Chloroform

Ventura Water Department

Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Read More.

In addition to tap water disinfection, chloroform pollution in the environment also comes from industrial discharges from pulp and paper mills, and from urban wastewater effluent. Human studies show that chloroform damages the kidneys, liver and central nervous system. In animals, chloroform causes infertility, birth defects and cancer.

Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

188

Samples

Samples exceeding legal limit (MCL)

171

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2013	N/A	0	0	N/A
2014	15.5 ppb	27	24	ND - 24.1 ppb
2015	26.8 ppb	35	33	ND - 60.6 ppb
2016	16.7 ppb	32	32	7.00 ppb - 27.8 ppb
2017	17.0 ppb	36	31	ND - 26.1 ppb
2018	23.8 ppb	33	27	ND - 44.0 ppb
2019	19.1 ppb	25	24	ND - 33.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.4 ppb

The EWG Health Guideline of 0.4 ppb for chloroform 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	2911-035-1005	24.1 ppb
2014-01-13	2911-036-1045	18.6 ppb
2014-01-13	2911-037-1115	20.5 ppb
2014-01-13	2911-038-0920	20.5 ppb
2014-01-13	2911-039-0945	22.7 ppb
2014-01-13	2911-040-0835	18.9 ppb
2014-01-13	2911-041-0900	16.6 ppb
2014-01-13	2911-042-1100	18.6 ppb
2014-04-02	5867-006-1000	ND
2014-04-02	5867-007-1030	ND
2014-04-02	5867-031-1130	ND
2014-04-07	2911-035-0900	21.7 ppb
2014-04-07	2911-036-0850	20.6 ppb
2014-04-07	2911-037-0955	2.80 ppb
2014-04-07	2911-038-1015	22.3 ppb
2014-04-07	2911-039-0810	17.2 ppb
2014-04-07	2911-040-0835	13.6 ppb
2014-04-07	2911-041-0920	20.2 ppb
2014-04-07	2911-042-0940	23.1 ppb
2014-07-14	2911-035-1000	13.8 ppb
2014-07-14	2911-036-0940	12.2 ppb
2014-07-14	2911-037-1110	16.4 ppb
2014-07-14	2911-038-1215	17.6 ppb
2014-07-14	2911-039-0800	13.6 ppb
2014-07-14	2911-040-0930	12.4 ppb
2014-07-14	2911-041-1030	15.9 ppb
2014-07-14	2911-042-1050	14.7 ppb
2015-01-12	2911-035-1025	40.2 ppb
2015-01-12	2911-036-1005	40.3 ppb
2015-01-12	2911-037-1115	16.6 ppb
2015-01-12	2911-038-1050	35.2 ppb
2015-01-12	2911-039-0845	23.3 ppb
2015-01-12	2911-040-0925	40.3 ppb
2015-01-12	2911-041-1135	56.9 ppb
2015-01-12	2911-042-1050	16.3 ppb
2015-04-02	5867-035-1035	15.2 ppb
2015-04-02	5867-036-1000	19.1 ppb
2015-04-02	5867-037-1155	19.9 ppb
2015-04-02	5867-038-1410	21.6 ppb
2015-04-02	5867-039-0830	15.5 ppb
2015-04-02	5867-040-0930	19.3 ppb
2015-04-02	5867-041-1330	18.2 ppb
2015-04-02	5867-042-1115	19.6 ppb
2015-04-06	5867-027-1115	ND
2015-07-13	5867-035-0955	22.6 ppb
2015-07-13	5867-036-0930	21.4 ppb
2015-07-13	5867-037-1230	24.8 ppb
2015-07-13	5867-038-1205	29.9 ppb
2015-07-13	5867-039-1025	20.9 ppb
2015-07-13	5867-040-0900	22.3 ppb
2015-07-13	5867-041-1110	29.9 ppb
2015-07-13	5867-042-1135	30.3 ppb
2015-10-06	5867-027-0825	ND
2015-10-12	5867-035-1000	27.5 ppb
2015-10-12	5867-036-0940	26.3 ppb
2015-10-12	5867-037-1120	37.5 ppb
2015-10-12	5867-038-1150	39.6 ppb
2015-10-12	5867-039-0905	36.2 ppb
2015-10-12	5867-040-0925	27.6 ppb
2015-10-12	5867-041-1100	60.6 ppb
2015-10-12	5867-042-1030	37.2 ppb
2015-12-03	5867-041-1430	25.2 ppb
2016-01-19	2911-035-0925	13.9 ppb
2016-01-19	2911-036-0900	14.8 ppb
2016-01-19	2911-037-1210	23.3 ppb
2016-01-19	2911-038-1230	21.2 ppb
2016-01-19	2911-039-0820	21.4 ppb
2016-01-19	2911-040-0945	14.9 ppb
2016-01-19	2911-041-1045	19.7 ppb
2016-01-19	2911-042-1105	26.5 ppb
2016-04-04	2911-035-1330	23.8 ppb
2016-04-04	2911-036-1400	18.8 ppb
2016-04-04	2911-037-1445	20.8 ppb
2016-04-04	2911-038-1515	25.5 ppb
2016-04-04	2911-039-1300	15.8 ppb
2016-04-04	2911-040-1315	25.2 ppb
2016-04-04	2911-041-1415	26.7 ppb
2016-04-04	2911-042-1430	8.70 ppb
2016-07-13	2911-035-1050	12.8 ppb
