Bromodichloromethane

Grafton Water District

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

122

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	0.521 ppb	9	2	ND - 4.10 ppb
2015	9.15 ppb	26	17	ND - 22.0 ppb
2016	9.65 ppb	25	17	ND - 21.0 ppb
2017	4.07 ppb	13	6	ND - 14.0 ppb
2018	11.4 ppb	21	14	ND - 27.4 ppb
2019	9.17 ppb	28	20	ND - 19.4 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	Result
2014-01-29	ND
2014-04-07	0.590 ppb
2014-05-12	ND
2014-05-12	4.10 ppb
2014-05-12	ND
2014-05-12	ND
2014-05-12	ND
2014-07-15	ND
2014-11-03	ND
2015-01-21	ND
2015-02-04	16.0 ppb
2015-02-04	11.0 ppb
2015-02-04	12.0 ppb
2015-02-04	12.0 ppb
2015-04-14	ND
2015-04-14	3.40 ppb
2015-04-14	ND
2015-04-14	ND
2015-04-14	ND
2015-04-27	ND
2015-05-05	10.00 ppb
2015-05-05	13.0 ppb
2015-05-05	10.00 ppb
2015-05-05	8.60 ppb
2015-07-14	ND
2015-08-05	18.0 ppb
2015-08-05	22.0 ppb
2015-08-05	14.0 ppb
2015-08-05	17.0 ppb
2015-10-21	ND
2015-11-03	19.0 ppb
2015-11-03	22.0 ppb
2015-11-03	17.0 ppb
2015-11-03	13.0 ppb
2015-11-09	ND
2016-02-02	ND
2016-02-02	10.00 ppb
2016-02-02	9.90 ppb
2016-02-02	9.60 ppb
2016-02-02	14.0 ppb
2016-04-14	ND
2016-04-14	3.70 ppb
2016-04-14	ND
2016-04-14	ND
2016-04-14	ND
2016-05-02	11.0 ppb
2016-05-02	15.0 ppb
2016-05-02	10.00 ppb
2016-05-02	11.0 ppb
2016-06-09	ND
2016-07-20	ND
2016-08-03	17.0 ppb
2016-08-03	21.0 ppb
2016-08-03	13.0 ppb
2016-08-03	21.0 ppb
2016-10-07	ND
2016-11-01	19.0 ppb
2016-11-01	20.0 ppb
2016-11-01	17.0 ppb
2016-11-01	19.0 ppb
2017-02-14	14.0 ppb
2017-02-14	12.0 ppb
2017-02-14	10.00 ppb
2017-02-14	12.0 ppb
2017-02-22	ND
2017-02-22	ND
2017-05-03	0.570 ppb
2017-05-03	ND
2017-05-03	ND
2017-05-31	4.34 ppb
2017-05-31	ND
2017-05-31	ND
2017-10-17	ND
2018-02-14	ND
2018-04-19	ND
2018-04-19	4.94 ppb
2018-04-19	ND
2018-04-19	ND
2018-04-19	ND
2018-05-07	13.0 ppb
2018-05-07	17.0 ppb
2018-05-07	12.0 ppb
2018-05-07	15.0 ppb
2018-06-27	0.900 ppb
2018-08-02	ND
2018-08-02	22.4 ppb
2018-08-02	22.1 ppb
2018-08-02	18.3 ppb
2018-08-02	19.2 ppb
2018-11-06	ND
2018-11-06	25.8 ppb
2018-11-06	18.8 ppb
2018-11-06	23.5 ppb
2018-11-06	27.4 ppb
2019-01-16	ND
2019-02-08	18.4 ppb
2019-02-08	13.2 ppb
2019-02-08	14.2 ppb
2019-02-08	18.3 ppb
2019-02-26	ND
2019-05-07	15.3 ppb
2019-05-07	4.99 ppb
2019-05-07	10.6 ppb
2019-05-07	14.4 ppb
2019-05-08	2.89 ppb
2019-05-08	ND
2019-05-08	ND
2019-05-20	ND
2019-05-28	6.54 ppb
2019-05-28	ND
2019-08-06	4.32 ppb
2019-08-06	19.1 ppb
2019-08-06	19.4 ppb
2019-08-06	16.5 ppb
2019-08-06	9.19 ppb
2019-08-20	ND
2019-09-04	1.18 ppb
2019-10-22	ND
2019-11-04	15.6 ppb
2019-11-04	19.4 ppb
2019-11-04	15.7 ppb
2019-11-04	17.5 ppb