Bromodichloromethane

Monona Waterworks

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	0.1000 ppb	5	1	ND - 0.500 ppb
2015	0.986 ppb	5	3	ND - 3.10 ppb
2016	0.842 ppb	5	2	ND - 3.50 ppb
2017	1.06 ppb	5	5	0.360 ppb - 2.90 ppb
2018	2.06 ppb	2	2	0.220 ppb - 3.90 ppb
2019	1.85 ppb	2	1	ND - 3.70 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
2014-09-02	154276001	ND
2014-09-02	154323001	ND
2014-09-05	155135001	ND
2014-09-25	159907001	0.500 ppb
2014-12-12	172471001	ND
2015-01-30	177607001	ND
2015-06-16	199937001	ND
2015-07-14	205376001	0.730 ppb
2015-07-14	205378001	3.10 ppb
2015-11-17	228870001	1.10 ppb
2016-02-01	237611001	ND
2016-04-06	247252001	0.710 ppb
2016-07-07	264567001	ND
2016-09-28	280796001	3.50 ppb
2016-10-20	285154001	ND
2017-03-30	306799001	0.740 ppb
2017-04-13	309656001	0.360 ppb
2017-04-13	309655001	0.440 ppb
2017-04-13	309654001	0.860 ppb
2017-09-22	344258001	2.90 ppb
2018-07-11	393604001	0.220 ppb
2018-09-25	410134001	3.90 ppb
2019-04-24	442084001	ND
2019-09-05	467810001	3.70 ppb