Dichloroacetic acid

City of Santa Clara

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

202

Samples

Samples exceeding legal limit (MCL)

157

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	5.60 ppb	32	22	ND - 18.0 ppb
2015	6.21 ppb	26	18	ND - 20.0 ppb
2016	11.3 ppb	40	32	ND - 27.0 ppb
2017	9.14 ppb	32	27	ND - 24.0 ppb
2018	9.01 ppb	40	34	ND - 28.0 ppb
2019	8.47 ppb	32	24	ND - 33.0 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
2014-01-22	9590-900-1044	7.70 ppb
2014-01-22	9590-901-1030	5.00 ppb
2014-01-22	9590-902-1105	7.30 ppb
2014-01-22	9590-903-1015	ND
2014-01-22	9590-904-0935	ND
2014-01-22	9590-905-0834	1.30 ppb
2014-01-22	9590-906-0854	2.60 ppb
2014-01-22	9590-907-0955	1.70 ppb
2014-04-23	9590-900-1025	13.0 ppb
2014-04-23	9590-901-1010	16.0 ppb
2014-04-23	9590-902-1040	14.0 ppb
2014-04-23	9590-903-0955	3.10 ppb
2014-04-23	9590-904-0910	ND
2014-04-23	9590-905-0835	9.50 ppb
2014-04-23	9590-906-0850	6.90 ppb
2014-04-23	9590-907-0930	ND
2014-07-23	9590-900-1340	13.0 ppb
2014-07-23	9590-901-0905	ND
2014-07-23	9590-902-0945	15.0 ppb
2014-07-23	9590-903-0845	ND
2014-07-23	9590-904-1005	ND
2014-07-23	9590-905-1025	ND
2014-07-23	9590-906-1045	ND
2014-07-23	9590-907-1130	ND
2014-10-24	9590-900-0910	15.0 ppb
2014-10-24	9590-901-0930	18.0 ppb
2014-10-24	9590-902-0855	17.0 ppb
2014-10-24	9590-903-0915	3.10 ppb
2014-10-24	9590-904-1025	1.50 ppb
2014-10-24	9590-905-0935	3.20 ppb
2014-10-24	9590-906-0955	2.80 ppb
2014-10-24	9590-907-1045	2.50 ppb
2015-01-21	9590-900-1215	14.0 ppb
2015-01-21	9590-901-1142	13.0 ppb
2015-01-21	9590-902-1126	14.0 ppb
2015-01-21	9590-903-1150	ND
2015-01-21	9590-904-0948	ND
2015-01-21	9590-905-1003	ND
2015-01-21	9590-906-1026	11.0 ppb
2015-01-21	9590-907-0926	6.10 ppb
2015-04-22	9590-900-0945	12.0 ppb
2015-04-22	9590-901-0915	14.0 ppb
2015-04-22	9590-902-1010	12.0 ppb
2015-04-22	9590-903-0858	ND
2015-04-22	9590-904-1125	2.20 ppb
2015-04-22	9590-905-1410	ND
2015-04-22	9590-906-1435	9.00 ppb
2015-04-22	9590-907-1140	ND
2015-07-23	9590-906-0910	2.40 ppb
2015-07-23	9590-907-1015	1.50 ppb
2015-10-21	9590-900-1321	20.0 ppb
2015-10-21	9590-901-1125	6.20 ppb
2015-10-21	9590-902-1340	20.0 ppb
2015-10-21	9590-903-1108	ND
2015-10-21	9590-904-1022	1.20 ppb
2015-10-21	9590-905-0923	ND
2015-10-21	9590-906-0957	1.50 ppb
2015-10-21	9590-907-1041	1.30 ppb
2016-01-20	9590-900-1000	24.0 ppb
