Dichloroacetic acid

San Diego County Water Authority

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

124

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	0.632 ppb	22	9	ND - 2.00 ppb
2015	0.775 ppb	24	12	ND - 2.60 ppb
2016	1.19 ppb	18	11	ND - 3.60 ppb
2017	3.36 ppb	20	19	ND - 9.50 ppb
2018	2.47 ppb	22	22	1.20 ppb - 3.80 ppb
2019	2.99 ppb	18	17	ND - 9.60 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
2014-01-04	9590-003-1020	ND
2014-01-06	9590-003-1022	1.20 ppb
2014-02-05	9590-003-1030	1.30 ppb
2014-03-03	9590-003-1223	ND
2014-04-05	9590-003-1340	ND
2014-04-07	9590-003-1342	ND
2014-05-03	9590-003-1027	ND
2014-05-05	9590-003-1250	ND
2014-06-01	9590-003-0734	ND
2014-06-03	9590-003-0739	ND
2014-07-05	9590-003-1150	1.40 ppb
2014-07-07	9590-003-1230	2.00 ppb
2014-08-02	9590-003-1139	ND
2014-08-04	9590-003-1401	1.40 ppb
2014-09-06	9590-003-1012	ND
2014-09-08	9590-003-1030	1.80 ppb
2014-10-04	9590-003-1145	ND
2014-10-06	9590-003-1204	1.80 ppb
2014-11-03	9590-003-1319	ND
2014-11-05	9590-003-1320	1.60 ppb
2014-12-06	9590-003-1220	ND
2014-12-08	9590-003-1228	1.40 ppb
2015-01-03	9590-003-1200	ND
2015-01-05	9590-003-1205	ND
2015-02-01	9590-003-0818	ND
2015-02-03	9590-003-0900	ND
2015-03-15	9590-003-1000	ND
2015-03-17	9590-003-1356	1.30 ppb
2015-04-04	9590-003-0805	ND
2015-04-06	9590-003-1120	1.30 ppb
2015-05-05	9590-003-1045	ND
2015-05-07	9590-003-1051	1.30 ppb
2015-06-01	9590-003-1205	ND
2015-06-03	9590-003-1207	1.10 ppb
2015-07-09	9590-003-1050	ND
2015-07-09	9590-003-1108	1.30 ppb
2015-08-03	9590-003-1020	1.20 ppb
2015-08-05	9590-003-1023	1.60 ppb
2015-09-01	9590-003-1129	ND
2015-09-03	9590-003-1300	2.00 ppb
2015-10-03	9590-003-0731	ND
2015-10-05	9590-003-0725	2.10 ppb
2015-11-01	9590-003-0950	1.10 ppb
2015-11-03	9590-003-0955	2.60 ppb
2015-12-08	9590-003-0707	ND
2015-12-10	9590-003-0731	1.70 ppb
2016-01-14	9590-003-2129	ND
2016-01-16	9590-003-2140	ND
2016-02-09	9590-003-1405	1.50 ppb
2016-02-11	9590-003-1406	2.70 ppb
2016-03-19	9590-003-0818	ND
2016-03-21	9590-003-0823	ND
2016-04-05	9590-003-1059	1.10 ppb
2016-04-07	9590-003-1117	1.80 ppb
2016-05-01	9590-003-1203	ND
2016-05-03	9590-003-1230	1.40 ppb
2016-07-05	9590-003-1200	ND
2016-07-07	9590-003-1225	2.20 ppb
2016-08-01	9590-003-1100	3.60 ppb
2016-08-03	9590-003-1103	2.20 ppb
2016-10-01	9590-003-0721	ND
2016-10-03	9590-003-0723	1.60 ppb
2016-11-01	9590-003-1000	1.50 ppb
2016-11-03	9590-003-1017	1.90 ppb
2017-01-24	9590-003-1345	ND
2017-01-26	9590-003-1347	1.20 ppb
2017-03-25	9590-003-1028	2.60 ppb
2017-03-27	9590-003-1030	3.60 ppb
2017-04-01	9590-003-1013	4.50 ppb
2017-04-03	9590-003-1015	7.20 ppb
2017-05-01	9590-003-1000	5.20 ppb
2017-05-03	9590-003-1059	9.50 ppb
2017-07-04	9590-003-1000	2.90 ppb
2017-07-06	9590-003-1142	5.80 ppb
2017-08-01	9590-003-0830	1.70 ppb
2017-08-03	9590-003-0833	3.90 ppb
2017-09-05	9590-003-0730	2.10 ppb
2017-09-07	9590-003-0838	3.80 ppb
2017-10-01	9590-003-1133	1.60 ppb
2017-10-03	9590-003-1135	4.30 ppb
2017-11-26	9590-003-1100	1.000 ppb
2017-11-28	9590-003-1103	2.00 ppb
2017-12-05	9590-003-0845	1.60 ppb
2017-12-07	9590-003-0859	2.70 ppb
2018-01-01	9590-003-0900	2.00 ppb
2018-01-03	9590-003-0902	3.40 ppb
2018-02-03	9590-003-0551	2.80 ppb
2018-02-05	9590-003-0555	3.80 ppb
2018-03-19	9590-003-0900	3.70 ppb
2018-03-21	9590-003-0900	2.90 ppb
2018-04-01	9590-003-0900	1.60 ppb
2018-04-03	9590-003-0903	3.50 ppb
2018-05-06	9590-003-0900	1.30 ppb
2018-05-08	9590-003-0903	2.40 ppb
2018-06-26	9590-003-1300	1.30 ppb
2018-06-28	9590-003-1303	2.60 ppb
2018-07-15	9590-003-0755	1.70 ppb
2018-07-17	9590-003-0759	3.30 ppb
2018-08-04	9590-003-1115	1.40 ppb
2018-08-06	9590-003-1116	3.60 ppb
2018-09-02	9590-003-0930	1.80 ppb
2018-09-04	9590-003-0933	2.90 ppb
2018-10-01	9590-003-1000	1.20 ppb
2018-10-03	9590-003-1003	3.70 ppb
2018-11-01	9590-003-1052	1.40 ppb
2018-11-03	9590-003-1100	2.10 ppb
2019-04-21	9590-003-0808	7.60 ppb
2019-04-23	9590-003-0811	9.60 ppb
2019-05-15	9590-003-0800	3.50 ppb
2019-05-17	9590-003-1029	4.50 ppb
2019-06-17	9590-003-0636	1.90 ppb
2019-06-19	9590-003-0852	2.80 ppb
2019-07-01	9590-003-0735	2.40 ppb
2019-07-03	9590-003-0800	2.90 ppb
2019-08-08	9590-003-0855	3.50 ppb
2019-08-08	9590-003-1050	2.00 ppb
2019-09-03	9590-003-0734	1.20 ppb
2019-09-04	9590-003-0712	3.40 ppb
2019-10-01	9590-003-0720	1.60 ppb
2019-10-03	9590-003-0418	2.80 ppb
2019-11-04	9590-003-0708	ND
2019-11-06	9590-003-0621	1.20 ppb
2019-12-11	9590-003-0615	1.20 ppb
2019-12-13	9590-003-0610	1.80 ppb