Trichloroacetic acid

Ontario Municipal Utilities Company

Trichloroacetic 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

185

Samples

Samples exceeding legal limit (MCL)

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	1.33 ppb	32	27	ND - 2.50 ppb
2015	0.541 ppb	32	8	ND - 2.80 ppb
2016	0.680 ppb	25	4	ND - 4.30 ppb
2017	1.06 ppb	32	14	ND - 5.60 ppb
2018	0.744 ppb	32	15	ND - 2.10 ppb
2019	1.27 ppb	32	17	ND - 4.00 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.1 ppb

The EWG Health Guideline of 0.1 ppb for trichloroacetic 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
2014-02-20	4790-601-0820	2.40 ppb
2014-02-20	4790-602-0745	ND
2014-02-20	4790-603-0855	2.50 ppb
2014-02-20	4790-604-1125	2.50 ppb
2014-02-20	4790-605-1105	2.40 ppb
2014-02-20	4790-606-0800	2.40 ppb
2014-02-20	4790-607-1115	2.50 ppb
2014-02-20	4790-608-0840	2.50 ppb
2014-05-21	4790-601-0820	1.20 ppb
2014-05-21	4790-602-0729	ND
2014-05-21	4790-603-0855	1.20 ppb
2014-05-21	4790-604-1145	1.20 ppb
2014-05-21	4790-605-1115	1.40 ppb
2014-05-21	4790-606-0800	1.30 ppb
2014-05-21	4790-607-1130	1.20 ppb
2014-05-21	4790-608-0840	1.20 ppb
2014-08-21	4790-601-0827	1.40 ppb
2014-08-21	4790-602-0758	ND
2014-08-21	4790-603-0900	1.40 ppb
2014-08-21	4790-604-1051	1.30 ppb
2014-08-21	4790-605-1116	1.40 ppb
2014-08-21	4790-606-0813	1.20 ppb
2014-08-21	4790-607-1103	1.50 ppb
2014-08-21	4790-608-0845	1.20 ppb
2014-11-20	4790-601-0820	1.30 ppb
2014-11-20	4790-602-0730	ND
2014-11-20	4790-603-0910	1.10 ppb
2014-11-20	4790-604-1145	ND
2014-11-20	4790-605-1125	1.10 ppb
2014-11-20	4790-606-0800	1.30 ppb
2014-11-20	4790-607-1135	1.20 ppb
2014-11-20	4790-608-0840	1.10 ppb
2015-02-19	4790-601-0755	ND
2015-02-19	4790-602-0730	ND
2015-02-19	4790-603-0825	ND
2015-02-19	4790-604-1105	ND
2015-02-19	4790-605-1045	ND
2015-02-19	4790-606-1125	ND
2015-02-19	4790-607-1055	ND
2015-02-19	4790-608-0815	ND
2015-05-21	4790-601-0817	1.80 ppb
2015-05-21	4790-602-0744	ND
2015-05-21	4790-603-0852	ND
2015-05-21	4790-604-1140	ND
2015-05-21	4790-605-1108	ND
2015-05-21	4790-606-0800	2.00 ppb
2015-05-21	4790-607-1125	2.40 ppb
2015-05-21	4790-608-0838	2.10 ppb
2015-08-13	4790-601-0930	2.20 ppb
2015-08-13	4790-602-0753	ND
2015-08-13	4790-603-0905	2.00 ppb
2015-08-13	4790-604-1225	ND
2015-08-13	4790-605-1207	ND
2015-08-13	4790-606-0830	2.00 ppb
2015-08-13	4790-607-1215	2.80 ppb
2015-08-13	4790-608-0915	ND
2015-11-19	4790-601-0835	ND
2015-11-19	4790-602-0750	ND
2015-11-19	4790-603-0910	ND
2015-11-19	4790-604-1210	ND
2015-11-19	4790-605-1140	ND
2015-11-19	4790-606-0810	ND
2015-11-19	4790-607-1155	ND
2015-11-19	4790-608-0850	ND
2016-02-18	4790-601-0815	ND
2016-05-26	4790-601-0750	ND
2016-05-26	4790-602-0716	ND
2016-05-26	4790-603-0823	ND
2016-05-26	4790-604-1055	4.30 ppb
2016-05-26	4790-605-1034	4.20 ppb
2016-05-26	4790-606-0734	ND
2016-05-26	4790-607-1044	4.20 ppb
2016-05-26	4790-608-0806	4.30 ppb
2016-08-25	4790-601-0811	ND
2016-08-25	4790-602-0730	ND
2016-08-25	4790-603-0841	ND
2016-08-25	4790-604-1115	ND
2016-08-25	4790-605-1134	ND
2016-08-25	4790-606-0749	ND
2016-08-25	4790-607-1124	ND
2016-08-25	4790-608-0824	ND
2016-11-17	4790-601-0802	ND
2016-11-17	4790-602-0715	ND