2016-01-20	9590-901-0935	18.0 ppb
2016-01-20	9590-902-1020	23.0 ppb
2016-01-20	9590-903-0915	1.50 ppb
2016-01-20	9590-904-1356	1.40 ppb
2016-01-20	9590-905-1045	2.80 ppb
2016-01-20	9590-906-1102	3.10 ppb
2016-01-20	9590-907-1413	2.80 ppb
2016-01-27	9590-900-1127	24.0 ppb
2016-01-27	9590-901-1105	25.0 ppb
2016-01-27	9590-902-1146	26.0 ppb
2016-01-27	9590-903-1050	26.0 ppb
2016-01-27	9590-904-1206	ND
2016-01-27	9590-905-1218	ND
2016-01-27	9590-906-1232	3.90 ppb
2016-01-27	9590-907-1356	4.10 ppb
2016-04-20	9590-900-1021	21.0 ppb
2016-04-20	9590-901-1002	18.0 ppb
2016-04-20	9590-902-1043	19.0 ppb
2016-04-20	9590-903-0942	ND
2016-04-20	9590-904-1159	ND
2016-04-20	9590-905-1106	ND
2016-04-20	9590-906-1129	13.0 ppb
2016-04-20	9590-907-1224	11.0 ppb
2016-07-20	9590-900-1103	25.0 ppb
2016-07-20	9590-901-0827	25.0 ppb
2016-07-20	9590-902-0855	26.0 ppb
2016-07-20	9590-903-0809	8.00 ppb
2016-07-20	9590-904-1007	5.00 ppb
2016-07-20	9590-905-0925	7.50 ppb
2016-07-20	9590-906-0942	8.00 ppb
2016-07-20	9590-907-1022	ND
2016-10-26	9590-900-0927	24.0 ppb
2016-10-26	9590-901-0914	27.0 ppb
2016-10-26	9590-902-0940	25.0 ppb
2016-10-26	9590-903-0901	ND
2016-10-26	9590-904-1055	1.50 ppb
2016-10-26	9590-905-1003	ND
2016-10-26	9590-906-1021	1.20 ppb
2016-10-26	9590-907-1108	1.30 ppb
2017-01-25	9590-900-1128	5.30 ppb
2017-01-25	9590-901-1201	6.20 ppb
2017-01-25	9590-902-1054	5.40 ppb
2017-01-25	9590-903-1146	5.40 ppb
2017-01-25	9590-904-0959	ND
2017-01-25	9590-905-0852	1.000 ppb
2017-01-25	9590-906-0915	2.20 ppb
2017-01-25	9590-907-1028	1.20 ppb
2017-04-19	9590-900-1200	20.0 ppb
2017-04-19	9590-901-1048	23.0 ppb
2017-04-19	9590-902-1219	20.0 ppb
2017-04-19	9590-903-1035	24.0 ppb
2017-04-19	9590-904-0952	ND
2017-04-19	9590-905-0838	ND
2017-04-19	9590-906-0903	3.40 ppb
2017-04-19	9590-907-1010	3.50 ppb
2017-08-02	9590-900-1053	21.0 ppb
2017-08-02	9590-901-1038	22.0 ppb
2017-08-02	9590-902-1118	21.0 ppb
2017-08-02	9590-903-1025	ND
2017-08-02	9590-904-0938	5.10 ppb
2017-08-02	9590-905-0841	6.10 ppb
2017-08-02	9590-906-0901	4.30 ppb
2017-08-02	9590-907-0953	ND
2017-10-18	9590-900-1014	17.0 ppb
2017-10-18	9590-901-0929	17.0 ppb
2017-10-18	9590-902-0959	17.0 ppb
2017-10-18	9590-903-0914	15.0 ppb
2017-10-18	9590-904-1144	7.10 ppb
2017-10-18	9590-905-1155	7.80 ppb
2017-10-18	9590-906-1253	7.20 ppb
2017-10-18	9590-907-1212	4.20 ppb
