Bromoform

Leroy, City of

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	0.549 ppb	5	2	ND - 2.20 ppb
2015	0.408 ppb	4	2	ND - 0.970 ppb
2016	0.353 ppb	4	2	ND - 0.870 ppb
2017	0.768 ppb	4	3	ND - 1.10 ppb
2018	0.638 ppb	4	3	ND - 1.10 ppb
2019	0.335 ppb	4	2	ND - 0.790 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
2014-01-13	606646TF	ND
2014-03-11	76345	0.543 ppb
2014-06-11	126933	2.20 ppb
2014-09-15	194287	ND
2014-12-03	239110	ND
2015-03-17	297298	0.970 ppb
2015-06-09	345977	ND
2015-09-22	409827	ND
2015-12-21	464212	0.660 ppb
2016-03-02	501070	0.540 ppb
2016-06-15	563784	ND
2016-09-21	627676	ND
2016-12-14	674471	0.870 ppb
2017-03-15	724525	1.10 ppb
2017-06-20	781510	ND
2017-09-27	847833	1.10 ppb
2017-12-13	892230	0.870 ppb
2018-03-13	936807	1.10 ppb
2018-09-18	1045313	0.730 ppb
2018-09-18	1045312	0.720 ppb
2018-12-11	1089365	ND
2019-03-12	1134769	ND
2019-06-18	1187646	ND
2019-09-25	1247341	0.550 ppb
2019-12-17	1290997	0.790 ppb