610-006TH	ND
2016-09-12	160913-010TH	ND
2016-09-12	160913-009TH	ND
2016-12-27	161228-002TH	ND
2016-12-27	161228-001TH	ND
2017-06-26	170627-005TH	ND
2017-06-26	170627-004TH	ND
2017-12-18	171219-004TH	ND
2017-12-18	171219-003TH	ND
2019-03-05	190306-008TH	ND
2019-03-05	190306-007TH	ND
2019-07-29	190730-015TH	ND
2019-09-24	190925-002TH	ND
2019-09-24	190925-003TH	ND