2018-01-29	9590-900-0755	12.0 ppb
2018-01-29	9590-901-0843	13.0 ppb
2018-01-29	9590-902-0817	13.0 ppb
2018-01-29	9590-903-0832	6.70 ppb
2018-01-29	9590-904-1008	ND
2018-01-29	9590-905-0909	1.10 ppb
2018-01-29	9590-906-0928	2.80 ppb
2018-01-29	9590-907-1023	2.80 ppb
2018-04-17	9590-900-0942	28.0 ppb
2018-04-17	9590-901-0924	22.0 ppb
2018-04-17	9590-902-1014	4.20 ppb
2018-04-17	9590-903-0910	8.30 ppb
2018-04-17	9590-904-1034	1.50 ppb
2018-04-17	9590-905-1048	ND
2018-04-17	9590-906-1107	11.0 ppb
2018-04-17	9590-907-1135	12.0 ppb
2018-04-26	9590-900-0940	25.0 ppb
2018-04-26	9590-901-0849	22.0 ppb
2018-04-26	9590-902-1003	5.00 ppb
2018-04-26	9590-903-0835	2.50 ppb
2018-04-26	9590-904-1101	2.60 ppb
2018-04-26	9590-905-1026	ND
2018-04-26	9590-906-1042	4.80 ppb
2018-04-26	9590-907-1115	ND
2018-07-25	9590-900-0900	22.0 ppb
2018-07-25	9590-901-0848	22.0 ppb
2018-07-25	9590-902-0915	1.40 ppb
2018-07-25	9590-903-0838	24.0 ppb
2018-07-25	9590-904-1015	4.80 ppb
2018-07-25	9590-905-0939	ND
2018-07-25	9590-906-0954	5.00 ppb
2018-07-25	9590-907-1027	4.30 ppb
2018-10-17	9590-900-0930	18.0 ppb
2018-10-17	9590-901-0904	18.0 ppb
2018-10-17	9590-902-0946	21.0 ppb
2018-10-17	9590-903-0850	11.0 ppb
2018-10-17	9590-904-1007	2.70 ppb
2018-10-17	9590-905-1019	3.00 ppb
2018-10-17	9590-906-1054	3.00 ppb
2018-10-17	9590-907-1117	ND
2019-01-16	9590-900-0957	6.20 ppb
2019-01-16	9590-901-0934	5.90 ppb
2019-01-16	9590-902-1016	ND
2019-01-16	9590-903-0924	5.90 ppb
2019-01-16	9590-904-0741	2.10 ppb
2019-01-16	9590-905-0753	3.20 ppb
2019-01-16	9590-906-0809	3.20 ppb
2019-01-16	9590-907-0852	ND
2019-04-17	9590-900-0934	18.0 ppb
2019-04-17	9590-901-0918	18.0 ppb
2019-04-17	9590-902-0949	1.60 ppb
2019-04-17	9590-903-0906	18.0 ppb
2019-04-17	9590-904-1012	ND
2019-04-17	9590-905-1028	ND
2019-04-17	9590-906-1055	3.40 ppb
2019-04-17	9590-907-1119	3.70 ppb
2019-07-15	9590-900-1116	26.0 ppb
2019-07-15	9590-901-1056	33.0 ppb
2019-07-15	9590-902-1129	28.0 ppb
2019-07-15	9590-903-1040	ND
2019-07-15	9590-904-0949	3.30 ppb
2019-07-15	9590-905-1009	3.40 ppb
2019-07-15	9590-906-0926	3.30 ppb
2019-07-15	9590-907-0843	ND
2019-10-15	9590-900-0814	20.0 ppb
2019-10-15	9590-901-0758	27.0 ppb
2019-10-15	9590-902-0834	21.0 ppb
2019-10-15	9590-903-0745	1.20 ppb
2019-10-15	9590-904-1017	5.50 ppb
2019-10-15	9590-905-0941	ND
2019-10-15	9590-906-0958	10.00 ppb
2019-10-15	9590-907-1028	ND