Dichloroacetic acid

Castaic Lake Water Agency

Dichloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids 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

191

Samples

Samples exceeding legal limit (MCL)

131

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	0.629 ppb	31	9	ND - 3.20 ppb
2015	0.484 ppb	32	10	ND - 3.00 ppb
2016	1.65 ppb	32	18	ND - 4.30 ppb
2017	2.75 ppb	32	31	ND - 4.20 ppb
2018	3.56 ppb	32	32	1.30 ppb - 6.10 ppb
2019	3.30 ppb	32	31	ND - 6.40 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.2 ppb

The EWG Health Guideline of 0.2 ppb for dichloroacetic acid was proposed in 2020 by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk.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	9590-805-1105	ND
2014-01-13	9590-807-1240	ND
2014-01-14	9590-800-0950	ND
2014-01-14	9590-801-1045	ND
2014-01-14	9590-809-1010	ND
2014-01-15	9590-802-1005	ND
2014-01-15	9590-804-0930	ND
2014-01-15	9590-806-1025	ND
2014-04-14	9590-805-1230	1.80 ppb
2014-04-14	9590-807-1335	2.30 ppb
2014-04-15	9590-800-1040	2.30 ppb
2014-04-15	9590-801-1105	3.20 ppb
2014-04-16	9590-802-1205	2.30 ppb
2014-04-16	9590-804-1055	2.80 ppb
2014-04-16	9590-806-1225	2.00 ppb
2014-07-14	9590-805-1205	ND
2014-07-14	9590-807-1330	ND
2014-07-15	9590-800-1030	ND
2014-07-15	9590-801-1115	1.50 ppb
2014-07-15	9590-809-1100	1.30 ppb
2014-07-16	9590-802-1200	ND
2014-07-16	9590-804-1045	ND
2014-07-16	9590-806-1230	ND
2014-10-14	9590-800-1040	ND
2014-10-14	9590-801-1125	ND
2014-10-14	9590-809-1100	ND
2014-10-15	9590-802-1100	ND
2014-10-15	9590-804-1020	ND
2014-10-15	9590-806-1125	ND
2014-10-16	9590-805-1050	ND
2014-10-16	9590-807-1300	ND
2015-01-12	9588-805-1055	ND
2015-01-12	9588-807-1305	ND
2015-01-13	9588-800-1015	ND
2015-01-13	9588-801-1150	ND
2015-01-13	9588-809-1040	ND
2015-01-14	9588-802-1105	ND
2015-01-14	9588-804-1020	ND
2015-01-14	9588-806-1130	ND
2015-04-13	9590-805-1130	ND
2015-04-13	9590-807-1305	3.00 ppb
2015-04-14	9590-800-1055	ND
2015-04-14	9590-801-1135	ND
2015-04-14	9590-809-1115	ND
2015-04-15	9590-802-1220	ND
2015-04-15	9590-804-1100	ND
2015-04-15	9590-806-1255	ND
2015-07-15	9590-802-0815	ND
2015-07-15	9590-804-0735	ND
2015-07-15	9590-806-0835	ND
2015-07-16	9590-805-1015	ND
2015-07-16	9590-807-1255	1.20 ppb
2015-07-17	9590-800-0945	ND
2015-07-17	9590-801-1010	ND
2015-07-17	9590-809-0955	ND
2015-10-13	9590-800-1020	1.40 ppb
2015-10-13	9590-801-1110	1.20 ppb
2015-10-13	9590-806-1135	1.40 ppb
2015-10-13	9590-809-1050	2.00 ppb
2015-10-14	9590-802-1110	1.20 ppb
2015-10-14	9590-804-1030	1.40 ppb
2015-10-15	9590-805-1020	1.10 ppb
2015-10-15	9590-807-1250	1.60 ppb
2016-02-08	9590-805-1250	1.60 ppb
2016-02-08	9590-807-1435	1.70 ppb
2016-02-09	9590-800-1020	2.30 ppb
2016-02-09	9590-801-1105	1.70 ppb
2016-02-09	9590-809-1045	1.80 ppb
2016-02-10	9590-802-1055	3.10 ppb
2016-02-10	9590-804-1015	2.60 ppb
2016-02-10	9590-806-1120	2.80 ppb
2016-04-11	9590-805-1225	ND
2016-04-11	9590-807-1405	ND
2016-04-12	9590-800-1040	ND
2016-04-12	9590-801-1120	3.60 ppb
2016-04-12	9590-809-1100	3.50 ppb
2016-04-13	9590-802-0805	ND
2016-04-13	9590-804-0735	ND
2016-04-13	9590-806-0855	ND
2016-07-11	9590-011-0925	ND
2016-07-11	9590-807-1110	ND
2016-07-12	9590-800-0930	ND
2016-07-12	9590-801-1030	ND
2016-07-12	9590-809-0955	ND
2016-07-13	9590-802-1045	ND
2016-07-13	9590-804-1010	ND
2016-07-13	9590-806-1110	ND
2016-10-10	9590-805-1155	4.20 ppb
2016-10-10	9590-807-1340	4.30 ppb
2016-10-11	9590-800-1030	2.40 ppb