2016-07-13	2911-036-1115	11.0 ppb
2016-07-13	2911-037-0920	12.6 ppb
2016-07-13	2911-038-0850	10.4 ppb
2016-07-13	2911-039-1200	7.00 ppb
2016-07-13	2911-040-1145	8.16 ppb
2016-07-13	2911-041-1020	9.70 ppb
2016-07-13	2911-042-0950	10.6 ppb
2016-10-11	2911-035-1015	13.0 ppb
2016-10-11	2911-036-0950	12.1 ppb
2016-10-11	2911-037-1215	7.10 ppb
2016-10-11	2911-038-0921	22.2 ppb
2016-10-11	2911-039-0837	16.1 ppb
2016-10-11	2911-040-0921	10.7 ppb
2016-10-11	2911-041-1050	21.8 ppb
2016-10-11	2911-042-1255	27.8 ppb
2017-01-17	2911-035-0915	21.5 ppb
2017-01-17	2911-036-0935	22.6 ppb
2017-01-17	2911-037-1110	18.5 ppb
2017-01-17	2911-038-1150	22.7 ppb
2017-01-17	2911-039-0850	16.2 ppb
2017-01-17	2911-040-0950	22.2 ppb
2017-01-17	2911-041-1020	19.1 ppb
2017-01-17	2911-042-1050	13.1 ppb
2017-04-03	5867-006-0815	ND
2017-04-03	5867-007-0830	ND
2017-04-03	5867-031-0955	ND
2017-04-12	2911-035-1205	21.3 ppb
2017-04-12	2911-036-1150	17.9 ppb
2017-04-12	2911-037-1315	23.0 ppb
2017-04-12	2911-038-1520	25.4 ppb
2017-04-12	2911-039-1005	17.9 ppb
2017-04-12	2911-040-1055	20.7 ppb
2017-04-12	2911-041-1230	21.4 ppb
2017-04-12	2911-042-1255	18.5 ppb
2017-04-18	5867-015-1000	ND
2017-07-10	2911-035-0905	22.2 ppb
2017-07-10	2911-036-0845	19.1 ppb
2017-07-10	2911-037-1020	19.3 ppb
2017-07-10	2911-038-1030	19.0 ppb
2017-07-10	2911-039-0805	16.0 ppb
2017-07-10	2911-040-0830	17.2 ppb
2017-07-10	2911-041-1000	17.9 ppb
2017-07-10	2911-042-0940	14.4 ppb
2017-10-09	2911-035-1105	24.6 ppb
2017-10-09	2911-036-1045	26.1 ppb
2017-10-09	2911-037-1205	21.2 ppb
2017-10-09	2911-038-1225	ND
2017-10-09	2911-039-1005	17.4 ppb
2017-10-09	2911-040-1030	23.2 ppb
2017-10-09	2911-041-1125	18.9 ppb
2017-10-09	2911-042-1145	14.6 ppb
2018-01-16	5867-035-1410	32.0 ppb
2018-01-16	5867-036-1440	35.0 ppb
2018-01-16	5867-037-1545	23.0 ppb
2018-01-16	5867-038-1605	ND
2018-01-16	5867-039-1425	25.0 ppb
2018-01-16	5867-040-1331	29.0 ppb
2018-01-16	5867-041-1500	23.0 ppb
2018-01-16	5867-042-1515	24.0 ppb
2018-04-12	5867-035-0945	44.0 ppb
2018-04-12	5867-036-0920	38.0 ppb
2018-04-12	5867-037-1100	8.00 ppb
2018-04-12	5867-038-1130	1.000 ppb
2018-04-12	5867-039-0820	32.0 ppb
2018-04-12	5867-040-0850	39.0 ppb
2018-04-12	5867-041-1015	34.0 ppb
2018-04-12	5867-042-1045	32.0 ppb
2018-07-16	5867-035-1100	32.0 ppb
2018-07-16	5867-036-1020	32.0 ppb
2018-07-16	5867-037-1300	ND
2018-07-16	5867-038-1330	ND
2018-07-16	5867-039-0930	27.0 ppb
2018-07-16	5867-040-0950	33.0 ppb
2018-07-16	5867-041-1140	34.0 ppb
2018-07-16	5867-042-1200	34.0 ppb
2018-10-19	5867-035-0940	30.0 ppb
2018-10-19	5867-036-0910	30.0 ppb
2018-10-19	5867-037-1210	ND
2018-10-19	5867-038-1250	ND
2018-10-19	5867-039-0855	27.0 ppb
2018-10-19	5867-040-1135	29.0 ppb
2018-10-19	5867-041-1015	31.0 ppb
2018-10-19	5867-042-1100	26.0 ppb
2018-12-26	5867-027-1005	ND
2019-01-25	5867-039-1450	7.00 ppb
2019-04-15	5867-035-1055	25.0 ppb
2019-04-15	5867-036-1020	23.0 ppb
2019-04-15	5867-037-1245	13.0 ppb
2019-04-15	5867-038-1320	7.00 ppb
2019-04-15	5867-039-0920	15.0 ppb
2019-04-15	5867-040-0950	23.0 ppb
2019-04-15	5867-041-1200	27.0 ppb
2019-04-15	5867-042-1132	27.0 ppb
2019-07-17	5867-035-0950	27.0 ppb
2019-07-17	5867-036-0915	32.0 ppb
2019-07-17	5867-037-1155	8.00 ppb
2019-07-17	5867-038-1120	ND
2019-07-17	5867-039-0820	14.0 ppb
2019-07-17	5867-040-0850	30.0 ppb
2019-07-17	5867-041-1020	16.0 ppb
2019-07-17	5867-042-1050	16.0 ppb
2019-10-22	5867-035-1010	30.0 ppb
2019-10-22	5867-036-0950	29.0 ppb
2019-10-22	5867-037-1220	22.0 ppb
2019-10-22	5867-038-1300	1.000 ppb
2019-10-22	5867-039-0850	12.0 ppb
2019-10-22	5867-040-0925	33.0 ppb
2019-10-22	5867-041-1130	28.0 ppb
2019-10-22	5867-042-1155	13.0 ppb