Dibromochloromethane

Mcneil Island Water

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	0.200 ppb	4	1	ND - 0.800 ppb
2015	0.350 ppb	4	2	ND - 0.800 ppb
2016	0.320 ppb	5	3	ND - 0.600 ppb
2017	0.233 ppb	3	1	ND - 0.700 ppb
2018	0.450 ppb	4	3	ND - 0.700 ppb
2019	0.460 ppb	5	3	ND - 0.940 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
2014-03-31	73458	0.800 ppb
2014-05-27	73620	ND
2014-08-19	74011	ND
2014-11-18	74536	ND
2015-02-10	74742	ND
2015-05-08	74984	ND
2015-08-20	75351	0.600 ppb
2015-11-16	75681	0.800 ppb
2016-03-23		0.600 ppb
2016-05-11		0.500 ppb
2016-06-22		ND
2016-08-17		0.500 ppb
2016-11-22		ND
2017-03-30		ND
2017-06-30		ND
2017-10-27		0.700 ppb
2018-03-28		0.700 ppb
2018-06-19		0.510 ppb
2018-08-14		0.590 ppb
2018-11-07		ND
2019-04-10		ND
2019-05-15		ND
2019-06-12		0.690 ppb
2019-08-14		0.940 ppb
2019-11-13		0.670 ppb