2016-10-11	9590-801-1120	3.00 ppb
2016-10-11	9590-809-1055	3.70 ppb
2016-10-12	9590-802-1130	3.40 ppb
2016-10-12	9590-804-1045	3.80 ppb
2016-10-12	9590-806-1200	3.20 ppb
2017-01-10	9590-800-1020	2.50 ppb
2017-01-10	9590-801-1110	2.10 ppb
2017-01-10	9590-809-1035	ND
2017-01-11	9590-802-1235	2.10 ppb
2017-01-11	9590-804-1150	1.60 ppb
2017-01-11	9590-806-1305	3.10 ppb
2017-01-12	9590-805-1200	2.70 ppb
2017-01-12	9590-807-1430	2.80 ppb
2017-04-10	9590-805-1145	2.20 ppb
2017-04-10	9590-807-1340	2.80 ppb
2017-04-11	9590-800-1050	2.20 ppb
2017-04-11	9590-801-1135	2.60 ppb
2017-04-11	9590-803-1120	2.40 ppb
2017-04-12	9590-802-1100	2.00 ppb
2017-04-12	9590-804-1015	1.40 ppb
2017-04-12	9590-806-1130	1.60 ppb
2017-07-10	9590-805-1235	2.60 ppb
2017-07-10	9590-807-1425	2.80 ppb
2017-07-11	9590-800-1015	3.40 ppb
2017-07-11	9590-801-1100	3.70 ppb
2017-07-11	9590-809-1035	3.50 ppb
2017-07-12	9590-802-0845	2.50 ppb
2017-07-12	9590-804-0805	2.80 ppb
2017-07-12	9590-806-0900	2.90 ppb
2017-10-10	9590-800-1025	3.60 ppb
2017-10-10	9590-801-1105	4.20 ppb
2017-10-10	9590-809-1045	3.90 ppb
2017-10-11	9590-802-1005	3.70 ppb
2017-10-11	9590-804-0935	4.10 ppb
2017-10-11	9590-806-1025	3.80 ppb
2017-10-12	9590-805-1030	3.60 ppb
2017-10-12	9590-807-1255	2.80 ppb
2018-01-09	9590-800-1045	2.00 ppb
2018-01-09	9590-801-1120	2.80 ppb
2018-01-09	9590-809-1100	1.40 ppb
2018-01-10	9590-802-1055	2.30 ppb
2018-01-10	9590-804-1010	2.40 ppb
2018-01-10	9590-806-1115	1.70 ppb
2018-01-11	9590-805-1205	4.20 ppb
2018-01-11	9590-807-1420	4.40 ppb
2018-04-09	9590-805-1210	2.20 ppb
2018-04-09	9590-807-1415	2.20 ppb
2018-04-10	9590-800-1000	5.40 ppb
2018-04-10	9590-801-1040	5.10 ppb
2018-04-10	9590-803-1020	5.00 ppb
2018-04-11	9590-802-1140	5.20 ppb
2018-04-11	9590-804-1045	5.60 ppb
2018-04-11	9590-806-1210	6.10 ppb
2018-07-09	9590-805-1020	2.30 ppb
2018-07-09	9590-807-1310	3.40 ppb
2018-07-10	9590-800-1015	5.00 ppb
2018-07-10	9590-801-1055	4.60 ppb
2018-07-10	9590-809-1040	4.70 ppb
2018-07-11	9590-802-1220	3.60 ppb
2018-07-11	9590-804-1040	3.60 ppb
2018-07-11	9590-806-1245	3.30 ppb
2018-10-08	9590-805-1225	1.30 ppb
2018-10-08	9590-807-1420	2.20 ppb
2018-10-09	9590-800-1010	3.80 ppb
2018-10-09	9590-801-1100	3.90 ppb
2018-10-09	9590-803-1040	3.70 ppb
2018-10-10	9590-802-1050	3.50 ppb
2018-10-10	9590-804-1015	3.60 ppb
2018-10-10	9590-806-1125	3.40 ppb
2019-01-14	9590-805-1200	2.20 ppb
2019-01-14	9590-807-1355	3.20 ppb
2019-01-15	9590-800-1000	4.60 ppb
2019-01-15	9590-801-1055	4.20 ppb
2019-01-15	9590-809-1035	3.60 ppb
2019-01-16	9590-802-1110	4.00 ppb
2019-01-16	9590-804-1030	4.00 ppb
2019-01-16	9590-806-1150	6.00 ppb
2019-04-08	9590-805-1150	2.40 ppb
2019-04-08	9590-807-1350	4.20 ppb
2019-04-09	9590-800-1010	5.20 ppb
2019-04-09	9590-801-1050	5.00 ppb
2019-04-09	9590-809-1035	4.60 ppb
2019-04-10	9590-802-1035	4.20 ppb
2019-04-10	9590-804-0955	4.90 ppb
2019-04-10	9590-806-1105	6.40 ppb
2019-07-08	9590-805-1230	1.60 ppb
2019-07-08	9590-807-1405	2.40 ppb
2019-07-09	9590-800-1000	1.20 ppb
2019-07-09	9590-801-1055	1.000 ppb
2019-07-09	9590-809-1030	ND
2019-07-10	9590-802-1120	1.50 ppb
2019-07-10	9590-804-1045	1.60 ppb
2019-07-10	9590-806-1155	1.40 ppb
2019-10-14	9590-805-1210	2.60 ppb
2019-10-14	9590-807-1400	3.50 ppb
2019-10-15	9590-800-1055	3.30 ppb
2019-10-15	9590-801-1140	3.30 ppb
2019-10-15	9590-809-1120	3.20 ppb
2019-10-16	9590-802-1130	3.10 ppb
2019-10-16	9590-804-1055	2.90 ppb
2019-10-16	9590-806-1210	4.30 ppb