Bromoform

Roche Harbor Water System Inc.

Bromoform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromoform 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	0.660 ppb	10	5	ND - 2.20 ppb
2015	1.20 ppb	5	4	ND - 4.00 ppb
2016	0.740 ppb	5	3	ND - 2.00 ppb
2017	1.32 ppb	5	5	0.500 ppb - 3.10 ppb
2018	0.720 ppb	5	3	ND - 1.50 ppb
2019	1.03 ppb	4	3	ND - 2.50 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.5 ppb

The EWG Health Guideline of 0.5 ppb for bromoform 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
2014-01-06	00612	ND
2014-02-04	04910	ND
2014-04-01	13662	ND
2014-05-06	19367	ND
2014-06-24	27755	0.600 ppb
2014-07-08	29679	2.10 ppb
2014-08-18	36662	2.20 ppb
2014-09-02	39409	0.700 ppb
2014-09-09	40509	ND
2014-10-06	44845	1.000 ppb
2015-01-06	00660	0.700 ppb
2015-04-06	14375	ND
2015-05-26	23697	0.700 ppb
2015-07-06	30421	4.00 ppb
2015-10-06	48112	0.600 ppb
2016-01-06		ND
2016-04-12		ND
2016-05-16		0.900 ppb
2016-07-05		2.00 ppb
2016-10-06		0.800 ppb
2017-01-10		0.500 ppb
2017-04-25		1.50 ppb
2017-05-18		0.900 ppb
2017-07-05		3.10 ppb
2017-10-04		0.600 ppb
2018-01-10		ND
2018-04-25		ND
2018-06-13		0.800 ppb
2018-07-10		1.30 ppb
2018-10-02		1.50 ppb
2019-01-02		0.900 ppb
2019-04-01		ND
2019-07-08		2.50 ppb
2019-10-07		0.700 ppb