2016-11-17	4790-603-0847	ND
2016-11-17	4790-604-1136	ND
2016-11-17	4790-605-1113	ND
2016-11-17	4790-606-0736	ND
2016-11-17	4790-607-1123	ND
2016-11-17	4790-608-0820	ND
2017-02-23	4790-601-1000	ND
2017-02-23	4790-602-0920	ND
2017-02-23	4790-603-1040	ND
2017-02-23	4790-604-1105	ND
2017-02-23	4790-605-1135	ND
2017-02-23	4790-606-0945	ND
2017-02-23	4790-607-1115	ND
2017-02-23	4790-608-1020	ND
2017-05-11	4790-601-0835	1.000 ppb
2017-05-11	4790-602-0745	ND
2017-05-11	4790-603-0925	1.40 ppb
2017-05-11	4790-604-1210	5.60 ppb
2017-05-11	4790-605-1150	5.00 ppb
2017-05-11	4790-606-0810	ND
2017-05-11	4790-608-0850	1.30 ppb
2017-05-30	4790-607-1452	5.30 ppb
2017-08-10	4790-601-0830	ND
2017-08-10	4790-602-0740	ND
2017-08-10	4790-603-0905	ND
2017-08-10	4790-604-1200	1.90 ppb
2017-08-10	4790-605-1125	1.80 ppb
2017-08-10	4790-606-0805	ND
2017-08-10	4790-607-1140	1.90 ppb
2017-08-10	4790-608-0855	2.10 ppb
2017-11-16	4790-601-0835	ND
2017-11-16	4790-602-0740	ND
2017-11-16	4790-603-0920	ND
2017-11-16	4790-604-1210	1.60 ppb
2017-11-16	4790-605-1142	1.60 ppb
2017-11-16	4790-606-0805	ND
2017-11-16	4790-607-1155	1.60 ppb
2017-11-16	4790-608-0900	1.70 ppb
2018-02-08	4790-601-0820	ND
2018-02-08	4790-602-0740	ND
2018-02-08	4790-603-0905	ND
2018-02-08	4790-604-1145	ND
2018-02-08	4790-605-1120	ND
2018-02-08	4790-606-0800	ND
2018-02-08	4790-607-1135	ND
2018-02-08	4790-608-0850	2.10 ppb
2018-05-10	4790-601-0825	ND
2018-05-10	4790-602-0740	ND
2018-05-10	4790-603-0905	ND
2018-05-10	4790-604-1205	1.70 ppb
2018-05-10	4790-605-1135	ND
2018-05-10	4790-606-0805	ND
2018-05-10	4790-607-1150	1.70 ppb
2018-05-10	4790-608-0845	1.70 ppb
2018-08-09	4790-601-0850	ND
2018-08-09	4790-602-0800	ND
2018-08-09	4790-603-0930	ND
2018-08-09	4790-604-1235	1.70 ppb
2018-08-09	4790-605-1205	1.90 ppb
2018-08-09	4790-606-0825	ND
2018-08-09	4790-607-1220	1.90 ppb
2018-08-09	4790-608-0910	2.00 ppb
2018-11-15	4790-601-0830	1.000 ppb
2018-11-15	4790-602-0740	ND
2018-11-15	4790-603-0910	1.10 ppb
2018-11-15	4790-604-1210	1.70 ppb
2018-11-15	4790-605-1140	1.50 ppb
2018-11-15	4790-606-0800	1.30 ppb
2018-11-15	4790-607-1155	1.40 ppb
2018-11-15	4790-608-0855	1.10 ppb
2019-02-13	4790-601-1130	1.30 ppb
2019-02-13	4790-602-1210	ND
2019-02-13	4790-603-1055	1.10 ppb
2019-02-13	4790-604-1035	3.80 ppb
2019-02-13	4790-605-1010	4.00 ppb
2019-02-13	4790-606-1150	1.60 ppb
2019-02-13	4790-607-1020	3.90 ppb
2019-02-13	4790-608-1110	4.00 ppb
2019-05-09	4790-601-0900	ND
2019-05-09	4790-602-0815	ND
2019-05-09	4790-603-0955	ND
2019-05-09	4790-604-1015	2.90 ppb
2019-05-09	4790-605-1045	2.90 ppb
2019-05-09	4790-606-0835	ND
2019-05-09	4790-607-1030	2.90 ppb
2019-05-09	4790-608-0935	2.80 ppb
2019-08-15	4790-601-0805	1.80 ppb
2019-08-15	4790-602-0725	ND
2019-08-15	4790-603-0850	1.70 ppb
2019-08-15	4790-604-1200	ND
2019-08-15	4790-605-1125	ND
2019-08-15	4790-606-0745	1.80 ppb
2019-08-15	4790-607-1140	ND
2019-08-15	4790-608-0830	ND
2019-11-14	4790-601-0810	1.40 ppb
2019-11-14	4790-602-0735	ND
2019-11-14	4790-603-0850	1.40 ppb
2019-11-14	4790-604-1135	ND
2019-11-14	4790-605-1110	ND
2019-11-14	4790-606-0750	1.40 ppb
2019-11-14	4790-607-1125	ND
2019-11-14	4790-608-0825	ND